Sample records for early uplift history

  1. Spatial and temporal uplift history of South America from calibrated drainage analysis

    NASA Astrophysics Data System (ADS)

    Rodríguez Tribaldos, V.; White, N. J.; Roberts, G. G.; Hoggard, M. J.

    2017-06-01

    A multidisciplinary approach is used to analyze the Cenozoic uplift history of South America. Residual depth anomalies of oceanic crust abutting this continent help to determine the pattern of present-day dynamic topography. Admittance analysis and crustal thickness measurements indicate that the elastic thickness of the Borborema and Altiplano regions is ≤10 km with evidence for sub-plate support at longer wavelengths. A drainage inventory of 1827 river profiles is assembled and used to investigate landscape development. Linear inverse modeling enables river profiles to be fitted as a function of the spatial and temporal history of regional uplift. Erosional parameters are calibrated using observations from the Borborema Plateau and tested against continent-wide stratigraphic and thermochronologic constraints. Our results predict that two phases of regional uplift of the Altiplano plateau occurred in Neogene times. Regional uplift of the southern Patagonian Andes also appears to have occurred in Early Miocene times. The consistency between observed and predicted histories for the Borborema, Altiplano, and Patagonian plateaux implies that drainage networks record coherent signals that are amenable to simple modeling strategies. Finally, the predicted pattern of incision across the Amazon catchment constrains solid sedimentary flux at the Foz do Amazonas. Observed and calculated flux estimates match, suggesting that erosion and deposition were triggered by regional Andean uplift during Miocene times.

  2. The Sedimentary History of Southern Central Crete: Implications for Neogene Uplift

    NASA Astrophysics Data System (ADS)

    Kröger, K.; Brachert, T. C.; Reuter, M.

    2003-04-01

    1000m since the Early Pliocene. At the Central Iraklion Ridge that separates the Messara and Iraclion Basins a similar history is indicated for the Psiloritis Mountains by fault movements within Neogene near shore sediments and their subsequent drowning. A structural model of the Neogene evolution of Crete therefore has to explain successive phases of uplift and subsidence in an over all extensional setting only slightly oblique to the modern direction of convergence between Africa and the Aegean microplate.

  3. Extracting Uplift Rate Histories From Longitudinal River Profiles: Examples From North America and Africa

    NASA Astrophysics Data System (ADS)

    Roberts, Gareth G.; White, Nicky; Paul, Jonathan

    2013-04-01

    The physiography of the Earth's surface is a manifestation of vertical motions, erosion, and deposition of sediment. We show that a history of uplift rate of the continents during the last ~ 100 million years can be determined by jointly inverting the longitudinal profiles of rivers. We assume that the shape of a river profile is controlled by the history of uplift rate and moderated by the erosional process. We have parameterized fluvial erosion using a nonlinear advective-diffusive formulation. A river profile per se contains no information about the erosional timescale; values of erosional parameters must be calibrated. If either vertical incision rate or knickzone retreat rate is known independently, for example when palaeo-river profiles are preserved, we can calibrate the erosional model directly. Independent spot measurements of uplift offer another way to calibrate a regional model. In our inverse model, uplift rate is allowed to vary smoothly as a function of space and time, and upstream drainage area is invariant. Using this inverse methodology, we show that there exist time-correlative commonalities in the shapes of river profiles draining uplifted regions. We find that the rate at which knickzones propagate upstream is linearly dependent on slope in nearly all cases (i.e. n = 1 in the detachment-limited erosional model for ~ 600 North American and African rivers). The exponent on upstream drainage, m, which controls knickzone retreat rate, is typically < 0.5. Calculated retreat rates are therefore insensitive to large changes in upstream drainage area. Simultaneous inversion of profiles from the Colorado, Columbia, Mississippi and Rio Grande catchments shows that western North America experienced three regional phases of uplift during the last 100 Ma. The first phase of uplift occurred between 80-50 Ma, which generated ~ 1 km of topography at a rate of ~ 0.03 mm/yr. A second phase of uplift generated ~ 1.5 km of topography between 35-15 Ma at a rate of

  4. Plate-mantle interaction through time explains two-phase uplift history of the eastern Australian passive margin

    NASA Astrophysics Data System (ADS)

    Dietmar Müller, R.; Flament, Nicolas; Matthews, Kara J.; Williams, Simon E.; Gurnis, Michael

    2015-04-01

    The origin of passive margin mountains is a hotly debated topic in geodynamics. The Eastern Highlands of Australia are a type example whose uplift history has been investigated for several decades, with suggested mechanisms ranging from flexural rift shoulder uplift, volcanism and underplating to mantle-convection driven dynamic topography. Most of the highlands have experienced a distinct two-phase uplift history, with the first phase being Late Cretaceous in age, followed by a mid-late Cenozoic renewal in uplift, but the timing and magnitude of uplift differs along strike. We investigate the origin of the Eastern Highlands with a coupled plate-mantle model, using a thorough parameter space analysis, including two alternative subduction boundary evolution models. The first model includes a large (~1000 km width at its maximum extent) Early Cretaceous (140-120 Ma) back-arc basin east of the Lord Howe Rise, representing the now subducted South Loyalty Basin which may have formed due to eastward rollback of the long-lived west-dipping eastern Gondwanaland subduction zone; the alternative scenario is based on the premise that west-dipping subduction is continuous to the East of the Lord Howe Rise between 140-85 Ma, without a large back-arc basin, and the South Loyalty Basin opening as a back arc basin from 85-55 Ma, which is subsequently consumed by subduction. We further investigate the influence of a low-viscosity asthenosphere and of the viscosity profile of the lower mantle on dynamic topography, as well as the effect of changing the buoyancy of the basal dense layer (LLSVP) that contributes to the long-wavelength Pacific superswell. Our best-fit model produces a total uplift up to ~400 m in the interval between 120 and 90-70 Ma, well-matched with recent published estimates from river profile inversion for the Snowy Mountains, New England and the Central Highlands. The driving mechanism is rebound from the eastwards motion of Australia over a sinking slab, first

  5. Burial, Uplift and Exhumation History of the Atlantic Margin of NE Brazil

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Bonow, Johan M.; Green, Paul F.; Cobbold, Peter R.; Chiossi, Dario; Lilletveit, Ragnhild

    2010-05-01

    We have undertaken a regional study of landscape development and thermo-tectonic evo-lution of NE Brazil. Our results reveal a long history of post-Devonian burial and exhuma-tion across NE Brazil. Uplift movements just prior to and during Early Cretaceous rifting led to further regional denudation, to filling of rift basins and finally to formation of the Atlantic margin. The rifted margin was buried by a km-thick post-rift section, but exhumation began in the Late Cretaceous as a result of plate-scale forces. The Cretaceous cover probably extended over much of NE Brazil where it is still preserved over extensive areas. The Late Cretaceous exhumation event was followed by events in the Paleogene and Neogene. The results of these events of uplift and exhumation are two regional peneplains that form steps in the landscape. The plateaux in the interior highlands are defined by the Higher Surface at c. 1 km above sea level. This surface formed by fluvial erosion after the Late Cretaceous event - and most likely after the Paleogene event - and thus formed as a Paleogene pene-plain near sea level. This surface was reburied prior to the Neogene event, in the interior by continental deposits and along the Atlantic margin by marine and coastal deposits. Neo-gene uplift led to reexposure of the Palaeogene peneplain and to formation of the Lower Surface by incision along rivers below the uplifted Higher Surface that characterise the pre-sent landscape. Our results show that the elevated landscapes along the Brazilian margin formed during the Neogene, c. 100 Myr after break-up. Studies in West Greenland have demonstrated that similar landscapes formed during the late Neogene, c. 50 Myr after break-up. Many passive continental margins around the world are characterised by such elevated plateaus and it thus seems possible, even likely, that they may also post-date rifting and continental separation by many Myr.

  6. Late Twentieth-Century Racial Uplift Work.

    ERIC Educational Resources Information Center

    Logan, Shirley Wilson

    This paper presents a description and brief history of the concept of "racial uplift" and describes its implications for a contemporary, Black college professor. The phrase "racial uplift," for 19th-century Black women, describes almost any type of political activity designed to improve conditions for Black people during the…

  7. The Colorado front range: anatomy of a Laramide uplift

    USGS Publications Warehouse

    Kellogg, Karl; Bryant, Bruce; Reed, John C.

    2004-01-01

    Along a transect across the Front Range from Denver to the Blue River valley near Dillon, the trip explores the geologic framework and Laramide (Late Cretaceous to early Eocene) uplift history of this basement-cored mountain range. Specific items for discussion at various stops are (1) the sedimentary and structural record along the upturned eastern margin of the range, which contains several discontinuous, east-directed reverse faults; (2) the western structural margin of the range, which contains a minimum of 9 km of thrust overhang and is significantly different in structural style from the eastern margin; (3) mid- to late-Tertiary modifications to the western margin of the range from extensional faulting along the northern Rio Grande rift trend; (4) the thermal and uplift history of the range as revealed by apatite fission track analysis; (5) the Proterozoic basement of the range, including the significance of northeast-trending shear zones; and (6) the geologic setting of the Colorado mineral belt, formed during Laramide and mid-Tertiary igneous activity.

  8. Variable uplift rate through time: Holocene coral reef and neotectonics of Lutao, eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Shen, Chuan-Chou; Wu, Chung-Che; Dai, Chang-Feng; Gong, Shou-Yeh

    2018-05-01

    Significant discrepancies have existed regarding rate and timing of the uplift of Lutao (Green Island), located at the border of the ongoing collision between the Eurasia continental plate and the Philippine Sea Plate. To document its neotectonic history, two cores were drilled into Holocene coral reefs exposed at the southeastern coast of Lutao. Twelve pristine fossil corals, nine taken from cores and three on the surface, were 230Th dated. The results show that the coral reefs started to develop at 8,736 ± 56 yr BP (before 1950 CE) with uplift rate varying from 3.6 mm/yr during 8.7-6.0 kyr BP to 1.2 mm/yr in the past six thousand years. Our study strongly suggests that the uplift rate can vary significantly on millennial time scale. Caution should be used when extrapolating uplift rate estimates based on Mid-late Holocene corals to early times for tectonic active locations, such as Lutao.

  9. Late Pleistocene and Holocene uplift history of Cyprus: implications for active tectonics along the southern margin of the Anatolian microplate

    USGS Publications Warehouse

    Harrison, R.W.; Tsiolakis, E.; Stone, B.D.; Lord, A.; McGeehin, J.P.; Mahan, S.A.; Chirico, P.

    2013-01-01

    The nature of the southern margin of the Anatolian microplate during the Neogene is complex, controversial and fundamental in understanding active plate-margin tectonics and natural hazards in the Eastern Mediterranean region. Our investigation provides new insights into the Late Pleistocene uplift history of Cyprus and the Troodos Ophiolite. We provide isotopic (14C) and radiogenic (luminescence) dates of outcropping marine sediments in eastern Cyprus that identify periods of deposition during marine isotope stages (MIS) 3, 4, 5 and 6. Past sea-levels indicated by these deposits are c. 95±25 m higher in elevation than estimates of worldwide eustatic sea-level. An uplift rate of c. 1.8 mm/year and possibly as much as c. 4.1 mm/year in the past c. 26–40 ka is indicated. Holocene marine deposits also occur at elevations higher than those expected for past SL and suggest uplift rates of c. 1.2–2.1 mm/year. MIS-3 marine deposits that crop out in southern and western Cyprus indicate uniform island-wide uplift. We propose a model of tectonic wedging at a plate-bounding restraining bend as a mechanism for Late Pleistocene to Holocene uplift of Cyprus; uplift is accommodated by deformation and seismicity along the margins of the Troodos Ophiolite and re-activation of its low-angle, basal shear zone.

  10. Integrating river incision rates over timescales in the Ecuadorian Andes: from uplift history to current erosion rates

    NASA Astrophysics Data System (ADS)

    Campforts, Benjamin; Govers, Gerard; Vanacker, Veerle; Tenorio, Gustavo

    2013-04-01

    River profile development is studied at different timescales, from the response to uplift over millions of years over steady state erosion rates over millennia to the response to a single event, such as a major landslide. At present, few attempts have been made to compare data obtained over various timescales. Therefore we do not know to what extent data and model results are compatible: do long-term river profile development models yield erosion rates that are compatible with information obtained over shorter time spans, both in terms of absolute rates and spatial patterns or not? Such comparisons could provide crucial insights into the nature of river development and allow us to assess the confidence we may have when predicting river response at different timescales (e.g. Kirchner et al., 2001). A major issue hampering such comparison is the uncertainty involved in the calibration of long-term river profile development models. Furthermore, calibration data on different timescales are rarely available for a specific region. In this research, we set up a river profile development model similar to the one used by Roberts & White (2010) and successfully calibrated it for the northern Ecuadorian Andes using detailed uplift and sedimentological data. Subsequently we used the calibrated model to simulate river profile development in the southern Ecuadorian Andes. The calibrated model allows to reconstruct the Andean uplift history in southern Ecuador, which is characterized by a very strong uplift phase during the last 5 My. Erosion rates derived from the modeled river incision rates were then compared with 10Be derived basin-wide erosion rates for a series of basins within the study area. We found that the model-inferred erosion rates for the last millennia are broadly compatible with the cosmogenic derived denudation rates, both in terms of absolute erosion rates as well as in terms of their spatial distribution. Hence, a relatively simple river profile development

  11. Episodic swell growth inferred from variable uplift of the Cape Verde hotspot islands

    USGS Publications Warehouse

    Ramalho, R.; Helffrich, G.; Cosca, M.; Vance, D.; Hoffmann, D.; Schmidt, D.N.

    2010-01-01

    On the Beagle voyage, Charles Darwin first noted the creation and subsidence of ocean islands, establishing in geology's infancy that island freeboard changes with time. Hotspot ocean islands have an obvious mechanism for freeboard change through the growth of the bathymetric anomaly, or swell, on which the islands rest. Models for swell development indicate that flexural, thermal or dynamic pressure contributions, as well as spreading of melt residue from the hotspot, can all contribute to island uplift. Here we test various models for swell development using the uplift histories for the islands of the Cape Verde hotspot, derived from isotopic dating of marine terraces and subaerial to submarine lava-flow morphologies. The island uplift histories, in conjunction with inter-island spacing, uplift rate and timing differences, rule out flexural, thermal or dynamic pressure contributions. We also find that uplift cannot be reconciled with models that advocate the spreading of melt residue in swell development unless swell growth is episodic. Instead, we infer from the uplift histories that two processes have acted to raise the islands during the past 6 Myr. During an initial phase, mantle processes acted to build the swell. Subsequently, magmatic intrusions at the island edifice caused 350 m of local uplift at the scale of individual islands. Finally, swell-wide uplift contributed a further 100 m of surface rise.

  12. Episodic swell growth inferred from variable uplift of the Cape Verde hotspot islands

    NASA Astrophysics Data System (ADS)

    Ramalho, R.; Helffrich, G.; Cosca, M.; Vance, D.; Hoffmann, D.; Schmidt, D. N.

    2010-11-01

    On the Beagle voyage, Charles Darwin first noted the creation and subsidence of ocean islands, establishing in geology's infancy that island freeboard changes with time. Hotspot ocean islands have an obvious mechanism for freeboard change through the growth of the bathymetric anomaly, or swell, on which the islands rest. Models for swell development indicate that flexural, thermal or dynamic pressure contributions, as well as spreading of melt residue from the hotspot, can all contribute to island uplift. Here we test various models for swell development using the uplift histories for the islands of the Cape Verde hotspot, derived from isotopic dating of marine terraces and subaerial to submarine lava-flow morphologies. The island uplift histories, in conjunction with inter-island spacing, uplift rate and timing differences, rule out flexural, thermal or dynamic pressure contributions. We also find that uplift cannot be reconciled with models that advocate the spreading of melt residue in swell development unless swell growth is episodic. Instead, we infer from the uplift histories that two processes have acted to raise the islands during the past 6Myr. During an initial phase, mantle processes acted to build the swell. Subsequently, magmatic intrusions at the island edifice caused 350m of local uplift at the scale of individual islands. Finally, swell-wide uplift contributed a further 100m of surface rise.

  13. Metamorphic fluids and uplift-erosion history of a portion of the Kapuskasing structural zone, Ontario, as deduced from fluid inclusions

    NASA Technical Reports Server (NTRS)

    Rudnick, R. L.; Ashwal, L. D.; Henry, D. J.

    1983-01-01

    Fluid inclusions can be used to determine the compositional evolution of fluids present in high grade metamorphic rocks (Touret, 1979) along with the general P-T path followed by the rocks during uplift and erosion (Hollister et al., 1979). In this context, samples of high grade gneisses from the Kapuskasing structural zone (KSZ, Fig. 1) of eastern Ontario were studied in an attempt to define the composition of syn- and post-metamorphic fluids and help constrain the uplift and erosion history of the KSZ. Recent work by Percival (1980), Percival and Card (1983) and Percival and Krogh (1983) shows that the KSZ represents lower crustal granulites that form the lower portion of an oblique cross section through the Archean crust, which was up faulted along a northeast striking thrust fault. The present fluid inclusion study places constraints upon the P-T path which the KSZ followed during uplift and erosion.

  14. Taxonomic composition and biostratigraphic value of the Early Riphean organic-walled microfossil association from the Ust'-Il'ya Formation of the Anabar Uplift, Northern Siberia

    NASA Astrophysics Data System (ADS)

    Sergeev, V. N.; Vorob'eva, N. G.; Petrov, P. Yu.; Semikhatov, M. A.

    2017-05-01

    It is demonstrated on the basis of the first monographic study of multiple and taxonomically variable organic-walled microfossils from the Ust'-Il'ya Formation of the Anabar Uplift that both prokaryotic and eukaryotic forms are present in the composition of this microbiota. They are divided into four formal groups on the basis of the specifics of the morphological indicators of the identified taxa. The review of the data on the isotopic age of hosting deposits showed that the Ust'-Il'ya Formation is of the Early Riphean in age which are currently evaluated as 1750 ± 10-1400 Ma. Relatively large and morphologically complex eukaryotic forms present in the Ust'-Il'ya Formation served in due time as the basis for an erroneous conclusion on the Late Riphean age of the specified formation and the overlying Lower Kotuikan Subformation of the Anabar Uplift. The paper provides a global comparative analysis of the Early Riphean microbiotas, demonstrates the position of the Ust'-Il'ya and Kotuikan microbiotas amidst the microbiotas of the same age, and shows that the relatively large acanthomorphic acritarchs Tappania, Valeria, Dictiosphaera, Satka, and Shuiyousphaeridium appeared in the geological history already during the Early Riphean Erathem. Moreover, the paper discusses the recently published data on the distribution of aerobic and anaerobic conditions in the Early Riphean paleobasins and provides the conclusion on the impact of the lateral change of these conditions on the taxonomic composition of the microbiota.

  15. First constraints on the timing of the Ecuadorian Coastal Cordillera uplift and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Vacherat, Arnaud; Brichau, Stéphanie; Reyes, Pedro; Michaud, François; Proust, Jean-Noël; Hernandez, Maria Jose

    2017-04-01

    The Carnegie Ridge subduction beneath the South American plate is currently considered as responsible for the acceleration of the northward escape of the North Andean Block, for the opening of the Guayaquil Gulf, and for the uplift of the coastal forearc domain of western Ecuador, since at least Late Pleistocene. However, the exact timing and amount of uplift of the coastal forearc domain and its Coastal Cordillera is poorly known. In this study, we provide the first detrital apatite (U-Th-Sm)/He (AHe) and zircon U/Pb ages from the coastal domain in order to constrain the thermal history of both the Coastal Cordillera and its foreland basin. Our preliminary results indicate that the Middle-Late Miocene Angostura Fm was buried during Late Miocene, recording high enough temperatures to partially reset AHe ages. We show that the basin then records 1 km of uplift associated to erosion and cooling since Early Pliocene ( 5 Ma).

  16. Geomorphic Evidence of a Complex late-Cenozoic Uplift and Lateral Displacement History Along the 2013 M7.7 Baluchistan, Pakistan Strike-slip Rupture

    NASA Astrophysics Data System (ADS)

    Harbor, D. J.; Barnhart, W. D.

    2017-12-01

    The 2013 M7.7 Baluchistan earthquake in southern Pakistan ruptured 200 km of the north-dipping Hoshab reverse fault with dominantly lateral motion, clearly at odds with the regional topography created by previous reverse fault offsets. The kinematics of this earthquake led to the hypotheses that the Hoshab fault may alternatively slip in a reverse and lateral sense (bi-modal slip), and that the southeast Makran rotates as a uniform block around the fault (ball-and-socket rotation). Here, we use river profiles, regional relief, fault locations, and detailed geomorphic maps derived from optical imagery and DEMs to evaluate the recent uplift history of this region. We find that late Cenozoic fault zone geomorphology supports a spatially complex transition from lateral-dominated offsets in the NE to reverse-dominated offsets in the SW. Additionally, fault zone geomorphology suggests that the location of the Hoshab fault itself may change through time, leading to active incision of footwall alluvial fans and pediments. Stream profiles likewise record incision patterns that vary along the Hoshab fault. Incision and deposition in the SW are illustrative of relative footwall subsidence, consistent with recent uplift on the Hoshab fault; whereas incision and deposition in the NE are illustrative of relative footwall uplift consistent with ongoing regional uplift due to ball-and-socket rotations and dominantly lateral offsets along the northern Hoshab fault. The largest streams also record multiple, discrete, base-level drops, including the presence of convex-up river profiles in the hanging wall of the Hoshab fault. These profiles along hanging wall streams highlight a complex spatial and temporal history of reverse offset, lateral channel offset, and base-level resetting in regional streams that are altogether inconsistent with the kinematics of the 2013 earthquake alone, but that are consistent with the bi-modal slip model. Additionally, the evidence of footwall uplift in

  17. Sedimentological constraints on the initial uplift of the West Bogda Mountains in Mid-Permian.

    PubMed

    Wang, Jian; Cao, Ying-Chang; Wang, Xin-Tong; Liu, Ke-Yu; Wang, Zhu-Kun; Xu, Qi-Song

    2018-01-23

    The Late Paleozoic is considered to be an important stage in the evolution of the Central Asian Orogenic Belt (CAOB). The Bogda Mountains, a northeastern branch of the Tianshan Mountains, record the complete Paleozoic history of the Tianshan orogenic belt. The tectonic and sedimentary evolution of the west Bogda area and the timing of initial uplift of the West Bogda Mountains were investigated based on detailed sedimentological study of outcrops, including lithology, sedimentary structures, rock and isotopic compositions and paleocurrent directions. At the end of the Early Permian, the West Bogda Trough was closed and an island arc was formed. The sedimentary and subsidence center of the Middle Permian inherited that of the Early Permian. The west Bogda area became an inherited catchment area, and developed a widespread shallow, deep and then shallow lacustrine succession during the Mid-Permian. At the end of the Mid-Permian, strong intracontinental collision caused the initial uplift of the West Bogda Mountains. Sedimentological evidence further confirmed that the West Bogda Mountains was a rift basin in the Carboniferous-Early Permian, and subsequently entered the Late Paleozoic large-scale intracontinental orogeny in the region.

  18. Radiogenic isotopes of arc lavas constrain uplift of the Andes

    NASA Astrophysics Data System (ADS)

    Scott, Erin; Allen, Mark B.; Macpherson, Colin; McCaffrey, Ken; Davidson, Jon; Saville, Christopher

    2017-04-01

    Orogenic plateaux are an ultimate expression of continental tectonics, but the timings and mechanisms of their formation are far from understood. The elevation history of the Andes is of particular importance for climatic reconstructions, as they pose the only barrier to atmospheric circulation in the Southern Hemisphere. Many varied techniques have been utilized over the last two decades to constrain Andean Plateau (AP) surface uplift. Two conflicting schools of thought are prominent: (1) recent, rapid rise since 10-6 Ma (Late Miocene), and (2) slow, continued uplift from 40 Ma. We propose a new, independent, approach to constrain AP surface uplift through time. By comparing isotopic compositions of Andean Quaternary arc lavas to present day crustal thickness and topography, we show that Sr and Nd isotopes are effective discriminants for the modern extent of the AP. As previously described, these isotopic systems are sensitive to crustal contamination, which in turn relates to crustal thickness, and, via isostasy, to regional surface elevation. We apply this relationship to a new compilation of published, age corrected, isotopic compositions of arc lavas, to constrain the surface uplift history of the Andes from the Jurassic to present day. Our results are consistent with significant AP surface uplift beginning in the Mid to Late Paleogene. We show that by 23 Ma, the AP was established at close to its modern elevations between at least 16-28 deg. S, thereby predating models for Late Miocene surface uplift. Between 23-10 Ma, surface uplift propagated south of 28 deg. S by a further 400 km. Our model has implications for understanding magma plumbing systems in regions of thick, wide crust, especially other orogenic plateaux.

  19. Polyphase exhumation in the western Qinling Mountains, China: Rapid Early Cretaceous cooling along a lithospheric-scale tear fault and pulsed Cenozoic uplift

    PubMed Central

    Heberer, Bianca; Anzenbacher, Thomas; Neubauer, Franz; Genser, Johann; Dong, Yunpeng; Dunkl, István

    2014-01-01

    The western sector of the Qinling–Dabie orogenic belt plays a key role in both Late Jurassic to Early Cretaceous “Yanshanian” intracontinental tectonics and Cenozoic lateral escape triggered by India–Asia collision. The Taibai granite in the northern Qinling Mountains is located at the westernmost tip of a Yanshanian granite belt. It consists of multiple intrusions, constrained by new Late Jurassic and Early Cretaceous U–Pb zircon ages (156 ± 3 Ma and 124 ± 1 Ma). Applying various geochronometers (40Ar/39Ar on hornblende, biotite and K-feldspar, apatite fission-track, apatite [U–Th–Sm]/He) along a vertical profile of the Taibai Mountain refines the cooling and exhumation history. The new age constraints record the prolonged pre-Cenozoic intracontinental deformation as well as the cooling history mostly related to India–Asia collision. We detected rapid cooling for the Taibai granite from ca. 800 to 100 °C during Early Cretaceous (ca. 123 to 100 Ma) followed by a period of slow cooling from ca. 100 Ma to ca. 25 Ma, and pulsed exhumation of the low-relief Cretaceous peneplain during Cenozoic times. We interpret the Early Cretaceous rapid cooling and exhumation as a result from activity along the southern sinistral lithospheric scale tear fault of the recently postulated intracontinental subduction of the Archean/Palaeoproterozoic North China Block beneath the Alashan Block. A Late Oligocene to Early Miocene cooling phase might be triggered either by the lateral motion during India–Asia collision and/or the Pacific subduction zone. Late Miocene intensified cooling is ascribed to uplift of the Tibetan Plateau. PMID:27065503

  20. Episodes of subsidence and uplift of the conjugate margins of Greenland and Norway after opening of the NE Atlantic

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.

    2015-04-01

    We have undertaken a regional study of the thermo-­tectonic development of East Greenland (68-75°N) and of southern Norway (58-64°N). We take advantage of the general observation that that the effects of uplift often are reflected more clearly onshore than offshore, and of the specific condition that the mountains of southern East Greenland expose thick basalts that were extruded onto a largely horizontal lava plain near sea level during breakup of the NE Atlantic at the Paleocene-Eocene transition. It is thus clear that the present-­day elevation of these basalts up to 3.7 km a.s.l. were reached after breakup. Our results based on apatite fission-­track analysis (AFTA) data from East Greenland reveal a long history of post-­Palaeozoic burial and exhumation across the region and show that the terrains of Palaeozoic and older rocks were buried below a 2-3 km­-thick cover prior to a series of Mesozoic events of uplift and exhumation. The AFTA results from southern Norway reveal events of Mesozoic uplift and exhumation that are broadly simultaneous with those in Greenland. Volcanic and sedimentary rocks accumulated on the subsiding, East Greenland margin during and following breakup and then began to be exhumed during late Eocene uplift that preceded a major, early Oligocene plate reorganization in the NE Atlantic. The Norwegian margin also experienced Eocene subsidence and burial. Our AFTA data from southern Norway show evidence of an event of mid­Cenozoic uplift and exhumation that overlap with the early Oligocene onset of progradation of clastic wedges towards the south and with the formation of a major, late Eocene unconformity along the NW European margin. The uplift event at the Eocene-Oligocene transition that affected wide areas in the NE Atlantic domain was followed by two regional events of uplift and incision of the East Greenland margin in the late Miocene and Pliocene whereas the Neogene uplift of southern Norway began in the early Miocene and was

  1. Cenozoic Uplift, Erosion and Dynamic Support of Madagascar

    NASA Astrophysics Data System (ADS)

    Stephenson, Simon; White, Nicky

    2016-04-01

    The physiography of Madagascar is characterised by high-elevation but low-relief topography; 42% of the landscape is above 500 m in elevation. Eocene (marine) nummulitic (marine) limestones at elevations of ˜400 m above sea level and newly dated, emergent 125 ka coral reefs suggest that Madagascar has experienced differential vertical motions during Cenozoic times. Malagasy rivers are often deeply incised and contain steepened reaches, implying that they have responded to changes in regional uplift rate. However, low temperature thermochronology and 10Be derived erosion rates suggest that both Cenozoic and Recent average denudation rates have been low. Extensive laterite-capped, low-relief surfaces also suggest that there have been long periods of tectonic quiescence. In contrast, the modern landscape is characterised by erosional gullies (i.e. lavaka), with very high local erosion rates. To bridge the gap between this disparate evidence, we inverted 2566 longitudinal river profiles using a damped non-negative, least-squares linear inversion to determine the history of regional uplift. We used a simplified version of the stream power erosional law. River profiles were extracted from the 3 arc-second Shuttle Radar Topography Mission (SRTM) digital elevation model. Calibration of the stream power erosional law is based upon Cenozoic limestones and new radiometrically dated marine terraces. The residual misfit between observed and calculated river profiles is small. Results suggest that Malagasy topography grew diachronously by 1-2 km over the last 15-20 Ma. Calculated uplift and denudation are consistent with independent observations. Thus drainage networks contain coherent signals that record regional uplift. The resultant waves of incision are the principal trigger for modern erosional processes. Admittance calculations, the history of basaltic volcanism and nearby oceanic residual age-depth measurements all suggest that as much as 0.8 - 1.1 km of Cenozoic uplift

  2. Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic 10Be erosion rates and river longitudinal profile analysis

    USGS Publications Warehouse

    Olivetti, Valerio; Cyr, Andrew J.; Molin, Paola; Faccenna, Claudio; Granger, Darryl E.

    2012-01-01

    The Sila Massif in the Calabrian Arc (southern Italy) is a key site to study the response of a landscape to rock uplift. Here an uplift rate of ∼1 mm/yr has imparted a deep imprint on the Sila landscape recorded by a high-standing low-relief surface on top of the massif, deeply incised fluvial valleys along its flanks, and flights of marine terraces in the coastal belt. In this framework, we combined river longitudinal profile analysis with hillslope erosion rates calculated by 10Be content in modern fluvial sediments to reconstruct the long-term uplift history of the massif. Cosmogenic data show a large variation in erosion rates, marking two main domains. The samples collected in the high-standing low-relief surface atop Sila provide low erosion rates (from 0.09 ± 0.01 to 0.13 ± 0.01 mm/yr). Conversely, high values of erosion rate (up to 0.92 ± 0.08 mm/yr) characterize the incised fluvial valleys on the massif flanks. The analyzed river profiles exhibit a wide range of shapes diverging from the commonly accepted equilibrium concave-up form. Generally, the studied river profiles show two or, more frequently, three concave-up segments bounded by knickpoints and characterized by different values of concavity and steepness indices. The wide variation in cosmogenic erosion rates and the non-equilibrated river profiles indicate that the Sila landscape is in a transient state of disequilibrium in response to a strong and unsteady uplift not yet counterbalanced by erosion.

  3. Uplift history of a transform continental margin revealed by the stratigraphic record: The case of the Agulhas transform margin along the Southern African Plateau

    NASA Astrophysics Data System (ADS)

    Baby, Guillaume; Guillocheau, François; Boulogne, Carl; Robin, Cécile; Dall'Asta, Massimo

    2018-04-01

    The south and southeast coast of southern Africa (from 28°S to 33°S) forms a high-elevated transform passive margin bounded to the east by the Agulhas-Falkland Fracture Zone (AFFZ). We analysed the stratigraphic record of the Outeniqua and Durban (Thekwini) Basins, located on the African side of the AFFZ, to determine the evolution of these margins from the rifting stage to present-day. The goal was to reconstruct the strike-slip evolution of the Agulhas Margin and the uplift of the inland high-elevation South African Plateau. The Agulhas transform passive margin results from four successive stages: Rifting stage, from Late Triassic to Early Cretaceous ( 200?-134 Ma), punctuated by three successive rifting episodes related to the Gondwana breakup; Wrench stage (134-131 Ma), evidenced by strike- and dip-slip deformations increasing toward the AFFZ; Active transform margin stage (131-92 Ma), during which the Falkland/Malvinas Plateau drifts away along the AFFZ, with an uplift of the northeastern part of the Outeniqua Basin progressively migrating toward the west; Thermal subsidence stage (92-0 Ma), marked by a major change in the configuration of the margin (onset of the shelf-break passive margin morphology). Two main periods of uplift were documented during the thermal subsidence stage of the Agulhas Margin: (1) a 92 Ma short-lived margin-scale uplift, followed by a second one at 76 Ma located along the Outeniqua Basin and; (2) a long-lasting uplift from 40 to 15 Ma limited to the Durban (Thekwini) Basin. This suggests that the South African Plateau is an old Upper Cretaceous relief (90-70 Ma) reactivated during Late Eocene to Early Miocene times (40-15 Ma).

  4. Neogene Uplift and Magmatism of Anatolia: New Insights from Drainage Analysis and Basalt Geochemistry

    NASA Astrophysics Data System (ADS)

    McNab, F.; Ball, P.; Hoggard, M.; White, N.

    2017-12-01

    The origin of Anatolia's high elevation and low relief plateaux has been the subject of much recent debate. Marine sedimentary rocks distributed across Central and Eastern Anatolia require significant regional uplift in Neogene times. This uplift cannot be explained by the present-day pattern of crustal deformation which, particularly across Central and Western Anatolia, is dominanted by strike-slip and extensional faulting. Positive long wavelength free-air gravity anomalies combined with slow upper mantle seismic wave speeds suggest that the sub-lithospheric mantle provides substantial topographic support. A range of geodynamic processes have been invoked, including complex slab fragmentation and lithospheric delamination. The temporal and spatial evolution of the Anatolian landscape should be recorded by drainage networks. Indeed, major catchments contain prominent knickzones with heights of hundreds of meters and length scales of several hundred kilometers. The stream power formulation for fluvial erosion permits these knickzones to be interpreted in terms of uplift history along a river's length. Here, we jointly invert an inventory of 1,844 river profiles to determine a spatial and temporal uplift rate history. When calibrated against independent observations of uplift rate, the resultant history provides significant new constraints for the evolution of Anatolian topography. In our model, the bulk of this topography appears to grow in Neogene times. Uplift initiates in Eastern Anatolia and propagates westward at uplift rates of up to 0.5 mm/yr. Coeval with this phase of uplift, abundant basaltic magmatism has occurred throughout Anatolia. We have compiled an extensive database of published geochemical analyses. Using this database, we analyse spatial and temporal patterns of basaltic compositions to discriminate between different modes of melt generation. Two independent techniques for estimating asthenospheric potential temperatures from the compositions of

  5. New constraints on Neogene uplift of the northern Colorado Plateau

    NASA Astrophysics Data System (ADS)

    Van Wijk, J. W.; Raschilla, R.

    2013-12-01

    The Late Cretaceous Uinta Basin is located in northeastern Utah within the northern most portion of the Colorado Plateau. The basin's uplift and subsidence history and thermal evolution have impacted the maturity of source beds in the Parachute Creek Member of the Green River Formation. Using measured data of the petroleum system of the Uinta Basin, we were able to constrain timing and amplitude of uplift of the northern Colorado Plateau. We used sixty wells in a basin modeling study of the Uinta Basin's thermal structure, tectonic history and petroleum system. The wells reached into basement, and four wells provided vitrinite reflectance measurements. Vitrinite reflectance is a measurement of the percentage of reflected light from a polished vitrinite sample. The percentage of reflected light is related to the temperature conditions the sample experienced during burial, and vitrinite reflectance is a maturity indicator that covers a broad temperature range from diagenesis through the latest stages of catagenesis and records the maximum temperature a rock experiences during its burial history All models were calibrated to measured data, including vitrinite reflectance and transformation ratios from Rock-Eval pyrolysis. The models predict that the heat flow ranges from 65 mW/m2 to 45 mW/m2 from south to north in the study area. Additionally, model calibration provides a means for estimating the amount of uplift and erosion in the Uinta Basin. Uplift predicted for the Uinta Basin ranges from ~2050 m to ~2200 m and started in the Late Miocene. Our models also predicted the maturity of the rich oil shales of the Parachute Creek Member.

  6. Mineralogy and Geochemical Evidence of the Late Early Miocene Aridification Intensification in Xining Basin Caused By the Northeastern Tibetan Plateau Uplift

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Xiao, G.; Wu, H.; Hao, Q.; Guo, Z.

    2014-12-01

    A typical inland aridification is present in Central Asia, global cooling, the retreat of Para-Tethys Sea and Tibetan Plateau uplift have been thought to be the main driving forces of the climate change in interior Asia during Cenozoic. However, only few terrestrial climate records from the Asian inland were extended to the late Oligocene-early Miocene, it is still unclear the evolution of aridification before the middle Miocene and which of these driving forces plays the key role. Here, a sedimentary, mineralogy and geochemical proxies record of the early Miocene sedimentary sequence (ca. 22.1 to 16.7 Ma) from Xining Basin was present in this paper, which locates in the northeastern side of Tibetan Plateau. Mineralogical and geochemical parameters show obvious two stages climate change. During ~ 22.1-19 Ma (Unit I), the enrichment of I/S (irregular mixed-layers of illite and smectite) content, high values of a*/L* and much stronger chemical weathering degree reveal a warm and humid climate condition. During 19-16.7 Ma (Unit II), the increase of chlorite and dolomite contents, the upward decrease of a*/L* and much weaker chemical weathering than Unit I suggest evidently increased aridity since ca. 19 Ma. Comprehensive comparisons among records from the central western China demonstrate that the aridification since ca. 19 Ma is widespread in northeastern of Tibetan Plateau. The early Miocene episodic uplift of the north and northeastern Tibetan Plateau, especially, the uplift of Laji Shan at ~22 Ma, possibly have played a key role in the aridification of the Xining Basin.

  7. Emergence and evolution of Santa Maria Island (Azores)—The conundrum of uplifted islands revisited

    USGS Publications Warehouse

    Ramalho, Ricardo; Helffrich, George; Madeira, Jose; Cosca, Michael A.; Thomas, Christine; Quartau, Rui; Hipolito, Ana; Rovere, Alessio; Hearty, Paul; Avila, Sergio

    2017-01-01

    The growth and decay of ocean-island volcanoes are intrinsically linked to vertical movements. While the causes for subsidence are better understood, uplift mechanisms remain enigmatic. Santa Maria Island in the Azores Archipelago is an ocean-island volcano resting on top of young lithosphere, barely 480 km away from the Mid-Atlantic Ridge. Like most other Azorean islands, Santa Maria should be experiencing subsidence. Yet, several features indicate an uplift trend instead. In this paper, we reconstruct the evolutionary history of Santa Maria with respect to the timing and magnitude of its vertical movements, using detailed field work and 40Ar/39Ar geochronology. Our investigations revealed a complex evolutionary history spanning ∼6 m.y., with subsidence up to ca. 3.5 Ma followed by uplift extending to the present day. The fact that an island located in young lithosphere experienced a pronounced uplift trend is remarkable and raises important questions concerning possible uplift mechanisms. Localized uplift in response to the tectonic regime affecting the southeastern tip of the Azores Plateau is unlikely, since the area is under transtension. Our analysis shows that the only viable mechanism able to explain the uplift is crustal thickening by basal intrusions, suggesting that intrusive processes play a significant role even on islands standing on young lithosphere, such as in the Azores.

  8. Proterozoic metamorphism and uplift history of the north-central Laramie Mountains, Wyoming, USA

    USGS Publications Warehouse

    Patel, S.C.; Frost, B.R.; Chamberlain, K.R.; Snyder, G.L.

    1999-01-01

    The Laramie Mountains of south-eastern Wyoming contain two metamorphic domains that are separated by the 1.76 Ga. Laramie Peak shear zone (LPSZ). South of the LPSZ lies the Palmer Canyon block, where apatite U-Pb ages are c. 1745 Ma and the rocks have undergone Proterozoic kyanite-grade Barrovian metamorphism. In contrast, in the Laramie Peak block, north of the shear zone, the U-Pb apatite ages are 2.4-2.1 Ga, the granitic rocks are unmetamorphosed and supracrustal rocks record only low-T amphibolite facies metamorphism that is Archean in age. Peak mineral assemblages in the Palmer Canyon block include (a) quartz-biotite-plagioclase-garnet-staurolite-kyanite in the pelitic schists; (b) quartz-biotite-plagioclase-low-Ca amphiboles-kyanite in Mg-Al-rich schists, and locally (c) hornblende-plagioclase-garnet in amphibolites. All rock types show abundant textural evidence of decompression and retrograde re-equilibration. Notable among the texturally late minerals are cordierite and sapphirine, which occur in coronas around kyanite in Mg-Al-rich schists. Thermobarometry from texturally early and late assemblages for samples from different areas within the Palmer Canyon block define decompression from > 7 kbar to < 3 kbar. The high-pressure regional metamorphism is interpreted to be a response to thrusting associated with the Medicine Bow orogeny at c. 1.78-1.76 Ga. At this time, the north-central Laramie Range was tectonically thickened by as much as 12 km. This crustal thickening extended for more than 60 km north of the Cheyenne belt in southern Wyoming. Late in the orogenic cycle, rocks of the Palmer Canyon block were uplifted and unroofed as the result of transpression along the Laramie Peak shear zone to produce the widespread decompression textures. The Proterozoic tectonic history of the central Laramie Range is similar to exhumation that accompanied late-orogenic oblique convergence in many Phanerozoic orogenic belts.

  9. History of the incipient Icelandic plume: Observations from ancient buried landscapes

    NASA Astrophysics Data System (ADS)

    Stucky de Quay, Gaia; Roberts, Gareth G.; Watson, Jonathan S.; Jackson, Christopher A.-L.

    2017-04-01

    Ancient buried terrestrial landscapes contain records of vertical motions which can be used to probe histories of geodynamical processes. In the North Atlantic Ocean, sedimentary basins contain excellent evidence that the continental shelf experienced staged subaerial exposure. For example, now buried landscapes were uplifted, rapidly eroded, and drowned close to the Paleocene-Eocene boundary. We use commercial wells and three-dimensional seismic data to reconstruct a 57-55 Ma landscape now buried 1.5 km beneath the seabed in the Bressay area of the northern North Sea. Geochemical analyses of organic matter from core samples intersecting the erosional landscape indicate the presence of angiosperm (flowering plant) debris. Combined with the presence of coarse clastic material, mapped beach ridges, and dendritic drainage patterns, these observations indicate that this landscape was of terrestrial origin. Longitudinal profiles of ancient rivers were extracted and inverted for an uplift rate history. The best-fitting uplift rate history has three phases and total cumulative uplift of 350 m. Biostratigraphic data from surrounding marine stratigraphy indicate that this landscape formed within 1-1.5 Ma. This uplift history is similar to that of a slightly older buried landscape in the Faeroe-Shetland basin 400 km to the west. These records of vertical motion can explained by pulses of anomalously hot asthenosphere spreading out from the incipient Icelandic plume. Using simple isostatic calculations we estimate that the maximum thermal anomaly beneath Bressay was 50˚. Our observations suggest that a thermal anomaly departed the Icelandic plume as early as 58.5 Ma and had highest average temperatures at 55.6 Ma.

  10. The evolution of the southern California uplift, 1955 through 1976

    USGS Publications Warehouse

    Castle, Robert O.; Elliot, Michael R.; Church, Jack P.; Wood, Spencer H.

    1984-01-01

    between 1953 and 1976. Exceptions to this generalization consist largely of the results of pre-1953 surveys through the western Transverse Ranges and the eastern Mojave Desert. Errors in measured height differences derive from blunders, systematic survey errors, random survey errors, improperly formulated orthometric corrections, and intrasurvey movement; the last of these has created the most serious problems encountered in our reconstruction of the basic data. A variety of independent tests indicate that survey error associated with the utilized levelings was generally small and fell largely within the predicted random-error range. Moreover, the redundancy and coherence displayed by the entire data set provide convincing evidence of survey accuracy and the virtual absence of height- and slope-dependent error in particular. Our reconstructions of the changing configuration of the uplift derive chiefly from comparisons among sequentially developed observed elevations along the same route. Most of the observed elevations from which the vertical displacements were computed have been reconstructed with respect to bench mark Tidal 8, San Pedro, as invariant in height. Because the San Pedro tide station has been characterized by a history of modest relative uplift, vertical displacements referred to this station are biased slightly toward the appearance of subsidence. Where the observed elevations cannot be conveniently tied to Tidal 8, they have been referred to secondary control points whose history with respect to Tidal 8 can be independently established. Each of the lines of observed elevation changes provides, accordingly, a section athwart or along the axis of the uplift from which the changes in the configuration of the uplift can be roughly generalized. Because relatively few surveys were run in 1955, which we choose as a representative temporal datum, we have commonly incorporated the results of earlier or of somewhat later levelings as the equivalents of 1955 surveys

  11. Coupling erosion and topographic development in the rainiest place on Earth: Reconstructing the Shillong Plateau uplift history with in-situ cosmogenic 10Be

    NASA Astrophysics Data System (ADS)

    Rosenkranz, Ruben; Schildgen, Taylor; Wittmann, Hella; Spiegel, Cornelia

    2018-02-01

    The uplift of the Shillong Plateau, in northeast India between the Bengal floodplain and the Himalaya Mountains, has had a significant impact on regional precipitation patterns, strain partitioning, and the path of the Brahmaputra River. Today, the plateau receives the highest measured yearly rainfall in the world and is tectonically active, having hosted one of the strongest intra-plate earthquakes ever recorded. Despite the unique tectonic and climatic setting of this prominent landscape feature, its exhumation and surface uplift history are poorly constrained. We collected 14 detrital river sand and 3 bedrock samples from the southern margin of the Shillong Plateau to measure erosion rates using the terrestrial cosmogenic nuclide 10Be. The calculated bedrock erosion rates range from 2.0 to 5.6 m My-1, whereas catchment average erosion rates from detrital river sands range from 48 to 214 m My-1. These rates are surprisingly low in the context of steep, tectonically active slopes and extreme rainfall. Moreover, the highest among these rates, which occur on the low-relief plateau surface, appear to have been affected by anthropogenic land-use change. To determine the onset of surface uplift, we coupled the catchment averaged erosion rates with topographic analyses of the plateau's southern margin. We interpolated an inclined, pre-incision surface from minimally eroded remnants along the valley interfluves and calculated the eroded volume of the valleys carved beneath the surface. The missing volume was then divided by the volume flux derived from the erosion rates to obtain the onset of uplift. The results of this calculation, ranging from 3.0 to 5.0 Ma for individual valleys, are in agreement with several lines of stratigraphic evidence from the Brahmaputra and Bengal basin that constrain the onset of topographic uplift, specifically the onset of flexural loading and the transgression from deltaic to marine deposition. Ultimately, our data corroborate the

  12. Uplifting Leadership

    ERIC Educational Resources Information Center

    Hargreaves, Andy; Boyle, Alan

    2015-01-01

    To find out how organizations turn failure into success, Andrew Hargreaves and his colleagues studied more than 15 business, sports, and education organizations. They found that the secret to these organizations' success came down to just two words: uplifting leadership. Uplifting leadership, write Hargreaves and Boyle in this article, raises the…

  13. Episodes of subsidence and uplift of the conjugate margins of Greenland and Norway after opening of the NE Atlantic

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.

    2016-04-01

    We have undertaken a regional study of the thermo-tectonic development of East Greenland (68-75°N; Bonow et al. 2014; Japsen et al. 2014) and of southern Norway (58-64°N) based on integration of apatite fission-track analysis (AFTA), stratigraphic landscape analysis and the geological record onshore and offshore. Volcanic and sedimentary rocks accumulated on the subsiding, East Greenland margin during and following breakup and then began to be exhumed during late Eocene uplift that preceded a major, early Oligocene plate reorganization in the NE Atlantic. The Norwegian margin also experienced Eocene subsidence and burial; there are hemipelagic, deep-marine sediments of Eocene age along the coast of southern Norway. End-Eocene uplift of the NW European margin led to the formation of a major unconformity along the entire margin and to progradation of clastic wedges from Norway towards the south. Our AFTA data from East Greenland and southern Norway reveal a long history of Mesozoic burial and exhumation across the region, with a number of broadly synchronous events being recorded on both margins. AFTA data from East Greenland show clear evidence for uplift at the Eocene-Oligocene transition whereas the data from Norway do not resolve any effects of exhumation related to this event. AFTA data from the East Greenland margin show evidence of two Neogene events of uplift and incision of the in the late Miocene and Pliocene whereas results from southern Norway define Neogene uplift and erosion which began in the early Miocene. A Pliocene uplift phase in southern Norway is evident from the stratigraphic landscape analysis and from the sedimentary sequences offshore. In East Greenland, a late Eocene phase of uplift led to formation of a regional erosion surface near sea level (the Upper Planation Surface, UPS). Uplift of the UPS in the late Miocene led to formation of the Lower Planation Surface (LPS) by incision below the uplifted UPS, and a Pliocene phase led to

  14. Modern Uplift of the Transantarctic Mountains: Preliminary Results of an Autonomous GPS Array

    NASA Technical Reports Server (NTRS)

    Raymond, C. A.; Heflin, M. B.; Ivins, E. R.; James, T. S.

    1998-01-01

    An autonomous GPS array is being implemented in the Transantarctic Mountains, sponsored by NSF and NASA, for the purpose of measuring uplift resulting from post-glacial rebound (PGR). The rebound of the solid earth due to unloading of ice since the Last Glacial Maximum is expected to dominate the measured uplift for most of West Antarctica, dwarfing the signals due to present-day ice sheet mass balance changes and tectonic motion, as long as mantle viscosity is greater than about 10(exp 20) Pa-s. Predicted uplift patterns have been calculated for a range of model scenarios, which illustrate how the uplift pattern might distinguish between different-sized ice sheets and deglaciation histories as represented by the competing models. The scenarios considered by James and Ivins (1998) include ICE-3G, CLIMAP and a variation of the CLIMAP model by Denton et al. For these models, peak uplift rates occur in the Transantarctic Mountains, and differences between models is often large there. Thus, the Transantarctic Mountains are an ideal place to obtain uplift measurements to constrain deglaciation models.

  15. Fermilab History and Archives Project | Golden Books - The Early History of

    Science.gov Websites

    Fermilab History and Archives Project Home About the Archives History and Archives Online Request Contact ; - The Early History of URA and Fermilab Fermilab Golden Book Collection main page Click on Image for Larger View The Early History of URA and Fermilab Viewpoint of a URA President (1966-1981) Norman F

  16. Diagenetic history of late Oligocene-early Miocene carbonates in East Sabah, Malaysia

    NASA Astrophysics Data System (ADS)

    Zainal Abidin, N. S.; Raymond, R. R.; Bashah, N. S. I.

    2017-10-01

    Limestones are particularly susceptible to drastic early diagenesis modifications, mainly cementation and dissolution. During the early Miocene, a major tectonic deformation has caused a widespread of uplift in Sabah. This has resulted change in depositional environment from deep to shallow marine, which favours the deposition of Gomantong Limestone. This study aims to investigate the diagenetic history of Gomantong Limestone in East Sabah. Thorough understanding of the diagenetic processes may provide data to unravel the tectonic activities which affected the reservoir quality of the carbonates. Combining the data from comprehensive petrographic analysis, and Scanning Electron Microscopy (SEM) of 30 samples, two main cements type were identified. These are microcrystalline cement and Mg-calcite cement of granular and blocky mosaics which are dominantly seen in all samples. The sequence of diagenesis events are determined as (1) micritization; (2) grain scale compaction; (3) cementation (pore-filling); (4) mechanical compaction and cementation infilling fractures and (5) chemical compaction. These diagenetic events are interpreted as reflection of changes in diagenetic environment from shallow marine to deep burial. The massive cementation in the Gomantong Limestone has resulted into a poor reservoir quality.

  17. Exhumation of Basement-cored Uplifts: Example of the Kyrgyz Range Quantified with Apatite Fission-track Thermochronology

    NASA Technical Reports Server (NTRS)

    Sobel, Edward R.; Oskin, Michael; Burbank, Douglas; Mikolaichuk, Alexander

    2005-01-01

    The Kyrgyz Range, the northernmost portion of the Kyrgyzstan Tien Shan, displays topographic evidence for lateral propagation of surface uplift and exhumation. The highest and most deeply dissected segment lies in the center of the range. To the east, topography and relief decrease, and preserved remnants of a Cretaceous regional erosion surface imply minimal amounts of bedrock exhumation. The timing of exhumation of range segments defines the lateral propagation rate of the range-bounding reverse fault and quantifies the time and erosion depth needed to transform a mountain range from a juvenile to a mature morphology. New apatite fission-track (AFT) data from three transects from the eastern Kyrgyz Range, combined with published AFT data, demonstrate that the range has propagated over 110 km eastwards over the last 7-11 Myr. Based on the thermal and topographic evolutionary history, we present a model for a time-varying exhumation rate driven by rock uplift and changes in erodability and the time scale of geomorphic adjustment to surface uplift. Easily eroded, Cenozoic sedimentary rocks overlying resistant basement control early, rapid exhumation and slow surface upliftrates. As increasing amounts of resistant basement are exposed, exhumation rates decrease while surface uplift rates are sustained or increase, thereby growing topography. As the range becomes high enough to cause ice accumulation and develop steep river valleys, fluvial and glacial erosion become more powerful and exhumation rates once again increase. Independently determined range-noma1 shortening rates have also varied over time, suggesting a feedback between erosional efficiency and shortening rate.

  18. Himalayan uplift shaped biomes in Miocene temperate Asia: evidence from leguminous Caragana.

    PubMed

    Zhang, Ming-Li; Xiang, Xiao-Guo; Xue, Juan-Juan; Sanderson, Stewart C; Fritsch, Peter W

    2016-11-09

    Caragana, with distinctive variation in leaf and rachis characters, exhibits three centers of geographic distribution, i.e., Central Asia, the Qinghai-Tibetan Plateau (QTP), and East Asia, corresponding to distinct biomes. Because Caragana species are often ecologically dominant components of the vegetation in these regions, it is regarded as a key taxon for the study of floristic evolution in the dry regions of temperate Asia. Based on an expanded data set of taxa and gene regions from those previously generated, we employed molecular clock and biogeographical analyses to infer the evolutionary history of Caragana and link it to floristic patterns, paleovegetation, and paleoclimate. Results indicate that Caragana is of arid origin from the Junggar steppe. Diversification of crown group Caragana, dated to the early Miocene ca. 18 Ma and onwards, can be linked to the Himalayan Motion stage of QTP uplift. Diversification of the major clades in the genus corresponding to taxonomic sections and morphological variation is inferred to have been driven by the uplift, as well as Asian interior aridification and East Asian monsoon formation, in the middle to late Miocene ca. 12~6 Ma. These findings demonstrate a synchronous evolution among floristics, vegetation and climate change in arid Central Asia, cold arid alpine QTP, and mesophytic East Asia.

  19. Evolutionary origin and demographic history of an ancient conifer (Juniperus microsperma) in the Qinghai-Tibetan Plateau

    PubMed Central

    Shang, Hui-Ying; Li, Zhong-Hu; Dong, Miao; Adams, Robert P.; Miehe, Georg; Opgenoorth, Lars; Mao, Kang-Shan

    2015-01-01

    All Qinghai-Tibetan Plateau (QTP) endemic species are assumed to have originated recently, although very rare species most likely diverged early. These ancient species provide an excellent model to examine the origin and evolution of QTP endemic plants in response to the QTP uplifts and the climate changes that followed in this high altitude region. In this study, we examined these hypotheses by employing sequence variation from multiple nuclear and chloroplast DNA of 239 individuals of Juniperus microsperma and its five congeners. Both phylogenetic and population genetic analyses revealed that J. microsperma diverged from its sister clade comprising two species with long isolation around the Early Miocene, which corresponds to early QTP uplift. Demographic modeling and coalescent tests suggest that J. microsperma experienced an obvious bottleneck event during the Quaternary when the global climate greatly oscillated. The results presented here support the hypotheses that the QTP uplifts and Quaternary climate changes played important roles in shaping the evolutionary history of this rare juniper. PMID:25977142

  20. Geomorphic Response to Spatial and Temporal Tectonic uplift on the Kenya Rift of East African Rift System

    NASA Astrophysics Data System (ADS)

    Xue, L.; Abdelsalam, M. G.

    2017-12-01

    Tectonic uplifts of the shoulders of the East Africa Rift System (EARS) have significant impact on the geological record by reorganizing drainage systems, increasing sediment supply, and changing climate and biogeography. Recent studies in geochronology, geomorphology and geophysics have provided some understanding of the timing of tectonic uplift and its distribution pattern of the (EARS). We do not know how the vertical motion is localized along the rift axis and the relative roles of upwelling of magma and rift extensional processes play in tectonic uplift history. This work presents detailed morphometric study of the fluvial landscape response to the tectonic uplift and climate shifting of the Kenya Rift shoulders in order to reconstruct their incision history, with special attention to timing, location, and intensity of uplift episodes. This work compiles the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) and Sentinel-2A data, summarized previous 39Ar-40Ar and thermochronology data, and calculates long-term incision rate and geomorphic proxies (normalized steepness and chi-integral) along the Kenya Rift. It also models the age of tectonic/climatic events by using knickpoint celerity model and R/SR integrative approach. It found that the maximum long-term incision rates of 300 mm/kyr to be at the central Kenya Rift, possibly related to the mantle-driven process and rapid tectonic uplift. The geomorphic proxies indicate southward decreasing pattern of the short-term incision rate, possibly related to the migration of the mantle plume.

  1. Constraining the Uplift History of the Jabal Akhdar and Saih Hatat Culminations, Al Hajar Mountains, Oman, with Fission Track and (U-Th)/He Ages

    NASA Astrophysics Data System (ADS)

    Hansman, R. J.; Ring, U.; Thomson, S. N.; Den Brok, B.; Stübner, K.

    2016-12-01

    We constrain the timing of the enigmatic uplift history of the Al Hajar Mountains in Oman by apatite (U-Th)/He and fission-track (AHe and AFT), as well as zircon (U-Th)/He (ZHe) ages. Our data show differential cooling between the two major culminations of the mountain range, which are separated by the Semail gap, a major NNE-oriented depression in the Al Hajar Mountains. In the up to 3 km high Jabal Akhdar Culmination west of the Semail Gap AHe sample mean ages range between 35.5 ± 4.3 Ma and 23.9 ± 8.8 Ma (1σ errors), AFT ages range 51 ± 4 to 32 ± 2 Ma (1σ errors), and ZHe sample mean ages range 50.6 ± 16.7 to 46.1 ± 7.1 Ma (1σ errors). Whereas, in the Saih Hatat Culmination to the east AHe ages range from 23.6 ± 1.7 Ma to 15.7 ± 4.1 Ma, AFT ages range 73 ± 10 to 57 ± 4 Ma, and ZHe ages range 70.6 ± 10.8 Ma through to 58.8 ± 1.8 Ma. These data demonstrate that the uplift initiated at 45 Ma and had ceased by 15 Ma, climaxing between 40 to 35 Ma. In addition, U-Pb dating of calcite tectonics also supports N-S shortening at 40 to 35 Ma. We propose that the Semail gap is a west-dipping thrust, which uplifted the Jabal Akhdar Culmination in the hanging-wall but hardly affected the Saih Hatat Culmination in the footwall. During mountain uplift, the Al Hajar Mountains were located at least 600 km outboard of the current Eurasia-Arabia subduction/collision zone on the continental margin of the downgoing Arabian Plate. We therefore conclude that the uplift of the Al Hajar Mountains preceded the Zagros collisional event by at least 15 Myr and were not causally related to the Zagros collision and Makran subduction.

  2. Two-stage Uplift of Granite-Gneiss-Migmatite Complex (GGMC) of Çataldaǧ Core Complex (Western Anatolia, Turkey): the role of detachment faults on uplift processes

    NASA Astrophysics Data System (ADS)

    Kamaci, Omer; Altunkaynak, Safak

    2016-04-01

    The most recently identified core complex of western Anatolia (Turkey), the Çataldaǧ Core Complex (ÇCC) consists of a granite-gneiss-migmatite complex (GGMC) representing deep crustal rocks of NW Turkey and a shallow level granodioritic body (ÇG: Çataldaǧ granodiorite). The GGMC is Latest Eocene-Early Oligocene and ÇG is Early Miocene in age, and both were exhumed in the footwall of the Çataldaǧ Detachment Fault Zone (ÇDFZ) in the Early Miocene. On the basis of correlation of age data and the closure temperatures of zircon, monazite, muscovite, biotite and K-feldspar, the T-time history of GGMC reveals that GGMC has experienced at least two stages of cooling and uplift, from 33.8 to 30.1 Ma and 21.3 to 20.7 Ma. In stage I, from 33.8 to 30.1 Ma, the cooling rate of GGMC was relatively slow (35°C/my) however cooling rate increase dramatically to ≥500°C/my in stage II between 21.3 and 20.7 Ma. T-time history also indicate that GGMC was elevated to the final location in at least 8-13 My according to the monazite and zircon and mica ages obtained from the same rock. Rapid slab rollback at the Hellenic trench at ca. 23 Ma may have increased extension rates leading to the development of detachment faults (i.e. ÇDFZ), core complexes and associated syn-extensional granitoids in Western Anatolia and the Aegean extensional province.

  3. Subsonic evolution of the radio bubbles in the nearby massive early-type galaxy NGC 4472: uplift, buoyancy, and heating

    NASA Astrophysics Data System (ADS)

    Kraft, Ralph P.; Gendron Marsolais, Marie-Lou; Bogdan, Akos; Su, Yuanyuan; Forman, William R.; Hlavacek-Larrondo, Julie; Jones, Christine; Nulsen, Paul; Randall, Scott W.; Roediger, Elke

    2017-01-01

    We present results from a deep (380 ks) Chandra observation of the hot gas in the nearby massive early-type galaxy NGC 4472. X-ray cavities were previously reported coincident with the radio lobes (Biller et al. 2004). In our deeper observation, we confirm the presence of the cavities and detect rims of enhanced emission surrounding the bubbles. The temperature of the gas in these rims is less than that of the ambient medium, demonstrating that they cold, low entropy material that has been drawn up from the group center by the buoyant rise of the bubbles and not shocks from supersonic inflation of the lobes. Interestingly, the gravitational energy required to lift these lobes from the group center is a significant fraction of the bubble enthalpy. This suggests that uplift by AGN bubbles may play an important role in some cases in offsetting the radiative cooling at cluster and group centers. This uplift also provides an efficient means of transporting enriched material from the group center to large radii.

  4. Andean surface uplift constrained by radiogenic isotopes of arc lavas.

    PubMed

    Scott, Erin M; Allen, Mark B; Macpherson, Colin G; McCaffrey, Ken J W; Davidson, Jon P; Saville, Christopher; Ducea, Mihai N

    2018-03-06

    Climate and tectonics have complex feedback systems which are difficult to resolve and remain controversial. Here we propose a new climate-independent approach to constrain regional Andean surface uplift. 87 Sr/ 86 Sr and 143 Nd/ 144 Nd ratios of Quaternary frontal-arc lavas from the Andean Plateau are distinctly crustal (>0.705 and <0.5125, respectively) compared to non-plateau arc lavas, which we identify as a plateau discriminant. Strong linear correlations exist between smoothed elevation and 87 Sr/ 86 Sr (R 2  = 0.858, n = 17) and 143 Nd/ 144 Nd (R 2  = 0.919, n = 16) ratios of non-plateau arc lavas. These relationships are used to constrain 200 Myr of surface uplift history for the Western Cordillera (present elevation 4200 ± 516 m). Between 16 and 26°S, Miocene to recent arc lavas have comparable isotopic signatures, which we infer indicates that current elevations were attained in the Western Cordillera from 23 Ma. From 23-10 Ma, surface uplift gradually propagated southwards by ~400 km.

  5. Spatial and temporal variation of tectonic uplift in the southeastern Ethiopian Plateau from morphotectonic analysis

    NASA Astrophysics Data System (ADS)

    Xue, Liang; Alemu, Tadesse; Gani, Nahid D.; Abdelsalam, Mohamed G.

    2018-05-01

    We use morphotectonic analysis to study the tectonic uplift history of the southeastern Ethiopian Plateau (SEEP). Based on studies conducted on the Northwestern Ethiopian Plateau, steady-state and pulsed tectonic uplift models were proposed to explain the growth of the plateau since 30 Ma. We test these two models for the largely unknown SEEP. We present the first quantitative morphotectonic study of the SEEP. First, in order to infer the spatial distribution of the tectonic uplift rates, we extract geomorphic proxies including normalized steepness index ksn, hypsometric integral HI, and chi integral χ from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model (DEM). Second, we compare these rates with the thickness of flood basalt that we estimated from geological maps. Third, to constrain the timing of regional tectonic uplift, we develop a knickpoint celerity model. Fourth, we compare our results to those from the Northwestern Ethiopian Plateau to suggest a possible mechanism to explain regional tectonic uplift of the entire Ethiopian Plateau. We find an increase in tectonic uplift rates from the southeastern escarpments of the Afar Depression in the northeast to that of the Main Ethiopian Rift to the southwest. We identify three regional tectonic uplift events at 11.7, 6.5, and 4.5 Ma recorded by the development of regionally distributed knickpoints. This is in good agreement with ages of tectonic uplift events reported from the Northwestern Ethiopian Plateau.

  6. Late Permian to Early Oligocene granitic magmatism of the Phan Si Pan uplift area, NW Vietnam: their relationship to Phanerozoic crustal evolution of Southwest China

    NASA Astrophysics Data System (ADS)

    Pham, T. T.; Shellnutt, G.

    2015-12-01

    The Phan Si Pan uplift area of NW Vietnam is a part of the Archean to Paleoproterozoic Yangtze Block, Southwest China. This area is of particular interest because it experienced a number of Phanerozoic crustal building events including the Emeishan Large Igneous Province, the India-Eurasia collision and Ailaoshan - Red River Fault displacement. In the Phan Si Pan uplift area, there are at least three different geochronological complexes, including: (1) Late Permian, (2) Eocene and (3) Early Oligocene. (1) The Late Permian silicic rocks are alkali ferroan A1-type granitic rocks with U/Pb ages of 251 ± 3 to 254 ± 3 Ma. The Late Permian silicic rocks of Phan Si Pan uplift area intrude the upper to middle crust and are considered to be part of the ELIP that was displaced during the India-Eurasian collision along the Ailaoshan-Red River Fault shear zone and adjacent structures (i.e. Song Da zone). Previous studies suggest the Late Permian granitic rocks were derived by fractional crystallization of high - Ti basaltic magma. (2) The Eocene rocks are alkali ferroan A1-type granites (U/Pb ages 49 ± 0.9 Ma) and are spatially associated with the Late Permian granitic rocks. The trace element ratios of this granite are similar to the Late Permian rocks (Th/Nb=0.2, Th/Ta = 2.5, Nb/U = 24, Nb/La =1.2, Sr/Y=1). The origin of the Eocene granite is uncertain but it is possible that it formed by fractional crystallization of a mafic magma during a period of extension within the Yangtze Block around the time of the India-Eurasia collision. (3) The Early Oligocene granite is characterized as a peraluminous within-plate granite with U/Pb ages of 31.3 ± 0.4 to 34 ± 1 Ma. The Early Oligocene granite has trace element ratios (Th/Nb = 2.1, Th/Ta = 22.6, Nb/U = 4.4, Nb/La = 0.4, Sr/Y = 60.4) similar to crust melts. The high Sr/Y ratio (Sr/Y = 20 - 205) indicates a lower crust source that was garnet-bearing. The Phan Si Pan uplift was neither a subduction zone nor an arc environment

  7. Quantification of Net Erosion and Uplift Experienced by the Barmer Basin, Rajasthan Using Sonic Log

    NASA Astrophysics Data System (ADS)

    Mitra, K.; Schulz, S.; Sarkar, A.

    2015-12-01

    Barmer Basin of Rajasthan, Western India is a hydrocarbon rich sedimentary basin currently being explored by Cairn India Limited. The hydrocarbon bearing Fatehgarh Formation is being found at different depths in different oil fields (e.g. From south to north: Guda, Vijaya & Vandana, Air field High) of the basin. The net uplift and erosion in the Barmer Basin has been quantified using compaction methodology. The sonic log, which is strongly controlled by porosity, is an appropriate indicator of compaction, and hence used for quantification of net uplift and erosion from compaction. The compaction methodology has been applied to the shale rich Dharvi Dungar Formation of Barmer Basin of Late Paleocene age. The net uplift and erosion is also being checked with the help of AFTA-VR and seismic sections. The results show relatively no uplift in the southernmost part of the basin and a Guda field well is thus taken to be the reference well with respect to which the uplifts in different parts of the basin have been calculated. The northern part of the basin i.e. Air Field High wells experienced maximum uplift (~2150m). Interestingly, a few wells further south of the reference well show evidence for uplift. The study was able to point out errors in the report produced with the help of AFTA-VR which found out less uplift in Vijaya & Vandana oil fields as opposed to sonic log data. The process of finding out uplift using sonic log has a standard deviation of 200m as compared to about 500m error in AFTA-VR method. This study has major implications for hydrocarbon exploration. Maturation of source rock will be higher for any given geothermal history if net uplift and erosion is incorporated in maturation modeling. They can also be used for porosity predictions of reservoir units in undrilled targets.

  8. Mercury's Early Geologic History

    NASA Astrophysics Data System (ADS)

    Denevi, B. W.; Ernst, C. M.; Klima, R. L.; Robinson, M. S.

    2018-05-01

    A combination of geologic mapping, compositional information, and geochemical models are providing a better understanding of Mercury's early geologic history, and allow us to place it in the context of the Moon and the terrestrial planets.

  9. Surface expression of Eastern Mediterranean slab dynamics: Uplift at the SW margin of the Central Anatolian Plateau

    NASA Astrophysics Data System (ADS)

    Schildgen, T. F.; Cosentino, D.; Caruso, A.; Yildirim, C.; Echtler, H.; Strecker, M. R.

    2011-12-01

    The Central Anatolian plateau in Turkey borders one of the most complex tectonic regions on Earth, where collision of the Arabian plate with Eurasia in Eastern Anatolia transitions to a cryptic pattern of subduction of the African beneath the Eurasian plate, with concurrent westward extrusion of the Anatolian microplate. Topographic growth of the southern margin of the Central Anatolian plateau has proceeded in discrete stages that can be distinguished based on the outcrop pattern and ages of uplifted marine sediments. These marine units, together with older basement rocks and younger continental sedimentary fills, also record an evolving nature of crustal deformation and uplift patterns that can be used to test the viability of different uplift mechanisms that have contributed to generate the world's third-largest orogenic plateau. Late Miocene marine sediments outcrop along the SW plateau margin at 1.5 km elevation, while they blanket the S and SE margins at up to more than 2 km elevation. Our new biostratigraphic data limit the age of 1.5-km-high marine sediments along the SW plateau margin to < 7.17 Ma, while regional lithostratigraphic correlations imply that the age is < 6.7 Ma. After reconstructing the post-Late Miocene surface uplift pattern from elevations of uplifted marine sediments and geomorphic reference surfaces, it is clear that regional surface uplift reaches maximum values along the modern plateau margin, with the SW margin experiencing less cumulative uplift compared to the S and SE margins. Our structural measurements and inversion modeling of faults within the uplifted region agree with previous findings in surrounding regions, with early contraction followed by strike-slip and extensional deformation. Shallow earthquake focal mechanisms show that the extensional phase has continued to the present. Broad similarities in the onset of surface uplift (after 7 Ma) and a change in the kinematic evolution of the plateau margin (after 8 Ma) suggest

  10. An integrated study on microtectonics, geothermometry and thermochronology of the Çataldaǧ Core Complex (NW Turkey): Implications for cooling, deformation and uplift history

    NASA Astrophysics Data System (ADS)

    Kamaci, Omer; Altunkaynak, Safak

    2017-04-01

    We present an integrated study on structure, microstructure, geothermometry and thermochronology of the Çataldaǧ Core Complex (ÇCC) in NW Turkey in order to understand the cooling, deformation and uplift mechanisms. ÇCC is formed from an Eo-Oligocene granite-gneiss-migmatite complex (GGMC) and an Early Miocene I-type granodioritic body (ÇG: Çataldaǧ granodiorite) which were exhumed as a dome-shaped core complex in the footwall of a ring-shaped low-angle detachment zone (The Çataldaǧ Detachment Fault Zone; ÇDFZ) in the Early Miocene. New U-Pb zircon (LA-ICPMS) and monazite ages of GGMC yielded magmatic ages of 33.8 and 30.1 Ma (Latest Eocene-Early Oligocene). 40Ar/39Ar muscovite, biotite and K-feldspar from the GGMC yielded the deformation age span 21.38±0,05 Ma and 20.81±0.04 Ma, which is also the emplacement age (20.84±0.13 Ma and 21.6±0.04 Ma) of ÇG. ÇDFZ is responsible for mainly top-to-the-north sense kinematic processes. The microstructural features of quartz, feldspar and mica indicate that the ÇCC has undergone continuous deformations during its cooling, from submagmatic to cataclastic conditions. Five microstructural grades have been classified under ductile (DZ) and ductile-to-brittle shear zone (SZ), according to the estimated deformation temperature and intensity of the strain. Microcline twinning, marginally replacement myrmekite and flame-perthite are predominant features for feldspar while chessboard extinction, grain boundary migration and subgrain rotation recrystallization is common for quartz in the DZ which has a deformation temperature range of >600°C to 400°C. Grain size reduction is an important factor for the ductile to brittle shear zone (SZ). Feldspar is represented by bulging recrystallization (BLG), feldspar-fish and domino-type microfracture/microfaulting and quartz show more elongated structures such as ribbons with high aspect ratios. Mineral-fish (muscovite, biotite and feldspar) structures indicate a temperature

  11. A stable isotope record of late Cenozoic surface uplift of southern Alaska

    NASA Astrophysics Data System (ADS)

    Bill, Nicholas S.; Mix, Hari T.; Clark, Peter U.; Reilly, Sean P.; Jensen, Britta J. L.; Benowitz, Jeffrey A.

    2018-01-01

    Although the timing of an acceleration in late-Cenozoic exhumation of southern Alaska is reasonably well constrained as beginning ∼5-∼6 Ma, the surface uplift history of this region remains poorly understood. To assess the extent of surface uplift relative to rapid exhumation, we developed a stable isotope record using the hydrogen isotope composition (δD) of paleo-meteoric water over the last ∼7 Ma from interior basins of Alaska and Yukon Territory. Our record, which is derived from authigenic clays (δDclay) in silicic tephras, documents a ∼50-60‰ increase in δD values from the late Miocene (∼6-∼7 Ma) through the Plio-Pleistocene transition (∼2-∼3 Ma), followed by near-constant values over at least the last ∼2 Ma. Although this enrichment trend is opposite that of a Rayleigh distillation model typically associated with surface uplift, we suggest that it is consistent with indirect effects of surface uplift on interior Alaska, including changes in aridity, moisture source, and seasonality of moisture. We conclude that the δDclay record documents the creation of a topographic barrier and the associated changes to the climate of interior Alaska and Yukon Territory.

  12. Regional uplift episodes along the NE Atlantic margin constrained by stratigraphic and thermochronologic data

    NASA Astrophysics Data System (ADS)

    Holford, S. P.; Green, P. F.; Hillis, R. R.; Duddy, I. R.; Turner, J. P.; Stoker, M. S.

    2008-12-01

    The magma-rich NE Atlantic passive margin provides a superb natural laboratory for studying vertical motions associated with continental rifting and the rift-drift transition. Here we present an extensive apatite fission-track analysis (AFTA) database from the British Isles which we combine with a detailed stratigraphic framework for the Cretaceous-Cenozoic sedimentary record of the NE Atlantic margin to constrain the uplift history along and inboard of this margin during the past 120 Myr. We show that the British Isles experienced a series of uplift episodes which began between 120 and 115 Ma, 65 and 55 Ma, 40 and 25 Ma and 20 and 15 Ma, respectively. Each episode is of regional extent (~100,000 sq km) and represents a major period of exhumation involving removal of up to 1 km or more of section. These uplift episodes can be correlated with a number of major tectonic unconformities recognised within the sedimentary succession of the NE Atlantic margin, suggesting that the margin was also affected by these uplift episodes. Anomalous syn- and post-rift uplift along this margin have been interpreted in terms of permanent and/or transient movements controlled by the Iceland plume, but neither the timing nor distribution of the uplift episodes, with the exception of the 65 to 55 Ma episode, supports a first-order control by plume activity on vertical motions. Each uplift episode correlates closely with key deformation events at adjacent plate boundaries, suggesting a causative link, and we examine the ways in which plate boundary forces can account for the observed uplift episodes. Similar km-scale uplift events are revealed by thermochronological studies in other magma-rich and magma-poor continental margins, e.g. SE Australia, South Africa, Brazil. The low angle unconformities which result from these regional episodes of km-scale burial and subsequent uplift are often incorrectly interpreted as representing periods of non-deposition and tectonic stability. Similar

  13. Active simultaneous uplift and margin-normal extension in a forearc high, Crete, Greece

    NASA Astrophysics Data System (ADS)

    Gallen, S. F.; Wegmann, K. W.; Bohnenstiehl, D. R.; Pazzaglia, F. J.; Brandon, M. T.; Fassoulas, C.

    2014-07-01

    The island of Crete occupies a forearc high in the central Hellenic subduction zone and is characterized by sustained exhumation, surface uplift and extension. The processes governing orogenesis and topographic development here remain poorly understood. Dramatic topographic relief (2-6 km) astride the southern coastline of Crete is associated with large margin-parallel faults responsible for deep bathymetric depressions known as the Hellenic troughs. These structures have been interpreted as both active and inactive with either contractional, strike-slip, or extensional movement histories. Distinguishing between these different structural styles and kinematic histories here allows us to explore more general models for improving our global understanding of the tectonic and geodynamic processes of syn-convergent extension. We present new observations from the south-central coastline of Crete that clarifies the role of these faults in the late Cenozoic evolution of the central Hellenic margin and the processes controlling Quaternary surface uplift. Pleistocene marine terraces are used in conjunction with optically stimulated luminesce dating and correlation to the Quaternary eustatic curve to document coastal uplift and identify active faults. Two south-dipping normal faults are observed, which extend offshore, offset these marine terrace deposits and indicate active N-S (margin-normal) extension. Further, marine terraces preserved in the footwall and hanging wall of both faults demonstrate that regional net uplift of Crete is occurring despite active extension. Field mapping and geometric reconstructions of an active onshore normal fault reveal that the subaqueous range-front fault of south-central Crete is synthetic to the south-dipping normal faults on shore. These findings are inconsistent with models of active horizontal shortening in the upper crust of the Hellenic forearc. Rather, they are consistent with topographic growth of the forearc in a viscous orogenic

  14. The High Arctic Large Igneous Province Mantle Plume caused uplift of Arctic Canada

    NASA Astrophysics Data System (ADS)

    Galloway, Jennifer; Ernst, Richard; Hadlari, Thomas

    2016-04-01

    The Sverdrup Basin is an east-west-trending extensional sedimentary basin underlying the northern Canadian Arctic Archipelago. The tectonic history of the basin began with Carboniferous-Early Permian rifting followed by thermal subsidence with minor tectonism. Tectonic activity rejuvenated in the Hauterivian-Aptian by renewed rifting and extension. Strata were deformed by diapiric structures that developed during episodic flow of Carboniferous evaporites during the Mesozoic and the basin contains igneous components associated with the High Arctic Large Igneous Province (HALIP). HALIP was a widespread event emplaced in multiple pulses spanning ca. 180 to 80 Ma, with igneous rocks on Svalbard, Franz Josef Island, New Siberian Islands, and also in the Sverdrup Basin on Ellef Ringnes, Axel Heiberg, and Ellesmere islands. Broadly contemporaneous igneous activity across this broad Arctic region along with a reconstructed giant radiating dyke swarm suggests that HALIP is a manifestation of large mantle plume activity probably centred near the Alpha Ridge. Significant surface uplift associated with the rise of a mantle plume is predicted to start ~10-20 my prior to the generation of flood basalt magmatism and to vary in shape and size subsequently throughout the LIP event (1,2,3) Initial uplift is due to dynamical support associated with the top of the ascending plume reaching a depth of about 1000 km, and with continued ascent the uplift topography broadens. Additional effects (erosion of the ductile lithosphere and thermal expansion caused by longer-term heating of the mechanical lithosphere) also affect the shape of the uplift. Topographic uplift can be between 1 to 4 km depending on various factors and may be followed by subsidence as the plume head decays or become permanent due to magmatic underplating. In the High Arctic, field and geochronological data from HALIP relevant to the timing of uplift, deformation, and volcanism are few. Here we present new evidence

  15. Cenozoic Uplift and Climate Change of the Northeast Tibetan Plateau: Evidence from Leaf Wax Stable Isotopic Records

    NASA Astrophysics Data System (ADS)

    Hou, M.; Zhuang, G.; Wu, M.

    2017-12-01

    Topics about the deformation history and uplift mechanism of Tibetan Plateau have been largely debated in the past few decades. Different geodynamic models present different predictions on the mountain building processes and hence the surface uplift history. For example, one tectonic model suggests a rapid uplift (>1.0 to 2.0 km) of the Tibetan Plateau in the period of ca. 10 to 8 Ma as result of isostatic rebound due to the removal of over-thickened mental lithosphere beneath. Whilst the stepwise uplift model infers that the high topography was growing progressively from south to north with the Northeast Tibetan Plateau being built in the Pliocene to present. In this case, the timing of Cenozoic uplift of Northeast Tibetan Plateau would provide information for distinguishing competing geodynamic processes. The stable isotope based paleoaltimetry holds the key to answering when the high topography was built. Additionally, the evolution of Cenozoic Asian climate was argued to be closely related to the high topography built up on the Tibetan Plateau since the India-Asian collision and/or impacted by the global change. To understand when the high topography was built and how the growth of Tibetan Plateau impacted the climate, we reconstructed the long-term histories of paleohydrology from hinterland and foreland basins in the Northeast Tibetan Plateau. We applied the compound-specific isotope hydrogen analysis to leaf wax n-alkanes (δ2Hn-alk) that are preserved in well-dated stratigraphic series (ca. 24 Ma to the present) in the Northeast Tibetan Plateau. The newly reconstructed δ2Hn-alk supports the inference of high topography on the Northeast Tibetan Plateau was built during the middle to late Miocene. Our inference is consistent with sedimentary and basement rock studies that show fundamental changes in facies and provenance and exhumation history. The new δ2Hn-alk record also reveals that the regional climate became drier since the middle Miocene following the

  16. Mode and mechanisms of plateau uplifts

    NASA Technical Reports Server (NTRS)

    Mcgetchin, T. R.; Burke, K. C.; Thompson, G. A.; Young, R. A.

    1980-01-01

    The mode and mechanisms of plateau uplifts are reported, based on discussions which occurred as part of a conference on plateau uplifts sponsored by the Inter-Union Commission on Geodynamics and the Lunar and Planetary Institute. Major plateaus and high plains of the world are discussed with emphasis on the Colorado Plateau, which possesses a shield-like crust 45 km thick and occupies most of eastern Utah and parts of Colorado, Arizona, and New Mexico. Several uplift mechanisms are described, including thermal expansion due to a deep mantle plume or hot spot, and hydration reactions such as serpentinization. It is concluded that uplifts are most commonly associated with either subduction and its direct effects, or deep-seated thermal disturbances.

  17. Patterns and average rates of late Neogene Recent uplift of the Betic Cordillera, SE Spain

    NASA Astrophysics Data System (ADS)

    Braga, Juan C.; Martín, José M.; Quesada, Cecilio

    2003-02-01

    The facies distribution in the sedimentary units infilling a series of Neogene basins has been used to reconstruct the relief generation and uplift across the Internal Zone of the Betic Cordillera in southern Spain. Uplift amounts and average rates can be estimated using the current elevation of the outcrops of well-dated deposits indicative of ancient sea-level positions. Coral reefs and coastal conglomerates record the initial development of emergent Betic relief during the Langhian. Continental and marginal marine deposits indicate the existence of a large island centred on the present Sierra Nevada-Sierra de los Filabres chain by the end of the Middle Miocene. The precursor of the Sierra Nevada-Sierra de los Filabres chain, originally part of this large island, remained emerged whilst the surrounding areas were re-invaded by the sea during the early Tortonian. At the end of the Tortonian the inland basins (Granada and Guadix basins) became continental, while the Sierras de la Contraviesa, Sierra de Gádor and Sierra Alhamilla emerged, separating the Alborán Basin from the Alpujarra, Tabernas and Sorbas basins, which became narrow passages of the Mediterranean Sea. In contrast, the Sierra Cabrera emerged during the late Messinian, suggesting a progressive uplift from west to east of the sierras south of the Sierra Nevada-Sierra de los Filabres chain. During the Pliocene, only the low areas closest to the present-day coast remained as marine basins and progressively emerged throughout this stage. The highest average uplift rate recorded is 280 m/Ma for the Sierra de Gádor, although the average uplift rates of upper-Neogene coastal marine rocks since depositon have maximum values of approximately 200 m/Ma. Most of the uplift of the Betic mountains took place before the early Pliocene. The recorded uplift of Neogene rocks was highest at the margins of western Sierra Nevada, where peaks higher than 3000 m occur. The average rates of uplift were lower to the east

  18. Cenozoic episodic uplift and kinematic evolution between the Pamir and Southwestern Tien Shan

    NASA Astrophysics Data System (ADS)

    Liu, Dongliang; Li, Haibing; Sun, Zhiming; Cao, Yong; Wang, Leizhen; Pan, Jiawei; Han, Liang; Ye, Xiaozhou

    2017-08-01

    The Pamir Salient and Southwestern Tien Shan belong to two different systems, which collided due to the continuous northward drift of the Indian Plate during the Cenozoic, resulting in a shortening of 300 km. The uplift history and kinematic evolution of the Pamir-Southwestern Tien Shan remain unclear. In this study, we chose the 2025 m-thick Pakabulake formation in the East Wuqia section, at the southern-most margin of the Southwestern Tien Shan system, to obtain a high-resolution magnetostratigraphic record spanning 16.61 Ma to 9.78 Ma. Based on its high sedimentation rate, stable ca. E-W paleocurrents and stable magnetic susceptibility values, the nearby Southwestern Tien Shan was inferred to have undergone stable uplift during this period of sedimentation. Combining our results with the previous low-temperature thermochronology, magnetostratigraphy and re-calculated block rotations, we conclude that four episodic uplift events occurred in the Pamir-Southwestern Tien Shan during the Cenozoic, at times of 50-40 Ma, 35-16 Ma, 11-7 Ma and < 5 Ma, and that the first episodic uplift only occurred in the Pamir Salient. In addition, the Pamir Salient underwent a tectonic transformation from entire- to a half-oroclinal bending rotation during the Miocene, caused by activity along the Karakorum Fault and Kashgar-Yecheng Transfer System.

  19. Tectonic uplift, threshold hillslopes, and denudation rates in a developing mountain range

    USGS Publications Warehouse

    Binnie, S.A.; Phillips, W.M.; Summerfield, M.A.; Fifield, L.K.

    2007-01-01

    Studies across a broad range of drainage basins have established a positive correlation between mean slope gradient and denudation rates. It has been suggested, however, that this relationship breaks down for catchments where slopes are at their threshold angle of stability because, in such cases, denudation is controlled by the rate of tectonic uplift through the rate of channel incision and frequency of slope failure. This mechanism is evaluated for the San Bernardino Mountains, California, a nascent range that incorporates both threshold hill-slopes and remnants of pre-uplift topography. Concentrations of in situ-produced cosmogenic 10Be in alluvial sediments are used to quantify catchment-wide denudation rates and show a broadly linear relationship with mean slope gradient up to ???30??: above this value denudation rates vary substantially for similar mean slope gradients. We propose that this decoupling in the slope gradient-denudation rate relationship marks the emergence of threshold topography and coincides with the transition from transport-limited to detachment-limited denudation. The survival in the San Bernardino Mountains of surfaces formed prior to uplift provides information on the topographic evolution of the range, in particular the transition from slope-gradient-dependent rates of denudation to a regime where denudation rates are controlled by rates of tectonic uplift. This type of transition may represent a general model for the denudational response to orogenic uplift and topographic evolution during the early stages of mountain building. ?? 2007 The Geological Society of America.

  20. Aseismic uplift in California

    USGS Publications Warehouse

    Castle, Robert O.; Elliot, Michael R.; Gilmore, Thomas D.; Mark, Robert K.; Newman, Evelyn B.; Tinsley, John C.; Jackson, D.D.; Lee, W.B.; Liu, C.-C.

    1981-01-01

    We disagree with several of the arguments cited by Jackson et al. in support of their view that "the inference of wide-spread aseismic uplift in southern California is not justified" (1). Specifically, the striking correlation shown in figure 1 of Jackson et al. (1) is an artifact of the construction, the rod calibration data are atypical, the cited regression techniques are of doubtful value, and the geologically and geodetically determined uplift rates are inappropriately compared.

  1. Tectonic and erosion-driven uplift in the Gamburtsev Subglacial Mountains of East Antarctica

    NASA Astrophysics Data System (ADS)

    Ferraccioli, Fausto; Jordan, Tom; Watts, Tony; Bell, Robin; Jamieson, Stewart; Finn, Carol; Damaske, Detlef

    2014-05-01

    -related exhumation in interior East Antarctica. This raises the question of whether the modern Gamburtsevs may instead have been uplifted solely in response to changes in Cenozoic erosion patterns during the early stages of East Antarctic Ice Sheet formation superimposed upon an a Permian-age rift flank, or an even older highland. To address this question we combine results from: i) analyses of the subglacial landscape for the GSM (Rose et al., 2013 EPSL) with; ii) 2D and preliminary 3D flexural models of peak uplift caused by the isostatic responses to fluvial and glacial valley incision processes. We also compare geophysical relief and isostatic model outputs with estimates of erosion rates since the Oligocene and the total amount of incision estimated for the adjacent Lambert rift region (Thomson et al. 2013, Nature Geoscience). Flexural modelling outputs were also compared against the present-day elevations of up to 1500 m a.s.l of uplifted Oligocene-early Miocene glacial-marine sediments in the Lambert Glacier (Hambrey et al., 2000, Geology). Flexural models yield new estimates of peak uplift and regional lowering for continuous and broken-plate approximations respectively. These results can also be used to re-assess the possible ranges of pre-incision elevations of the "Gamburtsev plateau", which is of key importance when modelling early East Antarctic ice sheet development (e.g. De Conto and Pollard, Nature 2003).

  2. Large-Scale Deformation and Uplift Associated with Serpentinization

    NASA Astrophysics Data System (ADS)

    Germanovich, L. N.; Lowell, R. P.; Smith, J. E.

    2014-12-01

    Geologic and geophysical data suggest that partially serpentinized peridotites and serpentinites are a significant part of the oceanic lithosphere. All serpentinization reactions are exothermic and result in volume expansion as high as 40%. Volume expansion beneath the seafloor will lead to surface uplift and elevated stresses in the neighborhood of the region undergoing serpentinization. The serpentinization-induced stresses are likely to result in faulting or tensile fracturing that promote the serpentinization process by creating new permeability and allowing fluid access to fresh peridotite. To explore these issues, we developed a first-order model of crustal deformation by considering an inclusion undergoing transformation strain in an elastic half-space. Using solutions for inclusions of different shapes, orientations, and depths, we calculate the surface uplift and mechanical stresses generated by the serpentinization processes. We discuss the topographic features at the TAG hydrothermal field (Mid-Atlantic Ridge, 26°N), uplift of the Miyazaki Plain (Southwestern Japan), and tectonic history of the Atlantic Massif (inside corner high of the Mid-Atlantic Ridge, 30°N, and the Atlantis Transform Fault). Our analysis suggests that an anomalous salient of 3 km in diameter and 100 m high at TAG may have resulted from approximately 20% transformational strain in a region beneath the footwall of the TAG detachment fault. This serpentinization process tends to promote slip along some overlying normal faults, which may then enhance fluid pathways to the deeper crust to continue the serpentinization process. The serpentinization also favors slip and seismicity along the antithetic faults identified below the TAG detachment fault. Our solution for the Miyazaki Plain above the Kyushu-Palau subduction zone explains the observed uplift of 120 m, but the transformational strain needs only be 3%. Transformational strains associated with serpentinization in this region may

  3. Research Spotlight: Extraordinary uplift of Yellowstone caldera

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-02-01

    In Yellowstone National Park, located in Wyoming, Montana, and Idaho, the Yellow­stone caldera, which extends about 40 kilometers by 60 kilometers, began in 2004 a period of accelerated uplift, with rates of uplift as high as 7 centimeters per year. From 2006 to 2009 the uplift rate slowed. Global Positioning System (GPS) and interferometric synthetic aperture radar (InSAR) ground deformation measurements described by Chang et al. show that in the northern caldera, uplift decreased from 7 centimeters per year in 2006 to 5 in 2008 and 2 in 2009. In the southwestern portion of the caldera, uplift decreased from 4 centimeters per year in 2006 to 2 in 2008 and 0.5 in 2009, demonstrating a spatial pattern of ground motion decrease from southwest to northeast along the caldera. (”Geophysical Research Letters, doi:10.1029/2010GL045451, 2010)

  4. GPS Imaging of Sierra Nevada Uplift

    NASA Astrophysics Data System (ADS)

    Hammond, W. C.; Blewitt, G.; Kreemer, C.

    2015-12-01

    Recent improvements in the scope and precision of GPS networks across California and Nevada have allowed for uplift of the Sierra Nevada to be observed directly. Much of the signal, in the range of 1 to 2 mm/yr, has been attributed to lithospheric scale rebound following massive groundwater withdrawal in the San Joaquin Valley in southern California, exacerbated by drought since 2011. However, natural tectonic deformation associated with long term uplift of the range may also contribute to the observed signal. We have developed new algorithms that enhance the signal of Sierra Nevada uplift and improve our ability to interpret and separate natural tectonic signals from anthropogenic contributions. We apply our new Median Interannual Difference Adjusted for Skewness (MIDAS) algorithm to the vertical times series and a inverse distance-weighted median spatial filtering and Delaunay-based interpolation to despeckle the rate map. The resulting spatially continuous vertical rate field is insensitive to outliers and steps in the GPS time series, and omits isolated features attributable to unstable stations or unrepresentative rates. The resulting vertical rate field for California and Nevada exhibits regionally coherent signals from the earthquake cycle including interseismic strain accumulation in Cascadia, postseismic relaxation of the mantle from recent large earthquakes in central Nevada and southern California, groundwater loading changes, and tectonic uplift of the Sierra Nevada and Coast Ranges. Uplift of the Sierra Nevada extends from the Garlock Fault in the south to an indefinite boundary in the north near the latitude of Mt. Lassen to the eastern Sierra Nevada range front in Owen's Valley. The rates transition to near zero in the southern Walker Lane. The eastern boundary of uplift coincides with the highest strain rates in the western Great Basin, suggesting higher normal fault slip rates and a component of tectonic uplift of the Sierra Nevada.

  5. Sedimentary facies and depositional history of the Swan Islands, Honduras

    NASA Astrophysics Data System (ADS)

    Ivey, Marvin L.; Breyer, John A.; Britton, Joseph C.

    1980-10-01

    Swan Island is a Honduran possession in the western Caribbean, located on the southeastern side of the Cayman Trench. Two sedimentary assemblages are found on the island: an older bedded sequence of mid-Tertiary age (Aquitanian or Burdigalian) and a younger sedimentary sequence of Late Pleistocene age. The older sequence is composed of a series of calcarenites, calcilutites, and siliciclastic mudstones; capping these are cliff-forming reefal carbonates of the younger sequence. The rocks of the older bedded sequence accumulated in deep water. Sedimentation consisted of a constant rain of pyroclastic debris interrupted by the episodic introduction of upslope carbonate material by turbidity currents. Uplift and deformation of this sequence was initiated sometime after the Early Miocene. By the Late Pleistocene, uplift had brought the rocks into water depths conducive to coral growth. Pleistocene sedimentation on the island was controlled by the interaction between tectonic uplift and eustatic sea-level changes. The primary controlling force on the tectonic history of the island is its proximity to the boundary between the North American and Caribbean plates.

  6. Surface Response to Regional Uplift of Madagascar Reveals Short Wavelength Dynamic Topography

    NASA Astrophysics Data System (ADS)

    Stephenson, S.; White, N.

    2016-12-01

    The physiography of Madagascar is characterized by high elevation but low relief topography with 42% of the landscape at an elevation grgeater than 500 m. Eocene marine limestones crop out at an elevation of 400 m, extensive low relief erosion surfaces capped by laterites occur at elevations of up to 2 km, and longitudinal river profiles are disequilibrated. Together, these observations suggest that Madagascar underwent regional uplift in Neogene times. Inverse modeling of drainage networks suggests that regional uplift is diachronous and has occurred on wavelengths of 1000 km. The existence of deeply incised river channels together with low-temperature thermochronologic measurements (i.e. AFT, AHe) implies that erosion occurred in response to regional Neogene uplift. Admittance analysis of long wavelength free-air gravity and topography shows that admittance, Z = 45 ± 5 mGal/km. The history of Neogene volcanism and a lack of significant tectonic shortening both suggest that uplift is dynamically supported. Here we present a suite of U-Th dates of emergent coral reef deposits from northern Madagascar, whose margins are sometimes considered `stable'. Elevation of these coeval coral reefs decreases from 7.2 m at the northern tip of Madagascar to sea level 100 km to the south. The existence of a spatial gradient suggests that differential vertical motions occurred during Late Quaternary times. These results raise significant questions about the reliability both of emergent coral reefs as global sea-level markers and the length-scale of variations in dynamic topography.

  7. Glacial isostatic uplift of the European Alps

    PubMed Central

    Mey, Jürgen; Scherler, Dirk; Wickert, Andrew D.; Egholm, David L.; Tesauro, Magdala; Schildgen, Taylor F.; Strecker, Manfred R.

    2016-01-01

    Following the last glacial maximum (LGM), the demise of continental ice sheets induced crustal rebound in tectonically stable regions of North America and Scandinavia that is still ongoing. Unlike the ice sheets, the Alpine ice cap developed in an orogen where the measured uplift is potentially attributed to tectonic shortening, lithospheric delamination and unloading due to deglaciation and erosion. Here we show that ∼90% of the geodetically measured rock uplift in the Alps can be explained by the Earth’s viscoelastic response to LGM deglaciation. We modelled rock uplift by reconstructing the Alpine ice cap, while accounting for postglacial erosion, sediment deposition and spatial variations in lithospheric rigidity. Clusters of excessive uplift in the Rhône Valley and in the Eastern Alps delineate regions potentially affected by mantle processes, crustal heterogeneity and active tectonics. Our study shows that even small LGM ice caps can dominate present-day rock uplift in tectonically active regions. PMID:27830704

  8. Glacial isostatic uplift of the European Alps.

    PubMed

    Mey, Jürgen; Scherler, Dirk; Wickert, Andrew D; Egholm, David L; Tesauro, Magdala; Schildgen, Taylor F; Strecker, Manfred R

    2016-11-10

    Following the last glacial maximum (LGM), the demise of continental ice sheets induced crustal rebound in tectonically stable regions of North America and Scandinavia that is still ongoing. Unlike the ice sheets, the Alpine ice cap developed in an orogen where the measured uplift is potentially attributed to tectonic shortening, lithospheric delamination and unloading due to deglaciation and erosion. Here we show that ∼90% of the geodetically measured rock uplift in the Alps can be explained by the Earth's viscoelastic response to LGM deglaciation. We modelled rock uplift by reconstructing the Alpine ice cap, while accounting for postglacial erosion, sediment deposition and spatial variations in lithospheric rigidity. Clusters of excessive uplift in the Rhône Valley and in the Eastern Alps delineate regions potentially affected by mantle processes, crustal heterogeneity and active tectonics. Our study shows that even small LGM ice caps can dominate present-day rock uplift in tectonically active regions.

  9. Drainage Evolution during the Uplift of the Central Anatolia Plateau

    NASA Astrophysics Data System (ADS)

    Brocard, G. Y.; Meijers, M. J.; Willenbring, J. K.; Kaymakci, N.; Whitney, D. L.

    2015-12-01

    The Central Anatolian plateau formed in the past 8-6 Myrs, associated to a change in tectonic regime, from contraction to extensional escape tectonics. We have examined the response of the river drainage of Central Anatolia to the rise of the plateau uplift and to the formation of the Anatolian microplate, tracking changes in drainage organization. Anatolia experienced widespread rock uplift and erosion in the Late Oligocene, generating a narrow, steep, and quickly eroding mountain range above the future southern plateau margin. A regionally widespread marine transgression resulted from wholesale foundering of this orogen in Early Miocene time. Widespread planation surfaces overlapped by Miocene marine carbonates bevel this topography, indicating that relief had been reduced to a low elevation pedimented landscape by the end of the Middle Miocene. Plateau uplift initiated around 11 My ago in Eastern Anatolia; it was echoed in Central Anatolia by a short-lived phase of contraction and localized uplifts that predate escape tectonics and mark the beginning of the current topographic differentiation of the southern plateau margin. The through-going drainage network inherited disintegrated, and a vast zone of inward drainage formed at the location of the future plateau interior. Between 8 and 6 My, the southern plateau margin (i.e. the Tauride Mountains) emerged. δ18O analyses on lacustrine and pedogenic carbonates show that the southern plateau margin, if not the plateau interior, had experienced enough uplift by 5 My to generate a substantial rain shadow over the plateau interior. Being disconnected from the regional base level from the start, the plateau interior was able to rise without experiencing substantial dissection. It reconnected to all surrounding sediment sinks (Mediterranean Sea, Black Sea and Persian Gulf) over the past 5 My. We discuss the mechanisms that have driven this reconnection. Bottom-up processes of integration such as drainage divide retreat

  10. Extinction vs. Rapid Radiation: The Juxtaposed Evolutionary Histories of Coelotine Spiders Support the Eocene-Oligocene Orogenesis of the Tibetan Plateau.

    PubMed

    Zhao, Zhe; Li, Shuqiang

    2017-11-01

    Evolutionary biology has long been concerned with how changing environments affect and drive the spatiotemporal development of organisms. Coelotine spiders (Agelenidae: Coelotinae) are common species in the temperate and subtropical areas of the Northern Hemisphere. Their long evolutionary history and the extremely imbalanced distribution of species richness suggest that Eurasian environments, especially since the Cenozoic, are the drivers of their diversification. We use phylogenetics, molecular dating, ancestral area reconstructions, diversity, and ecological niche analyses to investigate the spatiotemporal evolution of 286 coelotine species from throughout the region. Based on eight genes (6.5 kb) and 2323 de novo DNA sequences, analyses suggest an Eocene South China origin for them. Most extant, widespread species belong to the southern (SCG) or northern (NCG) clades. The origin of coelotine spiders appears to associate with either the Paleocene-Eocene Thermal Maximum or the hot period in early Eocene. Tibetan uplifting events influenced the current diversity patterns of coelotines. The origin of SCG lies outside of the Tibetan Plateau. Uplifting in the southeastern area of the plateau blocked dispersal since the Late Eocene. Continuous orogenesis appears to have created localized vicariant events, which drove rapid radiation in SCG. North-central Tibet is the likely location of origin for NCG and many lineages likely experienced extinction owing to uplifting since early Oligocene. Their evolutionary histories correspond with recent geological evidence that high-elevation orographical features existed in the Tibetan region as early as 40-35 Ma. Our discoveries may be the first empirical evidence that links the evolution of organisms to the Eocene-Oligocene uplifting of the Tibetan Plateau. [Tibet; biogeography; ecology; molecular clock; diversification.]. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic

  11. Uplifting model of the Longmenshan mountain in the eastern margin of Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Ding, R.; Mao, C.

    2010-12-01

    Longmenshan mountain is a vivid manifestation of the Cenozoic orogenesis in the eastern margin of the Tibetan plateau, and a key to understand the geodynamics of eastward extending of the plateau. Thus the uplift mechanism of Longmenshan mountain became a hot spot issue of geosciences about the Tibetan plateau. Two entirely different hypotheses, i.e., crustal shortening and lower crustal channel flow, were put forward, but the solution is open. Further discussion need our deeper understanding about the uplifting features of the Longmenshan mountain. Fortunately, the uplifting processes were recorded objectively by peneplains and river landforms. We first analysed the peneplains and pediplanes of Longmenshan mountain and its surrounding areas, and surveyed the terraces of Dadu river running across the mountain. Then we studied the uplifting features of the study areas in late Cenozoic time on the basis of landform geometries. Finaly we discussed the possible mechanisms for the uplifting. There are two levels of peneplains whose peneplanations may begin in early Cenozoic time and end at late Miocene when the final fluctuations of elevations were possibly less than one kilometers. The valley of Dadu river is incised into the peneplains and has a staircase of no less than ten levels of terraces. The highest terrace is a strath which was contemporary with the pediplane in the piedmont formed in late Pliocene or in early Pleistocene. Due to their originally flat features, the peneplains and the strath terraces were used as datum planes for judging neotectonic deformations. Since late Miocene, the southeastern side of Longmenshan mountain has been dominated by thrust-faulting with a total vertical displacement of about 4500 m against the Sichuan basin, meantime the northwest side has been maintained flexural uplift with syncline hinge approximately following the Longriba fault. As a landform barrier between Tibetan plateau and Sichuan basin, the crest lines of the

  12. Phanerozoic burial, uplift and denudation of the Equatorial Atlantic margin of South America

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Bonow, Johan M.; Green, Paul F.; dall'Asta, Massimo; Roig, Jean-Yves; Theveniaut, Hervé

    2017-04-01

    We have initiated a study aimed at understanding the history of burial, uplift and denudation of the South American Equatorial Atlantic Margin (SAEAM Uplift) including the Guiana Shield to provide a framework for investigating the hydrocarbon prospectivity of the offshore region. We report first results including observations from fieldwork at the northern and southern flank of the Guiana Shield. The study combines apatite fission-track analysis (AFTA) and vitrinite reflectance data from samples of outcrops and drillcores, sonic velocity data from drill holes and stratigraphic landscape analysis (mapping of peneplains) - all constrained by geological evidence, following the methods of Green et al. (2013). The study will thus combine the thermal history from AFTA data with the denudation history from stratigraphic landscape analysis to provide magnitudes and timing of vertical movements (Japsen et al. 2012, 2016). Along the Atlantic margin of Suriname and French Guiana, tilted and truncated Lower Cretaceous strata rest on Precambrian basement (Sapin et al. 2016). Our AFTA data show that the basement underwent Mesozoic exhumation prior to deposition of the Lower Cretaceous cover. Sub-horizontal peneplains define the landscape of the Guiana Shield at elevations up to 500 m a.s.l. As these sub-horizontal peneplains truncate the tilted, sub-Cretaceous surface along the Atlantic margin, these peneplains were therefore formed and uplifted in post-Cretaceous time. This interpretation is in good agreement with our AFTA data that define Paleogene exhumation along the margin and with the results of Theveniaut and Freyssinet (2002) who used palaeomagnetic data to conclude that bauxitic surfaces across basement at up to 400 m a.s.l. on the Guiana Shield formed during the Palaeogene. Integration of the results from AFTA with stratigraphic landscape analysis (currently in progress) and geological evidence will provide a robust reconstruction of the tectonic development of the

  13. Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body

    PubMed Central

    Perkins, Jonathan P.; Ward, Kevin M.; de Silva, Shanaka L.; Zandt, George; Beck, Susan L.; Finnegan, Noah J.

    2016-01-01

    The Altiplano-Puna Magma Body (APMB) in the Central Andes is the largest imaged magma reservoir on Earth, and is located within the second highest orogenic plateau on Earth, the Altiplano-Puna. Although the APMB is a first-order geologic feature similar to the Sierra Nevada batholith, its role in the surface uplift history of the Central Andes remains uncertain. Here we show that a long-wavelength topographic dome overlies the seismically measured extent of the APMB, and gravity data suggest that the uplift is isostatically compensated. Isostatic modelling of the magmatic contribution to dome growth yields melt volumes comparable to those estimated from tomography, and suggests that the APMB growth rate exceeds the peak Cretaceous magmatic flare-up in the Sierran batholith. Our analysis reveals that magmatic addition may provide a contribution to surface uplift on par with lithospheric removal, and illustrates that surface topography may help constrain the magnitude of pluton-scale melt production. PMID:27779183

  14. Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body.

    PubMed

    Perkins, Jonathan P; Ward, Kevin M; de Silva, Shanaka L; Zandt, George; Beck, Susan L; Finnegan, Noah J

    2016-10-25

    The Altiplano-Puna Magma Body (APMB) in the Central Andes is the largest imaged magma reservoir on Earth, and is located within the second highest orogenic plateau on Earth, the Altiplano-Puna. Although the APMB is a first-order geologic feature similar to the Sierra Nevada batholith, its role in the surface uplift history of the Central Andes remains uncertain. Here we show that a long-wavelength topographic dome overlies the seismically measured extent of the APMB, and gravity data suggest that the uplift is isostatically compensated. Isostatic modelling of the magmatic contribution to dome growth yields melt volumes comparable to those estimated from tomography, and suggests that the APMB growth rate exceeds the peak Cretaceous magmatic flare-up in the Sierran batholith. Our analysis reveals that magmatic addition may provide a contribution to surface uplift on par with lithospheric removal, and illustrates that surface topography may help constrain the magnitude of pluton-scale melt production.

  15. Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, NE China: evidence from basin provenance and geochronology

    NASA Astrophysics Data System (ADS)

    Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei

    2010-05-01

    The main part of Jiamusi Block, named as Huanan-Uplift, is located in the northeastern Heilongjiang, China. The Huanan-Uplift is surrounded by many relatively small Mesozoic-Cenozoic basins, e.g. Sanjiang Basin, Hulin Basin, Boli Basin, Jixi Basin, Shuangyashan Basin and Shuanghua Basin. However previous research works were mainly focused on stratigraphy and palaeontology of the basins, therefore, the coupling relation between the uplift and the surrounding basins have not been clear. Based on the field investigations, conglomerate provenance studies of the Houshigou Formation in Boli Basin, geochronology of the Huanan-Uplift basement, we have been studied the relationships between Huanan-Uplift and the surrounding basins. The regional stratigraphic correlations indicates that the isolated basins in the area experienced the same evolution during the period of the Chengzihe and the Muling Formations (the Early Cretaceous). The paleogeography reconstructions suggest that the area had been a large-scale basin as a whole during the Early Cretaceous. The Huanan-Uplift did not exist. The paleocurrent directions, sandstone and conglomerate provenance analyses show that the Huanan-Uplift started to be the source area of the surrounding basins during the period of Houshigou Formation (early Late Cretaceous), therefore, it suggests that the Jiamusi Block commenced uplift in the early Late Cretaceous. The granitic gneisses in Huanan-Uplift give 494-415 Ma monazite U-Th-total Pb ages, 262-259 Ma biotite and 246-241 Ma K-feldspar 40Ar/39Ar ages. The cooling rates of 1-2 ℃/Ma from 500-260 Ma and 10-11 ℃/Ma from 260-240 Ma have been calculated based on the ages. This suggests that the Jiamusi Block had a rapid exhumation during late Permian, which should be related to the closure of the Paleo-Asian Ocean between the Siberian and North China continents. It is concluded that during the late Paleozoic the Jiamusi Block was stable with a very slow uplifting. With the closure of

  16. Learning History in Early Childhood: Teaching Methods and Children's Understanding

    ERIC Educational Resources Information Center

    Skjaeveland, Yngve

    2017-01-01

    This article discusses the teaching of history in early childhood education and care centres and children's understanding of history. Based on interviews with eight Norwegian early childhood education and care teachers and on interpretative phenomenological analysis, the article shows how the early childhood education and care centres teach…

  17. Evidence of Himalayan uplift as seen in Neogene records of Indian monsoon variability from ODP Hole 722B, NW Arabian Sea

    NASA Astrophysics Data System (ADS)

    Muthusamy, Prakasam; Gupta, Anil K.; Saini, Naresh K.

    2013-04-01

    The Indian monsoon is one of the most interesting climatic features on Earth impacting most populous countries of South and East Asia. It is marked by seasonal reversals of wind direction with southwesterly winds in summer (June-September) and northeasterly winds in winter (December-February). The monsoon not only impacts socioeconomic conditions of Asia but also brings important changes in fauna and flora, ocean upwelling and primary productivity in the Arabian Sea. The Himalaya has undergone several phases of rapid uplift and exhumation since the early Miocene which led to major intensification of the Indian monsoon. The monsoon is driven by the thermal contrast between land and sea, and is intimately linked with the latitudinal movement of the Inter-Tropical Convergence Zone (ITCZ). The effect of Indian monsoon variability and the Himalayan uplift can be seen in numerous proxy records across the region. In this study we discussed about the Indian monsoon intensification and the Himalayan uplift since the early Miocene based on multi proxy records such as planktic foraminiferal relative abundances (Globigerina bulloides, Globigerinita glutinata and mixed layer species), total organic carbon (TOC), CaCO3 and elemental data from ODP Hole 722B (2028 mbsf), northwestern Arabian Sea. The TOC, CaCO3 and elemental variations of the ODP Hole 722B suggest multi phase of monsoonal intensification and Himalayan uplifts. Our results suggest that in the early Miocene (23.03 Ma) to ~15Ma, the wind strength and productivity were low. A major change is observed at ~15 Ma, during which time numerous proxies show abrupt changes. TOC, CaCO3 and Elemental analyses results reveal that a major change in the productivity, wind strength and chemical weathering starts around 15 Ma and extends up to 10 Ma. This suggests that a major Himalayan uplift occurred during ~15-10 Ma that drove Indian monsoon intensification. A similar change is also observed during 5 to 1 Ma. These long

  18. Coastal tectonics on the eastern margin of the Pacific Rim: Late Quaternary sea-level history and uplift rates, Channel Islands National Park, California, USA

    USGS Publications Warehouse

    Muhs, Daniel R.; Simmons, Kathleen R.; Schumann, R. Randall; Groves, Lindsey T.; DeVogel, Stephen B.; Minor, Scott A.; Laurel, Deanna

    2014-01-01

    The Pacific Rim is a region where tectonic processes play a significant role in coastal landscape evolution. Coastal California, on the eastern margin of the Pacific Rm, is very active tectonically and geomorphic expressions of this include uplifted marine terraces. There have been, however, conflicting estimates of the rate of late Quaternary uplift of marine terraces in coastal California, particularly for the orthern Channel Islands. In the present study, the terraces on San Miguel Island and Santa Rosa Island were mapped and new age estimates were generated using uranium-series dating of fossil corals and amino acid geochronology of fossil mollusks. Results indicate that the 2nd terrace on both islands is ~120 ka and the 1st terrace on Santa Rosa Island is ~80 ka. These ages correspond to two global high-sea stands of the Last Interglacial complex, marine isotope stages (MIS) 5.5 and 51, respectively. The age estimates indicate that San Miguel Island and Santa Rosa Island have been tectonically uplifted at rates of 0.12e0.20 m/ka in the late Quaternary, similar to uplift rates inferred from previous studies on neighboring San Cruz Island. The newly estimated uplift rates for the northern Channel Islands are, however, an order of magnitude lower than a recent study that generated uplift rates from an offshore terrace dating to the Last Glacial period. The differences between the estimated uplift rates in the present study and the offshore study are explained by the magnitude of glacial isostatic adjustment (GIA) effects that were not known at the time of the earlier study. Set in the larger context of northeastern Pacific Rim tectonics, Channel Islands uplift rates are higher than those coastal localities on the margin of the East Pacific Rise spreading center, but slightly lower than those of most localities adjacent to the Cascadia subduction zone. The uplift rates reported here for the northern Channel Islands are similar to those reported for most other

  19. Physiographic divisions and differential uplift in the Piedmont and Blue Ridge

    USGS Publications Warehouse

    Hack, John Tilton

    1982-01-01

    The Piedmont and Blue Ridge are dynamic landscapes that have undergone substantial change since the orogenies that ended in late Paleozoic or, as some believe, early Mesozoic time. The southern Blue Ridge region south of Roanoke, Va., lies on the crest of a topographic uplift that corresponds to the eastern continental drainage divide. To the north, this uplift and divide cross the Appalachian Valley and form the crest of the Appalachian Plateaus as far north as central Pennsylvania. The northern Blue Ridge Mountains as well as parts of the Piedmont are on the eastern part of the uplift area. The southeastern margin of the uplift corresponds to a line within the Piedmont physiographic province that extends northeastward from the Tallapoosa River at the Fall Zone and crosses the Rappahannock River at the Fall Zone. The differential elevation on either side of this line is sharp in some places, as, for example, northeast of Atlanta, Ga. In other places, the difference in elevation is difficult to detect, and, in effect, the line becomes a broad monoclinal slope. The region as a whole can be divided into at least six broad subregions that have somewhat different histories in late geologic time. The Piedmont Lowlands subprovince, southeast of the uplifted area, is dominated by a monotonous topography of low rounded ridges and ravines largely underlain by saprolite on crystalline rocks. Isolated ranges of hills of greater relief are scattered across the region; those investigated are directly related to the presence of erosionally resistant rocks. Stream patterns as well as broad topographic forms indicate that although the southern part of the Piedmont Lowlands was probably once covered by younger sediments, this area has been exposed to erosion for a long time. In North Carolina, the inner part of the Piedmont Lowlands has strongly trellised stream patterns, which suggest that subaerial erosion was active for an even longer time period, perhaps since the latest

  20. Linking erosion history and mantle processes in southern Africa

    NASA Astrophysics Data System (ADS)

    Stanley, J. R.; Braun, J.; Flowers, R. M.; Baby, G.; Wildman, M.; Guillocheau, F.; Robin, C.; Beucher, R.; Brown, R. W.

    2017-12-01

    The large, low relief, high elevation plateau of southern Africa has been the focus of many studies, but there is still considerable debate about how it formed. Lack of tectonic convergence and crustal thickening suggests mantle dynamics play an important role in the evolution of topography there, but the time and specific mechanisms of topographic development are still contested. Many mantle mechanisms of topographic support have been suggested including dynamic topography associated with either deep or shallow mantle thermal anomalies, thermochemical modification of the lithosphere, and plume tails related to Mesozoic magmatic activity. These mechanisms predict different timing and patterns of surface uplift such that better constraints on the uplift history have the potential to constrain the nature of the source of topographic support. Here we test several of these geodynamic hypotheses using a landscape evolution model that is used to predict the erosional response to surface uplift. Several recent studies have provided a clearer picture of the erosion history of the plateau surface and margins using low temperature thermochronology and the geometries of the surrounding offshore depositional systems. Model results are directly compared with these data. We use an inversion method (the Neighborhood Algorithm) to constrain the range in erosional and uplift parameters that can best reproduce the observed data. The combination of different types of geologic information including sedimentary flux, landscape shape, and thermochronolology is valuable for constraining many of these parameters. We show that both the characteristics of the geodynamic forcing as well as the physical characteristics of the eroding plateau have significant control on the plateau erosion patterns. Models that match the erosion history data well suggest uplift of the eastern margin in the Cretaceous ( 100 Ma) followed by uplift of the western margin 20 Myr later. The amplitude of this uplift

  1. Early History of Chronic Obstructive Pulmonary Disease 1808-1980.

    PubMed

    Watson, R Ann; Pride, Neil B

    2016-01-01

    COPD has become a more popular research area in the last 3 decades, yet the first clear descriptions of acute and chronic bronchitis were in 1808. This brief history, comprehensively referenced, leads us through the early developments in respiratory physiology and their applications. It emphasises the early history of chronic bronchitis and emphysema in the 19(th) and early 20(th) centuries, long before the dominant effects of cigarette smoking emerged. This remains relevant to developing countries today.

  2. Mountain uplift explains differences in Palaeogene patterns of mammalian evolution and extinction between North America and Europe

    PubMed Central

    Eronen, Jussi T.; Janis, Christine M.; Chamberlain, C. Page; Mulch, Andreas

    2015-01-01

    Patterns of late Palaeogene mammalian evolution appear to be very different between Eurasia and North America. Around the Eocene–Oligocene (EO) transition global temperatures in the Northern Hemisphere plummet: following this, European mammal faunas undergo a profound extinction event (the Grande Coupure), while in North America they appear to pass through this temperature event unscathed. Here, we investigate the role of surface uplift to environmental change and mammalian evolution through the Palaeogene (66–23 Ma). Palaeogene regional surface uplift in North America caused large-scale reorganization of precipitation patterns, particularly in the continental interior, in accord with our combined stable isotope and ecometric data. Changes in mammalian faunas reflect that these were dry and high-elevation palaeoenvironments. The scenario of Middle to Late Eocene (50–37 Ma) surface uplift, together with decreasing precipitation in higher-altitude regions of western North America, explains the enigma of the apparent lack of the large-scale mammal faunal change around the EO transition that characterized western Europe. We suggest that North American mammalian faunas were already pre-adapted to cooler and drier conditions preceding the EO boundary, resulting from the effects of a protracted history of surface uplift. PMID:26041349

  3. Uplift along passive continental margins, changes in plate motion and mantle convection

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Green, Paul F.; Chalmers, James A.; Bonow, Johan M.

    2014-05-01

    The origin of the forces that produce elevated, passive continental margins (EPCMs) is a hot topic in geoscience. It is, however, a new aspect in the debate that episodes of uplift coincide with changes in plate motion. This has been revealed, primarily, by studies of the burial, uplift and exhumation history of EPCMs based on integration on stratigraphic landscape analysis, low-temperature thermochronology and evidence from the geological record (Green et al., 2013). In the Campanian, Eocene and Miocene, uplift and erosion affected the margins of Brazil and Africa (Japsen et al., 2012b). The uplift phases in Brazil coincided with main phases of Andean orogeny which were periods of relatively rapid convergence at the Andean margin of South America (Cobbold et al., 2001). Because Campanian uplift in Brazil coincides, not only with rapid convergence at the Andean margin of South America, but also with a decline in Atlantic spreading rate, Japsen et al. (2012b) suggested that all these uplift events have a common cause, which is lateral resistance to plate motion. Because the uplift phases are common to margins of diverging plates, it was also suggested that the driving forces can transmit across the spreading axis; probably at great depth, e.g. in the asthenosphere. Late Eocene, Late Miocene and Pliocene uplift and erosion shaped the elevated margin of southern East Greenland (Bonow et al., in review; Japsen et al., in review). These regional uplift phases are synchronous with phases in West Greenland, overlap in time with similar events in North America and Europe and also correlate with changes in plate motion. The much higher elevation of East Greenland compared to West Greenland suggests dynamic support in the east from the Iceland plume. Japsen et al. (2012a) pointed out that EPCMs are typically located above thick crust/lithosphere that is closely juxtaposed to thinner crust/lithosphere. The presence of mountains along the Atlantic margin of Brazil and in East

  4. Apatite fission track evidence for Miocene denudation history in the Gangdese conglomerate belt and Yarlung Tsangpo River: Implications for the evolution of Southern Tibet

    NASA Astrophysics Data System (ADS)

    Song, Shiyu; Cao, Daiyong; Zhang, QingChao; Wang, Anming; Peng, Yangwen

    2018-07-01

    Low-temperature thermochronology is used widely in the Tibet plateau uplift. Some researches, however, have defined the time of rapid denudation as simply rock uplift and have neglected the fact that the rock denudation recorded by fission track (FT) data was controlled by both surface incision and rock uplift. The incision of the Yarlung Zangbo River had a significant influence on uplift history inversion in Southern Tibet. This paper simulated the bedrock denudation and river incision histories using apatite fission track (AFT) data sampled from the Gangdese conglomerate belt, which is located in the middle of Southern Tibet, and analyzed the geological meaning of the AFT age of each sample. The results showed the following: (1) In the early Miocene (22-16 Ma), both the value of the denudation rate and the incision rate were high (0.56 mm/yr and 0.24 mm/yr). (2) In the middle-late Miocene, the incision rate (0.12 mm/yr) was similar to the denudation rate (0.09-0.11 mm/yr). (3) The historical model between river incision and bedrock denudation revealed a significant difference in the denudation rate during the period ca. 8-6 Ma. Combining these data with previously published thermochronological ages and synthesizing these ages with regional geological, we arrived at the following conclusions: (1) In the early Miocene, the denudation event probably was caused by a combined result of Indian plate rollback and the incision of the Yarlung Zangbo River. (2) In the middle-late Miocene, the denudation rate was consistent with the incision rate, which suggested that the denudation episode was caused by climate change associated with Asian monsoon intensification. (3) After 8 Ma, the stable and slow incision rate indicated that regional drastic uplift had ceased. The paleo-elevation of the research area had approached, and even exceeded, the present-day elevation in the late Miocene.

  5. Early Childhood Education: History, Theory, and Practice

    ERIC Educational Resources Information Center

    Morgan, Harry

    2006-01-01

    In this book, the author covers the history, theory, and practices that influence early childhood education along with an emphasis on infant and toddler care and education. He also presents a comparison of the conflict between education planners who support early childhood studies and state school systems whose cost-saving measures are dismantling…

  6. Exhumation history of the western Kyrgyz Tien Shan: Implications for intramontane basin formation

    NASA Astrophysics Data System (ADS)

    Bande, Alejandro; Sobel, Edward R.; Mikolaichuk, Alexander; Schmidt, Alexander; Stockli, Daniel F.

    2017-01-01

    The dextral Talas-Fergana Fault separates the western from the central Tien Shan. Recent work has shed light on the Cenozoic evolution of the eastern and central Tien Shan; much less attention has been paid to the western Tien Shan. In this contribution we present new thermochronological ages for the Fergana and Alai ranges that, combined with the available data set, constrain the Cenozoic exhumation history of the western Tien Shan. Following a tectonically quiet early Cenozoic period, we suggest an onset of exhumation at 25 Ma. This early onset was followed by a period of slower exhumation and in some areas minor reheating. A final, strong late Miocene rapid cooling event is well represented in the western Tien Shan as in other sectors of the range. The early onset of uplift of the western Tien Shan dissected the previously continuous westernmost Parathethyan Sea, progressively isolating basins (e.g., Fergana, Tarim, and Alai basins) in the central Asian hinterland. Moreover, the coeval timing of late Miocene uplift along the length of entire Tien Shan implies that neither the Pamir nor Tarim can be the sole driver for exhumation of the entire range.

  7. Alchemy--A History of Early Technology.

    ERIC Educational Resources Information Center

    Pollard, A. M.

    1988-01-01

    Reviews the history of alchemy including personalities and methods. Discusses the philosophy associated with various early chemists and alchemists. Attempts to show that it was not unreasonable for ancient alchemists to believe in the possibility of transmutation. (CW)

  8. Present-day uplift of the western Alps.

    PubMed

    Nocquet, J-M; Sue, C; Walpersdorf, A; Tran, T; Lenôtre, N; Vernant, P; Cushing, M; Jouanne, F; Masson, F; Baize, S; Chéry, J; van der Beek, P A

    2016-06-27

    Collisional mountain belts grow as a consequence of continental plate convergence and eventually disappear under the combined effects of gravitational collapse and erosion. Using a decade of GPS data, we show that the western Alps are currently characterized by zero horizontal velocity boundary conditions, offering the opportunity to investigate orogen evolution at the time of cessation of plate convergence. We find no significant horizontal motion within the belt, but GPS and levelling measurements independently show a regional pattern of uplift reaching ~2.5 mm/yr in the northwestern Alps. Unless a low viscosity crustal root under the northwestern Alps locally enhances the vertical response to surface unloading, the summed effects of isostatic responses to erosion and glaciation explain at most 60% of the observed uplift rates. Rock-uplift rates corrected from transient glacial isostatic adjustment contributions likely exceed erosion rates in the northwestern Alps. In the absence of active convergence, the observed surface uplift must result from deep-seated processes.

  9. Uplift-driven diversification in the Hengduan Mountains, a temperate biodiversity hotspot.

    PubMed

    Xing, Yaowu; Ree, Richard H

    2017-04-25

    A common hypothesis for the rich biodiversity found in mountains is uplift-driven diversification-that orogeny creates conditions favoring rapid in situ speciation of resident lineages. We tested this hypothesis in the context of the Qinghai-Tibetan Plateau (QTP) and adjoining mountain ranges, using the phylogenetic and geographic histories of multiple groups of plants to infer the tempo (rate) and mode (colonization versus in situ diversification) of biotic assembly through time and across regions. We focused on the Hengduan Mountains region, which in comparison with the QTP and Himalayas was uplifted more recently (since the late Miocene) and is smaller in area and richer in species. Time-calibrated phylogenetic analyses show that about 8 million y ago the rate of in situ diversification increased in the Hengduan Mountains, significantly exceeding that in the geologically older QTP and Himalayas. By contrast, in the QTP and Himalayas during the same period the rate of in situ diversification remained relatively flat, with colonization dominating lineage accumulation. The Hengduan Mountains flora was thus assembled disproportionately by recent in situ diversification, temporally congruent with independent estimates of orogeny. This study shows quantitative evidence for uplift-driven diversification in this region, and more generally, tests the hypothesis by comparing the rate and mode of biotic assembly jointly across time and space. It thus complements the more prevalent method of examining endemic radiations individually and could be used as a template to augment such studies in other biodiversity hotspots.

  10. Uplift-driven diversification in the Hengduan Mountains, a temperate biodiversity hotspot

    PubMed Central

    Xing, Yaowu; Ree, Richard H.

    2017-01-01

    A common hypothesis for the rich biodiversity found in mountains is uplift-driven diversification—that orogeny creates conditions favoring rapid in situ speciation of resident lineages. We tested this hypothesis in the context of the Qinghai–Tibetan Plateau (QTP) and adjoining mountain ranges, using the phylogenetic and geographic histories of multiple groups of plants to infer the tempo (rate) and mode (colonization versus in situ diversification) of biotic assembly through time and across regions. We focused on the Hengduan Mountains region, which in comparison with the QTP and Himalayas was uplifted more recently (since the late Miocene) and is smaller in area and richer in species. Time-calibrated phylogenetic analyses show that about 8 million y ago the rate of in situ diversification increased in the Hengduan Mountains, significantly exceeding that in the geologically older QTP and Himalayas. By contrast, in the QTP and Himalayas during the same period the rate of in situ diversification remained relatively flat, with colonization dominating lineage accumulation. The Hengduan Mountains flora was thus assembled disproportionately by recent in situ diversification, temporally congruent with independent estimates of orogeny. This study shows quantitative evidence for uplift-driven diversification in this region, and more generally, tests the hypothesis by comparing the rate and mode of biotic assembly jointly across time and space. It thus complements the more prevalent method of examining endemic radiations individually and could be used as a template to augment such studies in other biodiversity hotspots. PMID:28373546

  11. Evaluating Neogene Uplift and Denudational History of the Colorado Rockies Using River Profiles and Incision Records

    NASA Astrophysics Data System (ADS)

    Darling, A.; Karlstrom, K.; Kirby, E.; Ouimet, W.; Coblentz, D.; Aslan, A.

    2008-12-01

    The goal of the Colorado Rockies Experiment and Seismic Transects (CREST) is to image the velocity structure beneath the Rocky Mountains (2008-2009) and evaluate mantle to surface interconnections that may illuminate causes and timing of uplift of the Rockies. Existing mantle tomography shows a zone of low- density mantle, the Aspen Anomaly, that underlies the highest topography in Colorado. The tectonic geomorphic component of the project involves understanding incision patterns in time and space throughout the bedrock fluvial systems of western Rocky Mountains and eastern Colorado Plateau. The Colorado River and its tributaries drain the western slope of highest topography of the Colorado Rockies; The Green River drains the Wyoming Rockies and northern Colorado Plateau. Both cross highly variable substrates (Precambrian basement to Cretaceous Mancos shale) and active faults. Preliminary analysis of longitudinal profiles of the trunk rivers indicates that for a given drainage area, the Colorado generally has a higher steepness index (a measure of gradient normalized for upstream drainage area) than the Green. Localized reaches of high steepness index along the Green are interpreted to reflect resistant substrate. We suggest that these rivers, of similar stream power, are responding to different sustained forcings, wherein the Colorado River is responding to uplift above the Aspen Anomaly. We have compiled all known incision rates for the region for the last 10 Ma. The bedrock incision rate at a given reach is determined by dates on elevated straths where gravels are overlain by or inter-layered with basalt flows (Ar-Ar dates), ash layers (tephrochronology), or can be dated by cosmogenic burial ages. A suite of new samples have also been taken for undated reaches of the Colorado River, with plans for sampling the Green for comparison of incision rates. Available data show differential incision along both the Green and Colorado rivers. When combined with profile

  12. For Their Musical Uplift: Emma Azalia Hackley and Voice Culture in African American Communities

    ERIC Educational Resources Information Center

    Karpf, Juanita

    2011-01-01

    The noted African American soprano Emma Azalia Hackley (1867-1922) abandoned her concert career in the early twentieth century and began travelling throughout the United States, organizing community choruses and promoting community music making. She spent the remainder of her life engaged in what she called "musical social uplift", which entailed…

  13. Surface uplift and atmospheric flow deflection in the Late Cenozoic southern Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Mix, H.; Caves, J. K.; Winnick, M.; Ritch, A. J.; Reilly, S.; Chamberlain, C. P.

    2016-12-01

    Given the intimate links between topography, tectonics, climate and biodiversity, considerable effort has been devoted to developing robust elevation histories of orogens. In particular, quantitative geochemical reconstructions using stable oxygen and hydrogen isotopes have been applied to many of the world's mountain belts. Yet after decades of study, determining the Cenozoic surface uplift history of the Sierra Nevada remains a challenge. While geological and geophysical evidence suggests the southern Sierra underwent 1-2 km of Late Cenozoic surface uplift, stable isotope paleoaltimetry studies to date have been restricted to the Basin and Range interior. Recent advances in atmospheric modeling have suggested that such stable isotope records from leeward sites can be affected by the complicating role that sufficiently elevated topography such as the southern (High) Sierra plays in diverting atmospheric circulation. In order to examine the potential role of these terrain blocking effects, we produced stable isotope records from three Late Cenozoic sedimentary basins in the Eastern Sierra and Basin and Range: 1) Authigenic clay minerals in the Mio-Pliocene Verdi Basin (VB), 2) Fluvial and lacustrine carbonates from the Plio-Pleistocene Coso Basin (CB), and 3) Miocene to Holocene pedogenic, fluvial and lacustrine carbonates of Fish Lake Valley (FLV). Whereas both the VB (near present-day Reno) and CB (southern Owens Valley) receive input of water directly from the Sierra crest, FLV is a region of proposed reconvergence of moisture in the Basin and Range. The oxygen isotope records in both CB and FLV increase during the Neogene by approximately 2 ‰, while the hydrogen isotope record of the VB decreases by <10 ‰. These results are consistent with a modestly-elevated Paleogene Sierra of 2 km over which air masses traversed and underwent orographic rainout and Rayleigh distillation. A Neogene pulse of uplift in the southern Sierra could have driven modern flow

  14. Crustal Uplift in the Southcentral Alaska Subduction Zones: A New Analysis and Interpretation of Tide Gauge Observations

    NASA Technical Reports Server (NTRS)

    Cohen, Steven C.; Freymueller, Jeffrey T.

    1999-01-01

    We have examined the sea level height tide records at seven tide gauge sites in the region of southcentral Alaska that were affected by the 1964 Prince William Sound earthquake to determine the history of crustal uplift subsequent to the earthquake. There is considerable variation in the behavior depending on the location of the site relative to the 1964 rupture. At Seward, on the eastern side of the Kenai Peninsula we find a slow uplift that is consistent with elastic strain accumulation while at Seldovia and Nikiski on the western side of the Kenai we find a persistent rapid uplift of about 1 cm/yr that most likely represents a long term transient response to the earthquake, but which cannot be sustained over the expected recurrence interval for a great earthquake of several hundred years. Further to the southwest, at Kodiak, we find evidence that the rate of uplift, which is still several mm/yr, has slowed significantly over the past three and a half decades. To the east of the Kenai Peninsula we find subsidence at Cordova and an uncertain behavior at Valdez. At both of these sites there is a mathematically significant time-dependence to the uplift behavior, but the data confirming this time dependence are not as convincing as at Kodiak. At Anchorage, to the north there is little evidence of vertical motion since the earthquake. We compare these long term tide gauge records to recent GPS observations. In general there is reasonable consistency except at Anchorage and Cordova where the GPS measurement indicate somewhat more rapid uplift and subsidence, respectively.

  15. Tracing Altiplano-Puna plateau surface uplift via radiogenic isotope composition of Andean arc lavas

    NASA Astrophysics Data System (ADS)

    Scott, E. M.; Allen, M. B.; Macpherson, C.; McCaffrey, K. J. W.; Davidson, J.; Saville, C.

    2016-12-01

    We have compiled published geochemical data for Jurassic to Holocene Andean arc lavas from 5oN to 47oS, covering the current extent of the northern, central and southern volcanic zones. Using this dataset we evaluate the spatial and temporal evolution of age corrected Sr- and Nd-radiogenic isotopes in arc lavas at a continental-scale, in order to understand the tectonic and surface uplift histories of the Andean margin. It has long been noted that baseline 87Sr/86Sr and 143Nd/144Nd ratios of Quaternary lavas from the central volcanic zone, located within the Altiplano-Puna plateau, are distinct from volcanic rocks to the north and south. This is commonly attributed to greater crustal thickness, which increases to roughly twice that of the average continental crust within the Altiplano-Puna plateau. By comparing 87Sr/86Sr and 143Nd/144Nd ratios in Quaternary lavas to published crustal thickness models, present day topography and the compositions of basement terranes, we note that Sr- and Nd-isotope values of Quaternary lavas are an effective proxy for present day regional elevation. In contrast, variation in basement terranes has only a small, second order effect on isotopic composition at the scale of our study. Using this isotopic proxy, we infer the spatial extent of the plateau and its surface uplift history from the Jurassic to the present. Our results concur with a crustal thickening model of continued surface uplift, which initiated in the Altiplano, with deformation propagating southwards into the Puna throughout the Neogene and then continuing in central Chile and Argentina up to the present day.

  16. Mountain uplift explains differences in Palaeogene patterns of mammalian evolution and extinction between North America and Europe.

    PubMed

    Eronen, Jussi T; Janis, Christine M; Chamberlain, C Page; Mulch, Andreas

    2015-06-22

    Patterns of late Palaeogene mammalian evolution appear to be very different between Eurasia and North America. Around the Eocene-Oligocene (EO) transition global temperatures in the Northern Hemisphere plummet: following this, European mammal faunas undergo a profound extinction event (the Grande Coupure), while in North America they appear to pass through this temperature event unscathed. Here, we investigate the role of surface uplift to environmental change and mammalian evolution through the Palaeogene (66-23 Ma). Palaeogene regional surface uplift in North America caused large-scale reorganization of precipitation patterns, particularly in the continental interior, in accord with our combined stable isotope and ecometric data. Changes in mammalian faunas reflect that these were dry and high-elevation palaeoenvironments. The scenario of Middle to Late Eocene (50-37 Ma) surface uplift, together with decreasing precipitation in higher-altitude regions of western North America, explains the enigma of the apparent lack of the large-scale mammal faunal change around the EO transition that characterized western Europe. We suggest that North American mammalian faunas were already pre-adapted to cooler and drier conditions preceding the EO boundary, resulting from the effects of a protracted history of surface uplift. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Neogene stratigraphy, foraminifera, diatoms, and depositional history of Maria Madre Island, Mexico: Evidence of early Neogene marine conditions in the southern Gulf of California

    USGS Publications Warehouse

    McCloy, C.; Ingle, J.C.; Barron, J.A.

    1988-01-01

    abundant planktonic foraminifera such as Pulleniatina obliquiloculata and Neogloboquadrina duterteri. Common benthic foraminifera in this unit are indicative of upper bathyal water depths. The Neogene depositional history recorded on Maria Madre Island involves an early late Miocene subsidence event marking formation of the Tre??s Marias Basin with relatively undiluted diatomaceous sediment deposited in a low oxygen setting. Subsidence and deepening of the basin continued into the early Pliocene along with rapid deposition of terrigenous clastics. Uplift of the basinal sequence began in late Pliocene time accompanied by deposition of upper Pliocene-Pleistocene foraminiferal limestones on a rising submarine bank. Continued episodic uplift of the Neogene deposits brought the island above sea level by late Pleistocene time. ?? 1988.

  18. Deconvolving regional and fault-driven uplift in Calabria using drainage inversion techniques and field observations

    NASA Astrophysics Data System (ADS)

    Quye-Sawyer, Jennifer; Whittaker, Alexander; Roberts, Gareth; Rood, Dylan

    2017-04-01

    A key challenge in the Earth Sciences is to understand the timing and extent of the coupling between geodynamics, tectonics, and surface processes. In principle, the landscape adjusts to surface uplift or tectonic events, and present-day topography records a convolution of these processes. The inverse problem, the ability to find the 'best fit' theoretical scenario to match present day observations, is particularly desirable as it makes use of real data, encompasses the complexity of natural systems and quantifies model uncertainty through misfit. The region of Calabria, Italy, is known to have experienced geologically rapid uplift ( 1 mm/yr) since the Early Pleistocene, inferred from widespread marine terraces (ca. 1 Myr old) at elevations greater than 1 km. In addition, this is a tectonically active area of normal faulting with several highly destructive earthquakes in recent centuries. Since there has been some debate about the relative magnitudes of the uplift caused by regional processes or by faulting, the ability to model these effects on a regional scale may help resolve this problem. Therefore, Calabria is both a suitable and important site to model large magnitude recent geomorphic change. 1368 river longitudinal profiles have been generated from satellite digital elevation models (DEMs). These longitudinal profiles were compared to aerial photography to confirm the accuracy of this automated process. The longitudinal profiles contain numerous non-lithologically controlled knickpoints. Field observations support the presence of knickpoints extracted from the DEM and measurements of pebble imbrication from fluvial terraces suggest the planform stability of the drainage network in the last 1 Myr. By assuming fluvial erosion obeys stream power laws with an exponent of upstream area of 0.5 ± 0.1, the evolution of the landscape is computed using a linearized joint inversion of the longitudinal profiles. This has produced a spatially and temporally continuous

  19. Geologic history and palynologic dating of Paleocene deposits, western Rock Springs uplift, Sweetwater County, Wyoming

    USGS Publications Warehouse

    Kirschbaum, M.A.; Nelson, S.N.

    1988-01-01

    During the latest Cretaceous or earliest Paleocene, a northwest-southeast trending anticline developed in the area of the present Rock springs uplift in southwestern Wyoming. This ancestral structure was eroded to a surface of fairly low relief on which a paleosol developed. The surface was formed on the Upper Cretaceous Almond Formation throughout the study area. In the early middle Paleocene (P3 palynomorph zone), topographic lows on the erosion surface were infilled by alluvial deposits that accumulated in channel, floodplain, and backswamp environments. An organic-rich facies contains numerous coal beds and is middle to late Paleocene in age (P3 to P5 zones). The assemblage of pollen that defines the late middle Paleocene (P4 zone) is absent from the area suggesting a hiatus, although no lithologic break was observed at this boundary. The younger organic-poor facies begins in the late Paleocene (P5 zone) and continues to the top of the studied sequence. This change in facies has been used to map the contact between the Fort Union Formation of Paleocene age in this area, and the Wasatch Formation which was though to be of Eocene age. This study demonstrates that, as currently mapped, the lower part of the Wasatch Formation is Paleocene in age. Stratigraphically higher parts of the Wasatch, which presumably contain rocks of latest Paleocene (P6 zone) and earliest Eocene age, were not studied. -Authors

  20. Dinetah: An Early History of the Navajo People.

    ERIC Educational Resources Information Center

    Sundberg, Lawrence D.

    Originally written for Navajo elementary school students, this book chronicles the history of the Navajo people from prehistory to 1868. The book presents a sympathetic history of a people who depended on their tenacity and creative adaptability to survive troubled times. Chapters examine how Navajo culture changed from that of an early hunting…

  1. Uplift rates of the marine terraces in the south coast of Japan deduced from in situ cosmogenic 10Be and 26Al

    NASA Astrophysics Data System (ADS)

    Yokoyama, Y.; Nagano, G.; Nakamura, A.; Maemoku, H.; Miyairi, Y.; Matsuzaki, H.

    2015-12-01

    Marine terraces are low-relief platforms located along coastal areas. They are formed by waves action with the changes in the relative sea level (RSL) that is affected by combined effects of the eustatic sea level (ESL) and the tectonic movements (e.g. uplift, subsidence and isostatic effect). Therefore, determining the ages and the elevations of the marine terraces allows us to reconstruct the ESL and/or the tectonic history of the study area. The Kii Peninsula and the southern coast of the Shikoku Island are located along the Nankai Trough where the Philippine Sea Plate is subducting under the Eurasian plate. There exist relatively well-preserved marine terraces along the coastal line with the elevation of ca. 50 -100 m. Because of this unique tectonic setting, the terraces are regarded as the suitable counterparts to reconstruct uplift history of the south coast of Japan. However, the ages of these terraces are poorly understood due to the lack of the ash layers that is suitable for the tephrochronology. In this study, we determine the age of the marine terraces using terrestrial in-situ cosmogenic radionuclides (TCN), 10Be and 26Al. This is the first age estimation of the marine terraces in Japan using TCN, allowing us to determine the uplift rates and the seismic history of the region.

  2. Effects of Mountain Uplift and Climatic Oscillations on Phylogeography and Species Divergence in Four Endangered Notopterygium Herbs

    PubMed Central

    Shahzad, Khurram; Jia, Yun; Chen, Fu-Lin; Zeb, Umar; Li, Zhong-Hu

    2017-01-01

    Mountain uplift and climatic fluctuations are important driving forces that have affected the geographic distribution and population dynamics history of organisms. However, it is unclear how geological and climatic events might have affected the phylogeographic history and species divergence in high-alpine herbal plants. In this study, we analyzed the population demographic history and species differentiation of four endangered Notopterygium herbs on the high-altitude Qinghai–Tibetan Plateau (QTP) and adjacent areas. We combined phylogeographic analysis with species distribution modeling to detect the genetic variations in four Notopterygium species (N. incisum, N. franchetii, N. oviforme, and N. forrestii). In total, 559 individuals from 74 populations of the four species were analyzed based on three maternally inherited chloroplast fragments (matK, rbcL, and trnS-trnG) and one nuclear DNA region (internal transcribed spacer, ITS). Fifty-five chloroplast DNA (cpDNA) and 48 ITS haplotypes were identified in the four species. All of the cpDNA and ITS haplotypes were species-specific, except N. franchetii and N. oviforme shared one cpDNA haplotype, H32. Phylogenetic analysis suggested that all four species formed a monophyletic clade with high bootstrap support, where N. franchetii and N. oviforme were sisters. In addition, each Notopterygium species generated an individual clade that corresponded to their respective species in the ITS tree. Population dynamics analyses and species distribution modeling showed that the two widely distributed herbs N. incisum and N. franchetii exhibited obvious demographic expansions during the Pleistocene ice ages. Molecular dating suggested that the divergence of the four Notopterygium species occurred approximately between 3.6 and 1.2 Mya, and it was significantly associated with recent extensive uplifts of the QTP. Our results support the hypothesis that mountain uplift and Quaternary climatic oscillations profoundly shaped the

  3. Effects of Mountain Uplift and Climatic Oscillations on Phylogeography and Species Divergence in Four Endangered Notopterygium Herbs.

    PubMed

    Shahzad, Khurram; Jia, Yun; Chen, Fu-Lin; Zeb, Umar; Li, Zhong-Hu

    2017-01-01

    Mountain uplift and climatic fluctuations are important driving forces that have affected the geographic distribution and population dynamics history of organisms. However, it is unclear how geological and climatic events might have affected the phylogeographic history and species divergence in high-alpine herbal plants. In this study, we analyzed the population demographic history and species differentiation of four endangered Notopterygium herbs on the high-altitude Qinghai-Tibetan Plateau (QTP) and adjacent areas. We combined phylogeographic analysis with species distribution modeling to detect the genetic variations in four Notopterygium species ( N. incisum , N. franchetii , N. oviforme , and N. forrestii ). In total, 559 individuals from 74 populations of the four species were analyzed based on three maternally inherited chloroplast fragments ( matK , rbcL , and trn S -trn G) and one nuclear DNA region (internal transcribed spacer, ITS). Fifty-five chloroplast DNA (cpDNA) and 48 ITS haplotypes were identified in the four species. All of the cpDNA and ITS haplotypes were species-specific, except N. franchetii and N. oviforme shared one cpDNA haplotype, H32. Phylogenetic analysis suggested that all four species formed a monophyletic clade with high bootstrap support, where N. franchetii and N. oviforme were sisters. In addition, each Notopterygium species generated an individual clade that corresponded to their respective species in the ITS tree. Population dynamics analyses and species distribution modeling showed that the two widely distributed herbs N. incisum and N. franchetii exhibited obvious demographic expansions during the Pleistocene ice ages. Molecular dating suggested that the divergence of the four Notopterygium species occurred approximately between 3.6 and 1.2 Mya, and it was significantly associated with recent extensive uplifts of the QTP. Our results support the hypothesis that mountain uplift and Quaternary climatic oscillations profoundly

  4. Uplift, Emergence, and Subsidence of the Gorda Escarpment Basement Ridge Offshore Cape Mendocino, CA

    NASA Astrophysics Data System (ADS)

    Hoover, Susan M.; Tréhu, Anne M.

    2017-12-01

    The Gorda Escarpment is a topographic step that characterizes the south side of the Mendocino Transform Fault east of 126oW and forms the northern edge of the Vizcaino Block. Seismic reflection data suggest that the basement beneath the northern edge of the Vizcaino is composed of east-west trending slivers of oceanic crust that form a 15 km wide band of buried ridges we call the Gorda Escarpment Basement Ridge (GEBR) to distinguish it from the northwest-trending basement structure that characterizes most of the Vizcaino Block. The history of uplift and subsidence of the GEBR is reconstructed by combining the seismic reflection profiles with age and lithological constraints from ODP Site 1022, gravity cores, and grab samples from the northern face of the Escarpment recovered using a remotely operated vehicle. Uplift of the GEBR began prior to 6 Ma, and it was above sea level 3.7-2.5 Ma. GEBR uplift and emergence coincided with sediment deposition on the southern flank of the GEBR that we interpret as indicative of strong upwelling and turbulence in the lee of a shallow ridge and island chain. A bright reflection, interpreted to be a sill, is observed south of the shallowest part of the GEBR. We speculate that this sill may reflect a larger, hidden intrusion at depth and that thermal expansion of the crust combined with tectonic forces to drive enhanced uplift of this segment of the plate boundary. The GEBR has been subsiding since 2.7 Ma, and its shallowest point is now 1,400 m below sea level.

  5. Control of paleoshorelines by trench forebulge uplift, Loyalty Islands

    NASA Astrophysics Data System (ADS)

    Dickinson, William R.

    2013-07-01

    Unlike most tropical Pacific islands, which lie along island arcs or hotspot chains, the Loyalty Islands between New Caledonia and Vanuatu owe their existence and morphology to the uplift of pre-existing atolls on the flexural forebulge of the New Hebrides Trench. The configuration and topography of each island is a function of distance from the crest of the uplifted forebulge. Both Maré and Lifou are fully emergent paleoatolls upon which ancient barrier reefs form highstanding annular ridges that enclose interior plateaus representing paleolagoon floors, whereas the partially emergent Ouvea paleoatoll rim flanks a drowned remnant lagoon. Emergent paleoshoreline features exposed by island uplift include paleoreef flats constructed as ancient fringing reefs built to past low tide levels and emergent tidal notches incised at past high tide levels. Present paleoshoreline elevations record uplift rates of the islands since last-interglacial and mid-Holocene highstands in global and regional sea levels, respectively, and paleoreef stratigraphy reflects net Quaternary island emergence. The empirical uplift rates vary in harmony with theoretical uplift rates inferred from the different positions of the islands in transit across the trench forebulge at the trench subduction rate. The Loyalty Islands provide a case study of island environments controlled primarily by neotectonics.

  6. Middle Pennsylvanian recurrent uplift of the Ouachita fold belt and basin subsidence in the Arkoma basin, Oklahoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elmore, R.D.; Sutherland, P.K.; White, P.B.

    1990-09-01

    Recurrent uplift of the Ouachita fold belt in Oklahoma coincided with the disruption of the Arkoma basin following the deposition of the Boggy Formation (early Desmoinesian time). The Boggy, composed of sandstone-shale sequences that record southerly progradation of coal-bearing, fluvially dominated deltaic complexes into the Arkoma basin, was folded at the time of uplift of the Ouachita fold belt. The uplift ended the progressive subsidence of the Arkoma basin and shifted the depocenter to the northwest. Subsequently, the Thurman Formation (middle Desmoinesian), which had a source in the southeast, was deposited in the smaller resurgent foreland basin over the foldedmore » and eroded surface of the Boggy. Chert-pebble conglomerates in the Thurman were derived from the erosion of newly elevated Ordovician and Devonian cherts in the core of the Ouachita foldbelt. Sandstone-shale packages are found in both formations. The origin of the coal-bearing cycles in the Boggy are enigmatic, but they probably were controlled by a combination of factors such as glacio-eustatic changes in sea level and delta-lobe abandonment. In contrast, cycles in the Thurman probably were strongly influenced by episodic thrust faulting and uplift in the Ouachitas.« less

  7. Crustal uplift in the south central Alaska subduction zone: New analysis and interpretation of tide gauge observations

    NASA Astrophysics Data System (ADS)

    Cohen, Steven C.; Freymueller, Jeffrey T.

    2001-06-01

    We have examined tide gauge measurements of apparent sea level height in south central Alaska to determine the history of crustal uplift subsequent to the 1964 Prince William Sound earthquake. There are spatial and temporal variations in the uplift rate since the 1994 earthquake that depend on the location of the tide gauge relative to the coseismic rupture features. At Seward, on the eastern side of the Kenai Peninsula, we find slow uplift that is consistent with elastic strain accumulation at the locked North American-Pacific Plate boundary. Conversely, at Seldovia and Nikiski, on the western side of the Kenai Peninsula, we find persistent rapid uplift of ˜10 mm yr-1 that may be longterm transient response to the earthquake but that cannot be sustained over the entire several hundred year recurrence interval for a great earthquake. Farther to the southwest, at Kodiak, the rate of uplift is several millimeters per year but has slowed significantly over the past three and a half decades. To the east of the Kenai Peninsula we find subsidence at Cordova and an uncertain behavior at Valdez. At Cordova, and to a lesser extent Valdez, there is a mathematically significant time dependence, although the evidence for the time dependence is less compelling than at Kodiak. At Anchorage, there is little evidence of vertical motion since the earthquake. The along-strike spatial variability in the relaxation time of the rates of vertical motion since the 1964 earthquake may be related to variations in the updip coseismic slip during the megathrust event.

  8. Uplift of quaternary shorelines in eastern Patagonia: Darwin revisited

    NASA Astrophysics Data System (ADS)

    Pedoja, Kevin; Regard, Vincent; Husson, Laurent; Martinod, Joseph; Guillaume, Benjamin; Fucks, Enrique; Iglesias, Maximiliano; Weill, Pierre

    2011-04-01

    During his journey on the Beagle, Darwin observed the uniformity in the elevation of coastal Eastern Patagonia along more than 2000 km. More than one century later, the sequences of Quaternary shorelines of eastern Patagonia have been described and their deposits dated but not yet interpreted in terms of geodynamics. Consequently, we i) mapped the repartition of the Quaternary coastal sequences in Argentinean Patagonia, ii) secured accurate altitudes of shoreline angles associated with erosional morphologies (i.e. marine terraces and notches), iii) took into account previous chrono-stratigraphical interpretations in order to calculate mean uplift rates since ~ 440 ka (MIS 11) and proposed age ranges for the higher and older features (up to ~ 180 m), and iv) focused on the Last Interglacial Maximum terrace (MIS 5e) as the best constrained marine terrace (in terms of age and altitude) in order to use it as a tectonic benchmark to quantify uplift rates along the entire passive margin of Eastern South America. Our results show that the eastern Patagonia uplift is constant through time and twice the uplift of the rest of the South American margin. We suggest that the enhanced uplift along the eastern Patagonian coast that interested Darwin during his journey around South America on the Beagle could originate from the subduction of the Chile ridge and the associated dynamic uplift.

  9. From ocean depths to mountain tops: uplift of the Troodos Massif (Cyprus) constrained by (U-Th)/He thermochronology and geomorphic analysis

    NASA Astrophysics Data System (ADS)

    Morag, N.; Haviv, I.; Katzir, Y.

    2013-12-01

    The Troodos Massif of Cyprus, rising to nearly 2000 meters above sea level, encompasses one of the world's classic ophiolites. Following its formation at a seafloor spreading center in Late Cretaceous times, this slice of the NeoTethyan oceanic lithosphere was uplifted and eventually exposed on mountain tops during the Neogene. The final uplift and exhumation of the Troodos was previously assigned to Pleistocene age by observations in the circum-Troodos sedimentary strata. However, quantitative thermochronological and geomorphological data from the Massif itself were not available. Here we use apatite (U-Th)/He low-temperature thermochronology complemented by zircon (U-Th)/He and apatite fission track data, and combined with geomorphic analysis to constrain the exhumation and uplift history of the Troodos ophiolite. Apatite (U-Th)/He ages vary with depth from ~ 22 Ma at the top of the Gabbro sequence to ~ 6 Ma at the bottom of the sequence. The deepest sample from a Gabbro pegmatitic dyke intruding the ultramafic sequence yielded an age of ~ 3 Ma. Thermal modeling of apatite (U-Th)/He and fission track data delineates Plio - Pleistocene initiation of rapid uplift and exhumation of the Troodos ophiolite. The estimated cumulative exhumation since its initiation is 2-3 km. No evidence was found for significant uplift of the central Troodos area prior to that time. The geomorphic analysis delineates a bull's-eye zone at the center of the Troodos Massif, where local relief and channel steepness index are highest. The boundaries of this zone roughly correspond with the Mt. Olympus mantle outcrop and suggest recent, differential uplift of this zone relative to its surroundings. The most likely mechanism, which could drive such a focused bull's-eye uplift pattern is hydration of ultramafic rocks (serpentinization) leading to a decrease in rock density and subsequent diapiric uplift of the serpentinized lithospheric mantle.

  10. Seventeenth-century uplift in eastern Hokkaido, Japan

    USGS Publications Warehouse

    Atwater, B.F.; Furakawa, R.; Hemphill-Haley, E.; Ikeda, Y.; Kashima, K.; Kawase, K.; Kelsey, H.M.; Moore, A.L.; Nanayama, F.; Nishimura, Y.; Odagiri, S.; Ota, Y.; Park, S.-C.; Satake, K.; Sawai, Y.; Shimokawa, K.

    2004-01-01

    Shores of eastern Hokkaido rose by perhaps 1 m a few centuries ago. The uplifted area extended at least 50 km along the southern Kuril Trench. It included the estuaries Akkeshi-ko and Hichirippu, on the Pacific coast, and Fu??ren-ko and Onneto??, which open to the Okhotsk Sea. At each estuary, intertidal and subtidal flats rose with respect to tide level; wetland plants colonized the emerging land; and peaty wetland deposits thereby covered mud and sand of the former flats. Previous work at Akkeshi-ko and Onneto?? showed that such emergence occurred at least three times in the past 3000 years. Volcanic-ash layers date the youngest emergence to the seventeenth century AD. New evidence from Akkeshi-ko, Hichirippu and Fu??ren-ko clarifies the age and amount of this youngest emergence. Much of it probably dates from the century's middle decades. Some of the newly emerged land remained above high tides into the middle of the eighteenth century or later. The emergence in the last half of the seventeenth century probably exceeded 0.5 m (inferred from stratigraphy and diatom palaeoecology) without far exceeding 1 m (estimated by comparing seventeenth- and eighteenth-century descriptions of Akkeshi-ko). The stratigraphy and palaeoecology of the emergence are better explained by tectonic uplift than by bay-mouth blockage, tidal-flat accretion or sea-level fall. Eastern Hokkaido needs occasional uplift, moreover, to help reconcile its raised marine terraces with its chronic twentieth-century subsidence. Because it took place above forearc mantle, eastern Hokkaido's seventeenth-century uplift probably lacks analogy with coseismic uplift that occurs above typical plate-boundary ruptures at subduction zones.

  11. Impact Constraints on Major Events in Early Mars History

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2004-01-01

    MOLA data have revealed a large population of "Quasi-Circular Depressions" (QCDs) with little or no visible expression in image data. These likely buried impact basins have important implications for the age of the lowland crust, how that compares with original highland crust, and when and how the crustal dichotomy may have formed. The buried lowlands are of Early Noachian age, likely slightly younger than the buried highlands but older than the exposed (visible) highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins. The global field appears to have disappeared at about the time the lowlands formed. It seems likely the topographic crustal dichotomy was produced very early in martian history by processes which operated very quickly. Thus there appears to have been a northern lowland throughout nearly all of martian history, predating the last of the really large impacts (Hellas, Argyre and Isidis) and their likely very significant environmental consequences.

  12. Quantification of surface uplift by using paleo beach deposits (Oman, Northern Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Hoffmann, Gösta; Schneider, Bastian; Monschau, Martin; Mechernich, Silke

    2017-04-01

    The study focusses on a coastal area along the Arabian Sea in Oman. Here, a staircase of marine terraces is seen as geomorphological evidence suggesting sub-recent uplift of a crustal block in the northeast of the Arabian Peninsula. The erosional terraces are cut into Paleocene to Early Eocene limestone formations. These limestone formations are underlain by allochtonous ophiolites. We mapped the terraces over a distance of 60 km and identified at least 8 terrace levels in elevations up to 350 m above present sea level. The uppermost terraces are erosional, whereas the lower ones are depositional in style. Mollusc and coral remains as well as beach-rock are encountered on the terrace surfaces. The formations are dissected by NW-SE trending faults. Some of the terraces are very pronounced features in the landscape and easy to trace, others are partly eroded and preserved as remnants only. The deposit along the shoreline angle act as a datum making use of the fact that the rocks formed in a defined horizontal level which is the paleo-sea level. Hence, any offset from the primary depositional level is evidence for neotectonic movements. We utilise differential GPS to map the elevation of beachrock deposits. Age constraints on terrace formation is derived by sampling the beachrock deposits and dating using cosmogenic nuclii. The results indicate ongoing uplift in the range of less than a millimetre per year. The uplift is differential as the terraces are tilted. We mapped oblique normal and strike-slip faults in the younger terraces. We hypothesise that the mechanism responsible for the uplift is not tectonics but driven by the serpentinisation of the ophiolite that underlie the limestone formations. One process during the serpentinisation is the hydration of the mantle rocks which is responsible for a decrease in density. The resulting buoyancy and significant solid volume increase lead to the observed deformation including uplift.

  13. Daily hassles and uplifts: a diary study on understanding relationship quality.

    PubMed

    Totenhagen, Casey J; Serido, Joyce; Curran, Melissa A; Butler, Emily A

    2012-10-01

    In this investigation, we use the Conservation of Resources (CoR) theory as a guide to examine how both uplifts and hassles are associated with positive (e.g., satisfaction, commitment) and negative (ambivalence, conflict) relational quality on a daily basis. In previous studies of hassles and uplifts, the focus has been primarily on negative outcomes at the individual level (e.g., affect). Here, we build on this previous research in examining both positive and negative events (i.e., uplifts and hassles) in associations with positive and negative relational qualities. Further, we focus on examining social and nonsocial events that are external to the relationship (i.e., do not involve the romantic partner) and how they are linked with relational qualities. Finally, we examine which patterns are confined to the same day and which carry over to subsequent days (i.e., lagged effects). Contrary to previous literature, we find that both social and nonsocial hassles are largely unrelated to relationship quality after accounting for the effects of social and nonsocial uplifts. In contrast, nonsocial uplifts bolster positive feelings about the relationship on that day. Results also show that hassles and uplifts may work together to explain relational commitment. Finally, we find that nonsocial uplifts experienced on one day are associated with trend-level declines in next day positive feelings about the relationship. Our findings suggest that preserving relationship quality through daily experiences is best achieved by equipping couples to recognize the benefits of uplifts to the relationship, especially uplifts that are nonsocial, in tandem with managing hassles. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  14. Modulation of the erosion rate of an uplifting landscape by long-term climate change: An experimental investigation

    NASA Astrophysics Data System (ADS)

    Moussirou, Bérangé; Bonnet, Stéphane

    2018-02-01

    Whether or not climatic variations play a major role in setting the erosion rate of continental landscapes is a key factor in demonstrating the influence of climate on the tectonic evolution of mountain belts and understanding how clastic deposits preserved in sedimentary basins may record climatic variations. Here, we investigate how a change in precipitation influences the erosional dynamics of laboratory-scale landscapes that evolved under a combination of uplift and rainfall forcings. We consider here the impact of a decrease in the precipitation rate of finite duration on the erosive response of a landscape forced by a constant uplift and initially at a steady state (SS1). We performed several experiments with the same amplitude but different durations of precipitation decrease (Tp). We observe that the decrease in precipitation induces a phase of surface uplift of landscapes to a new steady state condition (SS2); however, the details of the uplift histories (timing, rate) differ between the experiments according to Tp. We also observe a decrease in the erosion rate induced by the precipitation change; however, the timing and amplitude of this decrease vary according to Tp, defining a delayed and damped erosion signal. Our data show that the landscape response to precipitation change is dictated by a critical water-to-rock ratio (ratio of precipitation over uplift) that likely corresponds to a geomorphic threshold. Our study suggests that variations in precipitation that occur at a geological time scale (> 106 years) may have a weak impact on the erosion of landscapes and on the delivery of siliciclastic material to large rivers and sedimentary basins.

  15. Early history of scapular fractures.

    PubMed

    Bartoníček, Jan; Kozánek, Michal; Jupiter, Jesse B

    2016-01-01

    The first to use the term Scapula was Vesalius (1514-1564) and thus it has remained ever since. Probably the oldest injured scapula, from 250 million years ago, was described by Chinese authors of a skeletal examination of a fossilised remains of a dinosaur Yangchuanosaurus hepingensis. In humans, the oldest known scapular fractures date back to the prehistoric and early historic times. In ancient times, a fracture of acromion was described in the treatises of Hippocrates. Early modern history of the treatment of scapular fractures is closely interlinked with the history of the French surgery. The first to point out the existence of these fractures were Petit, Du Verney and Desault in the 18th century. The first study devoted solely to scapular fractures was published by Traugott Karl August Vogt in 1799. Thomas Callaway published in 1849 an extensive dissertation on injuries to the shoulder girdle, in which he discussed a number of cases known at that time. The first radiograph of a scapular fracture was published by Petty in 1907. Mayo Robson (1884), Lambotte (1913) and Lane (1914) were pioneers in the surgical treatment of these fractures, followed in 1923 by the French surgeons Lenormat, Dujarrier and Basset. The first internal fixation of the glenoid fossa, including a radiograph, was published by Fischer in 1939.

  16. Learning Early Twentieth-Century History through First-Person Interviews

    ERIC Educational Resources Information Center

    Lark, Lisa A.

    2007-01-01

    For many of the students in the author's American history class, early twentieth-century American history seems far removed from their daily lives. Being first and second-generation American citizens, many of the students do not have the luxury of hearing grandparents and great-grandparents telling stories about FDR and Henry Ford. More…

  17. Phylogeography of Cephalotaxus oliveri (Cephalotaxaceae) in relation to habitat heterogeneity, physical barriers and the uplift of the Yungui Plateau.

    PubMed

    Wang, C B; Wang, T; Su, Y J

    2014-11-01

    Habitat heterogeneity, physical barriers, and the uplift of the Yungui Plateau were found to deeply affect the phylogeographic pattern and evolutionary history of Cephalotaxus oliveri, a perennial conifer endemic to China. In this study, we explored the phylogeography using three chloroplast sequences (trnL-trnF, trnT-trnD and atpB-rbcL) in 22 natural populations of C. oliveri distributed throughout its range. The Yungui Plateau populations of C. oliveri were revealed to origin ca. 9.15Ma by molecular clock estimation, which is consistent with rapid uplift of the Qinghai-Tibetan Plateau (QTP) ca. 8-10Ma. Additionally, geological effects of the Yungui Plateau were suggested to promote the rapid intra-specific differentiation of C. oliveri in the Pliocene and Early Pleistocene. The relatively low level of genetic diversity (h=0.719, θ=1.17×10(-3)) and high population differentiation (NST=0.771 and GST=0.642) implied restricted gene flow among populations, which was confirmed by the Nested Clade Analysis (NCA). Mismatch distribution and haplotypes network provided evidences of recent demographic population expansion. Furthermore, the statistical dispersal-vicariance analysis indicated that the center of origin was in Central China. The comparison of haplotype distribution patterns indicated that the regions of HNHPS and HBLD were the potential refugia during the Pleistocene ice ages. Our results highlighted that habitat heterogeneity and physical barriers presenting in a species range can predict genetic patterns. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Assembling the dodo in early modern natural history.

    PubMed

    Lawrence, Natalie

    2015-09-01

    This paper explores the assimilation of the flightless dodo into early modern natural history. The dodo was first described by Dutch sailors landing on Mauritius in 1598, and became extinct in the 1680s or 1690s. Despite this brief period of encounter, the bird was a popular subject in natural-history works and a range of other genres. The dodo will be used here as a counterexample to the historical narratives of taxonomic crisis and abrupt shifts in natural history caused by exotic creatures coming to Europe. Though this bird had a bizarre form, early modern naturalists integrated the dodo and other flightless birds through several levels of conceptual categorization, including the geographical, morphological and symbolic. Naturalists such as Charles L'Ecluse produced a set of typical descriptive tropes that helped make up the European dodo. These long-lived images were used for a variety of symbolic purposes, demonstrated by the depiction of the Dutch East India enterprise in Willem Piso's 1658 publication. The case of the dodo shows that, far from there being a dramatic shift away from emblematics in the seventeenth century, the implicit symbolic roles attributed to exotic beasts by naturalists constructing them from scant information and specimens remained integral to natural history.

  19. Asperger's syndrome and autism: comparison of early history and outcome.

    PubMed

    Szatmari, P; Bartolucci, G; Bremner, R

    1989-12-01

    The authors compared children with Asperger syndrome (AS) with high-functioning autistic children and psychiatric outpatient controls on measures of early history and outcome. In terms of their early history, the autistic probands showed more social impairment, a higher frequency of echolalia and pronoun reversal, and a more restricted range of activities than the AS group. Cluster analysis suggested refinements to the diagnostic criteria, which resulted in larger differences between the groups on these early history measures. In terms of their outcome, the autistic probands spent more time in special education classes but developed fewer accessory psychiatric symptoms than the AS children. It was clear, however, that there were no substantive, qualitative differences between the AS and autistic groups, indicating that AS should be considered a mild form of high-functioning autism. The inclusion of AS among the autistic spectrum of disorders has implications both for aetiological studies and for prevalence estimates of the pervasive developmental disorders.

  20. Large eddy simulation of dust-uplift by haboob density currents

    NASA Astrophysics Data System (ADS)

    Huang, Q.

    2017-12-01

    Cold pool outflows have been shown from both observations and convection-permitting models to be a dominant source of dust uplift ("haboobs") in the summertime Sahel and Sahara, and to cause dust uplift over deserts across the world. In this paper large eddy model (LEM) simulations, which resolve the turbulence within the cold-pools much better than previous studies of haboobs which have used convection-permitting models, are used to investigate the winds that cause dust uplift in cold pools, and the resultant dust uplift and transport. Dust uplift largely occurs in the head of the density current, consistent with the few existing observations. In the modeled density current dust is largely restricted to the lowest coldest and well mixed layer of the cold pool outflow (below around 400 m), except above the head of the cold pool where some dust reaches 2.5 km. This rapid transport to high altitude will contribute to long atmospheric lifetimes of large dust particles from haboobs. Decreasing the model horizontal grid-spacing from 1.0 km to 100 m resolves more turbulence, locally increasing winds, increasing mixing and reducing the propagation speed of the density current. Total accumulated dust uplift is approximately twice as large in 1.0 km runs compared with 100 m runs, suggesting that for studying haboobs in convection-permitting runs the representation of turbulence and mixing is significant. Simulations with surface sensible heat fluxes representative of those from a desert region in daytime show that increasing surface fluxes slow the density current due to increased mixing, but increase dust uplift rates, due to increased downward transport of momentum to the surface.

  1. Increased Pre- and Early-Adolescent Stress in Youth with a Family History of Substance Use Disorder and Early Substance Use Initiation.

    PubMed

    Charles, Nora E; Mathias, Charles W; Acheson, Ashley; Bray, Bethany C; Ryan, Stacy R; Lake, Sarah L; Liang, Yuanyuan; Dougherty, Donald M

    2015-10-01

    Individuals with a family history of substance use disorders (Family History Positive) are more likely to have early-onset substance use (i.e., prior to age 15), which may contribute to their higher rates of substance use disorders. One factor that may differentiate Family History Positive youth who engage in early-onset substance use from other Family History Positive youth is exposure to stressors. The aim of this study was to quantify how exposure to stressors from age 11-15 varies as a function of family history of substance use disorders and early-onset substance use. Self-reported stressors were prospectively compared in a sample of predominately (78.9%) Hispanic youth that included 68 Family History Positive youth (50% female) who initiated substance use by age 15 and demographically matched non-users with (n = 136; 52.9% female) and without (n = 75; 54.7% female) family histories of substance use disorders. Stressors were assessed at 6-month intervals for up to 4 years. Both the severity of stressors and the degree to which stressors were caused by an individual's own behavior were evaluated. All three groups differed from one another in overall exposure to stressors and rates of increase in stressors over time, with Family History Positive youth who engaged in early-onset substance use reporting the greatest exposure to stressors. Group differences were more pronounced for stressors caused by the participants' behavior. Family History Positive users had higher cumulative severity of stressors of this type, both overall and across time. These results indicate greater exposure to stressors among Family History Positive youth with early-onset substance use, and suggest that higher rates of behavior-dependent stressors may be particularly related to early-onset use.

  2. Increased Pre- and Early-Adolescent Stress in Youth with a Family History of Substance Use Disorder and Early Substance Use Initiation

    PubMed Central

    Charles, Nora E.; Mathias, Charles W.; Acheson, Ashley; Bray, Bethany C.; Ryan, Stacy R.; Lake, Sarah L.; Liang, Yuanyuan; Dougherty, Donald M.

    2015-01-01

    Individuals with a family history of substance use disorders (Family History Positive) are more likely to have early-onset substance use (i.e., prior to age 15), which may contribute to their higher rates of substance use disorders. One factor that may differentiate Family History Positive youth who engage in early-onset substance use from other Family History Positive youth is exposure to stressors. The aim of this study was to quantify how exposure to stressors from age 11 to 15 varies as a function of family history of substance use disorders and early-onset substance use. Self-reported stressors were prospectively compared in a sample of predominately (78.9%) Hispanic youth that included 68 Family History Positive youth (50% female) who initiated substance use by age 15 and demographically matched non-users with (n=136; 52.9% female) and without (n=75; 54.7% female) family histories of substance use disorders. Stressors were assessed at 6-month intervals for up to 4 years. Both the severity of stressors and the degree to which stressors were caused by an individual’s own behavior were evaluated. All three groups differed from one another in overall exposure to stressors and rates of increase in stressors over time, with Family History Positive youth who engaged in early-onset substance use reporting the greatest exposure to stressors. Group differences were more pronounced for stressors caused by the participants’ behavior. Family History Positive users had higher cumulative severity of stressors of this type, both overall and across time. These results indicate greater exposure to stressors among Family History Positive youth with early-onset substance use, and suggest that higher rates of behavior-dependent stressors may be particularly related to early-onset use. PMID:25788123

  3. Evidence for Holocenic uplift at Somma-Vesuvius

    NASA Astrophysics Data System (ADS)

    Marturano, Aldo; Aiello, Giuseppe; Barra, Diana; Fedele, Lorenzo; Grifa, Celestino; Morra, Vincenzo; Berg, Ria; Varone, Antonio

    2009-07-01

    Detailed stratigraphical, archaeological, micropalaeontological, archaeometrical and petrochemical analyses of samples from trenches and boreholes at insula of Casti Amanti, in Pompeii, allowed a faithful reconstruction of the recent environmental evolution of the site. The present data clearly indicate the alternation of both subaerial and shallow marine conditions during Holocene times. Taking into account the relative local sea level variations, a ~ 30 m ground uplift event in the last 6 kyr (with an average vertical uplift rate of ~ 5 mm/yr) was inferred for the first time.

  4. Early Childhood Education: History, Theory, and Practice. Second Edition

    ERIC Educational Resources Information Center

    Morgan, Harry

    2010-01-01

    Harry Morgan lays the foundations of what early childhood education is by integrating the history of the field with the philosophy and theories behind this discipline. From birth to age eight, when children become integrated into society through their education at school and at home, "Early Childhood Education" examines the education of this age…

  5. Coseismic slip and early afterslip of the 2015 Illapel, Chile, earthquake: Implications for frictional heterogeneity and coastal uplift

    USGS Publications Warehouse

    Barnhart, William D.; Murray, Jessica R.; Briggs, Richard W.; Gomez, Francisco; Miles, Charles P. J.; Svarc, Jerry L.; Riquelme, Sebástian; Stressler, Bryan J.

    2016-01-01

    Great subduction earthquakes are thought to rupture portions of the megathrust, where interseismic coupling is high and velocity-weakening frictional behavior is dominant, releasing elastic deformation accrued over a seismic cycle. Conversely, postseismic afterslip is assumed to occur primarily in regions of velocity-strengthening frictional characteristics that may correlate with lower interseismic coupling. However, it remains unclear if fixed frictional properties of the subduction interface, coseismic or aftershock-induced stress redistribution, or other factors control the spatial distribution of afterslip. Here we use interferometric synthetic aperture radar and Global Position System observations to map the distribution of coseismic slip of the 2015 Mw 8.3 Illapel, Chile, earthquake and afterslip within the first 38 days following the earthquake. We find that afterslip overlaps the coseismic slip area and propagates along-strike into regions of both high and moderate interseismic coupling. The significance of these observations, however, is tempered by the limited resolution of geodetic inversions for both slip and coupling. Additional afterslip imaged deeper on the fault surface bounds a discrete region of deep coseismic slip, and both contribute to net uplift of the Chilean Coastal Cordillera. A simple partitioning of the subduction interface into regions of fixed frictional properties cannot reconcile our geodetic observations. Instead, stress heterogeneities, either preexisting or induced by the earthquake, likely provide the primary control on the afterslip distribution for this subduction zone earthquake. We also explore the occurrence of coseismic and postseismic coastal uplift in this sequence and its implications for recent hypotheses concerning the source of permanent coastal uplift along subduction zones.

  6. Uplift, Feedback, and Buoyancy: Radio Lobe Dynamics in NGC 4472

    NASA Astrophysics Data System (ADS)

    Gendron-Marsolais, M.; Kraft, R. P.; Bogdan, A.; Hlavacek-Larrondo, J.; Forman, W. R.; Jones, C.; Su, Y.; Nulsen, P.; Randall, S. W.; Roediger, E.

    2017-10-01

    We present results from deep (380 ks) Chandra observations of the active galactic nucleus (AGN) outburst in the massive early-type galaxy NGC 4472. We detect cavities in the gas coincident with the radio lobes and estimate the eastern and western lobe enthalpy to be (1.1+/- 0.5)× {10}56 erg and (3+/- 1)× {10}56 erg and the average power required to inflate the lobes to be (1.8+/- 0.9)× {10}41 erg s-1 and (6+/- 3)× {10}41 erg s-1, respectively. We also detect enhanced X-ray rims around the radio lobes with sharp surface brightness discontinuities between the shells and the ambient gas. The temperature of the gas in the shells is less than that of the ambient medium, suggesting that they are not AGN-driven shocks but rather gas uplifted from the core by the buoyant rise of the radio bubbles. We estimate the energy required to lift the gas to be up to (1.1+/- 0.3)× {10}56 erg and (3+/- 1)× {10}56 erg for the eastern and western rims, respectively, constituting a significant fraction of the total outburst energy. A more conservative estimate suggests that the gas in the rim was uplifted at a smaller distance, requiring only 20%-25% of this energy. In either case, if a significant fraction of this uplift energy is thermalized via hydrodynamic instabilities or thermal conduction, our results suggest that it could be an important source of heating in cool core clusters and groups. We also find evidence for a central abundance drop in NGC 4472. The iron abundance profile shows that the region along the cavity system has a lower metallicity than the surrounding undisturbed gas, similar to the central region. This also shows that bubbles have lifted low-metallicity gas from the center.

  7. Mantle plumes & lithospheric foundering: Determining the timing and amplitude of post-Miocene uplift in the Wallowa mountains, north-east Oregon with low-temperature thermochronometry.

    NASA Astrophysics Data System (ADS)

    Schoettle-Greene, P.; Duvall, A. R.

    2016-12-01

    The foundering of gravitationally unstable lithosphere, while frequently invoked to explain anomalous topography, proves difficult to verify from an Earth surface perspective. Theoretically, direct observables like sudden uplift associated with extension and mantle-sourced volcanism should help identify affected regions but these markers are often obscured by background stresses and heterogeneous lithosphere. To better understand topographic evolution following the removal of mantle lithosphere, we present new apatite U-Th/He thermocrhonometry data and field observations from the Wallowa mountains adjacent to Hells Canyon in the northwestern United States. The granodiorite-cored Wallowa are increasingly recognized as a type locality for the process of lithospheric foundering, as they are bound by extensional structures and were presumably uplifted contemporaneous with the intrusion of feeder dikes for the mantle-sourced Columbia River Basalts at 16 Ma. Cretaceous and early Cenozoic cooling ages from our study imply that in spite of the presumed 1-2 km of basalt flows eroded from the Wallowa and heating associated with the intrusion of the Chief Joseph dike swarm, and 2 km of proposed rapid post-foundering uplift, there has been little exhumation. We attempt to reconcile these conflicting observations with field mapping of folded basalt flows at the margins of the Wallowa mountains, modeling of geothermal response times following a thermal perturbation, and further study using the 4He/3He thermochronometer on a subset of samples to reveal more recent cooling histories. Our findings will improve our understanding of the landscape evolution of the Wallowa mountains, information pertinent to the geodynamics of lithosphere removal and the eruption of Columbia River Basalts.

  8. The Littlest Historians: Early Years Programming in History Museums

    ERIC Educational Resources Information Center

    Leftwich, Mariruth; Haywood, Clare

    2016-01-01

    Working with children under five years old and the adults that accompany them is a rapidly growing area within the museum and wider cultural sector, with important emphasis being placed on early learning in both the United Kingdom and United States. For history museums in particular, early learning offers a unique set of questions and challenges,…

  9. Can footwall unloading explain late Cenozoic uplift of the Sierra Nevada crest?

    USGS Publications Warehouse

    Thompson, G.A.; Parsons, T.

    2009-01-01

    Globally, normal-fault displacement bends and warps rift flanks upwards, as adjoining basins drop downwards. Perhaps the most evident manifestations are the flanks of the East African Rift, which cuts across the otherwise minimally deformed continent. Flank uplift was explained by Vening Meinesz (1950, Institut Royal Colonial Belge, Bulletin des Seances, v. 21, p. 539-552), who recognized that isostasy should cause uplift of a normal-faulted footwall and subsidence of its hanging wall. Uplift occurs because slip on a dipping normal fault creates a broader root of less-dense material beneath the footwall, and a narrowed one beneath the hanging wall. In this paper, we investigate the potential influence of this process on the latest stages of Sierra Nevada uplift. Through theoretical calculations and 3D finite element modelling, we find that cumulative slip of about 4km on range-front faults would have produced about 1.3km peak isostatic uplift at the ridge crest. Numerical models suggest that the zone of uplift is narrow, with the width controlled by bending resistance of the seismogenic crust. We conclude that footwall unloading cannot account for the entire elevation of the Sierran crest above sea level, but if range-front faulting initiated in an already elevated plateau like the adjacent Basin and Range Province, then a hybrid model of pre-existing regional uplift and localized footwall unloading can account for the older and newer uplift phases suggested by the geologic record.

  10. The Early History of Psychoanalysis in San Francisco.

    PubMed

    Benveniste, Daniel

    2006-01-01

    The early history of psychoanalysis in San Francisco begins in 1918 and ends in 1953. During those 35 years the San Francisco Bay Area witnessed the awakening of interest in psychoanalysis, the arrival of the European émigré analysts and the emergence of individuals and groups engaging in extraordinarily creative work and doing so in an ecumenical spirit and with a social commitment. This article provides an overview of this illustrious history and the people who participated in it.

  11. Buoyancy, Uplift, and AGN Feedback - Deep Chandra and XMM-Newton Observations of the Radio Outbursts in NGC 4472 and NGC 1399

    NASA Astrophysics Data System (ADS)

    Kraft, R.; Su, Y.; Gendron Marsolais, M.; Roediger, E.; Nulsen, P.; Hlavacek-Larrondo, J.; Forman, W.; Jones, C.; Randall, S.; Machacek, M.

    2017-10-01

    We present results from deep Chandra and XMM-Newton observations of the AGN outbursts in the nearby early-type galaxies NGC 4472 and NGC 1399. Both pairs of radio bubbles are surrounded by rims of enhanced X-ray emission. Spectral analysis shows that the temperatures of these rims are less than that of the surrounding medium, suggesting that they are gas uplifted from the group center by the buoyant rise of the radio bubbles and not shocks due to the supersonic inflation of the lobes. The energy required to uplift these shells can be a significant fraction of the total outburst energy, and thus may play an important role in the thermodynamic evolution of the galaxy core. Buoyant uplift could also be a very efficient means of transporting metals from the galaxy core to the halo.

  12. Gravity study of the Central African Rift system: a model of continental disruption 2. The Darfur domal uplift and associated Cainozoic volcanism

    NASA Astrophysics Data System (ADS)

    Bermingham, P. M.; Fairhead, J. D.; Stuart, G. W.

    1983-05-01

    Gravity studies of the Darfur uplift, Western Sudan, show it to be associated with a circular negative Bouguer anomaly, 50 mGal in amplitude and 700 km across. A three-dimensional model interpretation of the Darfur anomaly, using constraints deduced from geophysical studies of similar but more evolved Kenya and Ethiopia domes, suggests either a low-density laccolithic body at mid-lithospheric depth (~ 60 km) or a thinned lithosphere with emplacement at high level of low-density asthenospheric material. The regional setting of the Darfur uplift is described in terms of it being an integral part of the Central African Rift System which is shown to be broadly equivalent to the early to middle Miocene stage in the development of the Afro-Arabian Rift System. Comparisons between these rift systems suggest that extensional tectonics and passive rifting, resulting in the subsiding sedimentary rift basins associated with the Ngaoundere, Abu Gabra, Red Sea and Gulf of Aden rifts, are more typical of the early stage development of passive continental margins than the active domal uplift and development of rifted features associated with the Darfur, Kenya and Ethiopia domes.

  13. Music as therapy in early history.

    PubMed

    Thaut, Michael H

    2015-01-01

    The notion of music as therapy is based on ancient cross-cultural beliefs that music can have a "healing" effect on mind and body. Explanations for the therapeutic mechanisms in music have almost always included cultural and social science-based causalities about the uses and functions of music in society. However, it is also important to note that the view of music as "therapy" was also always strongly influenced by the view and understanding of the concepts and causes of disease. Magical/mystical concepts of illness and "rational" medicine probably lived side by side for thousands of years. Not until the late-nineteenth and early-twentieth centuries were the scientific foundations of medicine established, which allowed the foundations of music in therapy to progress from no science to soft science and most recently to actual brain science. Evidence for "early music therapy" will be discussed in four broad historical-cultural divisions: preliterate cultures; early civilizations in Mesopotamia, Egypt, Israel; Greek Antiquity; Middle Ages, Renaissance, and Baroque. In reviewing "early music therapy" practice, from mostly unknown periods of early history (using preliterate cultures as a window) to increasingly better documented times, including preserved notation samples of actual "healing" music, five theories and applications of early music therapy can be differentiated. © 2015 Elsevier B.V. All rights reserved.

  14. Oroclinal Bending and Mountain Uplift in the Central Andes

    NASA Astrophysics Data System (ADS)

    Mpodozis, C.; Arriagada, C.; Roperch, P.

    2007-05-01

    The large paleomagnetic database now available for the Central Andes permits a good understanding of the overall spatial and temporal variations of rotations. Mesozoic to Early Paleogene rocks along the forearc of northern Chile (23°-28°S) record significant clockwise rotations (>25°) [Arriagada et al., 2006, Tectonics, doi:10.1029/2005TC001923]. Along the forearc of southern Peru, counterclockwise rotations recorded within flat lying red-beds (Moquegua Formation) increase from about -30° at 17.5°S to - 45° at15.5°S and decrease through time from the late Eocene to the late Oligocene-early Miocene [Roperch et al., 2006, Tectonics, doi:10.1029/2005TC001882]. Recently published thermo-chronological studies show evidence for strong exhumation within Bolivian Eastern Cordillera and the Puna plateau starting in the Eocene while structural studies indicate that the majority of crustal shortening in the Eastern Cordillera occurred during the Eocene-Oligocene, although the final stages of deformation may have continued through the Early Miocene. Rotations in the Peruvian and north Chilean forearc thus occurred at the same time than deformation and exhumation/uplift within the Eastern Cordillera. In contrast Neogene forearc rocks in southern Peru and northern Chile do not show evidences of rotation but low magnitude (10°) counterclockwise rotations are usually found in mid to late Miocene rocks from the northern Altiplano. These Neogene rotations are concomitant with shortening in the Sub-Andean zone and sinistral strike-slip faulting along the eastern edge of the northern Altiplano. We interpret the rotation pattern along the southern Peru and north Chile forearc as a result of strong late Eocene- late Oligocene oroclinal bending of the Central Andes associated with shortening gradients along the Eastern Cordillera associated both with the Abancay deflection and the Arica bend. The amount and spatial distribution of pre-Neogene shortening needed to account for

  15. Uplift Patterns in the Forearc of the Middle America Trench, Costa Rica: Implications for Mass Balance and Fore-arc Kinematics

    NASA Astrophysics Data System (ADS)

    Fisher, D. M.; Gardner, T. W.; Sak, P.; Marshall, J. S.; Protti, M.

    2001-12-01

    Uplift patterns along the Pacific Coast of Costa Rica provide insight into the balance of mass in the fore arc and depict an inner forearc that thickens nonuniformly at the expense of a subsiding margin wedge. Offshore, incoming seamounts and ridges on the subducting Cocos plate result in embayment of the trench axis and scarring that reflects downdropping of fault bounded blocks in the wake of subducting seamounts. The upper slope displays a regional unconformity that records late Tertiary subsidence and arcward displacement of the trench axis. Uplifted marine wavecut benches along the coast of Costa Rica, combined with analysis of fault populations, indicate that the inner fore arc has experienced a history that is in marked contrast to the subsidence and erosion observed in the margin wedge. Regionally, the inner forearc, from Osa to Nicaragua, has experienced uplift. One way to produce this regional uplift signal is movement on an out-of-sequence fault, or an active fault arcward of the frontal thrust. The longitudinal fault that marks the front of the Fila Costena may be an example of such a fault. Wood from a raised wavecut platform along this thrust front was radiocarbon dated at 5540 yrs. A balanced cross section of the Fila Costena indicates a detachment at a depth of ~ 2 km near the contact between upper slope sediments of the Terraba basin and the underlying basement of the margin wedge. This cross section also requires a >10 km of shortening accomplished by underthrusting of the outer fore arc. Crustal thickening by this mechanism could explain the dichotomy between uplift of the mountainous Fila Costena and Talamanca Ranges and subsidence of the slope apron offshore. Superimposed on this regional uplift of the Costa Rican coast is a pattern of faster uplift within fault-bounded blocks that lie inboard of incoming seamount chains. Offshore of Nicoya, the subducting plate displays two parallel ridges: a ridge coincident with the trace of the Coc

  16. Colorado Plateau magmatism and uplift by warming of heterogeneous lithosphere.

    PubMed

    Roy, Mousumi; Jordan, Thomas H; Pederson, Joel

    2009-06-18

    The forces that drove rock uplift of the low-relief, high-elevation, tectonically stable Colorado Plateau are the subject of long-standing debate. While the adjacent Basin and Range province and Rio Grande rift province underwent Cenozoic shortening followed by extension, the plateau experienced approximately 2 km of rock uplift without significant internal deformation. Here we propose that warming of the thicker, more iron-depleted Colorado Plateau lithosphere over 35-40 Myr following mid-Cenozoic removal of the Farallon plate from beneath North America is the primary mechanism driving rock uplift. In our model, conductive re-equilibration not only explains the rock uplift of the plateau, but also provides a robust geodynamic interpretation of observed contrasts between the Colorado Plateau margins and the plateau interior. In particular, the model matches the encroachment of Cenozoic magmatism from the margins towards the plateau interior at rates of 3-6 km Myr(-1) and is consistent with lower seismic velocities and more negative Bouguer gravity at the margins than in the plateau interior. We suggest that warming of heterogeneous lithosphere is a powerful mechanism for driving epeirogenic rock uplift of the Colorado Plateau and may be of general importance in plate-interior settings.

  17. Constraining the thermal history of the North American Midcontinent Rift System using carbonate clumped isotopes and organic thermal maturity indices

    USGS Publications Warehouse

    Gallagher, Timothy M.; Sheldon, Nathan D.; Mauk, Jeffrey L.; Petersen, Sierra V.; Gueneli, Nur; Brocks, Jochen J.

    2017-01-01

    The Midcontinent Rift System (MRS) is a Late Mesoproterozoic (∼1.1 Ga) sequence of volcanic and sedimentary rocks exposed in the Lake Superior Region of North America. The MRS continues to be the focus of much research due to its economic mineral deposits as well as its archive of Precambrian life and tectonic processes. In order to constrain the post-depositional thermal history of the MRS, samples were analyzed for carbonate clumped isotope composition and organic thermal maturity. Clumped isotope values from sedimentary/early-diagenetic samples were partially reset during burial to temperatures between 68 and 75 °C. Solid-state reordering models indicate that maximum burial temperatures of 125–155 °C would reset the clumped isotope values to the observed temperature range prior to the onset of regional cooling and uplift. Clumped isotope results from late-stage veins in the White Pine Mine encompass a greater temperature range (49–116 °C), indicative of spatially variable hydrothermal activity and vein emplacement after burial temperatures fell below 100 °C during regional cooling and uplift. Clumped isotope and organic thermal maturity data do not indicate significant spatial differences in thermal history along the MRS. Observed variability in bulk organic matter composition and biomarker indices are therefore more likely a result of shifts in primary productivity or early-degradation processes. These results demonstrate that the MRS experienced a spatially consistent, relatively mild thermal history (125–155 °C) and is therefore a valuable archive for understanding the Late Mesoproterozoic environment.

  18. Seismicity and tectonic relationships of the Nemaha Uplift in Oklahoma. Part V. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luza, K.V.; Lawson, J.E. Jr.

    1983-02-01

    The Nemaha Ridge is composed of a number of crustal blocks typically 3 to 5 miles (5 to 8 km) wide and 5 to 20 miles (8 to 32 km) long. Structure-contour maps prepared of the top of the Viola Formation (Ordovician), the base of the Pennsylvanian, and the top of the Oswego Formation (Middle Pennsylvanian) reveal a complex fault pattern associated with the Nemaha Uplift. This fault pattern is dominated by several discontinuous uplifts, such as the Oklahoma City, Lovell, Garber, and Crescent Uplifts. A detailed study of the Oklahoma City Uplift suggests that a number of the Nemaha-relatedmore » faults were developed in pre-Mississippian time. Many of these faults exhibit both increasing and decreasing displacements from early to late Paleozoic time. However, the displacement for most of the Oklahoma City faults took place between the end of Oswego time and the end of Hunton time. A lineament map was prepared for north-central Oklahoma. A detailed gravity map was prepared for the Kingfisher and Medford maxima. A total-intensity aeromagnetic map for the Enid and Oklahoma City 1/sup 0/ by 2/sup 0/ Quadrangles was prepared. A regional seismograph network was established to supplement existing seismological capability. A local earthquake-location program, named HYPERCUBE, was developed. From 1897 through 1976, Oklahoma has had approximately 128 known earthquakes. After the network became operational in late 1977, 255 additional earthquakes were detected in Oklahoma (through 1981). A study of earthquake distribution and intensity values in Oklahoma led to the development of a seismic-source map for Oklahoma and parts of the adjacent states. Six seismic-source zones were identified. For each zone except one, a magnitude-frequency relationship was determined.« less

  19. Evidence for latest Pleistocene to Holocene uplift at the southern margin of the Central Anatolian Plateau (CAP), southern Turkey

    NASA Astrophysics Data System (ADS)

    Cosentino, Domenico; Öǧretmen, Nazik; Cipollari, Paola; Gliozzi, Elsa; Radeff, Giuditta; Yıldırım, Cengiz; Baykara, Oruc M.; Shen, Chuan-Chou

    2016-04-01

    Along the Mediterranean coastal area of southern Anatolia, markers of ancient sea-level have been reported west of Alanya and east of the Göksu delta. In both areas, bioconstructed fossil rims, consisting mainly of calcareous algae, are situated 0.5 m above the live counterpart. The fossil rim to the west of Alanya has been dated between 2690 to 1545 yrs BP, evidencing late Holocene rock uplift at the CAP southern margin. More recently, based on beachrocks along the coastal area from Incekum to the south of Adana, authors showed that the shoreline was raised around 0.5 m after 19 BC-200 AD. Based on new field observations along the coast between Aydı ncı k and Ayaş (Mersin, southern Turkey), together with AMS 14C dating and high-resolution U-Th chronology, a more complex uplift history can be suggested. Along the coast of Yeşilovacı k, we observed up to seven uplifted marine notches, from 0.5 m to 6.10 m above sea level. Some of them show relationships with a travertine crust that yielded U-Th ages of 2727 ± 1559 years and 5236 ± 2255 years. In the same area, a calcareous algae fossil trottoir related to a marine notch 5.40 m above sea level yielded an AMS 14C 2σ age of 32700 to 31645 years cal BP. Considering that the global ocean was 60 m below the present sea level at 32 ka, the Yeşilovacı k coastal area has been uplifted at 2 mm/yr. Moving to the east, in a small embayment at Eǧribük, two distinct well cemented beach deposits containing Murex brandaris, Cerithium vulgatum, and Columbella rustica have been uplifted at 0.3 m and 0.7 m above the present sea level. Although it is difficult to reconstruct the paleodepth of those beach deposits, AMS 14C 2σ ages of 5575 to 5445 years cal BP and 2130 to 1965 years cal BP show late Holocene uplift. In the Narlı kuyu area, up to seven different uplifted markers of sea level were observed between 0.8 and 7.2 m above the present sea level. In addition, near Ayaş new insights for late Holocene uplift are

  20. Quaternary uplift and tilting of Amorgos Island (southern Aegean) and the 1956 earthquake

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis C.; Marangou, Lila; Arnold, Maurice

    1994-12-01

    Uplifted Pleistocene marine sediments, submerged ancient ruins and raised beaches confirm earlier views that the asymmetry of the relief of Amorgos Island (southern Aegean) testifies to a fault-bounded block uplifted and tilted along a SW-NE trending horizontal axis; the uplifted coast corresponds to a high-gradient slope controlled by an oblique master normal fault. Furthermore, geomorphic and biological evidence, radiometric data and comparison of aerial photographs indicates that the 1956 earthquake (Ms = 7.4) uplifted the footwall of this normal fault by about 30 cm.

  1. Pennsylvanian history of the Chautauqua Arch

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bennison, A.P.

    1993-03-01

    Westward extension of the Ozark Uplift known as the Chautauqua Arch is concealed by a Pennsylvanian cover. This cover provides an insight into its later tectonic history subsequent to its major Late Devonian uplift and truncation. Part of this arch was episodically uplifted during Pennsylvanian time in an area extending west from southwestern Missouri along the Kansas-Oklahoma border to western Montgomery County. Recent stratigraphic mapping in that county indicates moderate Late Desmoinesian to Missourian tectonism. Some strata present on both flanks of the arch are either comparatively thin or missing owing to unconformity truncation or non-deposition. Stratal loss involves themore » Lenapah Limestone, the Hepler and Lost Branch formations, the Cherryvale Shale and the Hertha, Drum, Dewey, Stanton and Wyandotte Limestones. Earlier movements also account for the truncation of Morrowan, Atokan and possibly some Early Desmoinesian beds over the arch. Between tectonic episodes along the arch there were periods of relative tectonic quiescence accompanied by shelf-edge carbonate banks, condensed sequences and siliciclastic sedimentation. West of Montgomery County in Chautauqua County, the widespread Late Pennsylvanian Virgilian outcrops show practically no tectonism. Therefore, the name Chautauqua Arch seems inappropriate for this Pennsylvanian arch, and the name Tri-State Arch is proposed. This arch is bounded on the north by the Cherokee Basin and on the south by the northern rise of the Arkoma Basin. Although this arch is commonly omitted on many tectonic maps, it is a stronger gravity feature than the Bourbon Arch about 50 miles northward. Both tectonic and sedimentary structures have produced much oil and gas entrapment along this arch. For example, an east-west fault south of Independence, aligned with buried Proterozoic hills, has been specially productive.« less

  2. Application of Diversity Indices to Quantify Early Life-History Diversity for Chinook Salmon

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.

    2014-03-01

    We developed an index of early life history diversity (ELHD) for Pacific salmon (Oncorhynchus spp.) Early life history diversity is the variation in morphological and behavioral traits expressed within and among populations by individual juvenile salmon during their downstream migration. A standard quantitative method does not exist for this prominent concept in salmon biology.

  3. An Impaired View of Earth's Early History

    NASA Astrophysics Data System (ADS)

    Vervoort, J. D.; Kemp, A. I.; Bauer, A.; Bowring, S. A.; Fisher, C.

    2014-12-01

    The Hf and Nd isotope records of Earth's early history are sparse, difficult to interpret, and controversial, much like the few remnants of crust older than 4 Ga. New analytical techniques have been brought to bear on this problem but despite this recent work­-or, perhaps, because of it-the record is no clearer than it was 15 years ago. Several studies, based on highly variable calculated initial isotopic compositions, have argued for highly heterogeneous crust and mantle reservoirs in the early Earth1,2 and an ultra-depleted Eoarchean mantle3. These data come mostly from two sources: Hf-Nd isotope analyses of ultramafic rocks and Hf isotope analyses of zircons by solution or laser ablation. An important question for understanding the chemical evolution of the early Earth is: Do these data offer a unique window into the early Earth or are they artefacts not representative of crust/mantle evolution, giving an impaired view of the Earth's early history? In complex samples, measured isotopic compositions can result from open-system behavior in easily altered ultramafic compositions, in multicomponent, polymetamorphic gneisses, or in zircons with multiple generations of growth. Perhaps most importantly, accurate age assignment is often lacking, compromised, or impossible in these rocks, making calculation of initial epsilon Hf and Nd values ambiguous at best. In order to gain insight into crust mantle evolution in the early Earth we need, above all, a robust and unambiguous isotopic record to work with. This can be achieved by integrating zircon U-Pb and Hf and whole-rock Hf and Nd isotope compositions in relatively undisturbed igneous rocks with well-constrained ages. When this approach is used apparent isotopic heterogeneity decreases and a simpler model for crust-mantle evolution in the early Earth emerges. Careful screening of geological relationships, petrology, and geochemistry of samples from the early Earth should be done before interpreting isotopic data

  4. Tectonic and erosion-driven uplift for the Gamburtsev Mountains: a preliminary combined landscape analyses and flexural modelling approach

    NASA Astrophysics Data System (ADS)

    Ferraccioli, Fausto; Anderson, Lester; Jamieson, Stewart; Bell, Robin; Rose, Kathryn; Jordan, Tom; Finn, Carol; Damaske, Detlef

    2013-04-01

    whether the modern Gamburtsevs may have been uplifted solely in response to significant changes in Cenozoic erosion patterns during the early stages of East Antarctic ice sheet formation that were superimposed upon an old remnant Permian-age rift flank. To address this question we combine results from: i) analyses of the subglacial landscape of the GSM that includes valley network, hyposometry and geomorphic studies of the fluvial and glacial features identified within the range (Rose et al., 2013 EPSL in review) with; ii) preliminary flexural models of peak uplift caused by the isostatic responses to fluvial and glacial valley incision processes, both within the range and in the adjacent Lambert Glacier region. We also include in our geophysical relief and isostatic model calculations considerations on the major change in erosion rates since Oligocene times and the total amount of incision estimated for the Lambert Glacier system using the values proposed by Tochlin et al. (2012). Our models yield new estimates of peak uplift and regional lowering for continuous and broken-plate approximations that can also be used to assess the range of pre-incision elevation of the "Gamburtsev plateau". Our modelling outputs were also calibrated against the present-day elevations of up to 1500 m a.s.l of uplifted Oligocene-early Miocene glacial-marine sediments in the Lambert Glacier (Hambrey et al., 2000, Geology).

  5. Ongoing drought-induced uplift in the western United States.

    USGS Publications Warehouse

    Borsa, Adrian Antal; Agnew, Duncan Carr; Cayan, Daniel R.

    2014-01-01

    The western United States has been experiencing severe drought since 2013. The solid earth response to the accompanying loss of surface and near-surface water mass should be a broad region of uplift. We use seasonally adjusted time series from continuously operating global positioning system stations to measure this uplift, which we invert to estimate mass loss. The median uplift is 5 millimeters (mm), with values up to 15 mm in California’s mountains. The associated pattern of mass loss, ranging up to 50 centimeters (cm) of water equivalent, is consistent with observed decreases in precipitation and streamflow. We estimate the total deficit to be ~240 gigatons, equivalent to a 10-cm layer of water over the entire region, or the annual mass loss from the Greenland Ice Sheet.

  6. The southern California uplift and associated earthquakes

    USGS Publications Warehouse

    Castle, R.O.; Bernknopf, R.L.

    1996-01-01

    Southern California earthquakes ??? M5.5 during the period 1955/01/01-1994/01/17 were concentrated along or adjacent to the south flank of the southern California uplift, as defined both at its culmination and following its partial collapse. Spatial clustering of these earthquakes within three more-or-less distinct groups suggests either gaps along the south flank that were previously filled or are yet to be filled. Nearly all of the indicated earthquakes accompanied or followed partial collapse of the uplift, and seismic activity within this regime seems to have been increasing through at least 1994/01/17. Copyright 1996 by the American Geophysical Union.

  7. Submergence and Uplift Associated to Paleoearthquakes in the Northern Sunda Subduction System: Implications for Future Earthquakes.

    NASA Astrophysics Data System (ADS)

    Mondal, D. R.; McHugh, C. M.; Mortlock, R. A.; Steckler, M. S.; Seeber, L.; Goodbred, S. L., Jr.; Akhter, S. H.; Mustaque, S.

    2015-12-01

    Recent studies documented that the northern part of the Sunda subduction zone ruptured several times in the past 1500 years including one in 1762. To better understand megathrust surface ruptures and the hazards associated to them, we surveyed the SE coast of Bangladesh along the Teknaf peninsula and the Saint Martin anticline by dating coral microatolls of Porites lutea species by the U-Th dating method. Porites luteagrows a few centimeters below the low tide level creating a 5-12 mm thick skeletal band per year, which makes them a good indicator of relative sea level change that might be caused during tectonic submergence and uplift. U-Th ages were obtained from coral slabs and their growth bands interpreted from x-rays. The corals and marine terraces uplift were measured with high precision RTK GPS and modeled with high resolution DEM. The coral microatolls along the St. Martin anticline were dated to be ~ 250, 800 and 1300 years old. Since storm and other climatic phenomenon cannot cause uplift, we interpret that 2.5 m uplift was caused by 1762 earthquake that killed the coral microatolls. The coral slabs show three growth interruptions, where skeletal growth bands continued to grow onlapping the older growth bands. These growth onlaps could be the result of smaller uplift events after 1762 that did not result in coral mortality. The subsidence history extracted from vertical growth of the slabs suggests that the island is submerging at a rate of 11 mm/year. Corals growing 250 m from the dead coral colony post date the 1762 earthquake. Today living Porites lutea can be found 2.5 m below the dead coral heads and 9 cm above the spring low tide. The elevation of marine terraces (T1, T2 and T3) along the Teknaf coast is 2.5 m, 5-7 m and 11-13 m above sea level, respectively. A shell bed on top of T1 was dated at 1763 (dated by C14). This and the other two terraces could have been uplifted during the three earthquakes dated from coral microatolls. Considering the

  8. Holocene coseismic and aseismic uplift of Isla Mocha, south-central Chile

    USGS Publications Warehouse

    Nelson, A.R.; Manley, W.F.

    1992-01-01

    During the past 6000 years Isla Mocha, a 12 km-long island 30 km off the coast of south-central Chile, experienced a 38 m fall of relative sea level caused primarily by rapid tectonic uplift of the island. As many as 18 raised shorelines (strandlines) record this uplift. Historic accounts of uplift during the great earthquakes (M > 8) of 1835 and 1960 suggest some of the more prominent prehistoric strandlines also emerged during great earthquakes on the interface between the Nazca and South America plates. But the close elevational spacing of strandlines, subdued morphology of strandline beaches, scarcity of exposed bedrock wave-cut platforms, and the extremely high rates of aseismic uplift (ca. 70 mm/yr) of the island since the last great earthquake suggest that many strandlines were raised by aseismic rather than coseismic uplift. Strandline heights and 14 new radiocarbon ages on marine shells show that the present-day uplift rate is more than three times the net rate (ca. 20 mm/yr) of the past 1000 years. The recent high rate probably reflects increased aseismic slip on an inferred thrust fault in the overriding South America plate. Isla Mocha overlies an area of high stress concentration between two major segments of the Chilean subduction zone. The inferred high rate of slip on the thrust fault may be a response to stress changes on the plate interface near the boundary between the segments. ?? 1992.

  9. [The early history of "Ecstasy"].

    PubMed

    Benzenhöfer, U; Passie, T

    2006-01-01

    There is no consensus in the literature regarding the early history of MDMA (Methylendioxymethamphetamine, so-called "Ecstasy"). Various authors credit the first synthesis of MDMA to the German chemist Fritz Haber, but it appears neither in his doctoral thesis (Berlin 1891) nor in his accompanying articles. The man who first synthesized MDMA was the chemist Dr. Anton Köllisch, who worked for the German pharmaceutical company Merck. He created MDMA as a by-product while trying to synthesize hydrastinin, a styptic substance. In 1912, Merck filed to patent the applied method of preparation. The patent was issued in 1914, yet no pharmaceutical testing followed at that time.

  10. Paleofluid-flow circulation within a Triassic rift basin: Evidence from oil inclusions and thermal histories

    USGS Publications Warehouse

    Tseng, H.-Y.; Burruss, R.C.; Onstott, T.C.; Omar, G.

    1999-01-01

    The migration of subsurface fluid flow within continental rift basins has been increasingly recognized to significantly affect the thermal history of sediments and petroleum formation. To gain insight into these paleofluid flow effects, the thermal history of the Taylorsville basin in Virginia was reconstructed from fluid-inclusion studies, apatite fission-track data, and vitrinite reflectance data. Models of thermal history indicate that the basin was buried to the thermal maximum at 200 Ma; a cooling event followed during which the eastern side of the basin cooled earlier and faster than the western side, suggesting that there was a differential uplift and topographically driven fluid flow. This hypothesis is supported by analyses of secondary oil and aqueous inclusions trapped in calcite and quartz veins during the uplift stage. Gas chromatograms of inclusion oils exhibit variable but extensive depletion of light molecular-weight hydrocarbons. The relative abundance of n-alkanes, petrographic observations, and the geological data indicate that the alteration process on these inclusion oils was probably neither phase separation nor biodegradation, but water washing. Water:oil ratios necessary to produce the observed alteration are much greater than 10000:1. These exceedingly high ratios are consistent with the migration of inclusion oils along with fluid flow during the early stages of basin evolution. The results provide significant evidence about the role of a subsurface flow system in modifying the temperature structure of the basin and the composition of petroleum generated within the basin.

  11. [Contribution to the history of pharmacology (the early Roman empire)].

    PubMed

    Tesařová, Drahomíra

    2014-01-01

    This article is a contribution to the history of pharmacology in the early Roman empire. It contains texts mainly written in Latin: the works of Aulus Cornelius Celsus, Scribonius Largus and Plinius Maior (Pliny the Elder). It describes their structure and contributions to the history of medicine and gives examples of some prescriptions and drugs in the original language and in Czech.

  12. Geomorphic evidence for post-10 Ma uplift of the western flank of the central Andes 18°30'-22°S

    NASA Astrophysics Data System (ADS)

    Hoke, Gregory D.; Isacks, Bryan L.; Jordan, Teresa E.; Blanco, NicoláS.; Tomlinson, Andrew J.; Ramezani, Jahandar

    2007-10-01

    The western Andean mountain front forms the western edge of the central Andean Plateau. Between 18.5° and 22°S latitude, the mountain front has ˜3000 m of relief over ˜50 km horizontal distance that has developed in the absence of major local Neogene deformation. Models of the evolution of the plateau, as well as paleoaltimetry estimates, all call for continued large-magnitude uplift of the plateau surface into the late Miocene (i.e., younger than 10 Ma). Longitudinal river profiles from 20 catchments that drain the western Andean mountain front contain several streams with knickpoint-bounded segments that we use to reconstruct the history of post-10 Ma surface uplift of the western flank of the central Andean Plateau. The generation of knickpoints is attributed to tectonic processes and is not a consequence of base level change related to Pacific Ocean capture, eustatic change, or climate change as causes for creating the knickpoint-bounded stream segments observed. Minor valley-filling alluvial gravels intercalated with the 5.4 Ma Carcote ignimbrite suggest uplift related river incision was well under way by 5.4 Ma. The maximum age of river incision is provided by the regionally extensive, approximately 10 Ma El Diablo-Altos de Pica paleosurface. The river profiles reveal that relative surface uplift of at least1 km occurred after 10 Ma.

  13. Accelerating late Quaternary uplift of the New Georgia Island Group (Solomon island arc) in response to subduction of the recently active Woodlark spreading center and Coleman seamount

    NASA Astrophysics Data System (ADS)

    Mann, Paul; Taylor, Frederick W.; Lagoe, Martin B.; Quarles, Andrew; Burr, G.

    1998-10-01

    The New Georgia Island Group of the Solomon Islands is one of four places where an active or recently active spreading ridge has subducted beneath an island arc. We have used coral reef terraces, paleobathymetry of Neogene sedimentary rocks, and existing marine geophysical data to constrain patterns of regional Quaternary deformation related to subduction of the recently active Woodlark spreading center and its overlying Coleman seamount. These combined data indicate the following vertical tectonic history for the central part of the New Georgia Island Group: (1) subsidence of the forearc region (Tetepare and Rendova Islands) to water depths of ˜1500 m and deposition of marine turbidites until after 270 ka; (2) late Quaternary uplift of the forearc to sea level and erosion of an unconformity; (3) subsidence of the forearc to ˜500 m BSL and deposition of bathyal sediments; and (4) uplift of the forearc above sea level with Holocene uplift rates up to at least 7.5 mm/yr on Tetepare and 5 mm/yr on Rendova. In the northeastern part of the New Georgia Island Group, our combined data indicate a slightly different tectonic history characterized by lower-amplitude vertical motions and a more recent change from subsidence to uplift. Barrier reefs formed around New Georgia and Vangunu Islands as they subsided >300 m. By 50-100 ka, subsidence was replaced by uplift that accelerated to Holocene rates of ˜1 mm/yr on the volcanic arc compared with rates up to ˜7.5 mm/yr in the forearc area of Tetepare and Rendova. Uplift mechanisms, such as thermal effects due to subduction of spreading ridges, tectonic erosion, or underplating of deeply subducted bathymetric features, are not likely to function on the 270-ka period that these uplift events have occurred in the New Georgia Island Group. A more likely uplift mechanism for the post-270-ka accelerating uplift of the forearc and volcanic arc of the New Georgia Island Group is progressive impingement of the Coleman seamount or

  14. Evidence of uplift near Charleston, South Carolina

    USGS Publications Warehouse

    Rhea, S.

    1989-01-01

    In spite of extensive research, the causal structure of the 1886 magnitude 7 earthquake near Charleston, South Carolina, has not been identified. In this study I analyzed digital surface topography and river morphology in light of earlier studies using seismic reflection, seismic refraction, earthquake seismology, and gravity and magnetic surveys. This analysis revealed an area approximately 400 km2 northwest of Charleston that may have been repeatedly uplifted by earthquakes. Geologic and seismic reflection data confirm alteration of formations at depth. Deformation of the surface is supported by observations on aerial and LANDSAT photographs. Therefore, the structure on which the 1886 earthquake occurred may be within the uplifted area defined in this report. -Author

  15. The Invention and Early History of the N-Localizer for Stereotactic Neurosurgery

    PubMed Central

    Nelson, James A

    2016-01-01

    Nearly four decades after the invention of the N-localizer, its origin and history remain misunderstood. Some are unaware that a third-year medical student invented this technology. The following conspectus accurately chronicles the origin of the N-localizer, presents recently discovered evidence that documents its history, and corrects misconceptions related to its origin and early history. PMID:27462476

  16. Uplift in the Fiordland region, New Zealand: implications for incipient subduction.

    PubMed

    House, M A; Gurnis, M; Kamp, P J J; Sutherland, R

    2002-09-20

    Low-temperature thermochronometry reveals regional Late Cenozoic denudation in Fiordland, New Zealand, consistent with geodynamic models showing uplift of the overriding plate during incipient subduction. The data show a northward progression of exhumation in response to northward migration of the initiation of subduction. The locus of most recent uplift coincides with a large positive Bouguer gravity anomaly within Fiordland. Thermochronometrically deduced crustal thinning, anomalous gravity, and estimates of surface uplift are all consistent with approximately 2 kilometers of dynamic support. This amount of dynamic support is in accord with geodynamic predictions, suggesting that we have dated the initiation of subduction adjacent to Fiordland.

  17. Early history of Neanderthals and Denisovans

    PubMed Central

    Bohlender, Ryan J.; Huff, Chad D.

    2017-01-01

    Extensive DNA sequence data have made it possible to reconstruct human evolutionary history in unprecedented detail. We introduce a method to study the past several hundred thousand years. Our results show that (i) the Neanderthal–Denisovan lineage declined to a small size just after separating from the modern lineage, (ii) Neanderthals and Denisovans separated soon thereafter, and (iii) the subsequent Neanderthal population was large and deeply subdivided. They also (iv) support previous estimates of gene flow from Neanderthals into modern Eurasians. These results suggest an archaic human diaspora early in the Middle Pleistocene. PMID:28784789

  18. Quarternary evolution of fluvial systems in the northern Rio Grande rift: Implications for vertical crustal uplift and rift tectonics. Final report, October 1, 1988--September 30, 1989

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harrington, C.D.; Wells, S.G.

    1994-09-01

    We propose to establish the late Cenozoic history of incision of the Rio Grande in the northern rift and to relate the variations of drainage incision to vertical uplift and rift tectonics. Our objectives are to establish the nature and timing of Rio Grande gorge development across the boundary between the Espanola/Taos-San Luis basins using isotopic and varnish cation ratio dating, establishing isochrons along gorge walls and isoleths of incision rates throughout the gorge, and documenting spatial and temporal variations in the isopleth data that might reflect deformation resulting from crustal uplift. The results of this study will be significantmore » because the derived isochrons and incision rates can be used to date periods and to document the areal extent of vertical crustal uplift which may reflect asthenospheric and lithospheric interactions beneath the rift.« less

  19. Late Miocene uplift in the Romagnan Apennines and the detachment of subducted lithosphere

    NASA Astrophysics Data System (ADS)

    van der Meulen, M. J.; Kouwenhoven, T. J.; van der Zwaan, G. J.; Meulenkamp, J. E.; Wortel, M. J. R.

    1999-12-01

    We report part of a test of the hypothesis that detachment of subducted lithosphere may be a process of lateral propagation of a horizontal tear [Wortel and Spakman, Proc. Kon. Ned. Akad. Wetensch., 95 (1992) 325-347]. We have used the Apennines as a test area. The test procedure consists of the comparison of hypothetical vertical motions, predicted from the expected redistribution of slab pull forces, with observed vertical motions. We demonstrate that a Late Miocene depocentre migration from the Northern towards the Central Apennines is associated with uplift of (the fore-arc of) the Northern Apennines. Such a combination of a depocentre shift and uplift is thought to be diagnostic for lateral migration of slab detachment. The depocentre migration was identified in earlier work [van der Meulen et al., Earth Planet. Sci. Lett., 154 (1998) 203-219]. This contribution focuses on uplift, which has primarily been identified through the geohistory analysis of the Monte del Casino Section (Romagnan Apennines, Northern Italy). Owing to methodological problems, the start and duration of the uplift phase could not be constrained, and only a minimum estimate of the total amount of uplift (483±180 m) is obtained. The data do allow for an estimate of the uplift rate: 163±61 cm/ky. A review of regional data results in better constraints on the timing of the above lateral reorganisation of the fore-arc, and on the spatial extent of the uplifted area. Depocentre development in the Central Apennines began between 8.6 and 8.3 Ma B.P. Uplift started between 9 and 8 Ma B.P., and affected the entire northernmost Apennines.

  20. Receiver function and gravity constraints on crustal structure and vertical movements of the Upper Mississippi Embayment and Ozark Uplift

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Gao, Stephen S.; Liu, Kelly H.; Mickus, Kevin

    2017-06-01

    The Upper Mississippi Embayment (UME), where the seismically active New Madrid Seismic Zone resides, experienced two phases of subsidence commencing in the Late Precambrian and Cretaceous, respectively. To provide new constraints on models proposed for the mechanisms responsible for the subsidence, we computed and stacked P-to-S receiver functions recorded by 49 USArray and other seismic stations located in the UME and the adjacent Ozark Uplift and modeled Bouguer gravity anomaly data. The inferred thickness, density, and Vp/Vs of the upper and lower crustal layers suggest that the UME is characterized by a mafic and high-density upper crustal layer of ˜30 km thickness, which is underlain by a higher-density lower crustal layer of up to ˜15 km. Those measurements, in the background of previously published geological observations on the subsidence and uplift history of the UME, are in agreement with the model that the Cretaceous subsidence, which was suggested to be preceded by an approximately 2 km uplift, was the consequence of the passage of a previously proposed thermal plume. The thermoelastic effects of the plume would have induced wide-spread intrusion of mafic mantle material into the weak UME crust fractured by Precambrian rifting and increased its density, resulting in renewed subsidence after the thermal source was removed. In contrast, the Ozark Uplift has crustal density, thickness, and Vp/Vs measurements that are comparable to those observed on cratonic areas, suggesting an overall normal crust without significant modification by the proposed plume, probably owing to the relatively strong and thick lithosphere.

  1. Flexural analysis of uplifted rift flanks on Venus

    NASA Technical Reports Server (NTRS)

    Evans, Susan A.; Simons, Mark; Solomon, Sean C.

    1992-01-01

    Knowledge of the thermal structure of a planet is vital to a thorough understanding of its general scheme of tectonics. Since no direct measurements of heat flow or thermal gradient are available for Venus, most estimates have been derived from theoretical considerations or by analog with the Earth. The flexural response of the lithosphere to applied loads is sensitive to regional thermal structure. Under the assumption that the yield strength as a function of depth can be specified, the temperature gradient can be inferred from the effective elastic plate thickness. Previous estimates of the effective elastic plate thickness of Venus range from 11-18 km for the foredeep north of Uorsar Rupes to 30-60 km for the annular troughs around several coronae. Thermal gradients inferred for these regions are 14-23 K km(exp -1) and 4-9 K km(exp -1) respectively. In this study, we apply the same techniques to investigate the uplifted flanks of an extensional rift. Hypotheses for the origin of uplifted rift flanks on Earth include lateral transport of heat from the center of the rift, vertical transport of heat by small-scale convection, differential thinning of the lithosphere, dynamical uplift, and isostatic response to mechanical uploading of the lithosphere. The 1st hypothesis is considered the dominant contributor to terrestrial rift flanks lacking evidence for volcanic activity, particularly for rift structures that are no longer active. In this study, we model the uplifted flanks of a venusian rift as the flexural response to a vertical end load.

  2. Upper Pleistocene uplifted shorelines as tracers of (local rather than global) subduction dynamics

    NASA Astrophysics Data System (ADS)

    Henry, Hadrien; Regard, Vincent; Pedoja, Kevin; Husson, Laurent; Martinod, Joseph; Witt, Cesar; Heuret, Arnauld

    2014-08-01

    Past studies have shown that high coastal uplift rates are restricted to active areas, especially in a subduction context. The origin of coastal uplift in subduction zones, however, has not yet been globally investigated. Quaternary shorelines correlated to the last interglacial maximum (MIS 5e) were defined as a global tectonic benchmark (Pedoja et al., 2011). In order to investigate the relationships between the vertical motion and the subduction dynamic parameters, we cross-linked this coastal uplift database with the “geodynamical” databases from Heuret (2005), Conrad and Husson (2009) and Müller et al. (2008). Our statistical study shows that: (1) the most intuitive parameters one can think responsible for coastal uplift (e.g., subduction obliquity, trench motion, oceanic crust age, interplate friction and force, convergence variation, dynamic topography, overriding and subducted plate velocity) are not related with the uplift (and its magnitude); (2) the only intuitive parameter is the distance to the trench which shows in specific areas a decrease from the trench up to a distance of ˜300 km; (3) the slab dip (especially the deep slab dip), the position along the trench and the overriding plate tectonic regime are correlated with the coastal uplift, probably reflecting transient changes in subduction parameters. Finally we conclude that the first order parameter explaining coastal uplift is small-scale heterogeneities of the subducting plate, as for instance subducting aseismic ridges. The influence of large-scale geodynamic setting of subduction zones is secondary.

  3. Deep intrusions, lateral magma transport and related uplift at ocean island volcanoes

    NASA Astrophysics Data System (ADS)

    Klügel, Andreas; Longpré, Marc-Antoine; García-Cañada, Laura; Stix, John

    2015-12-01

    Oceanic intraplate volcanoes grow by accumulation of erupted material as well as by coeval or discrete magmatic intrusions. Dykes and other intrusive bodies within volcanic edifices are comparatively well studied, but intrusive processes deep beneath the volcanoes remain elusive. Although there is geological evidence for deep magmatic intrusions contributing to volcano growth through uplift, this has rarely been demonstrated by real-time monitoring. Here we use geophysical and petrological data from El Hierro, Canary Islands, to show that intrusions from the mantle and subhorizontal transport of magma within the oceanic crust result in rapid endogenous island growth. Seismicity and ground deformation associated with a submarine eruption in 2011-2012 reveal deep subhorizontal intrusive sheets (sills), which have caused island-scale uplift of tens of centimetres. The pre-eruptive intrusions migrated 15-20 km laterally within the lower oceanic crust, opening pathways that were subsequently used by the erupted magmas to ascend from the mantle to the surface. During six post-eruptive episodes between 2012 and 2014, further sill intrusions into the lower crust and upper mantle have caused magma to migrate up to 20 km laterally, resulting in magma accumulation exceeding that of the pre-eruptive phase. A comparison of geobarometric data for the 2011-2012 El Hierro eruption with data for other Atlantic intraplate volcanoes shows similar bimodal pressure distributions, suggesting that eruptive phases are commonly accompanied by deep intrusions of sills and lateral magma transport. These processes add significant material to the oceanic crust, cause uplift, and are thus fundamentally important for the growth and evolution of volcanic islands. We suggest that the development of such a magma accumulation zone in the lower oceanic crust begins early during volcano evolution, and is a consequence of increasing size and complexity of the mantle reservoir system, and potentially

  4. Development of the Earth's early crust: Implications from the Beartooth Mountains

    NASA Technical Reports Server (NTRS)

    Mueller, P. A.; Wooden, J. L.; Henry, D. J.; Mogk, D. W.

    1983-01-01

    The Beartooth Mountains of Montana and Wyoming are one of several major uplifts of Precambrian rocks in the northwestern of the Wyoming Province. The range is composed of a wide variety of rock types which record a complex geologic history that extends from early ( 3400 Ma) to late (approx 700 Ma) Precambrian time. The Archean geology of the range is complex and many areas remain unstudied in detail. In this discussion two areas are discussed for which there is considerable structural, geochemical and petrologic information. The easternmost portion of the range (EBT) and the northwesternmost portion, the North Snowy Block (NSB), contain rather extensive records of both early and late Archean geologic activity. These data are used to constrain a petrologic tectonic model for the development of continental crust in this area.

  5. Abrupt uplift within the past 1700 years at Southern Puget Sound, Washington

    USGS Publications Warehouse

    Bucknam, R.C.; Hemphill-Haley, E.; Leopold, E.B.

    1992-01-01

    Shorelines rose as much as 7 meters along southern Puget Sound and Hood Canal between 500 and 1700 years ago. Evidence for this uplift consists of elevated wave-cut shore platforms near Seattle and emerged, peat-covered tidal flats as much as 60 kilometers to the southwest. The uplift was too rapid for waves to leave intermediate shorelines on even the best preserved platform. The tidal flats also emerged abruptly; they changed into freshwater swamps and meadows without first becoming tidal marshes. Where uplift was greatest, it adjoined an inferred fault that crosses Puget Sound at Seattle and it probably accompanied reverse slip on that fault 1000 to 1100 years ago. The uplift and probable fault slip show that the crust of the North America plate contains potential sources of damaging earthquakes in the Puget Sound region.

  6. Depositional environments of the Rock Springs Formation, southwest flank of the Rock Springs Uplift, Wyoming.

    USGS Publications Warehouse

    Kirschbaum, M.A.

    1986-01-01

    This deltaic Upper Cretaceous Rock Springs Formation of the Mesaverde Group was deposited during early Campanian time near the end of the regressive phase of the Niobrara cyclothem. On the southwest end of the Uplift, part of the delta system is exposed near the seaward edge of a series of transgressive/regressive sequences, which consist of intertonguing prodelta, delta-front, and delta-plain deposits. Eight major delta-front sandstones are vertically stacked and laterally continuous throughout the main study area.-from Author

  7. Slowing extrusion tectonics: Lowered estimate of post-Early Miocene slip rate for the Altyn Tagh fault

    USGS Publications Warehouse

    Yue, Y.; Ritts, B.D.; Graham, S.A.; Wooden, J.L.; Gehrels, G.E.; Zhang, Z.

    2004-01-01

    Determination of long-term slip rate for the Altyn Tagh fault is essential for testing whether Asian tectonics is dominated by lateral extrusion or distributed crustal shortening. Previous slip-history studies focused on either Quaternary slip-rate measurements or pre-Early Miocene total-offset estimates and do not allow a clear distinction between rates based on the two. The magmatic and metamorphic history revealed by SHRIMP zircon dating of clasts from Miocene conglomerate in the Xorkol basin north of the Altyn Tagh fault strikingly matches that of basement in the southern Qilian Shan and northern Qaidam regions south of the fault. This match requires that the post-Early Miocene long-term slip rate along the Altyn Tagh fault cannot exceed 10 mm/year, supporting the hypothesis of distributed crustal thickening for post-Early Miocene times. This low long-term slip rate and recently documented large pre-Early Miocene cumulative offset across the fault support a two-stage evolution, wherein Asian tectonics was dominated by lateral extrusion before the end of Early Miocene, and since then has been dominated by distributed crustal thickening and rapid plateau uplift. ?? 2003 Elsevier B.V. All rights reserved.

  8. Quantitative dating of Pleistocene terrace deposits of the Kyrenia Range, northern Cyprus: implications for timing, rates of uplift and driving mechanisms in an incipient collision zone

    NASA Astrophysics Data System (ADS)

    Palamakumbura, Romesh; Robertson, Alastair; Kinnaird, Tim; van Calsteren, Peter; Kroon, Dick; Tait, Jenny

    2016-04-01

    The Kyrenia Range is a narrow E-W trending mountain range up to c. 180 km long by up to ca. 20 km wide, which is located <100 km south of the Anatolian orogenic plateau within the easternmost Mediterranean Sea. The Kyrenia Range structural lineament underwent tectonically driven uplift mainly during the Pleistocene in a setting dominated by incipient continental collision. The likely driver of the uplift was the collision of the Eratosthenes Seamount, an inferred promontory of north Africa, with a subduction zone located to the south of Cyprus. To help understand the tectonic processes driving the uplift of the Kyrenia Range several quantitative techniques have been used to date uplift-related terrace deposits exposed on the northern flank of the range. Uranium-series disequilibrium (U-series) dating provides ages of 127, 131 and 242 ka from solitary coral in shallow-marine deposits of the lowest terraces, whereas optically stimulated luminescence (OSL) dating gives ages of 53 and 76 ka from coastal aeolianite deposits. Prior to major tectonic uplift a shallow-marine carbonate-depositing sea existed in the vicinity of the Kyrenia Range. Some of the youngest pre-uplift marine carbonates yielded a reversed magnetic polarity, which constrains them as older than the last palaeomagnetic reversal (0.78 Ma). The combined evidence suggests that marine environments persisted into the Early Pleistocene, prior to major surface uplift of the Kyrenia Range lineament, which appears to have climaxed in the Mid-Pleistocene. The inferred uplift rates of the Kyrenia Range lineament range from >1.2 mm/yr during the Mid-Pleistocene to <0.2 mm/yr during the Late Pleistocene. The uplift rates of the Kyrenia Range appear to be, on average, significantly faster than those inferred for some adjacent regions of the Eastern Mediterranean during the Pleistocene (e.g. Lebanon coast; Anatolian plateau southern margin). The new data also suggest that the Kyrenia Range was uplifted

  9. History in the Early Nineteenth Century.

    PubMed

    Ratcliff, Jessica

    2016-09-01

    At the turn of the nineteenth century, at its headquarters in the City of London, the Honourable East India Company established a new museum and library. By midcentury this museum would contain one of Europe’s most extensive collections of the natural history, arts, and sciences of Asia. This essay uses the early history of the company’s museum, focusing in particular on its natural history collections, to explore the material relationship between scientific practice and the imperial political economy. Much of the collections had been gathered in the wake of military campaigns, trade missions, or administrative surveys. Once specimens and reports arrived in Leadenhall Street and passed through the museum storage areas, this plunder would become the stuff of science, going on to feed the growth of disciplines, societies, and projects in Britain and beyond. In this way, the East India Company was integral to the information and communication infrastructures within which many sciences then operated. Collections-based disciplines and societies flourished in this period; their growth, it is argued, was coextensive with administrative and political economic change at institutions like the East India Company. The essay first explores the company’s practices and patterns of collecting and then considers the consequences of this accumulation for aspects of scientific practice—particularly the growth of scientific societies—in both London and Calcutta.

  10. Continuous uplift near the seaward edge of the Prince William Sound megathrust: Middleton Island, Alaska

    USGS Publications Warehouse

    Savage, James C.; Plafker, George; Svarc, Jerry L.; Lisowski, Michael

    2014-01-01

    Middleton Island, located at the seaward edge of the continental shelf 50 km from the base of the inner wall of the Aleutian Trench, affords an opportunity to make land-based measurements of uplift near the toe of the Prince William Sound megathrust, site of the 1964, M = 9.2, Alaska earthquake. Leveling surveys (1973–1993) on Middleton Island indicate roughly uniform tilting (~1 µrad/a down to the northwest) of the island, and GPS surveys (1993–2012) show an uplift rate of 14 mm/a of the island relative to fixed North America. The data are consistent with a combined (coseismic and postseismic) uplift (in meters) due to the 1964 earthquake as a function of time τ (years after the earthquake) u(τ) = (3.5 + 1.21 log10 [1 + 1.67 τ]) H(τ) where 3.5 is the coseismic uplift and H(τ) is 0 for τ < 0 and 1 otherwise. The current uplift on Middleton Island is attributed to continuous slip on a fault splaying off from the megathrust, and the long-term uplift is the superposition of the effects of past earthquakes, each earthquake being similar to the 1964 event. Then, the predicted uplift at time t due to a sequence of earthquakes at times tiwould be . From studies of strandlines associated with the uplifted terraces on Middleton Island, Plafker et al. (1992) estimated the occurrence times of the last six earthquakes and measured the present-day elevations of those strandlines. The predicted uplift is in rough agreement with those measurements. About half of the predicted uplift is due to postseismic relaxation from previous earthquakes.

  11. Continuous uplift near the seaward edge of the Prince William Sound megathrust: Middleton Island, Alaska

    NASA Astrophysics Data System (ADS)

    Savage, J. C.; Plafker, G.; Svarc, J. L.; Lisowski, M.

    2014-07-01

    Middleton Island, located at the seaward edge of the continental shelf 50 km from the base of the inner wall of the Aleutian Trench, affords an opportunity to make land-based measurements of uplift near the toe of the Prince William Sound megathrust, site of the 1964, M = 9.2, Alaska earthquake. Leveling surveys (1973-1993) on Middleton Island indicate roughly uniform tilting ( 1 µrad/a down to the northwest) of the island, and GPS surveys (1993-2012) show an uplift rate of 14 mm/a of the island relative to fixed North America. The data are consistent with a combined (coseismic and postseismic) uplift (in meters) due to the 1964 earthquake as a function of time τ (years after the earthquake) u(τ) = (3.5 + 1.21 log10 [1 + 1.67 τ]) H(τ) where 3.5 is the coseismic uplift and H(τ) is 0 for τ < 0 and 1 otherwise. The current uplift on Middleton Island is attributed to continuous slip on a fault splaying off from the megathrust, and the long-term uplift is the superposition of the effects of past earthquakes, each earthquake being similar to the 1964 event. Then, the predicted uplift at time t due to a sequence of earthquakes at times ti would be ∑iut-ti. From studies of strandlines associated with the uplifted terraces on Middleton Island, Plafker et al. (1992) estimated the occurrence times of the last six earthquakes and measured the present-day elevations of those strandlines. The predicted uplift is in rough agreement with those measurements. About half of the predicted uplift is due to postseismic relaxation from previous earthquakes.

  12. An early history of T cell-mediated cytotoxicity.

    PubMed

    Golstein, Pierre; Griffiths, Gillian M

    2018-04-16

    After 60 years of intense fundamental research into T cell-mediated cytotoxicity, we have gained a detailed knowledge of the cells involved, specific recognition mechanisms and post-recognition perforin-granzyme-based and FAS-based molecular mechanisms. What could not be anticipated at the outset was how discovery of the mechanisms regulating the activation and function of cytotoxic T cells would lead to new developments in cancer immunotherapy. Given the profound recent interest in therapeutic manipulation of cytotoxic T cell responses, it is an opportune time to look back on the early history of the field. This Timeline describes how the early findings occurred and eventually led to current therapeutic applications.

  13. A qualitative study of early family histories and transitions of homeless youth.

    PubMed

    Tyler, Kimberly A

    2006-10-01

    Using intensive qualitative interviews with 40 homeless youth, this study examined their early family histories for abuse, neglect, and other family problems and the number and types of transitions that youth experienced. Multiple forms of child maltreatment, family alcoholism, drug use, and criminal activity characterized early family histories of many youth. Leaving home because of either running away or being removed by child protective services often resulted in multiple transitions, which regularly included moving from foster care homes to a group home, back to their parents, and then again returning to the streets. Although having experienced family disorganization set youth on trajectories for early independence, there were many unique paths that youth traveled prior to ending up on the streets.

  14. Upper Paleogene shallow-water events in the Sandino Forearc Basin, Nicaragua-Costa Rica - response to tectonic uplift

    NASA Astrophysics Data System (ADS)

    Andjic, Goran; Baumgartner-Mora, Claudia; Baumgartner, Peter O.

    2016-04-01

    The Upper Cretaceous-Neogene Sandino Forearc Basin is exposed in the southeastern Nicaraguan Isthmus and in the northwestern corner of Costa Rica. It consists of an elongated, slightly folded belt (160 km long/30 km wide). During Campanian to Oligocene, the predominantly deep-water pelagic, hemipelagic and turbiditic sequences were successively replaced by shelf siliciclastics and carbonates at different steps of the basin evolution. We have made an inventory of Tertiary shallow-water limestones in several areas of Nicaragua and northern Costa Rica. They always appear as isolated rock bodies, generally having an unconformable stratigraphic contact with the underlying detrital sequences. The presence of these short-lived carbonate shoals can be attributed to local or regional tectonic uplift in the forearc area. The best-preserved exposure of such a carbonate buildup is located on the small Isla Juanilla (0.15 km2, Junquillal Bay, NW Costa Rica). The whole island is made of reef carbonates, displaying corals in growth position, associated with coralline red algae (Juanilla Formation). Beds rich in Larger Benthic Foraminifera such as Lepidocyclina undosa -favosa group permit to date this reef as late Oligocene. A first uplift event affected the Nicaraguan Isthmus, that rose from deep-water to shelfal settings in the latest Eocene-earliest Oligocene. The upper Oligocene Juanilla Formation formed on an anticline that developed during the early Oligocene, contemporaneously with other folds observed in the offshore Sandino Forearc Basin. During the early Oligocene, a period of global sea-level fall, the folded tectonic high underwent deep erosion. During the late Oligocene, a time of overall stable eustatic sea level, tectonic uplift gave way to moderate subsidence, creating accommodation space for reef growth. A 4th or 5th order (Milankovic-type) glacio-eustatic sea level rise, could also have triggered reef growth, but its preservation implies at least moderate

  15. Do Hassles and Uplifts Change with Age? Longitudinal Findings from the VA Normative Aging Study

    PubMed Central

    Aldwin, Carolyn M.; Jeong, Yu-Jin; Igarashi, Heidi; Spiro, Avron

    2014-01-01

    To examine emotion regulation in later life, we contrasted the modified hedonic treadmill theory with developmental theories, using hassles and uplifts to assess emotion regulation in context. The sample was 1,315 men from the VA Normative Aging Study aged 53 to 85 years, who completed 3,894 observations between 1989 and 2004. We computed three scores for both hassles and uplifts: intensity (ratings reflecting appraisal processes), exposure (count), and summary (total) scores. Growth curves over age showed marked differences in trajectory patterns for intensity and exposure scores. Although exposure to hassles and uplifts decreased in later life, intensity scores increased. Growth based modelling showed individual differences in patterns of hassles and uplifts intensity and exposure, with relative stability in uplifts intensity, normative non-linear changes in hassles intensity, and complex patterns of individual differences in exposure for both hassles and uplifts. Analyses with the summary scores showed that emotion regulation in later life is a function of both developmental change and contextual exposure, with different patterns emerging for hassles and uplifts. Thus, support was found for both hedonic treadmill and developmental change theories, reflecting different aspects of emotion regulation in late life. PMID:24660796

  16. Do hassles and uplifts change with age? Longitudinal findings from the VA normative aging study.

    PubMed

    Aldwin, Carolyn M; Jeong, Yu-Jin; Igarashi, Heidi; Spiro, Avron

    2014-03-01

    To examine emotion regulation in later life, we contrasted the modified hedonic treadmill theory with developmental theories, using hassles and uplifts to assess emotion regulation in context. The sample was 1,315 men from the VA Normative Aging Study aged 53 to 85 years, who completed 3,894 observations between 1989 and 2004. We computed 3 scores for both hassles and uplifts: intensity (ratings reflecting appraisal processes), exposure (count), and summary (total) scores. Growth curves over age showed marked differences in trajectory patterns for intensity and exposure scores. Although exposure to hassles and uplifts decreased in later life, intensity scores increased. Group-based modeling showed individual differences in patterns of hassles and uplifts intensity and exposure, with relative stability in uplifts intensity, normative nonlinear changes in hassles intensity, and complex patterns of individual differences in exposure for both hassles and uplifts. Analyses with the summary scores showed that emotion regulation in later life is a function of both developmental change and contextual exposure, with different patterns emerging for hassles and uplifts. Thus, support was found for both hedonic treadmill and developmental change theories, reflecting different aspects of emotion regulation in late life. (c) 2014 APA, all rights reserved.

  17. Geologic history of the Colorado River: Chapter C in The Colorado River region and John Wesley Powell (Professional Paper 669)

    USGS Publications Warehouse

    Hunt, Charles B.

    1969-01-01

    John Wesley Powell clearly recognized that the spectacular features of the Colorado River - its many grand canyons - were dependent upon the structural history of the mountainous barriers crossed by the river. He conceived of three different historical relationships between rivers and structural features: (1) Newly uplifted land surfaces have rivers that flow down the initial slope of the uplift; these relationships he termed consequent. (2) A river may be older than an uplift that it crosses because it has been able to maintain its course by eroding downward as the uplift progresses; this relationship he named antecedent. (3) An uplifted block may have been buried by younger deposits upon which a river becomes established. The river, in cutting downward, uncovers the uplifted block and becomes incised into it; this relationship he called superimposed.The geologic history of the Colorado River involves all three relationships. In addition, although the position of the river course through a particular structural barrier may have been the result of superposition, the depth of the canyon at that point may be largely due to renewed uplift of the barrier; such deepening of the canyon, therefore, is due to antecedence. The problem of the Colorado River remains today very much as G. K. Gilbert stated it nearly 100 years ago: "How much is antecedent and how much is superimposed?" The question must be asked separately for each stretch of the river.

  18. Uplifted ophiolitic rocks on Isla Gordon, southernmost Chile: implications for the closure history of the Rocas Verdes marginal basin and the tectonic evolution of the Beagle Channel region

    NASA Astrophysics Data System (ADS)

    Cunningham, W. D.

    1994-04-01

    A succession of mafic rocks that includes gabbro, sheeted dikes and deformed pillow basalts has been mapped in detail on Isla Gordon, southernmost Chile and is identified as an upper ophiolitic complex representing the uplifted floor of the Late Jurassic-Early Cretaceous Rocas Verdes marginal basin. The complex was uplifted, deformed, and regionally metamorphosed prior to the intrusion of an undeformed 90 Ma granodiorite that cuts the complex. The complex appears para-autochthonous, is gently tilted to the northeast and is internally sheared by near-vertical foliation zones. No evidence for obduction was observed although the base of the complex is not exposed. The ophiolitic rocks have been regionally metamorphosed to mid-upper greenschist levels. Isla Gordon is bounded by the northwest and southwest arms of the Beagle Channel, two important structural boundaries in the southernmost Andes that are interpreted to have accommodated north-side-up and left-lateral displacements. Directly north of Isla Gordon is the Cordillera Darwin metamorphic complex that exposes the highest grade metamorphic rocks in the Andes south of Peru. On the north coast of Isla Gordon a volcaniclastic turbidite sequence that is interpreted to have been deposited above the mafic floor is metamorphosed to lower greenschist levels in strong metamorphic contrast to amphibolite-grade othogneisses exposed in Cordillera Darwin only 2 km away across the northwest arm of the Beagle Channel. The profound metamorphic break across the northwest arm of the Beagle Channel and the regional northeast tilt of the ophiolitic complex are consistent with the previously proposed hypothesis that Isla Gordon represents the upper plate to an extensional fault that accommodated tectonic unroofing of Cordillera Darwin. However, limited structural evidence for extension was identified in this study to support the model and further work is needed to determine the relative importance of contractional, extensional and

  19. Uplift of the Kenai Peninsula, Alaska, since the 1964 Prince William Sound earthquake

    NASA Technical Reports Server (NTRS)

    Cohen, Steven; Holdahl, Sandford; Caprette, Douglas; Hilla, Stephen; Safford, Robert; Schultz, Donald

    1995-01-01

    Using Global Positioning System (GPS) receivers, we reoccupied several leveling benchmarks on the Kenai Peninsula of Alaska which had been surveyed by conventional leveling immediately following the March 27, 1964, Prince William Sound earthquake (M(sub w) = 9.3). By combining the two sets of measurements with a new, high-resolution model of the geoid in the region, we were able to determine the cumulative 1993-1964 postseismic vertical displacement. We find uplift at all of our benchmarks, relative to Seward, Alaska, a point that is stable according to tide gauge data. The maximum uplift of about 1 m occurs near the middle of the peninsula. The region of maximum uplift appears to be shifted northwest relative to the point of maximum coseismic subsidence. If we use tide gauge data at Nikishka and Seward to constrain the vertical motion, then the observed uplift has a trenchward tilt (down to the southeast) as well as an arching component. To explain the observations, we use creep-at-depth models. Most acceptable models require a fault slip of about 2.75 m, although this result is not unique. If the slip has been continuous since the 1964 earthquake, then the average slip rate is nearly 100 mm/yr, twice the plate convergence rate. Comparing the net uplift achieved in 29 years with that observed over 11 years in an adjacent region southeast of Anchorage, Alaska, we conclude that the rate of uplift is decreasing. A further decrease in the uplift rate is expected as the 29-year averaged displacement rate is about twice the plate convergence rate and therefore cannot be sustained over the entire earthquake cycle.

  20. Flexural uplift of rift flanks in central Greece

    NASA Astrophysics Data System (ADS)

    Poulimenos, George; Doutsos, Theodor

    1997-12-01

    Uplifts, with elevations of up to 2000 m and short wavelengths (30-35 km), flank three major grabens in central Greece: the Rio, Sparta, and Atalanti grabens. They are bordered on their landward sides by narrow basins oriented parallel to the graben axes: the Manesi and Trichonis basins at the Rio graben and Copais and Istiea basins at the Atalanti graben. The flexural origin of these uplift profiles is investigated here by using thin, broken plate models. It is demonstrated that the observed topography of the graben flanks is consistent with the upward deflection of elastic and viscoelastic plates in response to upward directed forces applied at the graben flanks. In order to evaluate to applicability of each model, their predictions are checked against the observations. The elastic predictive modeling fits well with the observed flexural wavelengths and the flanking seismicity. However, it fails to predict the graben widths and the inferred elastic layer thickness. In contrast, the viscoelastic model successfully explains the graben widths and the "back" basins as flexural hinterland basins and matches the seismological data and the time constraints of rifting. It is therefore suggested that flexural uplift with viscoelastic relaxation accounts for the building of the graben flanks. The invoked viscoelastic models constrain the effective elastic thickness of the plates at 10 km for the Rio graben and 15 km for the Sparta and Atalanti grabens, suggesting a low-viscosity lower crust. Furthermore, they predict low rates of tectonic uplift of the order of 0.1 mm a-1 for the Atalanti graben, intermediate rates of 0.24-0.37 mm a-1 for the Rio graben, and high rates of 0.7-0.9 mm a-1 for the Sparta graben. The latter are quite possibly overestimated since napping events, capable of producing high local relief, are traced normal to the modeled profiles.

  1. Surface Evolution and Uplift History of the Central Apennines, Italy: New Constraints from Thermochronology and Paleoaltimetry

    NASA Astrophysics Data System (ADS)

    San José, M.; Faccenna, C.; Fellin, M. G.; Willett, S.; Funiciello, F.; Caves Rugenstein, J. K.

    2017-12-01

    The topography of mountain belts results from interactions between surface processes, lithospheric thickening, and mantle dynamics. However, the contributions of each mechanism have yet to be clearly quantified. The Apennines (Italy) provide a study area where all of these processes are at play. The central part of the Apennines is an orogenic wedge formed by the westward subducting Adriatic microplate during Miocene-Pliocene, and overlies an area of local slab detachment. Recent studies indicate anomalously high uplift rates in this area (Faccenna et al., 2015), as well as a simultaneous onset of post-orogenic extension across the Central Apennines at ̴ 2 Ma (Cosentino et al., 2017). These observations have been interpreted as an expression of dynamic topography due to the slab break-off and inherent mantle upwelling. In order to test this hypothesis and further constrain the topographic evolution of the orogen, we use low-temperature thermochronology to date the exhumation, and stable isotope paleoaltimetry (18O/16O on carbonates) to reconstruct paleoelevations. We couple this paleotopographic dataset with geomorphological analysis of the present day topography. Here we present a set of 30 new (U-Th)/He cooling ages on apatites (AHe) sampled from widespread syn-orogenic flysch basin deposits (including one high-resolution vertical profile), as well as preliminary isotopic measurements. Initial results show mean AHe ages ranging from 1.62 (± 0.38 ) Ma to 2.6 (±0.02) Ma, suggesting a regionally uniform exhumation during Pleistocene. Denudation rates inferred from our vertical profile are extremely high (>1 mm/year from 2 to 1 Ma). Some samples have not been thermally reset due to insufficient burial, and yield exhumation ages older than stratigraphic depositional ages (generally > 5 Ma). These results support the hypothesis that exhumation is mainly controlled by rapid regional scale uplift related to the opening of the Adriatic slab window at the end of the

  2. Tertiary uplift of the Mt. Doonerak antiform, central Brooks Range, Alaska: Apatite fission track evidence from the Trans-Alaska Crustal Transect

    USGS Publications Warehouse

    O'Sullivan, P. B.; Moore, Thomas E.; Murphy, J.M.; Oldow, J.S.; Ave Lallemant, H.G.

    1998-01-01

    The Mt. Doonerak antiform is a northeast-trending, doubly plunging antiform located along the axial part of the central Brooks Range. This antiform is a crustal-scale duplex estimated to have a vertical displacement of ~15 km. The antiform folds the Amawk thrust, which separates relatively less displaced lower plate rocks in a window in the core of the antiform from allochthonous upper plate rocks of the Endicott Mountains allochthon. Because regional geological relations indicate that displacement on the Amawk thrust occurred between early Neocomian and early Albian time, uplift of the antiform is post-early Neocomian in age.Zircon fission-track data from the Mt. Doonerak antiform suggest -8-12 km of vertical denudation has occurred within the antiform region since -70-65 Ma. whereas apatite fission-track data indicate the antiform has experienced a minimum of -46 km of denudation since late Oligocene time. Following rapid denudation at -24 + 3 Ma, the rocks have experienced continued denudation to present surface conditions at a slower rate.We conclude from the relative relations and timing that the Mt. Doonerak duplex was constructed in part during the late Oligocene by reactivation of an older duplex formed during the latest Cretaceous to Paleocene. Deformation and uplift of Oligocene age for the axial part of the Brooks Range orogen is anomalously young, but it is the same age as the youngest episode of north-vergent contractional uplift in the northeastern Brooks Range. Because the Mt. Doonerak antiform displays structural characteristics similar to those of antiforms in the northeastern Brooks Range and because both regions experienced simultaneous rapid denudation, we suggest that the Mt. Doonerak antiform formed in response to an episode of contractional deformation that affected both areas in the late Oligocene.

  3. Early history of the pre-excitation syndrome.

    PubMed

    Hanon, Sam; Shapiro, Michael; Schweitzer, Paul

    2005-01-01

    This brief review discusses the interesting early history of the pre-excitation syndrome. In 1913 Cohn and Fraser published the first patient with a short P-R interval, wide QRS complexes, and paroxysmal tachycardia. This was followed by other cases of pre-excitation syndrome, all of which were considered to be due to bundle branch blocks. In 1930 Wolff, Parkinson, and White reported 11 patients with the syndrome, which came to bear their name. Two years later, Holzmann and Scherf suggested bypass tracts as the most likely mechanism of pre-excitation syndrome. In 1942, Wood et al. documented the first accessory connection at autopsy. Despite these early studies supporting the bypass theory, the quest for alternative mechanisms continued until the 1970s when electrophysiological studies and surgical therapy confirmed accessory connections as the mechanism of pre-excitation syndrome.

  4. Regional uplift associated with continental large igneous provinces: The roles of mantle plumes and the lithosphere

    USGS Publications Warehouse

    Saunders, A.D.; Jones, S.M.; Morgan, L.A.; Pierce, K.L.; Widdowson, M.; Xu, Y.G.

    2007-01-01

    The timing and duration of surface uplift associated with large igneous provinces provide important constraints on mantle convection processes. Here we review geological indicators of surface uplift associated with five continent-based magmatic provinces: Emeishan Traps (260??million years ago: Ma), Siberian Traps (251??Ma), Deccan Traps (65??Ma), North Atlantic (Phase 1, 61??Ma and Phase 2, 55??Ma), and Yellowstone (16??Ma to recent). All five magmatic provinces were associated with surface uplift. Surface uplift can be measured directly from sedimentary indicators of sea-level in the North Atlantic and from geomorpholocial indicators of relative uplift and tilting in Yellowstone. In the other provinces, surface uplift is inferred from the record of erosion. In the Deccan, North Atlantic and Emeishan provinces, transient uplift that results from variations in thermal structure of the lithosphere and underlying mantle can be distinguished from permanent uplift that results from the extraction and emplacement of magma. Transient surface uplift is more useful in constraining mantle convection since models of melt generation and emplacement are not required for its interpretation. Observations of the spatial and temporal relationships between surface uplift, rifting and magmatism are also important in constraining models of LIP formation. Onset of surface uplift preceded magmatism in all five of the provinces. Biostratigraphic constraints on timing of uplift and erosion are best for the North Atlantic and Emeishan Provinces, where the time interval between significant uplift and first magmatism is less than 1??million years and 2.5??million years respectively. Rifting post-dates the earliest magmatism in the case of the North Atlantic Phase 1 and possibly in the case of Siberia. The relative age of onset of offshore rifting is not well constrained for the Deccan and the importance of rifting in controlling magmatism is disputed in the Emeishan and Yellowstone

  5. Initiation and development of the southern California uplift along its northern margin

    USGS Publications Warehouse

    Stein, R.S.; Thatcher, W.; Castle, R.O.

    1979-01-01

    Analysis of three first-order leveling lines that traverse the White Wolf fault (site of the 1952 M = 7.7 earthquake), each resurveyed nine times between 1926 and 1974, reveals probable preseismic tilting, major coseismic movements, and a spatial association between these movements and the subsequently recognized southern California uplift. In examining the vertical control record, we have both searched for evidence of systematic errors and excluded from consideration portions of the lines contaminated by subsurface fluid and gas extraction. Movements have been referred to an invariant datum based on the 1926 position of tidal BM 8 in San Pedro, corrected for subsequent eustatic sea-level change. An 8 ??rad up-to-the-north preseismic tilt (6 cm/7.5 km) was apparently recorded on two adjacent line segments within 10 km of the 1952 epicenter between 1942 and 1947. It is possible, however, that this tilt was in part caused by extraction-induced subsidence at one of the six releveled benchmarks. Data also show evidence of episodic tilts that are not earthquake related. At the junction of the Garlock and San Andreas faults, for example, an ???5 ??rad up-to-the-north tilt (7.2 cm/???16 km) took place between Lebec and Grapevine within three months during 1964. Comparison of the 1947 and 1953 surveys, which includes the coseismic interval, shows that the SW-fault end (nearest the epicenter) and the central fault reach sustained four times the uplift recorded at the NE end of the fault (+72 cm SW, +53 cm Central, +16 cm NE). A regional postseismic uplift of 4 cm extended ???25 km to either side of the fault after the main event, from 1953 to 1956. An interval of relative quiescence followed at least through 1959, in which the elevation change did not exceed ??3 cm. The detailed pattern of aseismic uplift demonstrates that movement proceeded in space-time pulses: one half of the uplift at the SW-fault end and extending southward occurred between 1959 and 1961, one half of

  6. Timing of uplift peripheral to the Red Sea, Saudi Arabia

    USGS Publications Warehouse

    Naeser, C.W.; Zimmermann, R.A.; Bohannon, R.G.; Schmidt, D.L.; ,

    1990-01-01

    A Prominent escarpment is found along the western margin of the Arabian Shield. Elevations along this escarpment are up to 3200 m above the Red Sea. Between the Red Sea and the crest of the escarpment is a relatively featureless coastal plane that is ??? 50 km across. The coastal plane abruptly gives way to the steep mountainous terrain, the elevation of which increases abruptly towards the high crest. The elevation slowly decreases to the east of the high crest. Forty-four apatite fission-track ages have been determined on rocks from the Proterozoic Arabian Shield in southwestern Saudi Arabia. These ages range from 13.8 to 568 Ma. In general, the youngest ages are found at low elevations along the base of the escarpment near the eastern edge of the coastal plane. The oldest ages are from along and to the east of the crest. The fission-track data from Saudi Arabia show that there was a period of minor uplift and cooling during the Cretaceous. This was followed by a relatively stable period which lasted until the Mid to Upper Miocene. The latest uplift and erosion began slightly younger than 13.8 Ma. This latest episode resulted in a minimum uplift of 3 km and is related to the Red Sea Rift. Samples totally annealed prior to this latest episode of uplift and cooling have not yet reached the surface.

  7. GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift.

    PubMed

    Hammond, William C; Blewitt, Geoffrey; Kreemer, Corné

    2016-10-01

    We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5-20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011-2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane.

  8. GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift

    PubMed Central

    Blewitt, Geoffrey; Kreemer, Corné

    2016-01-01

    Abstract We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5–20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011–2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane. PMID:27917328

  9. GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift

    NASA Astrophysics Data System (ADS)

    Hammond, William C.; Blewitt, Geoffrey; Kreemer, Corné

    2016-10-01

    We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5-20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011-2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane.

  10. Uplifting behavior of shallow buried pipe in liquefiable soil by dynamic centrifuge test.

    PubMed

    Huang, Bo; Liu, Jingwen; Lin, Peng; Ling, Daosheng

    2014-01-01

    Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure.

  11. Uplifting Behavior of Shallow Buried Pipe in Liquefiable Soil by Dynamic Centrifuge Test

    PubMed Central

    Liu, Jingwen; Ling, Daosheng

    2014-01-01

    Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure. PMID:25121140

  12. Modelling near field regional uplift patterns in West Greenland/Disko Bay with plane-Earth finite element models.

    NASA Astrophysics Data System (ADS)

    Meldgaard, Asger; Nielsen, Lars; Iaffaldano, Giampiero

    2017-04-01

    Relative sea level data, primarily obtained through isolation basin analysis in western Greenland and on Disko Island, indicates asynchronous rates of uplift during the Early Holocene with larger rates of uplift in southern Disko Bay compared to the northern part of the bay. Similar short-wavelength variations can be inferred from the Holocene marine limit as observations on the north and south side of Disko Island differ by as much as 60 m. While global isostatic adjustment models are needed to account for far field contributions to the relative sea level and for the calculation of accurate ocean functions, they are generally not suited for a detailed analysis of the short-wavelength uplift patterns observed close to present ice margins. This is in part due to the excessive computational cost required for sufficient resolution, and because these models generally ignore regional lateral heterogeneities in mantle and lithosphere rheology. To mitigate this problem, we perform sensitivity tests to investigate the effects of near field loading on a regional plane-Earth finite element model of the lithosphere and mantle of the Disko Bay area, where the global isostatic uplift chronology is well documented. By loading the model area through detailed regional ocean function and ice models, and by including a high resolution topography model of the area, we seek to assess the isostatic rebound generated by surface processes with wavelengths similar to those of the observed rebound signal. We also investigate possible effects of varying lithosphere and mantle rheology, which may play an important role in explaining the rebound signal. We use the abundance of relative sea level curves obtained in the region primarily through isolation basin analysis on Disko Island to constrain the parameters of the Earth model.

  13. Measuring plume-related exhumation of the British Isles in Early Cenozoic times

    NASA Astrophysics Data System (ADS)

    Cogné, Nathan; Doepke, Daniel; Chew, David; Stuart, Finlay M.; Mark, Chris

    2016-12-01

    Mantle plumes have been proposed to exert a first-order control on the morphology of Earth's surface. However, there is little consensus on the lifespan of the convectively supported topography. Here, we focus on the Cenozoic uplift and exhumation history of the British Isles. While uplift in the absence of major regional tectonic activity has long been documented, the causative mechanism is highly controversial, and direct exhumation estimates are hindered by the near-complete absence of onshore post-Cretaceous sediments (outside Northern Ireland) and the truncated stratigraphic record of many offshore basins. Two main hypotheses have been developed by previous studies: epeirogenic exhumation driven by the proto-Iceland plume, or multiple phases of Cenozoic compression driven by far-field stresses. Here, we present a new thermochronological dataset comprising 43 apatite fission track (AFT) and 102 (U-Th-Sm)/He (AHe) dates from the onshore British Isles. Inverse modelling of vertical sample profiles allows us to define well-constrained regional cooling histories. Crucially, during the Paleocene, the thermal history models show that a rapid exhumation pulse (1-2.5 km) occurred, focused on the Irish Sea. Exhumation is greatest in the north of the Irish Sea region, and decreases in intensity to the south and west. The spatial pattern of Paleocene exhumation is in agreement with the extent of magmatic underplating inferred from geophysical studies, and the timing of uplift and exhumation is synchronous with emplacement of the plume-related British and Irish Paleogene Igneous Province (BIPIP). Prior to the Paleocene exhumation pulse, the Mesozoic onshore exhumation pulse is mainly linked to the uplift and erosion of the hinterland during the complex and long-lived rifting history of the neighbouring offshore basins. The extent of Neogene exhumation is difficult to constrain due to the poor sensitivity of the AHe and AFT systems at low temperatures. We conclude that the

  14. Heating, cooling, and uplift during Tertiary time, northern Sangre de Cristo Range, Colorado ( USA).

    USGS Publications Warehouse

    Lindsay, D.A.; Andriessen, P.A.M.; Wardlaw, B.R.

    1986-01-01

    Paleozoic sedimentary rocks in a wide area of the northern Sangre de Cristo Range show effects of heating during Tertiary time. Heating is tentatively interpreted as a response to burial during Laramide folding and thrusting and also to high heat flow during Rio Grande rifting. Fission-track ages of apatite across a section of the range show that rocks cooled abruptly below 120oC, the blocking temperature for apatite, approx 19 Ma ago. Cooling was probably in response to rapid uplift and erosion of the northern Sangre de Cristo Range during early Rio Grande rifting.-from Authors

  15. Investigating uplift in the South-Western Barents Sea using sonic and density well log measurements

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Ellis, M.

    2014-12-01

    Sediments in the Barents Sea have undergone large amounts of uplift due to Plio-Pleistoncene deglaciation as well as Palaeocene-Eocene Atlantic rifting. Uplift affects the reservoir quality, seal capacity and fluid migration. Therefore, it is important to gain reliable uplift estimates in order to evaluate the petroleum prospectivity properly. To this end, a number of quantification methods have been proposed, such as Apatite Fission Track Analysis (AFTA), and integration of seismic surveys with well log data. AFTA usually provides accurate uplift estimates, but the data is limited due to its high cost. While the seismic survey can provide good uplift estimate when well data is available for calibration, the uncertainty can be large in areas where there is little to no well data. We estimated South-Western Barents Sea uplift based on well data from the Norwegian Petroleum Directorate. Primary assumptions include time-irreversible shale compaction trends and a universal normal compaction trend for a specified formation. Sonic and density logs from two Cenozoic shale formation intervals, Kolmule and Kolje, were used for the study. For each formation, we studied logs of all released wells, and established exponential normal compaction trends based on a single well. That well was then deemed the reference well, and relative uplift can be calculated at other well locations based on the offset from the normal compaction trend. We found that the amount of uplift increases along the SW to NE direction, with a maximum difference of 1,447 m from the Kolje FM estimate, and 699 m from the Kolmule FM estimate. The average standard deviation of the estimated uplift is 130 m for the Kolje FM, and 160 m for the Kolmule FM using the density log. While results from density logs and sonic logs have good agreement in general, the density log provides slightly better results in terms of higher consistency and lower standard deviation. Our results agree with published papers

  16. Quaternary fluvial terraces of the Tiber Valley: geochronologic and geometric constraints on the back-arc magmatism-related uplift in central Italy.

    PubMed

    Marra, Fabrizio; Florindo, Fabio; Petronio, Carmelo

    2017-05-31

    Through a geomorphological study relying on statistically assessed classes of hilltop elevations, we reconstruct a suite of paleo-surfaces along the Tiber River Valley north of Rome that we identify as fluvial terraces formed by interplay between global sea-level fluctuations and regional upift. Using biostratigraphic constraints provided by marine through continental deposits of Santernian age, we recognize the oldest terrace in this area, corresponding to an early coastal plain of late Santernian-Emilian age. By assuming the simple chronological principle of a staircase geometry we correlate the sea-level highstands of MIS 21 through MIS 5 with the lowest eight paleo-surfaces. By plotting against time the cumulated terrace elevations and the average elevation of the Santernian coastline in the investigated area, we detect rates of uplift during the last 1.8 Ma. Two major pulses of uplift are recognized 0.86 through 0.5 Ma, and 0.25 Ma through the Present, which are interpreted as driven by the subduction process and uprising of metasomatized magma bodies on the Tyrrhenian Sea Margin of central Italy, superimposied on a smaller isostatic component of uplift.

  17. Permanent uplift in magmatic systems with application to the Tharsis region of Mars

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.; Sleep, N. H.; Banerdt, W. B.

    1990-04-01

    A model is derived for predicting both crustal displacement (leading to permanent uplift) and topographic elevation in regional large-scale magmatic systems associated with partial melting of mantle rocks. The model is then applied to the Tharsis region of Mars to test the uplift versus construction. It was found that a lower bound estimate of the fraction of intrusives necessary for any uplift at all is about 85 percent of the total magmatic products at Tharsis. Thus, it is proposed that most of the magmas associated with Tharsis evolution ended up as intrusive bodies in the crust and upper mantle.

  18. Permanent uplift in magmatic systems with application to the Tharsis region of Mars

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.; Sleep, Norman H.; Banerdt, W. Bruce

    1990-01-01

    A model is derived for predicting both crustal displacement (leading to permanent uplift) and topographic elevation in regional large-scale magmatic systems associated with partial melting of mantle rocks. The model is then applied to the Tharsis region of Mars to test the uplift versus construction. It was found that a lower bound estimate of the fraction of intrusives necessary for any uplift at all is about 85 percent of the total magmatic products at Tharsis. Thus, it is proposed that most of the magmas associated with Tharsis evolution ended up as intrusive bodies in the crust and upper mantle.

  19. Early to Middle Jurassic tectonic evolution of the Bogda Mountains, Northwest China: Evidence from sedimentology and detrital zircon geochronology

    NASA Astrophysics Data System (ADS)

    Ji, Hongjie; Tao, Huifei; Wang, Qi; Qiu, Zhen; Ma, Dongxu; Qiu, Junli; Liao, Peng

    2018-03-01

    The Bogda Mountains, as an important intracontinental orogenic belt, are situated in the southern part of the Central Asian Orogenic Belt (CAOB), and are a key area for understanding the Mesozoic evolution of the CAOB. However, the tectonic evolution of the Bogda Mountains remains controversial during the Mesozoic Era, especially the Early to Middle Jurassic Periods. The successive Lower to Middle Jurassic strata are well preserved and exposed along the northern flank of the Western Bogda Mountains and record the uplift processes of the Bogda Mountains. In this study, we analysed sedimentary facies combined with detrital zircon U-Pb geochronology at five sections of Lower to Middle Jurassic strata to detect the tectonic evolution and changes of provenance in the Bogda area. During Early to Middle Jurassic times, the fluvial, deltaic and lacustrine environments dominated in the western section of the Bogda area. The existence of Early Triassic peak age indicates that the Bogda Mountains did not experience uplift during the period of early Badaowan Formation deposition. The Early Triassic to Late Permian granitoid plutons and Carboniferous volcanic rocks from the Barkol and Santanghu areas were the main provenances. The significant change in the U-Pb age spectrum implies that the Eastern Bogda Mountains initiated uplift in the period of late Badaowan Formation deposition, and the Eastern Junggar Basin and the Turpan-Hami Basin were partially partitioned. The Eastern Bogda Mountains gradually became the major provenance. From the period of early Sangonghe to early Toutunhe Formations deposition, the provenance of the sediments and basin-range frame were similar to that of late Badaowan. However, the Eastern Bogda Mountains suffered intermittent uplift three times, and successive denudation. The uplifts respectively happened in early Sangonghe, late Sangonghe to early Xishanyao, and late Xishanyao to early Toutunhe. During the deposition stage of Toutunhe Formation, a

  20. Thermal and exhumation history of the central Rwenzori Mountains, Western Rift of the East African Rift System, Uganda

    NASA Astrophysics Data System (ADS)

    Bauer, F. U.; Glasmacher, U. A.; Ring, U.; Schumann, A.; Nagudi, B.

    2010-10-01

    The Rwenzori Mountains (Mtns) in west Uganda are the highest rift mountains on Earth and rise to more than 5,000 m. We apply low-temperature thermochronology (apatite fission-track (AFT) and apatite (U-Th-Sm)/He (AHe) analysis) for tracking the cooling history of the Rwenzori Mtns. Samples from the central and northern Rwenzoris reveal AFT ages between 195.0 (±8.4) Ma and 85.3 (±5.3) Ma, and AHe ages between 210.0 (±6.0) Ma to 24.9 (±0.5) Ma. Modelled time-temperature paths reflect a protracted cooling history with accelerated cooling in Permo-Triassic and Jurassic times, followed by a long period of constant and slow cooling, than succeeded by a renewed accelerated cooling in the Neogene. During the last 10 Ma, differentiated erosion and surface uplift affected the Rwenzori Mtns, with more pronounced uplift along the western flank. The final rock uplift of the Rwenzori Mtns that partly led to the formation of the recent topography must have been fast and in the near past (Pliocene to Pleistocene). Erosion could not compensate for the latest rock uplift, resulting in Oligocene to Miocene AHe ages.

  1. The Transantarctic Mountains of southern Victoria Land: The application of Apatite fission track analysis to a rift shoulder uplift

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Paul G.

    1992-06-01

    A fission track study of the Transantarctic Mountains (TAM) in the Granite Harbour and Wilson Piedmont Glacier areas of southern Victoria Land reveals information on the timing of uplift, the amount of uplift and erosion, and the structure of the mountains, especially the onshore Transantarctic Mountain Front (TAM Front), which represents the boundary between East and West Antarctica. Apatite ages are < 175 Ma and represent a thermal regime established after heating accompanying Jurassic magmatism. An apatite age profile from Mount England records a break in slope indicating uplift began at ˜55 Ma. Horizontal sampling traverses, plus fieldwork, delineate the structure of the TAM Front as a zone of north-south striking, steeply dipping normal faults, with displacements, dominantly down to the east, of 40-1000 m. The overall structure of the mountains in the area studied can be envisaged as a large tilt block or flexure. Its westerly limb dips gently under the ice cap, compared to its faulted eastern edge, the TAM Front. The bounding structure to the south is the Ferrar fault and to the north is a graben through which the Mackay Glacier drains the polar plateau. The edge of the flexure, or axis of maximum uplift, lies at Mount Termination, ˜30 km west of the McMurdo Sound coast. There has been ˜6 km of uplift since the early Cenozoic and 4.5-5 km of erosion along this axis. The amount of uplift decreases to the west at the same rate as the decrease in dip of the Kukri Peneplain, but the amount of erosion decreases more quickly as indicated by the increasing height of the mountains to the west. The axis of maximum uplift is traced north to Granite Harbour. The axis does not parallel the coast but has a more northerly trend. North-south striking longitudinal faults that delineate the structure of the TAM Front lie at an acute angle to the axis, indicating a dextral component to the dominantly east-west extension in the Ross Embayment. Architecture of the TAM

  2. Uplifting the Stable Crust of the Colorado Plateau through Crustal Hydration and Warming

    NASA Astrophysics Data System (ADS)

    Porter, R. C.; Holt, W. E.

    2016-12-01

    The Colorado Plateau (CP) is a high ( 2 km above sea level), low-relief, orogenic plateau located within the interior of the southwestern United States that presents several outstanding geologic questions, most notably about the timing and mechanism(s) for uplift. The CP was located below sea level during the Cretaceous and was uplifted to its modern elevation with little crustal shortening, making the cause of uplift enigmatic. Numerous mechanisms have been hypothesized to explain the uplift of this stable block and include delamination, mantle heating/phase changes, mantle convection, volatile addition, and various combinations of these. In order to better understand the crustal contribution to uplift, we utilize data from the EarthScope Transportable Array network to image the CP lithosphere and inform thermodynamic models of CP lower crustal composition. Rayleigh wave phase velocities calculated using ambient noise tomography and surface wave gradiometry were inverted for shear velocity resulting in a high-resolution velocity model of the CP crust and upper mantle. In order to provide greater context to these results, the thermodynamic modeling code Perple_X was utilized to forward model crustal densities, seismic velocities, and water content based on psuedosections calculated using published major element chemistry. Our seismic and modeling results show that uplift of the plateau is partially driven by hydration and extension of the lower crust, both of which reduce its density. Hydration of the CP crust likely occurred due to dewatering of the Farallon slab during flat-slab subduction and reduced lower crustal density by 70 kg/m3. Warming and extension further reduced the lower crustal density by 90 kg/m3 at the CP margins. Though these processes played a role in the uplift of the CP, additional mechanisms, likely due to mantle processes, are required to fully explain its high elevation. Additionally, hydration and subsequent dehydration may play an

  3. History and early development of INCAP.

    PubMed

    Scrimshaw, Nevin S

    2010-02-01

    Nevin Scrimshaw was the founding Director of the Institute of Nutrition of Central America and Panama (INCAP), serving as Director from 1949 to 1961. In this article, he reviews the history of the founding of INCAP, including the role of the Rockefeller and Kellogg Foundations, the Central American governments, and the Pan American Health Organization. The objectives pursued by INCAP in its early years were to assess the nutrition and related health problems of Central America, to carry out research to find practical solutions to these problems, and to provide technical assistance to its member countries to implement solutions. INCAP pursued a strategy of selecting promising Central Americans for advanced education and training in the US who assumed positions of leadership on their return. After this early phase, talented non-Central Americans of diverse origins were brought to INCAP, as well as additional researchers from the region. Growth of INCAP, as reflected in its annual budget and in the physical plant, was rapid and this was accompanied by high scientific productivity. Several field studies were launched that contributed impetus and design elements for the Oriente Longitudinal Study, which is the focus of this supplement.

  4. Unroofing history of a suture zone in the Himalaya of Pakistan by means of fission-track annealing ages

    USGS Publications Warehouse

    Zeitler, P.K.; Tahirkheli, R.A.K.; Naeser, C.W.; Johnson, N.M.

    1982-01-01

    The uplift history of the Swat Valley and Hazara region of northwestern Pakistan has been established using 22 fission-track dates on apatite, zircon and sphene. A major fault, the Main Mantle Thrust (MMT) strikes east-west across the Swat Valley, separates regions of markedly differing fission-track age regimesm, and may be a suture zone separating an extinct island arc terrane on the north from the Indian plate to the south. Fission-track ages ranging from about 55 to 58 m.y. for sphene, 18 to 53 m.y. for zircon, and 9 to 17 m.y. for apatite were obtained from the region north of the MMT. To the south the fission-track age ranges are 20 to 25 m.y. for sphene, 17 to 26 m.y. for zircon, and 16 to 23 m.y. for apatite. Disparate zircon and sphene ages on each side of the MMT imply different cooling histories for each side of the fault prior to 15 m.y. Similar apatite ages on both sides of the fault imply similar cooling histories during the past 15 m.y. This may indicate that faulting ceased by 15 m.y. Mean uplift rates have been derived from the fission-track data using mainly the mineral-pair method. Uplift rates in the region north of the MMT increased from 0.07 to 0.20 mm/yr during the period 55 to 15 m.y. South of the fault, uplift rates averaged in excess of 0.70 mm/yr for the period 25 to 15 m.y. During the past 15 m.y. uplift across the MMT in the Swat Valley showsno discontinuities, ranging from 0.16 mm/yr in the south to 0.39 mm/yr in the north. A plausible interpretation for the fission-track uplift data has the MMT verging to the south with overthrusting taking place at a depth between 3.5 and 6.0 km, juxtaposing two terranes that were originally separated by a substantial, but unknown distance. In this model, regional uplift followed cessation of faulting just prior to 15 m.y. ?? 1982.

  5. Harmonic Structure Predicts the Enjoyment of Uplifting Trance Music.

    PubMed

    Agres, Kat; Herremans, Dorien; Bigo, Louis; Conklin, Darrell

    2016-01-01

    An empirical investigation of how local harmonic structures (e.g., chord progressions) contribute to the experience and enjoyment of uplifting trance (UT) music is presented. The connection between rhythmic and percussive elements and resulting trance-like states has been highlighted by musicologists, but no research, to our knowledge, has explored whether repeated harmonic elements influence affective responses in listeners of trance music. Two alternative hypotheses are discussed, the first highlighting the direct relationship between repetition/complexity and enjoyment, and the second based on the theoretical inverted-U relationship described by the Wundt curve. We investigate the connection between harmonic structure and subjective enjoyment through interdisciplinary behavioral and computational methods: First we discuss an experiment in which listeners provided enjoyment ratings for computer-generated UT anthems with varying levels of harmonic repetition and complexity. The anthems were generated using a statistical model trained on a corpus of 100 uplifting trance anthems created for this purpose, and harmonic structure was constrained by imposing particular repetition structures (semiotic patterns defining the order of chords in the sequence) on a professional UT music production template. Second, the relationship between harmonic structure and enjoyment is further explored using two computational approaches, one based on average Information Content, and another that measures average tonal tension between chords. The results of the listening experiment indicate that harmonic repetition does in fact contribute to the enjoyment of uplifting trance music. More compelling evidence was found for the second hypothesis discussed above, however some maximally repetitive structures were also preferred. Both computational models provide evidence for a Wundt-type relationship between complexity and enjoyment. By systematically manipulating the structure of chord

  6. Harmonic Structure Predicts the Enjoyment of Uplifting Trance Music

    PubMed Central

    Agres, Kat; Herremans, Dorien; Bigo, Louis; Conklin, Darrell

    2017-01-01

    An empirical investigation of how local harmonic structures (e.g., chord progressions) contribute to the experience and enjoyment of uplifting trance (UT) music is presented. The connection between rhythmic and percussive elements and resulting trance-like states has been highlighted by musicologists, but no research, to our knowledge, has explored whether repeated harmonic elements influence affective responses in listeners of trance music. Two alternative hypotheses are discussed, the first highlighting the direct relationship between repetition/complexity and enjoyment, and the second based on the theoretical inverted-U relationship described by the Wundt curve. We investigate the connection between harmonic structure and subjective enjoyment through interdisciplinary behavioral and computational methods: First we discuss an experiment in which listeners provided enjoyment ratings for computer-generated UT anthems with varying levels of harmonic repetition and complexity. The anthems were generated using a statistical model trained on a corpus of 100 uplifting trance anthems created for this purpose, and harmonic structure was constrained by imposing particular repetition structures (semiotic patterns defining the order of chords in the sequence) on a professional UT music production template. Second, the relationship between harmonic structure and enjoyment is further explored using two computational approaches, one based on average Information Content, and another that measures average tonal tension between chords. The results of the listening experiment indicate that harmonic repetition does in fact contribute to the enjoyment of uplifting trance music. More compelling evidence was found for the second hypothesis discussed above, however some maximally repetitive structures were also preferred. Both computational models provide evidence for a Wundt-type relationship between complexity and enjoyment. By systematically manipulating the structure of chord

  7. Large-eddy simulation of dust-uplift by a haboob density current

    NASA Astrophysics Data System (ADS)

    Huang, Qian; Marsham, John H.; Tian, Wenshou; Parker, Douglas J.; Garcia-Carreras, Luis

    2018-04-01

    Cold pool outflows have been shown from both observations and convection-permitting models to be a dominant source of dust emissions ("haboobs") in the summertime Sahel and Sahara, and to cause dust uplift over deserts across the world. In this paper Met Office Large Eddy Model (LEM) simulations, which resolve the turbulence within the cold-pools much better than previous studies of haboobs with convection-permitting models, are used to investigate the winds that uplift dust in cold pools, and the resultant dust transport. In order to simulate the cold pool outflow, an idealized cooling is added in the model during the first 2 h of 5.7 h run time. Given the short duration of the runs, dust is treated as a passive tracer. Dust uplift largely occurs in the "head" of the density current, consistent with the few existing observations. In the modeled density current dust is largely restricted to the lowest, coldest and well mixed layers of the cold pool outflow (below around 400 m), except above the "head" of the cold pool where some dust reaches 2.5 km. This rapid transport to above 2 km will contribute to long atmospheric lifetimes of large dust particles from haboobs. Decreasing the model horizontal grid-spacing from 1.0 km to 100 m resolves more turbulence, locally increasing winds, increasing mixing and reducing the propagation speed of the density current. Total accumulated dust uplift is approximately twice as large in 1.0 km runs compared with 100 m runs, suggesting that for studying haboobs in convection-permitting runs the representation of turbulence and mixing is significant. Simulations with surface sensible heat fluxes representative of those from a desert region during daytime show that increasing surface fluxes slows the density current due to increased mixing, but increase dust uplift rates, due to increased downward transport of momentum to the surface.

  8. Conversational Language Use as a Predictor of Early Reading Development: Language History as a Moderating Variable

    PubMed Central

    DeThorne, Laura Segebart; Petrill, Stephen A.; Schatschneider, Chris; Cutting, Laurie

    2010-01-01

    Purpose The present study examined the nature of concurrent and predictive associations between conversational language use and reading development during early school-age years. Method Language and reading data from 380 twins in the Western Reserve Reading Project were examined via phenotypic correlations and multilevel modeling on exploratory latent factors. Results In the concurrent prediction of children’s early reading abilities, a significant interaction emerged between children’s conversational language abilities and their history of reported language difficulties. Specifically, conversational language concurrently predicted reading development above and beyond variance accounted for by formal vocabulary scores, but only in children with a history of reported language difficulties. A similar trend was noted in predicting reading skills 1 year later, but the interaction was not statistically significant. Conclusions Findings suggest a more nuanced view of the association between spoken language and early reading than is commonly proposed. One possibility is that children with and without a history of reported language difficulties rely on different skills, or the same skills to differing degrees, when completing early reading-related tasks. Future studies should examine the causal link between conversational language and early reading specifically in children with a history of reported language difficulties. PMID:20150410

  9. Short-Term Uplift Rates and the Mountain Building Process in Southern Alaska

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne; Herring, Thomas A.; Meigs, Andrew; Meigs, Andrew

    1998-01-01

    We have used GPS at 10 stations in southern Alaska with three epochs of measurements to estimate short-term uplift rates. A number of great earthquakes as well as recent large earthquakes characterize the seismicity of the region this century. To reliably estimate uplift rates from GPS data, numerical models that included both the slip distribution in recent large earthquakes and the general slab geometry were constructed.

  10. Focused rock uplift above the subduction décollement at Montague and Hinchinbrook Islands, Prince William Sound, Alaska

    USGS Publications Warehouse

    Ferguson, Kelly M; Armstrong, Phillip A; Arkle Jeanette C,; Haeussler, Peter J.

    2014-01-01

    Megathrust splay fault systems in accretionary prisms have been identified as conduits for long-term plate motion and significant coseismic slip during subduction earthquakes. These fault systems are important because of their role in generating tsunamis, but rarely are emergent above sea level where their long-term (million year) history can be studied. We present 32 apatite (U-Th)/He (AHe) and 27 apatite fission-track (AFT) ages from rocks along an emergent megathrust splay fault system in the Prince William Sound region of Alaska above the shallowly subducting Yakutat microplate. The data show focused exhumation along the Patton Bay megathrust splay fault system since 3–2 Ma. Most AHe ages are younger than 5 Ma; some are as young as 1.1 Ma. AHe ages are youngest at the southwest end of Montague Island, where maximum fault displacement occurred on the Hanning Bay and Patton Bay faults and the highest shoreline uplift occurred during the 1964 earthquake. AFT ages range from ca. 20 to 5 Ma. Age changes across the Montague Strait fault, north of Montague Island, suggest that this fault may be a major structural boundary that acts as backstop to deformation and may be the westward mechanical continuation of the Bagley fault system backstop in the Saint Elias orogen. The regional pattern of ages and corresponding cooling and exhumation rates indicate that the Montague and Hinchinbrook Island splay faults, though separated by only a few kilometers, accommodate kilometer-scale exhumation above a shallowly subducting plate at million year time scales. This long-term pattern of exhumation also reflects short-term seismogenic uplift patterns formed during the 1964 earthquake. The increase in rock uplift and exhumation rate ca. 3–2 Ma is coincident with increased glacial erosion that, in combination with the fault-bounded, narrow width of the islands, has limited topographic development. Increased exhumation starting ca. 3–2 Ma is interpreted to be due to rock uplift

  11. Middle Proterozoic uplift events in the Dunbar dome of northeastern Wisconsin, USA

    USGS Publications Warehouse

    Peterman, Z.E.; Sims, P.K.; Zartman, R.E.; Schulz, K.J.

    1985-01-01

    Isotopic ages of granitic and metamorphic rocks exposed in the Dunbar structural dome of northeastern Wisconsin identify a protracted series of tectonic and "hydrothermal" events that culminated in major regional uplift during Middle Proterozoic (Keweenawan; ca 1,100 Ma) continental rifting and volcanism. The major rock-forming events and the structural development of the dome occurred during the interval 1,862+/-4 Ma to 1,836+/-6 Ma. Whole-rock Rb-Sr ages are partly reset in response to a widely recognized but cryptic event in Wisconsin and Michigan at about 1,630 Ma. The scale and systematic character of the whole-rock resetting strongly suggests the presence of a fluid phase derived in situ from water dissolved in the silicates or externally from a subthrust plate of low-grade metamorphic rocks. The regional nature of the 1,630-Ma disturbance possibly indicates that it is related to a major tectonic event such as an active plate margin far to the south. Rb-Sr biotite ages for the Dunbar dome (this study), the southern complex of the Marquette district (Van Schmus and Woolsey 1975) and the Felch trough area (Aldrich and others 1965) provide a remarkably coherent pattern that reflects multiple episodes of differential uplift. Younger events superimposed on a regional 1,630-Ma imprint are recorded at 1,330 Ma and 1,140 Ma. The 1,330 Ma disturbance could reflect stabilization following intrusion of the Wolf River batholith at 1,485 Ma. The 1,140-Ma uplift event occurred during Keweenawan rifting and volcanism as a result of stresses imposed on a mosaic of fault-bounded blocks with possible subcrustal influence. The remarkably small variance in the 1,140-Ma biotite age peak argues for rapid uplift and cooling, and hence rapid erosion. Detritus from the uplift probably was being shed into nearby tectonic basins most of which did not survive subsequent uplift and erosion. ?? 1985 Springer-Verlag.

  12. Late Cenozoic Colorado River Incision and Implications for Neogene Uplift of the Colorado Rockies

    NASA Astrophysics Data System (ADS)

    Aslan, A.; Karlstrom, K. E.; Kirby, E.; Heizler, M. T.

    2012-12-01

    Basalt flows and volcanic ashes serve as a datum for calculating post-10 Ma river incision rates in western Colorado. The main picture that emerges from the data is one of regional variability of incision rates, which we hypothesize to reflect differential uplift of the Colorado Rockies during the Neogene. Maximum rates (90-180 m/Ma) and magnitudes (750-1500 m) of river incision are recorded between Grand Mesa and Glenwood Canyon, and in the Flat Tops. Minimum rates (<30 m/Ma) and magnitudes (<250 m) of river incision are associated post-Laramide normal faults within the Browns Park-Sand Wash basin in northwestern Colorado and in Middle Park of north-central Colorado. Differential uplift of the Colorado Rockies during the late Cenozoic can be inferred by comparing incision rates and magnitudes at locations upstream and downstream of knickzones. Along the Colorado River, post-10 Ma incision rates and magnitudes incision remain fairly constant (rates >100 m/Ma; magnitudes >1000 m) from Grand Mesa upstream to Gore Canyon, and then decrease markedly in Middle Park (rates <10 m/Ma; magnitudes <100 m) across the Gore Canyon knickzone. Normal-faulting of ca. 10 Ma deposits in Middle Park shows that incision rate variations partly reflect late Cenozoic faulting. Along the Yampa River, post-10 Ma incision rates and magnitudes are low (rates 15-27 m/Ma; magnitudes < 230 m) immediately upstream of Yampa Canyon, and then increase significantly (rates 96-132 m/Ma; magnitudes ~1250 m) upstream near the headwaters. We interpret this upstream increase in river incision rate and magnitude to reflect Neogene uplift of the Yampa River headwaters relative to its lower reaches. Lastly, differential late Cenozoic uplift of the Colorado Rockies is suggested by differences in the timing of regional exhumation and river incision within different drainage basins. Colorado River incision and regional exhumation occurred between 9.8 and 7.8 Ma. In contrast, Yampa River incision began between

  13. Tectonic sequence stratigraphy, Early Permian Dry Mountain trough, east-central Nevada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Snyder, W.S.; Gallegos, D.M.; Spinosa, C.

    1991-06-01

    The Early Permian Dry Mountain trough (DMT) of east-central Nevada is one of several tectonic basins and associated uplifts that developed along the continenetal margin during the latest Pennsylvanian-Early Permian Dry Mountain tectonic phase. The sequence stratigraphy reflects a combination of eustatic sea level changes and tectonic uplift or subsidence. Fewer than one to only a few million years separate the development of sequence boundaries within the DMT. At this scale, differences among published eustasy curves preclude their use as definitive tools to identify eustatically controlled sequence boundaries. Nevertheless, available data indicate several pulses of tectonism affected sedimentation within themore » DMT. The authors are attempting to develop criteria to distinguish tectonic from eustatic sequence boundaries. Detailed biostratigraphic data are required to provide an independent check on the correlation of sequence boundaries between measured sections. For example, the same age boundary may reflect tectonic uplift in one part of the basin and subsidence in another. The uplift may or may not result in subaerial exposure and erosion. For those boundaries that do not result from subaerial exposure, lithofacies and biofacies analyses are required to infer relative uplift (water depth decrease) or subsidence (water depth increase). There are inherent resolution limitations in both the paleontologic and sedimentologic methodologies. These limitations, combined with those of eustasy curves, dictate the preliminary nature of their results.« less

  14. Basin Wide Erosion and Soil Production Rates of a High Altitude Plateau in the Korean Peninsula Considered as an Uplifted Paleo Erosional Surface: Implications for Its Development Process and the Tectonics

    NASA Astrophysics Data System (ADS)

    Byun, J.; Seong, Y.

    2012-12-01

    The development process of High Altitude Plateaus (HAPs) has been a controversial issue in geomorphology. HAPs have been interpreted as uplifted erosional surfaces mainly controlled by fluvial processes. Recent studies, however, argued that the definition of the Paleo Erosional Surfaces (PESs) is ambiguous and HAPs, considered as the uplifted PESs, could be formed under various local lithologic, tectonic and climatic conditions. But these suggestions were severely limited by the lack of quantitative data in the field. Here, we investigate this issue of the development process of HAPs through estimating both basin wide erosion rates and soil production rates of the Daegwanryeong area in the Korean Peninsula (KP), where a HAP with low-relief hilly landscape is found. Study area has been known as a typical one of PESs in the KP, which have been uplifted since the early Miocene. Particularly deeply weathered saprolites, easily found in the study area, have also been believed to be resulted from the Tertiary deep weathering under higher temperature at the paleo sea level. First, analysis of 10Be in saprolite from the base of the soil column, except one under no soil mantle, shows that soil production rates decline linearly with increasing soil depth. These data provide a soil production function with a maximum soil production rate of 70.6m/m.y. under 24cm of soil and a minimum of 22m/m.y. under 75cm of soil. Accordingly it means that the interface between soil and saprolite have gone down maximum 141.2 m since the Quaternary. Thus it suggests that the saprolites are the results under current local climatic and geomorphic conditions rather than the relict of the Tertiary deep weathering. Second, measurements of 10Be in alluvial sediments show that the average erosion rate (70.7m/m.y.) of the study area is close to the maximum soil production rate, thus basin wide erosion rates of the study area are controlled by the current soil production rates. It means that about 1

  15. Pre-mare cratering and early solar system history

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wetherill, G.W.

    1974-01-01

    An evaluation of the application of the high extra-lunar flux in pre- mare times to more general problems of early solar system history is attempted by combining the results of dynamic studies with lunar chronological data. Dynamical studies permit separate evaluation of the possible sources for both the normal flux during the first 600 m.y. years of lunar history as well as the peak which apparently occurred 4.0 b.y. ago. Dynamical studies have been carried out in order to determine the extent to which a heliocentric flux could be confined to the Moon (and Earth). A Monte Carlo method hasmore » been used to calculate the relative impact rates of planet-crossing bodies with the moon and the terrestrial planets. It is concluded that the time-variation of the flux on these planets is closely related to that on the moon. (STAR)« less

  16. Mechanism for generating the anomalous uplift of oceanic core complexes: Atlantis Bank, southwest Indian Ridge

    NASA Astrophysics Data System (ADS)

    Baines, A. Graham; Cheadle, Michael J.; Dick, Henry J. B.; Hosford Scheirer, Allegra; John, Barbara E.; Kusznir, Nick J.; Matsumoto, Takeshi

    2003-12-01

    Atlantis Bank is an anomalously uplifted oceanic core complex adjacent to the Atlantis II transform, on the southwest Indian Ridge, that rises >3 km above normal seafloor of the same age. Models of flexural uplift due to detachment faulting can account for ˜1 km of this uplift. Postdetachment normal faults have been observed during submersible dives and on swath bathymetry. Two transform-parallel, large-offset (hundreds of meters) normal faults are identified on the eastern flank of Atlantis Bank, with numerous smaller faults (tens of meters) on the western flank. Flexural uplift associated with this transform-parallel normal faulting is consistent with gravity data and can account for the remaining anomalous uplift of Atlantis Bank. Extension normal to the Atlantis II transform may have occurred during a 12 m.y. period of transtension initiated by a 10° change in spreading direction ca. 19.5 Ma. This extension may have produced the 120-km-long transverse ridge of which Atlantis Bank is a part, and is consistent with stress reorientation about a weak transform fault.

  17. Mechanism for generating the anomalous uplift of oceanic core complexes: Atlantis Bank, southwest Indian Ridge

    USGS Publications Warehouse

    Baines, A.G.; Cheadle, Michael J.; Dick, H.J.B.; Scheirer, A.H.; John, Barbara E.; Kusznir, N.J.; Matsumoto, T.

    2003-01-01

    Atlantis Bank is an anomalously uplifted oceanic core complex adjacent to the Atlantis II transform, on the southwest Indian Ridge, that rises >3 km above normal seafloor of the same age. Models of flexural uplift due to detachment faulting can account for ???1 km of this uplift. Postdetachment normal faults have been observed during submersible dives and on swath bathymetry. Two transform-parallel, large-offset (hundreds of meters) normal faults are identified on the eastern flank of Atlantis Bank, with numerous smaller faults (tens of meters) on the western flank. Flexural uplift associated with this transform-parallel normal faulting is consistent with gravity data and can account for the remaining anomalous uplift of Atlantis Bank. Extension normal to the Atlantis II transform may have occurred during a 12 m.y. period of transtension initiated by a 10?? change in spreading direction ca. 19.5 Ma. This extension may have produced the 120-km-long transverse ridge of which Atlantis Bank is a part, and is consistent with stress reorientation about a weak transform fault.

  18. Thermochronology, Uplift and Erosion at the Australian-Pacific Plate Boundary Alpine Fault restraining bend, New Zealand

    NASA Astrophysics Data System (ADS)

    Sagar, M. W.; Seward, D.; Norton, K. P.

    2016-12-01

    The 650 km-long Australian-Pacific plate boundary Alpine Fault is remarkably straight at a regional scale, except for a prominent S-shaped bend in the northern South Island. This is a restraining bend and has been referred to as the `Big Bend' due to similarities with the Transverse Ranges section of the San Andreas Fault. The Alpine Fault is the main source of seismic hazard in the South Island, yet there are no constraints on slip rates at the Big Bend. Furthermore, the timing of Big Bend development is poorly constrained to the Miocene. To address these issues we are using the fission-track (FT) and 40Ar/39Ar thermochronometers, together with basin-averaged cosmogenic nuclide 10Be concentrations to constrain the onset and rate of Neogene-Quaternary exhumation of the Australian and Pacific plates at the Big Bend. Exhumation rates at the Big Bend are expected to be greater than those for adjoining sections of the Alpine Fault due to locally enhanced shortening. Apatite FT ages and modelled thermal histories indicate that exhumation of the Australian Plate had begun by 13 Ma and 3 km of exhumation has occurred since that time, requiring a minimum exhumation rate of 0.2 mm/year. In contrast, on the Pacific Plate, zircon FT cooling ages suggest ≥7 km of exhumation in the past 2-3 Ma, corresponding to a minimum exhumation rate of 2 mm/year. Preliminary assessment of stream channel gradients either side of the Big Bend suggests equilibrium between uplift and erosion. The implication of this is that Quaternary erosion rates estimated from 10Be concentrations will approximate uplift rates. These uplift rates will help to better constrain the dip-slip rate of the Alpine Fault, which will allow the National Seismic Hazard Model to be updated.

  19. Drip tectonics and the enigmatic uplift of the Central Anatolian Plateau.

    PubMed

    Göğüş, Oğuz H; Pysklywec, Russell N; Şengör, A M C; Gün, Erkan

    2017-11-16

    Lithospheric drips have been interpreted for various regions around the globe to account for the recycling of the continental lithosphere and rapid plateau uplift. However, the validity of such hypothesis is not well documented in the context of geological, geophysical and petrological observations that are tested against geodynamical models. Here we propose that the folding of the Central Anatolian (Kırşehir) arc led to thickening of the lithosphere and onset of "dripping" of the arc root. Our geodynamic model explains the seismic data showing missing lithosphere and a remnant structure characteristic of a dripping arc root, as well as enigmatic >1 km uplift over the entire plateau, Cappadocia and Galatia volcanism at the southern and northern plateau margins since ~10 Ma, respectively. Models show that arc root removal yields initial surface subsidence that inverts >1 km of uplift as the vertical loading and crustal deformation change during drip evolution.

  20. Modulation of erosion rates of uplifting landscapes by long-term climate change: Experimental investigation

    NASA Astrophysics Data System (ADS)

    Moussirou, Bérangé; Bonnet, Stéphane

    2017-04-01

    Whether climatic variations play a major role, or not, in setting the erosion rate of continental landscapes is key for demonstrating the influence of climate on the tectonic evolution of mountain belts, as expected from analytical, numerical and analog modelling approaches. These models actually demonstrate that any modification in surface erosion rate that would affect significantly the gravitational loading of the continental crust might change its state of stress and consequently its deformation. However field evidences of these interactions has proved challenging to demonstrate unambiguously, the question of the climatic control on erosion efficiency at the geological time-scale being among the most critical issues. Here, we investigate how a change in precipitation influences the erosional dynamics of a landscape on the basis of an experimental approach where we surveyed the erosion by runoff of water of laboratory-scale landscapes that evolved under the combination of uplift and rainfall forcings (e.g. Bonnet and Crave, 2006). The experimental facility used is a modified of a device initially developed in the Geosciences Rennes laboratory and now set up in the Geosciences Environnement Toulouse laboratory. Following early experiments of Bonnet and Crave (2003) where the effect of a sudden drop in precipitation was investigated, we consider here the impact of decreasing rainfall events of finite duration on the erosive response of a landscape forced by a constant uplift (10 mm/h) and initially at steady-state (SS1). We performed several experiments with the same amplitude (from 160 to 60mm/h) but with different duration of rainfall drop (Tp: 0, 60, 300, 500, 700 min). As predicted theoretically and already observed in numerical and experimental modelling studies, a sudden drop of precipitation rate (Tp=0) induced a decrease of the mean erosion rate of the landscape (E), resulting in surface uplift. Then, landscape mean elevation stabilized to a higher value

  1. PROJECT UPLIFT--REFLECTIONS ON A QUIET SUMMER.

    ERIC Educational Resources Information Center

    WOOCK, ROGER

    PROJECT UPLIFT WAS ESTABLISHED IN THE SUMMER OF 1965 IN HARLEM IN PART TO AVOID POSSIBLE RIOTS. CONNECTED WITH HARYOU-ACT, AND FUNDED THROUGH THE OFFICE OF ECONOMIC OPPORTUNITY, THE PROJECT'S ACTIVITIES INCLUDED--CONSTRUCTION OF VEST POCKET PARKS, PLANTING OF TREES IN CENTRAL HARLEM, A REMEDIAL READING PROGRAM, BOOTHS TO GIVE INFORMATION ABOUT…

  2. Notes on the Early History of Technical Higher

    NASA Astrophysics Data System (ADS)

    Teodorescu, Horia Nicolai

    We perform a brief analysis of the economical and political context of establishing the first technical higher school in Romania. We urge for a revision of the current point of view on the educational level in Yashi (Iaši) and Bucharest at the epoch, highlighting that these were, at the time, important academic centers we may not recognize or may not be aware of today. We also plead for a long due serious approach about the history of early modern education in Romania.

  3. LiDAR Mapping of Earthquake Uplifted Paleo-shorelines, Southern Wairarapa Coast, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Valenciano, J.; Angenent, J.; Marshall, J. S.; Clark, K.; Litchfield, N. J.

    2017-12-01

    The Hikurangi subduction margin along the east coast of the North Island, New Zealand accommodates oblique convergence of the Pacific Plate westward beneath the Australian plate at 45 mm/yr. Pronounced forearc uplift occurs at the southern end of the margin along the Wairarapa coast, onshore of the subducting Hikurangi plateau. Along a narrow coastal lowland, a series of uplifted Holocene marine terraces and beach ridges preserve a geologic record of prehistoric coseismic uplift events. In January 2017, we participated in the Research Experience for Undergraduates (REU) program of the NSF SHIRE Project (Subduction at Hikurangi Integrated Research Experiment). We visited multiple coastal sites for reconnaissance fieldwork to select locations for future in-depth study. For the coastline between Flat Point and Te Kaukau Point, we used airborne LiDAR data provided by Land Information New Zealand (LINZ) to create ArcGIS digital terrain models for mapping and correlating uplifted paleo-shorelines. Terrace elevations derived from the LiDAR data were calibrated through the use of Real Time Kinematic (RTK) GPS surveying at one field site (Glenburn Station). Prior field mapping and radiocarbon dating results (Berryman et al., 2001; Litchfield and Clark, 2015) were used to guide our LiDAR mapping efforts. The resultant maps show between four and seven uplifted terraces and associated beach ridges along this coastal segment. At some sites, terrace mapping and lateral correlation are impeded by discontinuous exposures and the presence of landslide debris, alluvial fan deposits, and sand dunes. Tectonic uplift along the southern Hikurangi margin is generated by a complex interaction between deep megathrust slip and shallow upper-plate faulting. Each uplifted Holocene paleo-shoreline is interpreted to represent a single coseismic uplift event. Continued mapping, surveying, and age dating may help differentiate between very large margin-wide megathrust earthquakes (M8.0-9.0+) and

  4. Responses of dune plant communities to continental uplift from a major earthquake: sudden releases from coastal squeeze.

    PubMed

    Rodil, Iván F; Jaramillo, Eduardo; Hubbard, David M; Dugan, Jenifer E; Melnick, Daniel; Velasquez, Carlos

    2015-01-01

    Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5º S) caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco) over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the effects of natural

  5. Responses of Dune Plant Communities to Continental Uplift from a Major Earthquake: Sudden Releases from Coastal Squeeze

    PubMed Central

    Rodil, Iván F.; Jaramillo, Eduardo; Hubbard, David M.; Dugan, Jenifer E.; Melnick, Daniel; Velasquez, Carlos

    2015-01-01

    Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5º S) caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco) over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the effects of natural

  6. SCANLIPS - A Study of Epirogenic Uplift of Scandinavia

    NASA Astrophysics Data System (ADS)

    England, R. W.; Ebbing, J.

    2007-12-01

    Thermochronology data and geomorphological interpretation indicate that parts of the Scandinavian mountains have risen by over 1 km since the Miocene. This permanent uplift, the cause of which is still disputed, varies across Norway, being greatest in southern and northern areas and least in the central region. To investigate this the SCANLIPS project employs passive seismology, coupled with modelling of potential field data to determine variations in crustal properties and structure across Norway and Sweden. Initially we intend to test whether lateral variations in crustal structure and properties are correlated with the uplift pattern. This would suggest that the cause of the differential uplift lies in a modification of the crust. If the test of this hypothesis is null we will use the data to investigate the present day upper mantle structure for the cause. Between April and October 2006 28 seismometers were deployed at sites along a c. 600 km long profile between Trondheim in Norway and Harnosand in Sweden to record teleseismic arrivals. Receiver Functions have been calculated for teleseismic events recorded at these stations and then modelled to determine crustal velocity structure, estimate Vp/Vs and depth to Moho. Preliminary results suggest that crustal thickness increases eastward beneath Norway and then remains deep beneath the lower topography of central Sweden. Along the profile a gradual eastward increase in seismic velocity, including a very high velocity lower crust beneath Sweden explains the compensation of shallow topography by thick crust. Forward density and isostatic modelling shows that the introduction of the high-density lower crust adjusts both the gravity field and the isostatic compensation. Beneath Norway the crust thins rapidly toward the continental margin at a rate that is faster than the topography decreases. This suggests that at least part of the topography is supported by the flexural strength of the crust in the footwall of the

  7. Height Connections and Land Uplift Rates in West-Estonian Archipelago

    NASA Astrophysics Data System (ADS)

    Jürgenson, H.; Liibusk, A.; Kall, T.

    2012-04-01

    Land uplift rates are largest in the western part of Estonia. The uplift is due to post-glacial rebound. In 2001-2011, the Estonian national high-precision levelling network was completely renewed and levelled. This was the third precise levelling campaign in the re-gion. The first one had taken place before the Second World War and the second one in the 1950s. The Estonian mainland was connected with the two largest islands (Saaremaa and Hiiumaa) in the west-Estonian archipelago using the water level monitoring (hydrody-namic levelling) method. Three pairs of automatic tide gauges were installed on opposite coasts of each waterway. The tide gauges were equipped with piezoresistive pressure sen-sors. This represented the first use of such kind of equipment in Estonia. The hydrodynamic levelling series span up to two calendar years. Nevertheless, the obtained hydrodynamic levelling results need to be additionally verified using alternative geodetic methods. The obtained results were compared with the previous high-precision levelling data from the 1960s and 1970s. As well, the new Estonian gravimetric geoid model and the GPS survey were used for GPS-levelling. All the three methods were analyzed, and the preliminary results coincided within a 1-2 cm margin. Additionally, the tide gauges on the mainland and on both islands were connected using high-precision levelling. In this manner, three hydrodynamic and three digital levelling height differences formed a closed loop with the length of 250 km. The closing error of the loop was less than 1 cm. Finally, the Fennoscandian post-glacial rebound was determined from repeated levelling as well as from repeated GPS survey. The time span between the two campaigns of the first-order GPS survey was almost 13 years. According to new calculations, the relative land uplift rates within the study area reached up to +2 mm/year. This is an area with a rela-tively small amount of input data for the Nordic models. In addition, a

  8. A history of early geologic research in the Deep River Triassic Basin, North Carolina

    USGS Publications Warehouse

    Clark, T.W.

    1998-01-01

    The Deep River Triassic basin has one of the longest recorded histories of geologic research in North Carolina. A quick perusal of nineteenth century geologic literature in North Carolina reveals the Deep River basin has received a tremendous amount of attention, second only, perhaps, to the gold deposits of the Carolina slate belt. While these early researchers' primary interests were coal deposits, many other important discoveries, observations, and hypotheses resulted from their investigations. This article highlights many of the important advances made by these early geo-explorers by trying to include information from every major geologic investigation made in the Deep River basin from 1820 to 1955. This article also provides as thorough a consolidated history as is possible to preserve the exploration history of the Deep River basin for future investigators.

  9. Possible origin of the Bighorn uplift, WY, by lithospheric buckling during the Laramide orogeny

    NASA Astrophysics Data System (ADS)

    Tikoff, B.; Siddoway, C. S.; Worthington, L. L.; Anderson, M. L.

    2017-12-01

    The EarthScope Bighorn Project investigated the Bighorn uplift, Wyoming, a foreland structure developed during the 75-55 Ma Laramide orogeny. Any model for the Bighorn uplift must account for several geological and geophysical results from the EarthScope broadband and passive-active seismic study, the broader context provided by USArray, and legacy datasets: 1) The Moho is bulged up below portions of the surface exposure of the basement arch; 2) a high-velocity, high-density material (the "7.x layer") is absent in the lower crust beneath the arch culmination; 3) Shear wave splitting analysis shows distinct mantle fabrics on either side of the uplift; 4) Crustal thicknesses varied widely prior to the Laramide-age deformation; 5) A lack of reflectors associated with a regional decollement; 6) The Bighorn arch forms one in an array of low-amplitude, large-wavelength folds throughout the High Plains region. The uplift borders a NNW-trending (E-dipping?) geophysical anomaly inferred to be Proterozoic suture. A lithospheric buckling model offers a framework that accommodates most of the geological and geophysical data. Lithospheric buckling is the concept of low-amplitude, large-wavelength (150-350 km) lithospheric folding developed in response to an end-load, replicated in scaled physical models. A buckling instability focuses initial deformation, with faults developed in layered media/crustal section as shortening progresses. The strength/age of the mantle controls the fold wavelength, based on examples from multiple orogens (e.g. Urals, central Asia). Rarely does the geometry of the upward Moho deflection identically mirror the surface uplift in scaled models, nor does it in the Bighorn uplift, where fold localization is likely controlled by a pre-existing Proterozoic suture and/or mantle asperity. Indicated by shear wave SKS splitting data, distinct mantle fabrics on either side of the uplift extend into the lithospheric mantle, indicated the presence of a deep

  10. Measurement of tectonic surface uplift rate in a young collisional mountain belt

    USGS Publications Warehouse

    Abbott, L.D.; Silver, E.A.; Anderson, R. Scott; Smith, R.; Ingle, J.C.; Kling, S.A.; Haig, D.; Small, E.; Galewsky, J.; Sliter, W.

    1997-01-01

    Measurement of the rate of tectonically driven surface uplift is crucial to a complete understanding of mountain building dynamics. The lack of a suitable rock record typically prevents determination of this quantity, but the unusual geology of Papua New Guinea's Finisterre mountains makes measurement of this rate possible. The tectonic surface uplift rate at the Finisterre range is 0.8-2.1 mm yr-1, approximately that expected to arise from crustal thickening.

  11. A Third Note: Helmholtz, Palestrina, and the Early History of Musicology.

    PubMed

    Kursell, Julia

    2015-06-01

    This contribution focuses on Hermann von Helmholtz's work on Renaissance composer Giovanni Pierluigi da Palestrina. Helmholtz used his scientific concept of distortion to analyze this music and, reversely, to find corroboration for the concept in his musical analyses. In this, his work interlocked with nineteenth-century aesthetic and scholarly ideals. His eagerness to use the latest products of historical scholarship in early music reveals a specific view of music history. Historical documents of music provide the opportunity for the discovery of new experimental research topics and thereby also reveal insights into hearing under different conditions. The essay argues that this work occupies a peculiar position in the history of musicology; it falls under the header of "systematic musicology," which eventually emerged as a discipline of musicology at the end of the nineteenth century. That this discipline has a history at all is easily overlooked, as many of its contributors were scientists with an interest in music. A history of musicology therefore must consider at least the following two caveats: parts of it take place outside the institutionalized field of musicology, and any history of musicology must, in the last instance, be embedded in a history of music.

  12. Respite Care, Stress, Uplifts, and Marital Quality in Parents of Children with Down Syndrome.

    PubMed

    Norton, Michelle; Dyches, Tina Taylor; Harper, James M; Roper, Susanne Olsen; Caldarella, Paul

    2016-12-01

    Parents of children with disabilities are at risk for high stress and low marital quality; therefore, this study surveyed couples (n = 112) of children with Down syndrome (n = 120), assessing whether respite hours, stress, and uplifts were related to marital quality. Structural equation modeling indicated that respite hours were negatively related to wife/husband stress, which was in turn negatively related to wife/husband marital quality. Also, wife uplifts were positively related to both wife and husband marital quality. Husband uplifts were positively related to husband marital quality. Therefore, it is important that respite care is provided and accessible to parents of children with Down syndrome.

  13. Evolution of CO2 and H2O on Mars: A cold Early History?

    NASA Technical Reports Server (NTRS)

    Niles, P. B.; Michalski, J.

    2011-01-01

    The martian climate has long been thought to have evolved substantially through history from a warm and wet period to the current cold and dry conditions on the martian surface. This view has been challenged based primarily on evidence that the early Sun had a substantially reduced luminosity and that a greenhouse atmosphere would be difficult to sustain on Mars for long periods of time. In addition, the evidence for a warm, wet period of martian history is far from conclusive with many of the salient features capable of being explained by an early cold climate. An important test of the warm, wet early Mars hypothesis is the abundance of carbonates in the crust [1]. Recent high precision isotopic measurements of the martian atmosphere and discoveries of carbonates on the martian surface provide new constraints on the evolution of the martian atmosphere. This work seeks to apply these constraints to test the feasibility of the cold early scenario

  14. Uplift and subsidence reveal a nonpersistent megathrust rupture boundary (Sitkinak Island, Alaska)

    USGS Publications Warehouse

    Briggs, Richard W.; Engelhart, Simon E.; Nelson, Alan R.; Dura, Tina; Kemp, Andrew C.; Haeussler, Peter J.; Corbett, D. Reide; Angster, Stephen J.; Bradley, Lee-Ann

    2014-01-01

    We report stratigraphic evidence of land-level change and tsunami inundation along the Alaska-Aleutian megathrust during prehistoric and historical earthquakes west of Kodiak Island. On Sitkinak Island, cores and tidal outcrops fringing a lagoon reveal five sharp lithologic contacts that record coseismic land-level change. Radiocarbon dates, 137Cs profiles, CT scans, and microfossil assemblages are consistent with rapid uplift ca. 290-0, 520-300, and 1050-790 cal yr BP, and subsidence in AD 1964 and ca. 640-510 cal yr BP. Radiocarbon, 137Cs, and 210Pb ages bracketing a sand bed traced 1.5 km inland and evidence for sudden uplift are consistent with Russian accounts of an earthquake and tsunami in AD 1788. The mixed uplift and subsidence record suggests that Sitkinak Island sits above a non-persistent boundary near the southwestern limit of the AD 1964 Mw 9.2 megathrust rupture.

  15. Surface Uplift Rate Constrained by Multiple Terrestrial Cosmogenic Nuclides: Theory and Application from the Central Andean Plateau

    NASA Astrophysics Data System (ADS)

    McPhillips, D. F.; Hoke, G. D.; Niedermann, S.; Wittmann, H.

    2015-12-01

    There is widespread interest in quantifying the growth and decay of topography. However, prominent methods for quantitative determinations of paleoelevation rely on assumptions that are often difficult to test. For example, stable isotope paleoaltimetry relies on the knowledge of past lapse rates and moisture sources. Here, we demonstrate how cosmogenic 10Be - 21Ne and/or 10Be - 26Al sample pairs can be applied to provide independent estimates of surface uplift rate using both published data and new data from the Atacama Desert. Our approach requires a priori knowledge of the maximum age of exposure of the sampled surface. Ignimbrite surfaces provide practical sampling targets. When erosion is very slow (roughly, ≤1 m/Ma), it is often possible to constrain paleo surface uplift rate with precision comparable to that of stable isotopic methods (approximately ±50%). The likelihood of a successful measurement is increased by taking n samples from a landscape surface and solving for one regional paleo surface uplift rate and n local erosion rates. In northern Chile, we solve for surface uplift and erosion rates using three sample groups from the literature (Kober et al., 2007). In the two lower elevation groups, we calculate surface uplift rates of 110 (+60/-12) m/Myr and 160 (+120/-6) m/Myr and estimate uncertainties with a bootstrap approach. The rates agree with independent estimates derived from stream profile analyses nearby (Hoke et al., 2007). Our calculated uplift rates correspond to total uplift of 1200 and 850 m, respectively, when integrated over appropriate timescales. Erosion rates were too high to reliably calculate the uplift rate in the third, high elevation group. New cosmogenic nuclide analyses from the Atacama Desert are in progress, and preliminary results are encouraging. In particular, a replicate sample in the vicinity of the first Kober et al. (2007) group independently yields a surface uplift rate of 110 m/Myr. Compared to stable isotope

  16. Still Missing? History Chapters in Introductory Early Childhood Education Textbooks From the 1990s to the 2010s

    ERIC Educational Resources Information Center

    Prochner, Larry; Woitte, Sherry

    2013-01-01

    This article compares history chapters in recent introductory early childhood education textbooks with those from an earlier study, reviewing history chapters on four dimensions: the rationale for the study of history, the dominant story of the history, the facts of the history, and the image of the history. Ten textbooks are reviewed, including…

  17. Late Palaeocene Mantle Plume Uplift on The Fugloy Ridge, NE Faroes

    NASA Astrophysics Data System (ADS)

    Hurst, N. W.; Kusznir, N. J.; Roberts, A. M.

    2004-12-01

    compressional fold structure, however the results from this modelling show that its present anticlinal structure can be explained purely as a result of a combination of differential sediment loading and post-breakup thermal subsidence. Modelling results show a discrepant bathymetry of ~500m when restored to breakup. Our preferred interpretation is that this discrepant bathymetry is due to ~500 m of transient Palaeocene uplift, for which a likely mechanism is dynamic uplift by the early Iceland mantle plume. This plume uplift estimate is consistent with values from previous work for the northern North Sea Basin (Nadin et al., 1997) and the Faroe-Shetland Basin (Jones & White, 2003). This work forms part of the NERC Margins iSIMM project. iSIMM investigators are from Liverpool and Cambridge Universities, Schlumberger Cambridge Research & Badley Geoscience, supported by the NERC, the DTI, Agip UK, BP, Amerada Hess Ltd, Anadarko, Conoco-Phillips, Shell, Statoil and WesternGeco. The iSIMM team comprises NJ Kusznir, RS White, AM Roberts, PAF Christie, R Spitzer, NW Hurst, ZC Lunnon, CJ Parkin, AW Roberts, LK Smith, D Healy & V Tymms.

  18. Role of erosion and isostasy in the Cordillera Blanca uplift: Insights from landscape evolution modeling (northern Peru, Andes)

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Braun, Jean; Robert, Xavier; Audin, Laurence

    2018-03-01

    The processes driving uplift and exhumation of the highest Peruvian peaks (the Cordillera Blanca) are not well understood. Uplift and exhumation seem closely linked to the formation and movement on the Cordillera Blanca normal fault (CBNF) that delimits and shapes the western flank of the Cordillera Blanca. Several models have been proposed to explain the presence of this major normal fault in a compressional setting, but the CBNF and the Cordillera Blanca recent rapid uplift remain enigmatic. Whereas the Cordillera Blanca morphology demonstrates important erosion and thus a significant mass of rocks removal, the impact of erosion and isostasy on the evolution of the Cordillera Blanca uplift rates has never been explored. We address the role of erosion and associated flexural rebound in the uplift and exhumation of the Cordillera Blanca with numerical modeling of landscape evolution. We perform inversions of the broad features of the present-day topography, total exhumation and thermochronological data using a landscape evolution model (FastScape) to provide constraints on the erosion efficiency factor, the uplift rate and the temperature gradient. Our results evidence the not negligible contribution of erosion and associated flexural rebound to the uplift of the Cordillera Blanca and allow us to question the models previously proposed for the formation of the CBNF.

  19. Uplift of symmetrical anchor plates by using grid-fixed reinforced reinforcement in cohesionless soil

    NASA Astrophysics Data System (ADS)

    Niroumand, Hamed; Kassim, Khairul Anuar

    2014-03-01

    Uplift response of symmetrical anchor plates with and without grid fixed reinforced (GFR) reinforcement was evaluated in model tests and numerical simulations by Plaxis. Many variations of reinforcement layers were used to reinforce the sandy soil over symmetrical anchor plates. In the current research, different factors such as relative density of sand, embedment ratios, and various GFR parameters including size, number of layers, and the proximity of the layer to the symmetrical anchor plate were investigated in a scale model. The failure mechanism and the associated rupture surface were observed and evaluated. GFR, a tied up system made of fiber reinforcement polymer (FRP) strips and end balls, was connected to the geosynthetic material and anchored into the soil. Test results showed that using GFR reinforcement significantly improved the uplift capacity of anchor plates. It was found that the inclusion of one layer of GFR, which rested directly on the top of the anchor plate, was more effective in enhancing the anchor capacity itself than other methods. It was found that by including GFR the uplift response was improved by 29%. Multi layers of GFR proved more effective in enhancing the uplift capacity than a single GFR reinforcement. This is due to the additional anchorage provided by the GFR at each level of reinforcement. In general, the results show that the uplift capacity of symmetrical anchor plates in loose and dense sand can be significantly increased by the inclusion of GFR. It was also observed that the inclusion of GFR reduced the requirement for a large L/D ratio to achieve the required uplift capacity. The laboratory and numerical analysis results are found to be in agreement in terms of breakout factor and failure mechanism pattern.

  20. The physics and early history of the intergalactic medium

    NASA Astrophysics Data System (ADS)

    Barkana, Rennan; Loeb, Abraham

    2007-04-01

    The intergalactic medium—the cosmic gas that fills the great spaces between the galaxies—is affected by processes ranging from quantum fluctuations in the very early Universe to radiative emission from newly formed stars. This gives the intergalactic medium a dual role as a powerful probe both of fundamental physics and of astrophysics. The heading of fundamental physics includes conditions in the very early Universe and cosmological parameters that determine the age of the Universe and its matter content. The astrophysics refers to chapters of the long cosmic history of stars and galaxies that are being revealed through the effects of stellar feedback on the cosmic gas. This review describes the physics of the intergalactic medium, focusing on recent theoretical and observational developments in understanding early cosmic history. In particular, the earliest generation of stars is thought to have transformed the Universe from darkness to light and to have had an enormous impact on the intergalactic medium. Half a million years after the Big Bang the Universe was filled with atomic hydrogen. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms back into free electrons and ions. From the observed spectral absorption signatures of the gas between us and distant sources, we know that the process of reionization pervaded most of space a billion years after the Big Bang, so that only a small fraction of the primordial hydrogen atoms remained between galaxies. Knowing exactly when and how the reionization process happened is a primary goal of cosmologists, because this would tell us when the early stars and black holes formed and in what kinds of galaxies. The distribution and clustering of these galaxies is particularly interesting since it is driven by primordial density fluctuations in the dark matter. Cosmic reionization is beginning to be understood with the help of theoretical models and computer

  1. An assessment of the accuracy of the geodetic measurements that define the southern California uplift.

    USGS Publications Warehouse

    Mark, R.K.; Tinsley, J. C.; Newman, E.B.; Gilmore, T.D.; Castle, R.O.

    1981-01-01

    Examination of the charge that the geodetic measurements which define the southern California uplift are seriously flawed by height-dependent systematic errors indicates that this charge is unfounded. Comparisons between the results of measurements in which the correlation between topography and signal is generally poor reveal large aseismic tilts in a number of places within and around the margins of the uplift. Especially significant in this context are the results of preuplift and postuplift levellings over routes characterized by diverse length, topography, and atmospheric conditions that produce closely matching, temporally equivalent heights for a representative bench mark within the uplift.-from Authors

  2. Effects of perceived stress and uplifts on inflammation and coagulability.

    PubMed

    Jain, Shamini; Mills, Paul J; von Känel, Roland; Hong, Suzi; Dimsdale, Joel E

    2007-01-01

    We investigated whether depressed mood and chronic hassles and uplifts predicted levels of hemostasis markers D-Dimer and type-1 plasminogen activator inhibitor (PAI-1), as well as the proinflammatory markers interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) in 108 healthy individuals. One hundred eight African-American and Euro-American men and women were studied (58 men, 50 women; mean age = 36.5 +/- 8 years). D-Dimer, PAI-1, IL-6, and sICAM-1 plasma levels were analyzed from fasting venous blood samples. Data were analyzed via hierarchical linear regression and followed with partial correlation analysis. Regression analyses combined with partial correlation analyses suggested that increases in hassle frequency predicted elevated levels of sICAM-1 (p= .034), and increases in hassle severity predicted elevated levels of D-Dimer (p= .017). Increases in uplift intensity predicted lower levels of PAI-1 (p= .004) as well as showed a trend for decreased IL-6 (p= .069). Depressed mood did not significantly predict any dependent variable. These results were independent of sociodemographic, biological, and other related mood variables. The findings suggest that for even relatively healthy persons, increased perceptions of hassles are independently associated with greater inflammation and hypercoagulability, whereas increased perceptions of uplifts are independently associated with decreased hypercoagulability.

  3. History Of Self-Disclosure In Females And Early Defection From Psychotherapy

    ERIC Educational Resources Information Center

    Heilbrun, Alfred B., Jr.

    1973-01-01

    Late adolescent girls who would more likely defect from psychotherapy early had a self-rated history of greater self-disclosure than did girls who would more likely continue. This difference was especially clear with male targets. The second experimental study revealed a similar finding; terminators are higher self-disclosers to males whereas…

  4. Pre-mare cratering and early solar system history

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.

    1977-01-01

    An evaluation of the application of the high extralunar flux in pre-mare times to more general problems of early solar system history is attempted by combining the results of dynamic studies with lunar chronological data. There is a twofold to fourfold contrast in the integral impact flux between the Apollo 14 and 16 sites and the older mare surfaces. This is judged insufficient to account for the contrasting lithology between these two sites: basalts and soil breccias in the maria, annealed breccias and impact melts in the highlands. Therefore, these rocks and their ages (3.9-4.0 b.y.) are thought to predate the surfaces in which they are found. Estimation of the flux needed to produce these lithologies, and difficulties associated with extrapolating this further back in lunar history give support to the "cataclysm" hypothesis of Tera, Papanastassiou, and Wasserburg. Dynamical studies permit separate evaluation of the possible sources for both the "normal" flux during the first 600 million years of lunar history and the "peak" that apparently occurred 4.0 billion years ago. The most likely sources for the normal flux are comets from the vicinity of Uranus and Neptune. The most promising source for the peak is tidal disruption by Earth or Venus of a Ceres-size asteroid initially in a Mars-crossing orbit. Alternative possibilities are suggested.

  5. Central Alpine Denudation equals Rock Uplift: Steady State or Coincidence?

    NASA Astrophysics Data System (ADS)

    Wittmann, H.; von Blanckenburg, F.; Kruesmann, T.; Norton, K. P.; Kubik, P. W.

    2006-12-01

    The Central Alps of Switzerland represent a mountain belt in which an exceptional wealth of geophysical data allows the unique test of tectono-geomorphic models. Levelling measurements show that the Central Alps are uplifting today with 0.5-1.6 mm/yr (Kahle et al. 1997). Here we present a North-South denudation rate transect through the Swiss Central Alps from a study of in situ-produced cosmogenic 10Be in river-borne quartz. Denudation rates range from 0.1 to 1.5 mm/yr. They yield a mean of 0.27+/-0.14 mm/yr for the Alpine foreland, where integration times are 2-8 ky, and of 0.9+/-0.3 mm/yr for the high crystalline Central Alps, where integration times are 0.5-1.5 ky. The measured cosmogenic nuclide-derived denudation rates are in good agreement with post-LGM lake infill rates and significantly higher than recent denudation rates from river loads. We attribute this discrepancy to differences in methodology and integration time scale. Our new rates are in the same range as denudation rates from apatite fission tracks that record denudation 3-5 Ma ago. Denudation rates correlate with hill slope in the Mittelland catchments, but they are independent of slope in the high Alps. We interprete this to mean that high Alpine landscapes are at threshold hillslope, where slopes cannot increase any further before failure occurs. In general, denudation rates are high in areas of high relief and high altitude. Importantly, good spatial agreement exists between denudation rates and recent rock uplift rates. Since all of the mentioned parameters are also highest where crustal thickness is largest, a major driving force for rock uplift and concomitant denudation is likely to be isostatic. However, given that crustal thickening of the Alps has all but ceased, the relief-forming events that set the rate of denudation and uplift must be presented by transient perturbations, such as increased erosional response to climate cycling. Thereby a quasi-steady state has been achieved in

  6. Wilcox group (Paleocene to Eocene) coals of the Sabine Uplift area, Texas and Louisiana

    USGS Publications Warehouse

    Hook, Robert W.; Warwick, Peter D.; SanFilipo, John R.; Warwick, Peter D.; Karlsen, Alexander K.; Merrill, Matthew D.; Valentine, Brett J.

    2011-01-01

    The Wilcox Group (Paleocene to Eocene) of the Sabine uplift, a structural arch in northeastern Texas and northwestern Louisiana (Figure 1), has lignite zones that approach subbituminous rank (see Chapter 4, this publication). These coals are among the highest quality resources known within the Gulf Coastal Plain because of their low ash yield and sulfur content. The surface expression of the Sabine uplift is defined by the contact between coal-bearing rocks of the Wilcox Group and overlying fluvial rocks of the Carrizo Sand, which is the basal unit of the Claiborne Group (Figures 2, 3). The Sabine uplift study area includes parts of Harrison, Marion, Nacogdoches, Panola, Rusk, Sabine, San Augustine, and Shelby Counties in Texas and Bossier, Caddo, De Soto, Natchitoches, Red River, and Sabine Parishes in Louisiana (Figure 1). Adjacent counties and parishes that include the subsurface Wilcox Group extend the regional Sabine uplift area. The Wilcox in the subsurface is underlain by the Midway Group (Figure 3), a mudstone-dominated marine sequence of Paleocene age. Quaternary alluvium and terrace deposits overlying the Wilcox Group at the surface are limited to areas of modern drainage.The total thickness of the Wilcox Group within the Sabine uplift area ranges from approximately 400 ft on outcrop to 2500 ft in subsurface (Kaiser, 1990). In a few places, the contact between the overlying Carrizo Sand and Wilcox Group is erosional, but in other places, the contact is gradational.

  7. Challenges of Holocene sea-level reconstructions in area of low uplift rate

    NASA Astrophysics Data System (ADS)

    Grudzinska, Ieva; Vassiljev, Jüri; Stivrins, Normunds

    2017-04-01

    Isolated coastal water bodies provide an excellent sedimentary archive of the evolutionary stages of the coastal regions. It is relatively easy to determine lake isolation threshold, time and contact, where marine and brackish diatoms are replaced by halophilous and subsequently by freshwater diatoms, in areas with high land uplift rates and hard bedrock. Whereas, in areas where the land uplift rate is near zero and sedimentary cover of sand, silt and/or clay exists, determination of the lake isolation threshold and time is a rather complicated task. Such an area is the coast of the Gulf of Riga, where the apparent land uplift is about 1 mm yr-1 in the northern part and near zero in the southern part of the area. The aim of the study is to improve the understanding of the nature and extent of the Holocene sea level changes in the eastern Baltic Sea region, in the area with low land uplift rate. This study marks the first attempt to reconstruct sea level changes for a wide variety of settings based on high-resolution bio-, litho-, and chronostratigraphical evidence from sediment records of isolation basins in Latvia. In total, eight lakes were studied in order to revise the relative sea level (RSL) changes at the southern coast of the Gulf of Riga based on new litho- and biostratigraphical data and radiocarbon datings. The palaeogeographical reconstruction was challenging because we had to take into account that the process of isolation was influenced by various factors, such as gradual eustatic sea level (ESL) rise, river delta infilling by sediments and long-shore sediment transport. The water level in the Baltic Sea basin until 8,500 cal BP was influenced primarily by deglaciation dynamics, whereas in the last 8,500 years, the main factor was complicated interplay between the ESL rise and the land uplift rate. According to diatom composition and radiocarbon dates, the Litorina Sea transgression was a long-lasting event (ca. 2,200 years) in the southern part of

  8. Geologic Map of the Denver West 30' x 60' Quadrangle, North-Central Colorado

    USGS Publications Warehouse

    Kellogg, Karl S.; Shroba, Ralph R.; Bryant, Bruce; Premo, Wayne R.

    2008-01-01

    The Denver West quadrangle extends east-west across the entire axis of the Front Range, one of numerous uplifts in the Rocky Mountain region in which Precambrian rocks are exposed. The history of the basement rocks in the Denver West quadrangle is as old as 1,790 Ma. Along the east side of the range, a sequence of sedimentary rocks as old as Pennsylvanian, but dominated by Cretaceous-age rocks, overlies these ancient basement rocks and was upturned and locally faulted during Laramide (Late Cretaceous to early Tertiary) uplift of the range. The increasingly coarser grained sediments up section in rocks of latest Cretaceous to early Tertiary age record in remarkable detail this Laramide period of mountain building. On the west side of the range, a major Laramide fault (Williams Range thrust) places Precambrian rocks over Cretaceous sedimentary rocks. The geologic history of the quadrangle, therefore, can be divided into four major periods: (1) Proterozoic history, (2) Pennsylvanian to pre-Laramide, Late Cretaceous history, (3) Late Cretaceous to early Tertiary Laramide mountain building, and (4) post-Laramide history. In particular, the Quaternary history of the Denver West quadrangle is described in detail, based largely on extensive new mapping.

  9. A brief history of early neuroanesthesia.

    PubMed

    Chivukula, Srinivas; Grandhi, Ramesh; Friedlander, Robert M

    2014-04-01

    Two key discoveries in the 19th century--infection control and the development of general anesthesia--provided an impetus for the rapid advancement of surgery, especially within the field of neurosurgery. Improvements in anesthesia and perioperative care, in particular, fostered the development of meticulous surgical technique conducive to the refinement of neuroanatomical understanding and optimization of neurosurgical procedures and outcomes. Yet, even dating back to the earliest times, some form of anesthesia or perioperative pain management was used during neurosurgical procedures. Despite a few reports on anesthesia published around the time of William Morton's now-famous public demonstration of ether anesthesia in 1846, relatively little is known or written of early anesthetics in neurosurgery. In the present article the authors discuss the history of anesthesia pertaining to neurosurgical procedures and draw parallels between the refinements and developments in anesthesia care over time with some of the concomitant advances in neurosurgery.

  10. An early history of human breast cancer: West meets East.

    PubMed

    Yan, Shou-He

    2013-09-01

    Cancer has been increasingly recognized as a global issue. This is especially true in countries like China, where cancer incidence has increased likely because of changes in environment and lifestyle. However, cancer is not a modern disease; early cases have been recorded in ancient medical books in the West and in China. Here, we provide a brief history of cancer, focusing on cancer of the breast, and review the etymology of ai, the Chinese character for cancer. Notable findings from both Western and Chinese traditional medicine are presented to give an overview of the most important, early contributors to our evolving understanding of human breast cancer. We also discuss the earliest historical documents to record patients with breast cancer.

  11. Los Angeles-Long Beach Harbor Areas Prehistory and Early History, Los Angeles County, California,

    DTIC Science & Technology

    1978-04-01

    H - R136 656 LOS ANGELES-LONG BEACH HARBOR ARE AS PREHISTORY AND I/i EARLY HISTORY LO S ANGELES COUNTY CALIFORNIA(U) ARMY ENGINEER DISTRICT LOS...world. The The Early Systems Period (50,000? to 7,000 creation of this megalopolis, unfortunately, years ago) had severe impacts on the natural...called amino acid dating. Using this of early occupation. There is data which system , archeologists determined that human suggests that some of the

  12. An Oblique View of Uplifted Rocks

    NASA Image and Video Library

    2017-05-24

    This image from NASA's Mars Reconnaissance Orbiter shows part of the central uplifted region of an impact crater more than 50 kilometers wide. That means that the bedrock has been raised from a depth of about 5 kilometers, exposing ancient materials. The warm (yellowish-reddish) colors mark the presence of minerals altered by water, whereas the bluish and greenish rocks have escaped alteration. Sharp-crested ridges and smooth areas are young windblown materials. https://photojournal.jpl.nasa.gov/catalog/PIA21640

  13. Workshop on Pristine Highlands Rocks and the early History of the Moon

    NASA Technical Reports Server (NTRS)

    Longhi, J. (Editor); Ryder, G. (Editor)

    1983-01-01

    Oxide composition of the Moon, evidence for an initially totally molten Moon, geophysical contraints on lunar composition, random sampling of a layered intrusion, lunar highland rocks, early evolution of the Moon, mineralogy and petrology of the pristine rocks, relationship of the pristine nonmore rocks to the highlands soils and breccias, ferroan anorthositic norite, early lunar igneous history, compositional variation in ferroan anosthosites, a lunar magma ocean, deposits of lunar pristine rocks, lunar and planetary compositions and early fractionation in the solar nebula, Moon composition models, petrogenesis in a Moon with a chondritic refractory lithophile pattern, a terrestrial analog of lunar ilmenite bearing camulates, and the lunar magma ocean are summarized.

  14. Ongoing Uplift Rates and Topography Across the Aleutian Forearc Region on Kodiak Island, Alaska.

    NASA Astrophysics Data System (ADS)

    Sauber, J. M.; Carver, G. A.

    2002-12-01

    The Kodiak Islands are part of a large subduction complex that comprises the eastern Aleutian forearc; the islands form the subaerial part of a broad topographic ridge that includes a Mesozoic-Cenozoic accretionary complex. To explore the relation between the ongoing subduction process, uplift rates and topographic characteristics, we have used a 30 m digital elevation map (DEM) derived from the Shuttle Radar Topography Mission (SRTM), an older 90 m DEM and ocean bathymetry. The topographic characteristics of Kodiak Island vary along strike and as a function of distance from the trench. From the northern to southern part of island, the distance from the 5800 m bathymetric contour (Aleutian Trench) and the eastern coast of Kodiak Island, as well as the width of the island, narrows by about 10% and probably reflects a steepening of the dip of the downgoing Pacific plate under the southern part of the island. The northern and central part of the island have similar topographic profiles as a function of distance from the trench; the highest peaks are located in the central part of the island. Although most of the island was glaciated during the last glacial maximum, the southwest portion of the island remained unglaciated; this region is distinctly less dissected. Preliminary uplift rates across the forearc region have been estimated from coastal marine terraces and short-term geodetic observations. Elevation changes over the last 103 - 104 years are being obtained from kinematic GPS observations across two sets of Holocene marine terrace sequences and from elevation measurements in northern Kodiak of an extensive late Pleistocene marine terrace (probably an oxygen isotope stage 5a, 120 - 130 ka). Initial measurements from the older terrace in northern Kodiak suggest an average uplift rate for the eastern side of Kodiak, above the down-dip end of the locked zone on the megathrust, to be about 1.2 mm/yr; on the western side of the island the uplift rate decreases by an

  15. Uplift and subsidence associated with the great Aceh-Andaman earthquake of 2004

    USGS Publications Warehouse

    Meltzner, A.J.; Sieh, K.; Abrams, M.; Agnew, D.C.; Hudnut, K.W.; Avouac, J.-P.; Natawidjaja, D.H.

    2006-01-01

    Rupture of the Sunda megathrust on 26 December 2004 produced broad regions of uplift and subsidence. We define the pivot line separating these regions as a first step in defining the lateral extent and the downdip limit of rupture during that great Mw ??? 9.2 earthquake. In the region of the Andaman and Nicobar islands we rely exclusively on the interpretation of satellite imagery and a tidal model. At the southern limit of the great rupture we rely principally on field measurements of emerged coral microatolls. Uplift extends from the middle of Simeulue Island, Sumatra, at ??? 2.5??N, to Preparis Island, Myanmar (Burma), at ??? 14.9??N. Thus the rupture is ??? 1600 km long. The distance from the pivot line to the trench varies appreciably. The northern and western Andaman Islands rose, whereas the southern and eastern portion of the islands subsided. The Nicobar Islands and the west coast of Aceh province, Sumatra, subsided. Tilt at the southern end of the rupture is steep; the distance from 1.5 m of uplift to the pivot line is just 60 km. Our method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions. Copyright 2006 by the American Geophysical Union.

  16. In the Footsteps of Charles Darwin: Patterns of Coastal Subsidence and Uplift Associated with Seamount Subduction, Basal Fore-arc Erosion and Seamount Accretion in Latin America

    NASA Astrophysics Data System (ADS)

    Fisher, D. M.; Kirby, S. H.; David, S. W.

    2004-12-01

    . Such basal decoupling is known to occur under active volcanic islands in the open ocean in connection with rifting and gravitational spreading, such as beneath the island of Hawaii. The spatial and temporal patterns of coastal uplift and subsidence on active margins can therefore record the local history of seamount subduction. This conceptual model explains the spatial patterns of offshore subsidence and coastal uplift in Chile and Costa Rica and also has implications for patterns of seismicity along the interplate thrust boundary.

  17. Sombrero uplift above the Altiplano-Puna Magma Body: evidence of a ballooning mid-crustal diapir.

    PubMed

    Fialko, Yuri; Pearse, Jill

    2012-10-12

    The Altiplano-Puna ultralow-velocity zone in the central Andes, South America, is the largest active magma body in Earth's continental crust. Space geodetic observations reported an uplift in the Altiplano-Puna proper at a rate of ~10 mm/year; however, the nature of the inferred inflation source has been uncertain. We present data showing that the uplift has persisted at a nearly constant rate over the past two decades, and is surrounded by a broad zone of subsidence. We show that the ongoing uplift and peripheral subsidence may result from a large mid-crustal diapir fed by partial melt from the Altiplano-Puna Magma Body.

  18. Low-accommodation detrital apron alongside a basement uplift, Pennsylvanian of Midcontinent North America

    NASA Astrophysics Data System (ADS)

    Joeckel, R. M.; Nicklen, B. L.; Carlson, M. P.

    2007-04-01

    The northern end of the 650-km-long Nemaha Uplift (Nebraska and Kansas, USA) is an important example of basin-margin sedimentation in the North American Midcontinent. An apron of coarse, basal Pennsylvanian arkosic clastic sediments (BPC) was deposited on the flanks of the uplift while marine cyclothems were encroaching from the east. Small-scale fining-upward intervals, many with demonstrably erosional bases, dominate the BPC and are interpreted as overridingly fluvial in origin. Weak paleosols, desiccation cracks, and reddened intervals in the BPC record episodic subaerial exposure. Multiple, burrowed horizons and heterolithic strata of probable tidal origin and rare marine fossils also indicate episodic marine influence. The BPC appear to have been deposited as a thin apron of coalesced, alluvial fans and fan deltas. Deposition of the BPC occurred during the waning of uplift and subsequent quiescence. The comparative thinness and large-scale packaging of the BPC are compatible with the controlling effects of relict relief, regional subsidence, and eustasy, rather than ongoing, major vertical displacements along active faults. A strong autocyclic influence on sedimentation is evidenced by stacked fining-upward intervals of poorly-sorted conglomerates, sandstones, and sandy mudstones. Correlations demonstrate that the accumulation of the BPC took place over more than seven major sea-level cycles, beginning in Cherokee Group times (middle Moscovian/middle Pennsylvanian) and ending only when the eroded uplift was inundated and buried by marine cyclothems. On the basis of local correlations with marine cyclothems, and using black phosphatic shales (so-called "core shales" of Heckel, P.H., 1986. Sea-level surve for Pennsylvanian eustatic marine transgressive-regressive depositional cycles along Midcontinent outcrop belt, North America: Geology 14, 330-334., Heckel, P.H., 1994. Evaluation of evidence for glacio-eustatic control over marine Pennsylvanian cyclothems in

  19. Determination of sub-daily glacier uplift and horizontal flow velocity with time-lapse images using ImGRAFT

    NASA Astrophysics Data System (ADS)

    Egli, Pascal; Mankoff, Ken; Mettra, François; Lane, Stuart

    2017-04-01

    This study investigates the application of feature tracking algorithms to monitoring of glacier uplift. Several publications have confirmed the occurrence of an uplift of the glacier surface in the late morning hours of the mid to late ablation season. This uplift is thought to be caused by high sub-glacial water pressures at the onset of melt caused by overnight-deposited sediment that blocks subglacial channels. We use time-lapse images from a camera mounted in front of the glacier tongue of Haut Glacier d'Arolla during August 2016 in combination with a Digital Elevation Model and GPS measurements in order to investigate the phenomenon of glacier uplift using the feature tracking toolbox ImGRAFT. Camera position is corrected for all images and the images are geo-rectified using Ground Control Points visible in every image. Changing lighting conditions due to different sun angles create substantial noise and complicate the image analysis. A small glacier uplift of the order of 5 cm over a time span of 3 hours may be observed on certain days, confirming previous research.

  20. Mélange versus forearc contributions to sedimentation and uplift, during rapid denudation of a young Banda forearc-continent collisional belt

    NASA Astrophysics Data System (ADS)

    Duffy, Brendan; Kalansky, Julie; Bassett, Kari; Harris, Ron; Quigley, Mark; van Hinsbergen, Douwe J. J.; Strachan, Lorna J.; Rosenthal, Yair

    2017-05-01

    New sedimentary geochemistry and petrographic analyses provide the most extensive sedimentary documentation yet of the rapid denudation of the young Timor orogen. The data from three basins including two widely-separated, well-dated sections of the Synorogenic Megasequence of Timor-Leste, and a re-dated DSDP 262, constrain the source and timing of detrital sediment flux during forearc-continent collision along the Timor sector of the Banda Arc. The exhumed synorogenic piggy-back basins formed above a mélange unit that developed at the expense of a weak stratigraphic horizon in the Mesozoic stratigraphy, and was exhumed to the sea floor in latest Messinian time. Following an interval of deep marine chalky marl sedimentation, an increasingly muddy sediment flux indicates that the island of Timor became emergent and shed sediment by 4.5 Ma. Comparison of exhumed sections with similar patterns in the DSDP262 chemistry suggests that the sediment source was probably located some 50-60 km distant from the basin, which is consistent with the Aileu region of Timor-Leste that shows an appropriate exhumation history. All sedimentation between 4.5 and 3.2 Ma was probably derived from a low-relief, rapidly eroding, and mudstone-dominated landscape with geochemical affinities to the Triassic-mudstone-derived synorogenic mélange. The mélange unit overlies and surrounds the Banda Terrane, and was presumably structurally emplaced by propagation of a decollement through the Triassic rocks during the collision. After 3.2 Ma, sedimentation was dominated by hard rock lithologies of the Banda Terrane, consisting of forearc cover and basement, the latter including elements of metamafic rocks and metapelites. This phase of sedimentation was accompanied by rapid uplift, which may have been partly driven by a transient imbalance between rock uplift and denudation as resistant lithologies emerged from below mélange-like mudstone. Previous work has suggested that the timing of collision

  1. Sr isotope evidence for a lacustrine origin for the upper Miocene to Pliocene Bouse Formation, lower Colorado River trough, and implications for timing of Colorado Plateau uplift

    USGS Publications Warehouse

    Spencer, J.E.; Patchett, P.J.

    1997-01-01

    The upper Miocene to Pliocene Bouse Formation in the lower Colorado River trough, which consists largely of siltstone with basal tufa and marl, has been interpreted as estuarine on the basis of paleontology. This interpretation requires abrupt marine inundation that has been linked to early rifting in the Gulf of California and Salton trough. New strontium isotope measurements reported here from carbonates and invertebrate shells in the Bouse Formation reveal no evidence of marine water, but are consistent with deposition in a lake or chain of lakes fed by the Colorado River. Furthermore, the absence of a southward decrease in 87Sr/86Sr within the Bouse Formation does not support the estuarine model in which low 87Sr/86Sr marine Sr would have dominated the mouth of the hypothetical Bouse estuary. Elevation of originally marine 87Sr/86Sr in the Bouse Formation to its present level, due to postdepositional interaction with ground water, is unlikely because Sr from secondary calcite above, below, and within the Bouse Formation is consistently less radiogenic, not more, than Bouse marl and shells. In contrast to Bouse Sr, strontium from mollusks in tidal-flat and delta-front paleoenvironments in the contemporaneous Imperial Formation in the Salton trough and from the subsurface south of Yuma was derived from sea water and confirms the dominance of marine strontium near or at the mouth of the late Miocene to early Pliocene Colorado River. Inferred post-early Pliocene uplift of the Bouse Formation from below sea level to modern elevations of up to 550 m has been used to support a late Cenozoic uplift age for the nearby Colorado Plateau. This constraint on uplift timing is eliminated if the Bouse Formation is lacustrine.

  2. Mechanical behaviour of the lithosphere beneath the Adamawa uplift (Cameroon, West Africa) based on gravity data

    NASA Astrophysics Data System (ADS)

    Poudjom Djomani, Y. H.; Diament, M.; Albouy, Y.

    1992-07-01

    The Adamawa massif in Central Cameroon is one of the African domal uplifts of volcanic origin. It is an elongated feature, 200 km wide. The gravity anomalies over the Adamawa uplift were studied to determine the mechanical behaviour of the lithosphere. Two approaches were used to analyse six gravity profiles that are 600 km long and that run perpendicular to the Adamawa trend. Firstly, the coherence function between topography and gravity was interpreted; secondly, source depth estimations by spectral analysis of the gravity data was performed. To get significant information for the interpretation of the experimental coherence function, the length of the profiles was varied from 320 km to 600 km. This treatment allows one to obtain numerical estimates of the coherence function. The coherence function analysis points out that the lithosphere is deflected and thin beneath the Adamawa uplift, and the Effective Elastic Thickness is of about 20 km. To fit the coherence, a load from below needs to be taken into account. This result on the Adamawa massif is of the same order of magnitude as those obtained on other African uplifts such as Hoggar, Darfur and Kenya domes. For the depth estimation, three major density contrasts were found: the shallowest depth (4-15 km) can be correlated to shear zone structures and the associated sedimentary basins beneath the uplift; the second density contrast (18-38 km) corresponds to the Moho; and finally, the last depth (70-90 km) would be the top of the upper mantle and demotes the low density zone beneath the Adamawa uplift.

  3. Radiation and diversification within the Ligularia-Cremanthodium-Parasenecio complex (Asteraceae) triggered by uplift of the Qinghai-Tibetan Plateau.

    PubMed

    Liu, Jian-Quan; Wang, Yu-Jing; Wang, Ai-Lan; Hideaki, Ohba; Abbott, Richard J

    2006-01-01

    The Ligularia-Cremanthodium-Parasenecio (L-C-P) complex of the Tussilagininae (Asteraceae: Senecioneae) contains more than 200 species that are endemic to the Qinghai-Tibetan Plateau in eastern Asia. These species are morphologically distinct; however, their relationships appear complex. A phylogenetic analysis of members of the complex and selected taxa of the tribe Senecioneae was conducted using chloroplast (ndhF and trnL-F) and nuclear (ITS) sequences. Phylogenetic trees were constructed from individual and combined datasets of the three different sequences. All analyses suggested that Doronicum, a genus that has been included in the Tussilagininae, should be excluded from this subtribe and placed at the base of the tribe Senecioneae. In addition, the Tussilagininae should be broadly circumscribed to include the Tephroseridinae. Within the expanded Tussilagininae containing all 13 genera occurring in eastern Asia, Tussilago and Petasites diverged early as a separate lineage, while the remaining 11 genera comprise an expanded L-C-P complex clade. We suggest that the L-C-P clade, which is largely unresolved, most likely originated as a consequence of an explosive radiation. The few monophyletic subclades identified in the L-C-P clade with robust support further suggest that some genera of Tussilagininae from eastern Asia require generic re-circumscriptions given the occurrence of subclades containing species of the same genus in different parts of the phylogentic tree due to homoplasy of important morphological characters used to delimit them. Molecular-clock analyses suggest that the explosive radiation of the L-C-P complex occurred mostly within the last 20 million years, which falls well within the period of recent major uplifts of the Qinghai-Tibetan Plateau between the early Miocene to the Pleistocene. It is proposed that significant increases in geological and ecological diversity that accompanied such uplifting, most likely promoted rapid and continuous

  4. A lithospheric instability origin for Columbia River flood basalts and Wallowa Mountains uplift in northeast Oregon.

    PubMed

    Hales, T C; Abt, D L; Humphreys, E D; Roering, J J

    2005-12-08

    Flood basalts appear to form during the initiation of hotspot magmatism. The Columbia River basalts (CRB) represent the largest volume of flood basalts associated with the Yellowstone hotspot, yet their source appears to be in the vicinity of the Wallowa Mountains, about 500 km north of the projected hotspot track. These mountains are composed of a large granitic pluton intruded into a region of oceanic lithosphere affinity. The elevation of the interface between Columbia River basalts and other geological formations indicates that mild pre-eruptive subsidence took place in the Wallowa Mountains, followed by syn-eruptive uplift of several hundred metres and a long-term uplift of about 2 km. The mapped surface uplift mimics regional topography, with the Wallowa Mountains in the centre of a 'bull's eye' pattern of valleys and low-elevation mountains. Here we present the seismic velocity structure of the mantle underlying this region and erosion-corrected elevation maps of lava flows, and show that an area of reduced mantle melt content coincides with the 200-km-wide topographic uplift. We conclude that convective downwelling and detachment of a compositionally dense plutonic root can explain the timing and magnitude of Columbia River basalt magmatism, as well as the surface uplift and existence of the observed melt-depleted mantle.

  5. Uplift of Zagros Mountains slows plate convergence

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-05-01

    Research has indicated that mountain ranges can slow down the convergence between two tectonic plates on timescales as short as a few million years, as the growing mountains provide enough tectonic force to impact plate motions. Focusing on the convergence of the Arabian and Eurasian plates at the Zagros mountain range, which runs across Iran and Iraq, Austermann and Iaffaldano reconstructed the relative motion of the plates using published paleomagnetic data covering the past 13 million years, as well as current geodetic measurements. They show that the convergence of the two plates has decreased by about 30% over the past 5 million years. Looking at the geological record to infer past topography and using a computer model of the mantle-lithosphere system, the authors examined whether the recent uplift across the Zagros Mountains could have caused the observed slowdown. They also considered several other geological events that might have influenced the convergence rate, but the authors were able to rule those out as dominant controls. The authors conclude that the uplift across the Zagros Mountains in the past 5 million years did indeed play a key role in slowing down the convergence between the Eurasian and Arabian plates. (Tectonics, doi:10.1002/tect.20027, 2013)

  6. Rapid uplift in Laguna del Maule volcanic field of the Andean Southern Volcanic Zone (Chile) measured by satellite radar interferometry

    NASA Astrophysics Data System (ADS)

    Feigl, K.; Ali, T.; Singer, B. S.; Pesicek, J. D.; Thurber, C. H.; Jicha, B. R.; Lara, L. E.; Hildreth, E. W.; Fierstein, J.; Williams-Jones, G.; Unsworth, M. J.; Keranen, K. M.

    2011-12-01

    The Laguna del Maule (LdM) volcanic field of the Andean Southern Volcanic Zone extends over 500 square kilometers and comprises more than 130 individual vents. As described by Hildreth et al. (2010), the history has been defined from sixty-eight Ar/Ar and K-Ar dates. Silicic eruptions have occurred throughout the past 3.7 Ma, including welded ignimbrite associated with caldera formation at 950 ka, small rhyolitic eruptions between 336 and 38 ka, and a culminating ring of 36 post-glacial rhyodacite and rhyolite coulees and domes that encircle the lake. Dating of five post-glacial flows implies that these silicic eruptions occurred within the last 25 kyr. Field relations indicate that initial eruptions comprised modest volumes of mafic rhyodacite magma that were followed by larger volumes of high silica rhyolite. The post-glacial flare-up of silicic magmatism from vents distributed around the lake, is unprecedented in the history of this volcanic field. Using satellite radar interferometry (InSAR), Fournier et al. (2010) measured uplift at a rate of more than 180 mm/year between 2007 and 2008 in a round pattern centered on the west side of LdM. More recent InSAR observations suggest that rapid uplift has continued from 2008 through early 2011. In contrast, Fournier et al. found no measurable deformation in an interferogram spanning 2003 through 2004. In this study, we model the deformation field using the General Inversion of Phase Technique (GIPhT), as described by Feigl and Thurber (2009). Two different models fit the data. The first model assumes a sill at ~5 km depth has been inflating at a rate of more than 20 million cubic meters per year since 2007. The second model assumes that the water level in the lake dropped at a rate of 20 m/yr from January 2007 through February 2010, thus reducing the load on an elastic simulation of the crust. The rate of intrusion inferred from InSAR is an order of magnitude higher than the average rate derived from well-dated arc

  7. Local magnetic fields, uplift, gravity, and dilational strain changes in Southern California ( USA).

    USGS Publications Warehouse

    Johnston, M.J.S.

    1986-01-01

    Measurements of regional magnetic field near the San Andreas fault at Cajon, Palmdale and Tejon are strongly correlated with changes in gravity, areal strain, and uplift in these regions during the period 1977-1984. Because the inferred relationships between these parameters are in approximate agreement with those obtained from simple deformation models, the preferred explanation appeals to short-term strain episodes independently detected in each data set. Transfer functions from magnetic to strain, gravity, and uplift perturbations, obtained by least-square linear fits to the data, are -0.98 nT/ppm, -0.03 nT/mu Gal, and 9.1 nT/m respectively. Tectonomagnetic model calculations underestimate the observed changes and those reported previously for dam loading and volcano-magnetic observations. A less likely alternative explanation of the observed data appeals to a common source of meteorologically generated crustal or instrumental noise in the strain, gravity, magnetic, and uplift data.-from Author

  8. Uplift, thermal unrest and magma intrusion at Yellowstone caldera

    USGS Publications Warehouse

    Wicks, Charles W.; Thatcher, Wayne; Dzurisin, Daniel; Svarc, Jerry

    2006-01-01

    The Yellowstone caldera, in the western United States, formed 640,000 years ago when an explosive eruption ejected 1,000 km3 of material1. It is the youngest of a series of large calderas that formed during sequential cataclysmic eruptions that began 16 million years ago in eastern Oregon and northern Nevada. The Yellowstone caldera was largely buried by rhyolite lava flows during eruptions that occurred from 150,000 to 70,000 years ago1. Since the last eruption, Yellowstone has remained restless, with high seismicity, continuing uplift/subsidence episodes with movements of 70 cm historically2 to several metres since the Pleistocene epoch3, and intense hydrothermal activity. Here we present observations of a new mode of surface deformation in Yellowstone, based on radar interferometry observations from the European Space Agency ERS-2 satellite. We infer that the observed pattern of uplift and subsidence results from variations in the movement of molten basalt into and out of the Yellowstone volcanic system.

  9. Data Shared Lasso: A Novel Tool to Discover Uplift.

    PubMed

    Gross, Samuel M; Tibshirani, Robert

    2016-09-01

    A model is presented for the supervised learning problem where the observations come from a fixed number of pre-specified groups, and the regression coefficients may vary sparsely between groups. The model spans the continuum between individual models for each group and one model for all groups. The resulting algorithm is designed with a high dimensional framework in mind. The approach is applied to a sentiment analysis dataset to show its efficacy and interpretability. One particularly useful application is for finding sub-populations in a randomized trial for which an intervention (treatment) is beneficial, often called the uplift problem. Some new concepts are introduced that are useful for uplift analysis. The value is demonstrated in an application to a real world credit card promotion dataset. In this example, although sending the promotion has a very small average effect, by targeting a particular subgroup with the promotion one can obtain a 15% increase in the proportion of people who purchase the new credit card.

  10. Uplift, thermal unrest and magma intrusion at Yellowstone caldera.

    PubMed

    Wicks, Charles W; Thatcher, Wayne; Dzurisin, Daniel; Svarc, Jerry

    2006-03-02

    The Yellowstone caldera, in the western United States, formed approximately 640,000 years ago when an explosive eruption ejected approximately 1,000 km3 of material. It is the youngest of a series of large calderas that formed during sequential cataclysmic eruptions that began approximately 16 million years ago in eastern Oregon and northern Nevada. The Yellowstone caldera was largely buried by rhyolite lava flows during eruptions that occurred from approximately 150,000 to approximately 70,000 years ago. Since the last eruption, Yellowstone has remained restless, with high seismicity, continuing uplift/subsidence episodes with movements of approximately 70 cm historically to several metres since the Pleistocene epoch, and intense hydrothermal activity. Here we present observations of a new mode of surface deformation in Yellowstone, based on radar interferometry observations from the European Space Agency ERS-2 satellite. We infer that the observed pattern of uplift and subsidence results from variations in the movement of molten basalt into and out of the Yellowstone volcanic system.

  11. Data Shared Lasso: A Novel Tool to Discover Uplift

    PubMed Central

    Gross, Samuel M.; Tibshirani, Robert

    2017-01-01

    A model is presented for the supervised learning problem where the observations come from a fixed number of pre-specified groups, and the regression coefficients may vary sparsely between groups. The model spans the continuum between individual models for each group and one model for all groups. The resulting algorithm is designed with a high dimensional framework in mind. The approach is applied to a sentiment analysis dataset to show its efficacy and interpretability. One particularly useful application is for finding sub-populations in a randomized trial for which an intervention (treatment) is beneficial, often called the uplift problem. Some new concepts are introduced that are useful for uplift analysis. The value is demonstrated in an application to a real world credit card promotion dataset. In this example, although sending the promotion has a very small average effect, by targeting a particular subgroup with the promotion one can obtain a 15% increase in the proportion of people who purchase the new credit card. PMID:29056802

  12. Rb-Sr and K-Ar age of globular phyllosilicates and biostratigraphy of the Riphean deposits of the Olenek Uplift (North Siberia)

    NASA Astrophysics Data System (ADS)

    Zaitseva, T. S.; Gorokhov, I. M.; Semikhatov, M. A.; Ivanovskaya, T. A.; Kuznetsov, A. B.; Dorzhieva, O. V.

    2017-11-01

    This work presents results of the complex mineralogical, geochemical, and isotope-geochronological investigation of globular dioctahedral 2: 1 phyllosilicates (GPS) of the illite-glauconite series from the Riphean sequences of the Olenek Uplift. It is established that GPS (glauconite, Al-glauconite, Fe-illite) in deposits of the Arymass, Debengda, and Khaipakh formations are represented by mixed-layer varieties of two types: (1) with relatively low (<10%) and (2) higher (10-20%) contents of expandable layers. Among the mixed-layer varieties are those with disordered alternation of micaceous and smectite layers (R = 0), as well as with tendency to ordering (R ≥ 1). The parameter b of an elementary cell of minerals varies from 9.18 to 9.72 Å. The Rb-Sr age dating of GPS was first carried out in combination with the calculation of theoretical pattern of the cation distribution in the mineral structure and comparison of the calculation results obtained with the Mössbauer and IR spectroscopy data. This approach is based on the assumption that development and evolution of isotope systems in GPS are synchronous with the evolution of the crystalline structure of the mineral at various stages of the geological and geochemical history of the development of sedimentary units. Analysis of the obtained data allows us to state that the structural features of the Riphean GPS from the Olenek section reflect the early diagenetic stages of the formation of the minerals studied. The 87Sr/86Sr initial ratios in the studied sediments are consistent with the range of variations in this ratio in the Middle Riphean Ocean (0.7049-0.7061). The Rb-Sr and K-Ar ages of the GPS of the Arymass (1305 ± 8 and 1302 Ma, respectively), Debengda (1265 ± 12 and 1284 ± 22 Ma), and Khaipakh (1172 ± 18 and 1112 ± 24 Ma) formations in the Olenek Uplift section are close to the accumulation time of corresponding deposits and, correspondingly, have significance for stratigraphic correlations.

  13. Late Quaternary uplift rate across the Shimokita peninsula, northeastern Japan forearc

    NASA Astrophysics Data System (ADS)

    Matsu'Ura, T.

    2009-12-01

    I estimated the late Quaternary uplift rate across the northeastern Japan forearc (Shimokita peninsula) by using the height distribution of MIS 5.5 marine terraces as determined from tephra and cryptotephra stratigraphy. The heights of inner-margins (shoreline angles) of the MIS 5.5 marine terrace surface were previously reported to be 43-45 m and 30 m around Shiriyazaki and Gamanosawa, respectively. These heights decrease westward and are possibly due to a west-dipping offshore fault. But in some places, the heights of terrace inner-margins are probably overestimated by thick sediments. I found the MIS 5.5 wave-cut platform which is overlain by gravels and loess deposits containing a basal Toya tephra horizon (MIS 5.4) at Shiriyazaki by boring. The MIS 5.5 wave-cut platform (paleo sea level) is about 25 m above sea level, nearly half of the reported height of the terrace inner-margin. My result shows that the late Quaternary uplift rate across the Shimokita peninsula should be reconsidered. Further studies are also required whether or not the intra-plate (offshore) fault is a factor of the forearc uplifting at the peninsula. This research project has been conducted under the research contract with Nuclear and Industrial Safety Agency (NISA).

  14. Widespread uplift and 'trapdoor' faulting on Galápagos volcanoes observed with radar interferometry.

    PubMed

    Amelung, F; Jónsson, S; Zebker, H; Segall, P

    2000-10-26

    Volcanic uplift, caused by the accumulation of magma in subsurface reservoirs, is a common precursor to eruptions. But, for some volcanoes, uplift of metres or more has not yet led to an eruption. Here we present displacement maps of volcanoes in the Galápagos Islands, constructed using satellite radar interferometry, that might help explain this dichotomy. We show that all but one of the seven volcanoes on the islands of Isabela and Fernandina deformed during 1992-99. Cerro Azul and Fernandina erupted during the observation period and show evidence of inflation, co-eruptive deflation and shallow dyke intrusion. In contrast, the largest volcano, Sierra Negra, has not erupted, yet exhibits spatially and temporally variable deformation, with a maximum uplift of 2.7 m between 1992 and 1999, which can be modelled by a shallow inflating sill. Inflation during 1997-98, however, was accompanied by 'trapdoor' faulting on a steeply dipping fracture system within the caldera. Repeated trapdoor faulting over geological time has formed an arcuate intra-caldera ridge within Sierra Negra and may have acted to relax stresses above the magma chamber, inhibiting summit eruptions. Similar processes may help explain large uplift unaccompanied by eruptive activity at other volcanoes.

  15. Ice cap melting and low viscosity crustal root explain narrow geodetic uplift of the Western Alps

    NASA Astrophysics Data System (ADS)

    Chery, Jean; Genti, Manon; Vernant, Philippe

    2016-04-01

    More than 10 years of geodetic measurements demonstrate an uplift rate of 1-3 mm/yr of the high topography region of the Western Alps. By contrast, no significant horizontal motion has been detected. Three uplift mechanisms have been proposed so far: (1) the isostatic response to denudation. However this process is responsible for only a fraction of the observed uplift and (2) the rebound induced by the Wurmian ice cap melting. This process leads to a broader uplifting region than the one evidenced by geodetic observations. (3) a deep source motion associated with slab motion or some deep isostatic unbalance. Using a numerical model accounting for crustal and mantle rheology of the Alps and its foreland, we model the response to Wurmian ice cap melting. We show that a crustal viscosity contrast between the foreland and the central part of the Alps, the later being weaker with a viscosity of 1021 Pa.s, is needed to produce a narrow uplift. The vertical rates are enhanced if the strong uppermost mantle beneath the Moho is interrupted across the Alps, therefore allowing a weak vertical rheological anomaly thanks to the continuity between the low viscosity parts of the crust and mantle. References: Champagnac, J.-D., F. Schlunegger, K. Norton, F. von Blanckenburg, L. M. Abbühl, and M. Schwab (2009), Erosion-driven uplift of the modern Central Alps, Tectonophysics, 474(1-2), 236-249. Vernant, P., F. Hivert, J. Chéry, P. Steer, R. Cattin, and A. Rigo (2013), Erosion-induced isostatic rebound triggers extension in low convergent mountain ranges, geology, 41(4), 467-470.

  16. Early type galaxies: Mapping out the two-dimensional space of galaxy star formation histories

    NASA Astrophysics Data System (ADS)

    Graves, Genevieve J.

    Early type galaxies form a multi-parameter family, as evidenced by the two- dimensional (2-D) Fundamental Plane relationship. However, their star formation histories are often treated as a one-dimensional mass sequence. This dissertation presents a systematic study of the relationship between the multi- parameter structural properties of early type galaxies and their star formation histoires. We demonstrate that the stellar populations of early type galaxies span a 2-D space, which means that their star formation histories form a two- parameter family. This 2-D family is then mapped onto several familiar early type galaxy scaling relations, including the color-magnitude relation, the Fundamental Plane, and a cross-section through the Fundamental Plane. We find that the stellar population properties, and therefore the star formation histories of early type galaxies depend most strongly on galaxy velocity dispersion (s), rather than on luminosity ( L ), stellar mass ( M [low *] ), or dynamical mass ( M dyn ). Interestingly, stellar populations are independent of the radius ( R e ) of the galaxies. At fixed s, they show correlated residuals through the thickness of the Fundamental Plane (FP) in the surface-brightness ( I e ) dimension, such that low-surface-brightness galaxies are older, less metal-enriched, and more enhanced in Mg relative to Fe than their counterparts at the same s and R e on the FP midplane. Similarly, high- surface-brightness galaxies are younger, more metal-rich, and less Mg-enhanced than their counterparts on the FP midplane. These differences suggest that the duration of star formation varies through the thickness of the FP. If the dynamical mass-to-light ratios of early type galaxies ( M dyn /L ) were constant for all such galaxies, the FP would be equivalent to the plane predicted by the virial relation. However, the observed FP does not exactly match the virial plane. The FP is tilted from the virial plane, indicating that M dyn /L varies

  17. Geochronological and sedimentological evidences of Panyangshan foreland basin for tectonic control on the Late Paleozoic plate marginal orogenic belt along the northern margin of the North China Craton

    NASA Astrophysics Data System (ADS)

    Li, Jialiang; Zhou, Zhiguang; He, Yingfu; Wang, Guosheng; Wu, Chen; Liu, Changfeng; Yao, Guang; Xu, Wentao; Zhao, Xiaoqi; Dai, Pengfei

    2017-08-01

    There is a wide support that the Inner Mongolia Palaeo-uplift on the northern margin of the North China Craton has undergone an uplifting history. However, when and how did the uplift occurred keeps controversial. Extensive field-based structural, metamorphic, geochemical, geochronological and geophysical investigations on the Inner Mongolia Palaeo-uplift, which suggested that the Inner Mongolia Palaeo-uplift was an uplifted region since the Early Precambrian or range from Late Carboniferous-Early Jurassic. The geochemical characteristics of the Late Paleozoic to Early Mesozoic intrusive rocks indicated that the Inner Mongolia Palaeo-uplift was an Andean-type continental margin that is the extensional tectonic setting. To address the spatial and temporal development of the Inner Mongolia Palaeo-uplift, we have carried out provenance analysis of Permian sedimentary rocks which collected from the Panyangshan basin along the northern margin of the North China Craton. The QFL diagram revealed a dissected arc-recycled orogenic tectonic setting. Moreover, the framework grains are abundant with feldspar (36-50%), indicating the short transport distance and unstable tectonic setting. Detrital zircon U-Pb analysis ascertained possible provenance information: the Precambrian basement ( 2490 and 1840 Ma) and continental arc magmatic action ( 279 and 295 Ma) along the northern margin of the North China Craton. The projection in rose diagrams of the mean palaeocurrent direction, revealing the SSW and SSE palaeoflow direction, also shows the provenance of the Panyangshan basin sources mainly from the Inner Mongolia Palaeo-uplift. The andesite overlying the Naobaogou Formation has yielded U-Pb age of 277.3 ± 1.4 Ma. The additional dioritic porphyry dike intruded the Naobaogou and Laowopu Formations, which has an emplacement age of 236 ± 1 Ma. The above data identify that the basin formed ranges from Early Permian to Middle Triassic (277-236 Ma). Accordingly, the Inner Mongolia

  18. Geochronological and sedimentological evidences of Panyangshan foreland basin for tectonic control on the Late Paleozoic plate marginal orogenic belt along the northern margin of the North China Craton

    NASA Astrophysics Data System (ADS)

    Li, Jialiang; Zhou, Zhiguang; He, Yingfu; Wang, Guosheng; Wu, Chen; Liu, Changfeng; Yao, Guang; Xu, Wentao; Zhao, Xiaoqi; Dai, Pengfei

    2018-06-01

    There is a wide support that the Inner Mongolia Palaeo-uplift on the northern margin of the North China Craton has undergone an uplifting history. However, when and how did the uplift occurred keeps controversial. Extensive field-based structural, metamorphic, geochemical, geochronological and geophysical investigations on the Inner Mongolia Palaeo-uplift, which suggested that the Inner Mongolia Palaeo-uplift was an uplifted region since the Early Precambrian or range from Late Carboniferous-Early Jurassic. The geochemical characteristics of the Late Paleozoic to Early Mesozoic intrusive rocks indicated that the Inner Mongolia Palaeo-uplift was an Andean-type continental margin that is the extensional tectonic setting. To address the spatial and temporal development of the Inner Mongolia Palaeo-uplift, we have carried out provenance analysis of Permian sedimentary rocks which collected from the Panyangshan basin along the northern margin of the North China Craton. The QFL diagram revealed a dissected arc-recycled orogenic tectonic setting. Moreover, the framework grains are abundant with feldspar (36-50%), indicating the short transport distance and unstable tectonic setting. Detrital zircon U-Pb analysis ascertained possible provenance information: the Precambrian basement ( 2490 and 1840 Ma) and continental arc magmatic action ( 279 and 295 Ma) along the northern margin of the North China Craton. The projection in rose diagrams of the mean palaeocurrent direction, revealing the SSW and SSE palaeoflow direction, also shows the provenance of the Panyangshan basin sources mainly from the Inner Mongolia Palaeo-uplift. The andesite overlying the Naobaogou Formation has yielded U-Pb age of 277.3 ± 1.4 Ma. The additional dioritic porphyry dike intruded the Naobaogou and Laowopu Formations, which has an emplacement age of 236 ± 1 Ma. The above data identify that the basin formed ranges from Early Permian to Middle Triassic (277-236 Ma). Accordingly, the Inner Mongolia

  19. Family history of skin cancer is associated with early-onset basal cell carcinoma independent of MC1R genotype.

    PubMed

    Berlin, Nicholas L; Cartmel, Brenda; Leffell, David J; Bale, Allen E; Mayne, Susan T; Ferrucci, Leah M

    2015-12-01

    As a marker of genetic susceptibility and shared lifestyle characteristics, family history of cancer is often used to evaluate an individual's risk for developing a particular malignancy. With comprehensive data on pigment characteristics, lifestyle factors, and melanocortin 1 receptor (MC1R) gene sequence, we sought to clarify the role of family history of skin cancer in early-onset basal cell carcinoma (BCC). Early onset BCC cases (n=376) and controls with benign skin conditions (n=383) under age 40 were identified through Yale dermatopathology. Self-report data on family history of skin cancer (melanoma and non-melanoma skin cancer), including age of onset in relatives, was available from a structured interview. Participants also provided saliva samples for sequencing of MC1R. A family history of skin cancer was associated with an increased risk of early-onset BCC (OR 2.49, 95% CI 1.80-3.45). In multivariate models, family history remained a strong risk factor for early-onset BCC after adjustment for pigment characteristics, UV exposure, and MC1R genotype (OR 2.41, 95% CI 1.74-3.35). Risk for BCC varied based upon the type and age of onset of skin cancer among affected relatives; individuals with a first-degree relative diagnosed with skin cancer prior to age 50 were at highest risk for BCC (OR 4.79, 95% CI 2.90-7.90). Even after taking into account potential confounding effects of MC1R genotype and various lifestyle factors that close relatives may share, family history of skin cancer remained strongly associated with early-onset BCC. Copyright © 2015. Published by Elsevier Ltd.

  20. Early Childhood Education and Care for Native Hawaiian Children in Hawai'i: A Brief History

    ERIC Educational Resources Information Center

    Grace, Donna J.; Ku'ulei Serna, Alethea

    2013-01-01

    This study provides a brief overview of the history of early childhood education and care for Native Hawaiian children in Hawai'i. Data sources include a literature review, examination of archival documents, and interviews with a sample of Native Hawaiian parents and community members. We trace the emergence of outside-the-home early childhood…

  1. Predicting and testing continental vertical motion histories since the Paleozoic

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Zhong, Shijie; Flowers, Rebecca M.

    2012-02-01

    Dynamic topography at the Earth's surface caused by mantle convection can affect a range of geophysical and geological observations including bathymetry, sea-level change, continental flooding, sedimentation and erosion. These observations provide important constraints on and test of mantle dynamic models. Based on global mantle convection models coupled with the surface plate motion history, we compute dynamic topography and its history for the last 400 Ma associated with Pangea assembly and breakup, with particular focus on cratonic regions. We propose that burial-unroofing histories of cratons inferred from thermochronology data can be used as a new diagnostic to test dynamic topography and mantle dynamic models. Our models show that there are currently two broad dynamic topography highs in the Pacific and Africa for the present-day Earth that are associated with the broad, warm structures (i.e., superplumes) in the deep mantle, consistent with previous proposals of dynamical support for the Pacific and African superswells. Our models reveal that Pangea assembly and breakup, by affecting subduction and mantle upwelling processes, have significant effects on continental vertical motions. Our models predict that the Slave craton in North America subsides before Pangea assembly at 330 Ma but uplifts significantly from 330 Ma to 240 Ma in response to pre-Pangea subduction and post-assembly mantle warming. The Kaapvaal craton of Africa is predicted to undergo uplift from ~180 Ma to 90 Ma after Pangea breakup, but its dynamic topography remains stable for the last 90 Ma. The predicted histories of elevation change for the Slave and Kaapvaal cratons compare well with the burial-unroofing histories inferred from thermochronology studies, thus supporting our dynamic models including the development of the African superplume mantle structure. The vertical motion histories for other cratons can provide further tests of and constraints on our mantle dynamic models.

  2. Predicting and testing continental vertical motion histories since the Paleozoic

    NASA Astrophysics Data System (ADS)

    Zhang, N.; Zhong, S.; Flowers, R. M.

    2011-12-01

    Dynamic topography at the Earth's surface caused by mantle convection can affect a range of geophysical and geological observations including bathymetry, sea-level change, continental flooding, sedimentation and erosion. These observations provide important constraints on and test of mantle dynamic models. Based on global mantle convection models coupled with the surface plate motion history, we compute dynamic topography and its history for the last 400 Ma associated with Pangea assembly and breakup, with particular focus on continental cratonic regions. We propose that burial-unroofing histories of continental cratons inferred from thermochronology data can be used as a new diagnostic to test dynamic topography and mantle dynamic models. Our models show that there are currently two broad dynamic topography highs in the Pacific and Africa for the present-day Earth that are associated with the broad, warm structures (i.e., superplumes) in the deep mantle, consistent with previous proposals of dynamical support for the Pacific and African superswells. Our models reveal that Pangea assembly and breakup, by affecting subduction and mantle upwelling processes, have significant effects on continental vertical motions. Our models predict that the Slave craton in North America subsides before Pangea assembly at 330 Ma but uplifts significantly from 330 Ma to 240 Ma in response to pre-Pangea subduction and post-assembly mantle warming. The Kaapvaal craton of Africa is predicted to undergo uplift from ~180 Ma to 90 Ma after Pangea breakup, but its dynamic topography remains stable for the last 90 Ma. The predicted histories of elevation change for the Slave and Kaapvaal cratons compare well with the burial-unroofing histories inferred from thermochronology studies, thus supporting our dynamic models including the development of the African superplume mantle structure. The vertical motion histories for other cratons can provide further tests and constraints on our mantle

  3. Calculation of ejecta thickness and structural uplift for Lunar and Martian complex crater rims.

    NASA Astrophysics Data System (ADS)

    Krüger, Tim; Sturm, Sebastian; Kenkmann, Thomas

    2014-05-01

    Crater rims of simple and complex craters have an elevation that is formed during the excavation stage of crater formation. For simple crater rims it is believed that the elevation is due to the sum of two equal parts, the thickness of the most proximal impact ejecta blanket (overturned flap) plus the thickness that results from plastic deformation including injection [1, 2, 3]. We intend to measure and quantify the kinematics of mass movements, especially concerning the question why complex impact craters have elevated crater rims like simple craters and precisely constrain the ejecta thickness and structural uplift of Lunar and Martian crater rims to understand what the main contributor to the elevated rim is [4]. We investigated a pristine 16 km-diameter unnamed Martian complex crater (21.52°N, 184.35°) and the lunar complex craters Bessel (21.8°N, 17.9°E) 16 km in diameter and Euler (23.3°N, 29.2°W) 28 km in diameter [5, 6]. In the crater walls of these craters we found columnar lavas on Mars and basaltic layering on the Moon. We used the uppermost layers of these exposed outcrops along the crater wall to determine the dip of the target rocks (Mars) and to distinguish between the bedrock and the overlying ejecta. We precisely measured the structural uplift and ejecta thickness of these complex craters. The unnamed crater on Mars has a mean rim height of 375.75 m, with a structural uplift of 233.88 m (57.44%), exposed as columnar lavas and the superposing ejecta has a height of 141.87 m (43.56%). For the Lunar complex crater Euler the mean total rim height is 790 ± 100 m, with a minimal structural uplift of 475 ± 100 m (60 ± 10 %), exposed as basaltic layers [e.g., 7, 8] and a maximum ejecta thickness of 315 ± 100 m (40 ± 10%). The Lunar complex crater Bessel has a total rim height of 430 ± 15 m , with a minimal structural uplift of 290 ± 15 m (67 ± 3 %), exposed as basaltic layers and a maximum ejecta thickness of 140 ± 115 m (33 ± 3%). For the

  4. Uplift and transtension within the Al Hoceima region, Morocco

    NASA Astrophysics Data System (ADS)

    Poujol, A. P.; Ritz, J. F.; Vernant, P.; Braucher, R.; Blard, P. H.; Tahayt, A.; Maate, S.; Raji, O.

    2016-12-01

    On the southern margin of the Western Mediterranean sea, the Moroccan Rif Cordillera is a thin-skinned fold and thrust belt resulting from the NW-SE convergence between the African and Eurasian lithospheric plates. At the present-day, the kinematics of the W and S borders of the Rif are characterized by active thrusting consistent with the compressional setting. However, in the NE Rif, the present-day deformation is characterized by normal/transtensional faults oblique to the convergence and coeval with regional uplift movement. How did extensional/transtensional faults set up in a compressive regional stress field? And then how to explain uplift in this extensional pattern? In order to better constrain the present-day deformation in the NE Rif, we present results of morphotectonics and quaternary geochronology analysis performed along N-S (the Trougout, Rouadi and Boujibar conjugated faults) and NE-SW faults (the Nekor faults) surrounding the Al-Hoceima Bay hit by two destructives earthquakes in 1994 (Mw 6) and 2004 (Mw 6.4). High-resolution Digital Elevation Models (DEM) of depleted alluvial/marine markers and faults scarps coupled to 14C and TCN (terrestrial Cosmogenic Nuclides) dating of key sites allow determining (i) vertical and horizontal slip rates of 2 mm/yr and 1.5 mm/yr, respectively along the Trougout transtensional fault, (ii) horizontal slip rate of 1.5 mm/yr along the Nekor sinistral fault and (iii) < 1mm/yr along the Rouadi and Boujibar normal faults. Cosmogenic 10Be/3He dating of perched fluvial and marine surfaces yields an average uplift of 0.2mm/yr consistent with previous U/Th dating. These new morphotectonics constraints are consistent with the occurrence of an asymmetric 15-km wide pull-apart basin structure controlled by two major sinistral faults: the Nekor fault to the south and the Trans-Alboran Shear Zone to the north (?). The eastern side of the bay is likely controlled by the main Trougout fault, while on the western side the

  5. Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction

    NASA Astrophysics Data System (ADS)

    Kar, Nandini; Garzione, Carmala N.; Jaramillo, Carlos; Shanahan, Timothy; Carlotto, Victor; Pullen, Alex; Moreno, Federico; Anderson, Veronica; Moreno, Enrique; Eiler, John

    2016-08-01

    The central Altiplano is inferred to have experienced ∼ 2.5 ± 1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene-Pliocene deposits of the Descanso-Yauri basin (14-15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ47 values), carbonate δ18Oc, leaf wax δDwax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ47) and meteoric water isotope values (δ18Oc, δDwax). Our results show that the northernmost plateau remained at low elevation (0.9 ± 0.8 to 2.1 ± 0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23 ± 4 °C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ18Omw (VSMOW) of - 8.3 ± 2.0 ‰ (2 σ) from carbonate (δ18Oc) and - 8.6 ± 1.8 ‰ (2 σ) from leaf wax (δDwax). Modern elevations of 4 km were not reached until 5.4 ± 1.0Ma, as indicated by a negative shift in δDwax (VSMOW) from - 143.4 ± 12.8 ‰ (2 σ) to - 209.2 ± 21.1 ‰ (2 σ) between 9.1 ± 0.7 and 5.4 ± 1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16-19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern-central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19-22°S) between ∼16

  6. Ice cap melting and low-viscosity crustal root explain the narrow geodetic uplift of the Western Alps

    NASA Astrophysics Data System (ADS)

    Chéry, J.; Genti, M.; Vernant, P.

    2016-04-01

    More than 10 years of geodetic measurements demonstrate an uplift rate of 1-3 mm/yr of the high topography region of the Western Alps. By contrast, no significant horizontal motion has been detected. Two uplift mechanisms have been proposed: (1) the isostatic response to denudation responsible for only a fraction of the observed uplift and (2) the rebound induced by the Wurmian ice cap melting which predicts a broader uplifting region than the one evidenced by geodetic observations. Using a numerical model to fit the geodetic data, we show that a crustal viscosity contrast between the foreland and the central part of the Alps, the latter being weaker with a viscosity of 1021 Pa s, is needed. The vertical rates are enhanced if the strong uppermost mantle beneath the Moho is interrupted across the Alps, therefore allowing a weak vertical rheological anomaly over the entire lithosphere.

  7. Flexurally-resisted uplift of the Tharsis Province, Mars

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Sleep, N. H.

    1987-01-01

    The tectonic style of Mars is dominated by vertical motion, perhaps more than any of the terrestrial planets. The imprint of this tectonic activity has left a surface widely faulted even though younger volcanism has masked the expression of tectonism in many places. Geological activity associated with the Tharsis and, to a lesser extent, Elysium provinces is responsible for a significant portion of this faulting, while the origins of the remaining features are enigmatic in many cases. The origin and evolution of the Tharsis and Elysium provinces, in terms of their great elevation, volcanic activity, and tectonic style, has sparked intense debate over the last fifteen years. Central to these discussions are the relative roles of structural uplift and volcanic construction in the creation of immense topographic relief. For example, it is argued that the presence of very old and cratered terrain high on the Tharsis rise, in the vicinity of Claritas Fossae, points to structural uplift of an ancient crust. Others have pointed out, however, that there is no reason that this terrain could not be of volcanic origin and thus part of the constructional mechanism.

  8. The Ellsworth Mountains: critical and enduringly enigmatic

    USGS Publications Warehouse

    Dalziel, I.W.D.

    2007-01-01

    The elevation (~5000m) is high for an early Mesozoic fold belt. Thermal uplift could have been initiated during Jurassic-Cretaceous block rotation and Weddell Sea opening and continued into the Cenozoic. The history of glaciation provides input for models of ice loading and unloading. Measurements of present-day uplift test these models and help assess change in the mass of the ice sheet and hence in global sea level.

  9. A case of rapid rock riverbed incision in a coseismic uplift reach and its implications

    NASA Astrophysics Data System (ADS)

    Huang, Ming-Wan; Pan, Yii-Wen; Liao, Jyh-Jong

    2013-02-01

    During the 1999 Chi-Chi earthquake (Mw = 7.6) in Taiwan, the coseismic displacement induced fault scarps and a pop-up structure in the Taan River. The fault scarps across the river experienced maximum vertical slip of 10 m, which disturbed the dynamic equilibrium of the fluvial system. As a result, rapid incision in the weak bedrock, with a maximum depth of 20 m, was activated within a decade after its armor layer was removed. This case provides an excellent opportunity for closely tracking and recording the progressive evolution of river morphology that is subjected to coseismic uplift. Based on multistaged orthophotographs and digital elevation model (DEM) data, the process of morphology evolution in the uplift reach was divided into four consecutive stages. Plucking is the dominant mechanism of bedrock erosion associated with channel incision and knickpoint migration. The astonishingly high rate of knickpoint retreat (KPR), as rapid as a few hundred meters per year, may be responsible for the rapid incision in the main channel. The reasons for the high rate of KPR are discussed in depth. The total length of the river affected by the coseismic uplift is 5 km: 1 km in the uplift reach and 4 km in the downstream reach. The downstream reach was affected by a reduction in sediment supply and increase in stream power. The KPR cut through the uplift reach within roughly a decade; further significant flooding in the future will mainly cause widening instead of deepening of the channel.

  10. Renewed uplift of the Central Andes Forearc revealed by coastal evolution during the Quaternary

    NASA Astrophysics Data System (ADS)

    Regard, Vincent; Saillard, Marianne; Martinod, Joseph; Audin, Laurence; Carretier, Sébastien; Pedoja, Kevin; Riquelme, Rodrigo; Paredes, Paola; Hérail, Gérard

    2010-08-01

    Most of the Pacific coast of the Central Andes, between 15°S and 30°S, display a wide (a couple of kilometres) planar feature, gently dipping oceanwards and backed by a cliff. This morphology, usually of marine origin, is called rasa, and argues for a recent and spatially continuous uplift of the margin over the 1500-km-long coastal region we describe. The cliff foot is found at a similar elevation (˜ 110 m amsl) all over the studied area, with the exception of peninsulas such as the Mejillones Peninsula. The compilation of published chronological data and the extrapolation of re-appraised uplift rates provide evidence for a common cliff foot age of around 400 ka (i.e., Marine Isotopic Stage MIS 11). This, together with other geological constraints, indicates a Quaternary renewal of uplift in the Central Andes Forearc after a late Pliocene quiescence or subsidence.

  11. Dynamic topography of the southern Central Anatolian Plateau, Turkey, and geodynamic driving mechanisms

    NASA Astrophysics Data System (ADS)

    Schildgen, T. F.; Cosentino, D.; Dudas, F. O.; Niedermann, S.; Strecker, M. R.; Echler, H.; Yildirim, C.

    2010-12-01

    Collision between Eurasia and Arabia and subsequent westward extrusion of the Anatolian microplate explains the development of major intracontinental fault systems in Anatolia that have remained active to the present-day. Concurrent, and probable episodic uplift of the Central and Eastern Anatolian plateaus (CAP and EAP), however, suggests that additional geodynamic mechanisms have contributed to the late Cenozoic morphologic development of the region. Sedimentary basins spanning the southern margin of the CAP provide insights on the timing and rates of different phases of surface uplift, giving constraints to test which geodynamic processes have contributed to surface uplift, orogenic plateau growth, and coupled landscape/climate evolution. Stratigraphic and geomorphic records of uplift and subsidence in the Mut Basin at the southern CAP margin and along the Göksu River record dynamic topographic development. Biostratigraphy and Sr isotope stratigraphy on the highest (ca. 2 km) uplifted marine sediments of the Mut basin furnish a maximum age of ca. 8 Ma for the onset of late Cenozoic uplift of the region. A Pliocene to early Pleistocene marine section, inset within the older stratigraphy at ca. 0.2 to 1.2 km elevation, reveals a history of subsidence and renewed uplift, following the initial uplift that occurred between ca. 8 Ma and Pliocene time. The most recent phase of uplift continued with possibly minor interruptions during the Quaternary, and is recorded by a series of fluvial terraces preserved between 30 and 143 m above the modern Göksu River. One terrace (143 m) reveals a 21Ne model exposure age of ca. 160 ka; ongoing exposure age determination will further constrain the uplift history. Different geodynamic mechanisms have likely contributed to surface uplift along the southern CAP margin. Initial uplift may have been associated with the predominantly sinistral Ecemis fault system that spans the southern and southeastern CAP margin. Neogene counter

  12. Impact of hydrogeological and geomechanical properties on surface uplift at a CO2 injection site: Parameter estimation and uncertainty quantification

    NASA Astrophysics Data System (ADS)

    Newell, P.; Yoon, H.; Martinez, M. J.; Bishop, J. E.; Arnold, B. W.; Bryant, S.

    2013-12-01

    It is essential to couple multiphase flow and geomechanical response in order to predict a consequence of geological storage of CO2. In this study, we estimate key hydrogeologic features to govern the geomechanical response (i.e., surface uplift) at a large-scale CO2 injection project at In Salah, Algeria using the Sierra Toolkit - a multi-physics simulation code developed at Sandia National Laboratories. Importantly, a jointed rock model is used to study the effect of postulated fractures in the injection zone on the surface uplift. The In Salah Gas Project includes an industrial-scale demonstration of CO2 storage in an active gas field where CO2 from natural gas production is being re-injected into a brine-filled portion of the structure downdip of the gas accumulation. The observed data include millimeter scale surface deformations (e.g., uplift) reported in the literature and injection well locations and rate histories provided by the operators. Our preliminary results show that the intrinsic permeability and Biot coefficient of the injection zone are important. Moreover pre-existing fractures within the injection zone affect the uplift significantly. Estimation of additional (i.e., anisotropy ratio) and coupled parameters will help us to develop models, which account for the complex relationship between mechanical integrity and CO2 injection-induced pressure changes. Uncertainty quantification of model predictions will be also performed using various algorithms including null-space Monte Carlo and polynomial-chaos expansion methods. This work will highlight that our coupled reservoir and geomechanical simulations associated with parameter estimation can provide a practical solution for designing operating conditions and understanding subsurface processes associated with the CO2 injection. This work is supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office

  13. The central uplift of Ritchey crater, Mars

    NASA Astrophysics Data System (ADS)

    Ding, Ning; Bray, Veronica J.; McEwen, Alfred S.; Mattson, Sarah S.; Okubo, Chris H.; Chojnacki, Matthew; Tornabene, Livio L.

    2015-05-01

    Ritchey crater is a ∼79 km diameter complex crater near the boundary between Hesperian ridged plains and Noachian highland terrain on Mars (28.8°S, 309.0°E) that formed after the Noachian. High Resolution Imaging Science Experiment (HiRISE) images of the central peak reveal fractured massive bedrock and megabreccia with large clasts. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral analysis reveals low calcium pyroxene (LCP), olivine (OL), hydrated silicates (phyllosilicates) and a possible identification of plagioclase bedrock. We mapped the Ritchey crater central uplift into ten units, with 4 main groups from oldest and originally deepest to youngest: (1) megabreccia with large clasts rich in LCP and OL, and with alteration to phyllosilicates; (2) massive bedrock with bright and dark regions rich in LCP or OL, respectively; (3) LCP and OL-rich impactites draped over the central uplift; and (4) aeolian deposits. We interpret the primitive martian crust as igneous rocks rich in LCP, OL, and probably plagioclase, as previously observed in eastern Valles Marineris. We do not observe high-calcium pyroxene (HCP) rich bedrock as seen in Argyre or western Valles Marineris. The association of phyllosilicates with deep megabreccia could be from impact-induced alteration, either as a result of the Richey impact, or alteration of pre-existing impactites from Argyre basin and other large impacts that preceded the Ritchey impact, or both.

  14. The central uplift of Ritchey crater, Mars

    USGS Publications Warehouse

    Ding, Ning; Bray, Veronica J.; McEwen, Alfred S.; Mattson, Sarah S.; Okubo, Chris H.; Chojnacki, Matthew; Tornabene, Livio L.

    2015-01-01

    Ritchey crater is a ∼79 km diameter complex crater near the boundary between Hesperian ridged plains and Noachian highland terrain on Mars (28.8°S, 309.0°E) that formed after the Noachian. High Resolution Imaging Science Experiment (HiRISE) images of the central peak reveal fractured massive bedrock and megabreccia with large clasts. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral analysis reveals low calcium pyroxene (LCP), olivine (OL), hydrated silicates (phyllosilicates) and a possible identification of plagioclase bedrock. We mapped the Ritchey crater central uplift into ten units, with 4 main groups from oldest and originally deepest to youngest: (1) megabreccia with large clasts rich in LCP and OL, and with alteration to phyllosilicates; (2) massive bedrock with bright and dark regions rich in LCP or OL, respectively; (3) LCP and OL-rich impactites draped over the central uplift; and (4) aeolian deposits. We interpret the primitive martian crust as igneous rocks rich in LCP, OL, and probably plagioclase, as previously observed in eastern Valles Marineris. We do not observe high-calcium pyroxene (HCP) rich bedrock as seen in Argyre or western Valles Marineris. The association of phyllosilicates with deep megabreccia could be from impact-induced alteration, either as a result of the Richey impact, or alteration of pre-existing impactites from Argyre basin and other large impacts that preceded the Ritchey impact, or both.

  15. Topographic form of the Coast Ranges of the Cascadia Margin in relation ot coastal uplift rates and plate subduction

    NASA Technical Reports Server (NTRS)

    Kelsey, Harvey M.; Engebretson, David C.; Mitchell, Clifton E.; Ticknor, Robert L.

    1994-01-01

    The Coast Ranges of the Cascadia margin are overriding the subducted Juan de Fuca/Gorda plate. We investigate the extent to which the latitudinal change in attributes related to the subduction process. These attributes include the varibale age of the subducted slab that underlies the Coast Ranges and average vertical crustal velocities of the western margin of the Coast Rnages for two markedly different time periods, the last 45 years and the last 100 kyr. These vertical crustal velocities are computed from the resurveying of highway bech marks and from the present elevation of shore platforms that have been uplifted in the late Quaternary, respectively. Topogarphy of the Coast Ranges is in part a function of the age and bouyancy of the underlying subducted plate. This is evident in the fact that the two highest topographic elements of the Coast Rnages, the Klamath Mountains and the Olympic Mountains, are underlain by youngest subducted oceanic crust. The subducted Blanco Fracture Zone in southernmost Oregon is responsible for an age discontinuity of subducted crust under the Klamath Mountains. The norhtern terminus of hte topographically higher Klamaths is offset to the north relative to the position of the underlying Blanco Fracture Zone, teh offset being in the direction of migration of the farcture zone, as dictated by relative plate motions. Vertical crustal velocities at the coast, derived from becnh mark surveys, are as much as an order of magnitude greater than vertical crustal velocities derived from uplifted shore platforms. This uplift rate discrepancy indicates that strain is accumulating on the plate margin, to be released during the next interplate earthquake. In a latitudinal sense, average Coast Rnage topography is relatively high where bench mark-derived, short-term vertical crustal velocities are highest. Becuase the shore platform vertical crustal velocities reflect longer-term, premanent uplift, we infer that a small percentage of the

  16. Colluvial deposits as a possible weathering reservoir in uplifting mountains

    NASA Astrophysics Data System (ADS)

    Carretier, Sébastien; Goddéris, Yves; Martinez, Javier; Reich, Martin; Martinod, Pierre

    2018-03-01

    The role of mountain uplift in the evolution of the global climate over geological times is controversial. At the heart of this debate is the capacity of rapid denudation to drive silicate weathering, which consumes CO2. Here we present the results of a 3-D model that couples erosion and weathering during mountain uplift, in which, for the first time, the weathered material is traced during its stochastic transport from the hillslopes to the mountain outlet. To explore the response of weathering fluxes to progressively cooler and drier climatic conditions, we run model simulations accounting for a decrease in temperature with or without modifications in the rainfall pattern based on a simple orographic model. At this stage, the model does not simulate the deep water circulation, the precipitation of secondary minerals, variations in the pH, below-ground pCO2, and the chemical affinity of the water in contact with minerals. Consequently, the predicted silicate weathering fluxes probably represent a maximum, although the predicted silicate weathering rates are within the range of silicate and total weathering rates estimated from field data. In all cases, the erosion rate increases during mountain uplift, which thins the regolith and produces a hump in the weathering rate evolution. This model thus predicts that the weathering outflux reaches a peak and then falls, consistent with predictions of previous 1-D models. By tracking the pathways of particles, the model can also consider how lateral river erosion drives mass wasting and the temporary storage of colluvial deposits on the valley sides. This reservoir is comprised of fresh material that has a residence time ranging from several years up to several thousand years. During this period, the weathering of colluvium appears to sustain the mountain weathering flux. The relative weathering contribution of colluvium depends on the area covered by regolith on the hillslopes. For mountains sparsely covered by regolith

  17. Coastal uplift west of Algiers (Algeria): pre- and post-Messinian sequences of marine terraces and rasas and their associated drainage pattern

    NASA Astrophysics Data System (ADS)

    Authemayou, Christine; Pedoja, Kevin; Heddar, Aicha; Molliex, Stéphane; Boudiaf, Azzedine; Ghaleb, Bassam; Van Vliet Lanoe, Brigitte; Delcaillau, Bernard; Djellit, Hamou; Yelles, Karim; Nexer, Maelle

    2017-01-01

    The North Africa passive margin is affected by the ongoing convergence between the African and Eurasian plates. This convergence is responsible for coastal uplift, folding, and reverse faulting on new and reactivated faults on the margin. The active deformation is diffuse and thus rather difficult to locate precisely. We aim to determine how a coastal landscape evolve in this geodynamic setting and gain insights into active tectonics. More particularly, we evidence and quantify coastal uplift pattern of the Chenoua, Sahel, and Algiers reliefs (Algeria), using sequences of marine terraces and rasas and computing several morphometric indices from the drainage pattern. Upper and Middle Pleistocene uplift rates are obtained by fossil shoreline mapping and preliminary U/Th dating of associated coastal deposits. Extrapolation of these rates combined to analyses of sea-level referential data and spatial relationships between marine terraces/rasas and other geological markers lead us to tentatively propose an age for the highest coastal indicators (purported the oldest). Values of morphometric indices showing correlations with uplift rate allow us to analyze uplift variation on area devoid of coastal sequence. Geological and geomorphological data suggest that coastal uplift probably occurred since the Middle Miocene. It resulted in the emergence of the Algiers massif, followed by the Sahel ridge massif. The Sahel ridge has asymmetrically grown by folding from west to east and was affected by temporal variation of uplift. Compared to previous study, the location of the Sahel fold axis has been shifted offshore, near the coast. The Chenoua fault vertical motion does not offset significantly the coastal sequence. Mean apparent uplift rates and corrected uplift rates since 120 ka are globally steady all along the coast with a mean value of 0.055 ± 0.015 mm/year (apparent) and of 0.005 ± 0.045 mm/year (corrected for eustasy). Mean apparent coastal uplift rates between 120 and

  18. Deglaciation-induced uplift of the Petermann glacier ice margin observed with InSAR

    NASA Astrophysics Data System (ADS)

    Lu, Q.; Amelung, F.; Wdowinski, S.

    2016-12-01

    The Greenland ice sheet is rapidly shrinking with the fastest retreat and thinning occurring at the ice sheet margin and near the outlet glaciers. The changes of the ice mass cause an elastic response of the bedrock. Ice mass loss during the summer months is associated with uplift, whereas ice mass increase during the winter months is associated with subsidence.The German TerraSAR-X and TanDEM-X satellites have systematically observed selected sites along the Greenland Petermann ice sheet margin since summer 2012. Here we present ground deformation observations obtained using an InSAR time-series approach based on small baseline interferograms. We observed rapid deglaciation-induced uplift on naked bedrock near the Petermann glacier ice margin Deformation observed by InSAR is consistent with GPS vertical observations. The time series displacement data reveal not only net uplift but also the seasonal variations. There is no strong relative between displacement changes and SMB ice mass change. The seasonal variations in local area may caused by both nearby SMB changes and ice dynamic changes.

  19. Constraints on early events in Martian history as derived from the cratering record

    NASA Technical Reports Server (NTRS)

    Barlow, Nadine G.

    1990-01-01

    Constrains on early events in Martian history are derived using the planet's cratering record. Variations in the shapes of the crater size-frequency distribution curves are interpreted as indicative of the size-frequency distribution of the production populations, thus providing information about the age of the unit relative to the end of the heavy bombardment period. Results from the analysis of craters superposed on heavily cratered units across the Martian surface provide constraints on the hemispheric dichotomy and the early erosional conditions on Mars.

  20. Miocene Surface Temperature Estimates of the Southern Altiplano and Their Implications for Surface Uplift

    NASA Astrophysics Data System (ADS)

    Smith, J. J.; Garzione, C.; Higgins, P.; MacFadden, B.; Auerbach, D.; Croft, D.

    2008-12-01

    Surface temperature estimates derived from stable isotopes can be used to infer tectonic history and subsequent climate change of the Bolivian Altiplano. This study compares surface temperatures calculated from two fossil localities (Cerdas and Quehua) that span middle to late Miocene age in the southern Altiplano. Temperatures were calculated using the approach of Zanazzi et al. (2007) by comparing the stable isotopes of fossil tooth enamel and concurrent fossilized bones. The δ18O of the surface water is derived from fossil tooth enamel that mineralized at a known mammal body temperature. Surface water compositions are then used to calculate the temperature at which fossil bones were diagenetically altered, using the assumption that most alteration of fossil bones occurs within 20 to 50 thousand years of deposition. These surface temperature estimates can be used as a proxy for the amount of surface uplift based on modern temperature lapse rates. The vertical surface temperature gradient observed in the present-day Andes is about 4.66°C/km. Changes in surface elevations may explain large temperature changes reflected throughout the middle to late Miocene. Cerdas and Quehua, at modern elevations of ~3800m, have fossil records that include teeth and diagenetically altered bones that were deposited before and during a period of inferred rapid surface uplift of the northern Altiplano of 2.5 ± 1 km between ~10 to 6 Ma. Both sites have been dated by magnetostratigraphy and by 40Ar/39Ar dating of tuffs: Cerdas dates from 16.358 ± 0.071 to 15.105 ± 0.073 Ma, and Quehua ranges from 12.611 ± 0.034 to 6.844 ± 0.386 Ma. The close proximity and current elevation of Cerdas (21.9°S, 3800m) and Quehua (20.0°S, 3800m) allows for the assumption that their elevations were closely correlated through time. Thus the temperatures and elevation estimates derived from each location are assumed to reflect the larger extent of the southern Altiplano. If analysis of fossil enamel

  1. The quantum defect: Early history and recent developments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rau, A.R.; Inokuti, M.

    1997-03-01

    The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term {open_quotes}quantum defect{close_quotes} does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schr{umlt o}dinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. We present the early history of the quantum-defect idea, and sketch its recent developments. {copyright}more » {ital 1997 American Association of Physics Teachers.}« less

  2. The carbon-isotopic composition of Proterozoic carbonates: Riphean successions from northwestern Siberia (Anabar Massif, Turukhansk Uplift)

    NASA Technical Reports Server (NTRS)

    Knoll, A. H.; Kaufman, A. J.; Semikhatov, M. A.

    1995-01-01

    Thick carbonate-dominated successions in northwestern Siberia document secular variations in the C-isotopic composition of seawater through Mesoproterozoic and early Neoproterozoic (Early to early Late Riphean) time. Mesoproterozoic dolomites of the Billyakh Group, Anabar Massif, have delta 13C values that fall between 0 and -1.9 permil versus PDB, with values in the upper part of the succession (Yusmastakh Formation) consistently higher than those of the lower (Ust'-Il'ya and Kotuikan formations). Consistent with available biostratigraphic and radiometric data, delta 13C values for Billyakh carbonates compare closely with those characterizing early Mesoproterozoic carbonates (about 1600-1200 Ma) worldwide. In contrast, late Mesoproterozoic to early Neoproterozoic limestones and dolomites in the Turukhansk Uplift exhibit moderate levels of secular variation. Only the lowermost carbonates in the Turukhansk succession (Linok Formation) have delta 13C values that approximate Billyakh values. Higher in the Turukhansk succession, delta 13C values vary from -2.7 to +4.6 permil (with outliers as low as -5.0 permil interpreted as diagentically altered). Again, consistent with paleontological and radiometric data, these values compare well with isotopic values from 1200 to 850 Ma successions elsewhere. Five sections measured in different parts of the Turukhansk basin show nearly identical patterns of variation, confirming that carbonate delta 13C correlates primarily with time and not facies. The Siberian sections illustrate the potential of integrated biostratigraphic and chemostratigraphic data in the intra- and interbasinal correlation of Mesoproterozoic and early Neoproterozoic rocks.

  3. Transpressive mantle uplift at large offset oceanic transform faults

    NASA Astrophysics Data System (ADS)

    Maia, M.; Briais, A.; Brunelli, D.; Ligi, M.; Sichel, S. E.; Campos, T.

    2017-12-01

    Large-offset transform faults deform due to changes in plate motions and local processes. At the St. Paul transform, in the Equatorial Atlantic, a large body of ultramafic rocks composed of variably serpentinized and mylonitized peridotites is presently being tectonically uplifted. We recently discovered that the origin of the regional mantle uplift is linked to long-standing compressive stresses along the transform fault (1). A positive flower structure, mainly made of mylonitized mantle rocks, can be recognized on the 200 km large push-up ridge. Compressive earthquakes mechanisms reveal seismically active thrust faults on the southern flank of the ridge . The regional transpressive stress field affects a large portion of the ridge segment south of the transform, as revealed by the presence of faults and dykes striking obliquely to the direction of the central ridge axis. A smaller thrust, affecting recent sediments, was mapped south of this segment, suggesting a regional active compressive stress field. The transpressive stress field is interpreted to derive from the propagation of the Mid-Atlantic Ridge (MAR) segment into the transform domain as a response to the enhanced melt supply at the ridge axis. The propagation forced the migration and segmentation of the transform fault southward and the formation of restraining step-overs. The process started after a counterclockwise change in plate motion at 11 Ma initially resulting in extensive stress of the transform domain. A flexural transverse ridge formed in response. Shortly after plate reorganization, the MAR segment started to propagate southwards due to the interaction of the ridge and the Sierra Leone thermal anomaly. 1- Maia et al., 2016. Extreme mantle uplift and exhumation along a transpressive transform fault Nat. Geo. doi:10.1038/ngeo2759

  4. Score As You Lift (SAYL): A Statistical Relational Learning Approach to Uplift Modeling.

    PubMed

    Nassif, Houssam; Kuusisto, Finn; Burnside, Elizabeth S; Page, David; Shavlik, Jude; Costa, Vítor Santos

    We introduce Score As You Lift (SAYL), a novel Statistical Relational Learning (SRL) algorithm, and apply it to an important task in the diagnosis of breast cancer. SAYL combines SRL with the marketing concept of uplift modeling, uses the area under the uplift curve to direct clause construction and final theory evaluation, integrates rule learning and probability assignment, and conditions the addition of each new theory rule to existing ones. Breast cancer, the most common type of cancer among women, is categorized into two subtypes: an earlier in situ stage where cancer cells are still confined, and a subsequent invasive stage. Currently older women with in situ cancer are treated to prevent cancer progression, regardless of the fact that treatment may generate undesirable side-effects, and the woman may die of other causes. Younger women tend to have more aggressive cancers, while older women tend to have more indolent tumors. Therefore older women whose in situ tumors show significant dissimilarity with in situ cancer in younger women are less likely to progress, and can thus be considered for watchful waiting. Motivated by this important problem, this work makes two main contributions. First, we present the first multi-relational uplift modeling system, and introduce, implement and evaluate a novel method to guide search in an SRL framework. Second, we compare our algorithm to previous approaches, and demonstrate that the system can indeed obtain differential rules of interest to an expert on real data, while significantly improving the data uplift.

  5. Erosion-driven uplift in the Gamburtsev Subglacial Mountains of East Antarctica

    NASA Astrophysics Data System (ADS)

    Paxman, G. J. G.; Watts, A. B.; Ferraccioli, F.; Jordan, T. A.; Bell, R. E.; Jamieson, S. S. R.; Finn, C. A.

    2016-10-01

    The relative roles of climate and tectonics in mountain building have been widely debated. Central to this debate is the process of flexural uplift in response to valley incision. Here we quantify this process in the Gamburtsev Subglacial Mountains, a paradoxical tectonic feature in cratonic East Antarctica. Previous studies indicate that rifting and strike-slip tectonics may have provided a key trigger for the initial uplift of the Gamburtsevs, but the contribution of more recent valley incision remains to be quantified. Inverse spectral (free-air admittance and Bouguer coherence) methods indicate that, unusually for continents, the coherence between free-air gravity anomalies and bedrock topography is high (>0.5) and that the elastic thickness of the lithosphere is anomalously low (<15 km), in contrast to previously reported values of up to ∼70 km. The isostatic effects of two different styles of erosion are quantified: dendritic fluvial incision overprinted by Alpine-style glacial erosion in the Gamburtsevs and outlet glacier-type selective linear erosion in the Lambert Rift, part of the East Antarctic Rift System. 3D flexural models indicate that valley incision has contributed ca. 500 m of peak uplift in the Gamburtsevs and up to 1.2 km in the Lambert Rift, which is consistent with the present-day elevation of Oligocene-Miocene glaciomarine sediments. Overall, we find that 17-25% of Gamburtsev peak uplift can be explained by erosional unloading. These relatively low values are typical of temperate mountain ranges, suggesting that most of the valley incision in the Gamburtsevs occurred prior to widespread glaciation at 34 Ma. The pre-incision topography of the Gamburtsevs lies at 2-2.5 km above sea-level, confirming that they were a key inception point for the development of the East Antarctic Ice Sheet. Tectonic and/or dynamic processes were therefore responsible for ca. 80% of the elevation of the modern Gamburtsev Subglacial Mountains.

  6. Outcomes of patients with a pretransplant history of early-stage melanoma.

    PubMed

    Puza, Charles J; Barbas, Andrew S; Mosca, Paul J

    2018-06-25

    A history of melanoma within the preceding 5 years is commonly considered a contraindication to solid organ transplantation. We investigated how a pretransplant history of melanoma impacts patient survival and melanoma recurrence. Institutional Review Board approval was obtained, and Duke's retrospective database was used to identify 4552 patients who underwent a solid organ transplant at Duke University from 1 January 2001 to 31 December 2016. Data with regard to the transplant, melanoma characteristics, rejection episodes, and survival were recorded. Of 4552 patients who underwent a solid organ transplant, 12 (0.3%) had a history of melanoma before transplant (six with melanoma in situ and six with stage I disease). The median time between melanoma diagnosis and transplant was 4.13 years (range: 1.1-13.3 years). The study cohort consisted of four liver transplants, four lung transplants, one kidney transplant, one heart transplant, one small bowel transplant, and one multivisceral transplant. At the median follow-up time of 2.8 years, 10 (83.3%) patients were alive. In nonmelanoma cohorts, the 3-year survival is 70% for thoracic transplants, 78% for liver transplants, and 88% for kidney transplants. In well-selected patients with a history of early-stage melanoma and an appropriate time interval between melanoma treatment and transplant, post-transplant outcomes are favorable.

  7. Architecture and morphology of coral reef sequences. Modeling and observations from uplifting islands of SE Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Pastier, Anne-Morwenn; Husson, Laurent; Bezos, Antoine; Pedoja, Kevin; Elliot, Mary; Hafidz, Abdul; Imran, Muhammad; Lacroix, Pascal; Robert, Xavier

    2016-04-01

    During the Late Neogene, sea level oscillations have profoundly shaped the morphology of the coastlines of intertropical zones, wherein relative sea level simultaneously controlled reef expansion and erosion of earlier reef bodies. In uplifted domains like SE Sulawesi, the sequences of fossil reefs display a variety of fossil morphologies. Similarly, the morphologies of the modern reefs are highly variable, including cliff notches, narrow fringing reefs, wide flat terraces, and barriers reefs. In this region, where uplift rates vary rapidly laterally, the entire set of morphologies is displayed within short distances. We developed a numerical model that predicts the architecture of fossil reefs sequences and apply it to observations from SE Sulawesi, accounting -amongst other parameters- for reef growth, coastal erosion, and uplift rates. The observations that we use to calibrate our models are mostly the morphology of both the onshore (dGPS and high-resolution Pleiades DEM) and offshore (sonar) coast, as well as U-Th radiometrically dated coral samples. Our method allows unravelling the spatial and temporal evolution of large domains on map view. Our analysis indicates that the architecture and morphology of uplifting coastlines is almost systematically polyphased (as attested by samples of different ages within a unique terrace), which assigns a primordial role to erosion, comparable to reef growth. Our models also reproduce the variety of modern morphologies, which are chiefly dictated by the uplift rates of the pre-existing morphology of the substratum, itself responding to the joint effects of reef building and subsequent erosion. In turn, we find that fossil and modern morphologies can be returned to uplift rates rather precisely, as the parametric window of each specific morphology is often narrow.

  8. Late Miocene to present-day exhumation and uplift of the Internal Zone of the Rif chain: Insights from low temperature thermochronometry and basin analysis

    NASA Astrophysics Data System (ADS)

    Romagny, A.; Ph. Münch; Cornée, J.-J.; Corsini, M.; Azdimousa, A.; Melinte-Dobrinescu, M. C.; Drinia, H.; Bonno, M.; Arnaud, N.; Monié, P.; Quillévéré, F.; Ben Moussa, A.

    2014-07-01

    Located on the margin of the west Alboran basin, the Gibraltar Arc (Betic-Rif mountain belt) displays post-Pliocene vertical movements evidenced by uplifted marine sedimentary basins and marine terraces. Quantification of vertical movements is an important clue to understand the origin of present-day relief generation in the Betic-Rif mountain chain together with the causes of the Messinian Salinity Crisis. In this paper, we present the results of a pluridisciplinary study combining an analysis of low temperature thermochronology and Pliocene basins evolution to constrain the exhumation history and surface uplift of internals units of the Rif belt (Northern Morocco). The mean (U-Th)/He apatite ages obtained from 11 samples are comprised between 14.1 and 17.8 Ma and display a wide dispersion, which could be explained by a great variability of apatite chemistries in the analyzed samples. No correlations between altitude and age have been found along altitudinal profile suggesting a rapid exhumation during this period. Thermal modeling using our (U-Th)/He apatite ages and geochronological data previously obtained in the same area (40Ar/39Ar and K/Ar data on biotite, zircon and apatite fission track) allow us to propose a cooling history. The rocks suffered a rapid cooling at 60-100 °C/Ma between 22.5 and 19 Ma, then cooled to temperatures around 40 °C between 19 and 18 Ma. They were re-heated at around 110 °C between 18 and 15 Ma then rapidly cooled and exhumed to reach the surface temperature at around 13 Ma. The re-heating could be related to a renewal in thrusting and burying of the inner zones. Between 15 and 13 Ma the cooling resumed at a rate of 50 °C/Ma indicating an exhumation rate of 0.8 mm/y considering an average 40 °C/km geothermal gradient. This exhumation may be linked to the extension in the Alboran Sea. Otherwise biostratigraphic and sedimentological analysis of Pliocene basins of the internal Rif provided informations on the more recent events

  9. Early parental loss and depression history: associations with recent life stress in major depressive disorder.

    PubMed

    Slavich, George M; Monroe, Scott M; Gotlib, Ian H

    2011-09-01

    Although exposure to early adversity and prior experiences with depression have both been associated with lower levels of precipitating life stress in depression, it is unclear whether these stress sensitization effects are similar for all types of stress or whether they are specific to stressors that may be particularly depressogenic, such as those involving interpersonal loss. To investigate this issue, we administered structured, interview-based measures of early adversity, depression history, and recent life stress to one hundred adults who were diagnosed with major depressive disorder. As predicted, individuals who experienced early parental loss or prolonged separation (i.e., lasting one year or longer) and persons with more lifetime episodes of depression became depressed following lower levels of life stress occurring in the etiologically-central time period of three months prior to onset of depression. Importantly, however, additional analyses revealed that these effects were unique to stressors involving interpersonal loss. These data highlight potential stressor-specific effects in stress sensitization and demonstrate for the first time that individuals exposed to early parental loss or separation, and persons with greater histories of MDD, may be selectively sensitized to stressors involving interpersonal loss. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Earthquake-caused coastal uplift and its effects on rocky intertidal kelp communities.

    PubMed

    Castilla, J C

    1988-10-21

    The coastal uplift(approximately 40 to 60 centimeters) associated with the Chilean earthquake of 3 March 1985 caused extensive mortality of intertidal organisms at the Estación Costera de Investigaciones Marinas, Las Cruces. The kelp belt of the laminarian Lessonia nigrescens was particularly affected. Most of the primary space liberated at the upper border of this belt was invaded by species of barnacles, which showed an opportunistic colonization strategy. Drastic modifications in the environment such as coastal uplift, subsidence, or the effects of the El Niño phenomenon are characteristic of the southern Pacific. Modifications in the marine ecosystem that generate catastrophic and widespread mortalities of intertidal organisms can affect species composition, diversity, or local biogeography.

  11. The origin of large local uplift in extensional regions

    USGS Publications Warehouse

    King, G.; Ellis, M.

    1990-01-01

    Large localized uplift is commonly observed in continental regions undergoing extension. These observations can be modelled by planar, high-angle normal faulting of an elastic upper crust overlying an inviscid lower crust. Isostasy provides the necessary driving force. The model quantifies the role of flexural rigidity, density variations in the crust, and erosion and deposition of sediment.

  12. Effects of Caribbean oceanic plateau shallow subduction on topographic uplift and exhumation of the northwestern Maracaibo block, Colombia

    NASA Astrophysics Data System (ADS)

    Sanchez, J.; Mann, P.

    2013-12-01

    central SP show several slope-break knickpoints and changes in steepness indices by factor of ~1.9, all indicative of fault control in this area; 3) perturbations in stream profiles with change in steepness indices by a factor of ~1.6 occur in the southern SP are interpreted as the expression of the active Santa-Marta Bucaramanga fault system, 4) although most of the knickpoints in SSM profiles seem to be associated with changes in bedrock lithology, the alignments, slope-breaking character, and change in steepness indices by factor of ~1.8-2.2 indicate active ENE-WSW fault control along the south-southeastern edge of the SSM, 5) generally undisturbed profiles at northern SSM suggest current quiescence in rock uplift in this area; and 6) basin modeling of the CRB constrain the most recent uplift event as Mio-Pliocene at rates of 0.15-0.18 mm/yr. We propose that the most likely tectonic mechanism to explain widespread active fault activity and uplift within the SSM and SP is oblique, low-angle (20 degrees), southeastward subduction of the Caribbean plate beneath the area. The present rate of subduction and length of slab would have initiated uplift and fault activity at Early Miocene.

  13. Miocene mass-transport sediments, Troodos Massif, Cyprus

    USGS Publications Warehouse

    Lord, A.R.; Harrison, R.W.; BouDagher-Fadel, M.; Stone, B.D.; Varol, O.

    2009-01-01

    Sediment mass-transport layers of submarine origin on the northern and southern flanks of the Troodos ophiolitic massif are dated biostratigraphically as early Miocene and late Miocene, respectively and therefore represent different seismogenic events in the uplift and erosional history of the Troodos terrane. Analysis of such events has potential for documenting Miocene seismic and uplift events regionally in the context of changing stress field directions and plate vectors through time. ?? 2009 The Geologists' Association.

  14. Comparative thermometry on pelitic rocks and marbles of the Llano uplift, Texas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Letargo, C.M.R.; Lamb, W.M.

    1992-01-01

    The Llano Uplift in central Texas is a Grenville-aged metamorphic complex consisting of amphibolite facies assemblages whose development has been attributed to the emplacement of granite plutons between 1.0--1.1 Ga. Temperatures have been obtained from garnet-biotite, garnet-ilmenite, and calcite-dolomite pairs as well as from various silicate equilibria. Application of these geothermometers yield consistent results and are thus indicative of peak conditions attending the amphibolite facies metamorphism. Temperature determined using garnet-biotite and garnet-ilmenite thermometry compare favorably with calcite-dolomite temperatures obtained from marbles in contact with granite plutons in the southeastern part of the uplift. The highest calcite-dolomite temperatures of [approximately]600 Cmore » are obtained from marbles containing an isobarically invariant assemblage consisting of calcite + dolomite + diopside + tremolite + forsterite. At pressures of 2--3 kbar, this isobarically invariant assemblage will be stable at a temperature range of [approximately]600--650 C. Also in close proximity to granites in the southeast uplift is the assemblage muscovite + quartz + k-feldspar + sillimanite [approximately] andalusite which indicate T 650 C and P 2.5 kbar. Assemblages consisting of garnet + sillimanite + quartz + plagioclase (GASP) and garnet + rutile + ilmenite + plagioclase + quartz (GRIPS) are currently being studied to provide additional constraints on pressures of amphibolite facies metamorphism.« less

  15. Tidal friction and the early history of the moon's orbit

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1975-01-01

    The present work investigates the consequences implied by various rheological models of the early earth for the orbital history of the moon subsequent to its formation. Models of the earth that yield small tidal angles, such as low-viscosity models, imply that the moon never orbited in the earth's equatorial plane, thereby ruling out an equatorial origin for the moon. A high-viscosity model is shown to permit the moon to originate in the equatorial plane and still account for the present-day characteristics of the moon's orbit.

  16. Social Confidence in Early Adulthood among Young People with and without a History of Language Impairment

    ERIC Educational Resources Information Center

    Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew; Conti-Ramsden, Gina

    2017-01-01

    Purpose: The purposes of this study were to test the predictions that lower self-esteem and higher shyness in individuals with a history of language impairment (LI) would continue from adolescence into early adulthood and that those with LI would have lower social self-efficacy in early adulthood. Method: Participants were young people with a…

  17. Uplift Sequence of the Main Morphoestructural Units of the South Central Andes at 30°S: Insights from a Multidisciplinary Approach

    NASA Astrophysics Data System (ADS)

    Lossada, A. C.; Mardónez, D.; Suriano, J.; Hoke, G. D.; Fitzgerald, P. G.; Mahoney, J. B.; Giambiagi, L.; Aragon, E.

    2015-12-01

    The South Central Andes at 30°S represent a key area to understand the Andes geodynamics as it corresponds to the flat slab segment, characterized by a subhorizontal subduction angle, absence of Neogene magmatism and a highly compressive tectonic regime. Under these settings, crustal shortening is believed to be the principal mechanism responsible for the rise of the Andes. However, the sequence of uplift of the different morphoestructural units composing the orogen is not fully understood; neither do the location and time of activity of intracrustal detachments and their connection with shallower structures. We attempt to develop a multidisciplinary analysis that allow us to characterize the timing, magnitude and activity of the principal structures involved in the construction of the Andes at 30°S trough the Coastal Range, the Frontal Cordillera and the Precordillera. The main phase of deformation in the Coastal Range occurred between 60 and 40Ma, based on published thermochronological and structural data. Our structural analyses constrain the Frontal Cordillera uplift between 18 and 13Ma. In the Precordillera area, in turn, we carried out structural, sedimentological and U-Pb provenience studies. Provenience studies and the 12 and 9Ma ages obtained for the youngest zircons indicated that the main thrusts uplifting the western sector of the Precordillera thrust system were activated since 13Ma at this latitude, and not before that time as it was previously suggested. In order to better constrain the exhumation and thermal history of Frontal Cordillera, a thermochronological study is being conducted. Twenty samples for apatite fission tracks (AFT) and apatite (U-Th)/He (AHe) were collected from two vertical profiles located at western sector (Guanta granitoid) and eastern sector (Colanguil granitoid) of the Frontal Cordillera system. Samples are currently being processed, and they are partially reseted, which will allow us to obtain a cooling age. The aim is to

  18. The early history of the synapse: from Plato to Sherrington.

    PubMed

    Bennett, M R

    1999-09-15

    One hundred years ago, in 1897, Sherrington adopted the name synapse. However, the concept of the synapse emerged from considerations of how muscles are contracted and so locomotion affected over a period of 2400 years, from the time of Plato and Aristotle in the 4th century BC to the early part of the 20th century. This early history is considered in the present review. In terms of duration of influence, the early history was dominated by Aristotle's concept of vital pneuma. This was derived from the ether which filled all space, taken in by the lungs, transformed to vital pneuma in the heart, and then conducted in the blood stream to be transmitted to muscles. The vital pneuma then initiated the final phase of the muscle's psyche, that is, its contraction leading to locomotion. Aristotle's ideas had to be modified with the discovery by Galen and his students in the 2nd and 3rd centuries AD that nerves arising from the brain and spinal cord are necessary for the initiation of muscle contraction. They modified the Aristotlean account so that the vital pneuma delivered by blood vessels to the brain was converted there to psychic pneuma, from whence it was conducted along nerves to be transmitted to muscle, so allowing the muscle to contract. There matters rested for about 1300 years until Descartes. Descartes rejected the idea of organs and muscles possessing a psyche with a final cause that was released by the conduction and transmission of psychic pneuma in nerves, emphasising that mechanical explanations must be sought when determining the function of an organ or muscle. He argued in his corpuscular theory that fine particles derived from the blood in the brain, which he gave the unfortunate name of animal spirits, were conducted and transmitted along nerves to enter muscle during transmission, so leading to the increase in width of the muscle fibres, their shortening and contraction. This description was elaborated on in great detail by Descartes, and by his

  19. Uplift and submarine formation of some Melanesian porphyry copper deposits: Stable isotope evidence

    USGS Publications Warehouse

    Chivas, A.R.; O'Neil, J.R.; Katchan, G.

    1984-01-01

    Hydrogen and oxygen isotope analyses of sericites and kaolinites from four young porphyry copper deposits (Ok Tedi (1.2 Ma) and Yandera (6.5 Ma), Papua New Guinea; Koloula (1.5 Ma), Solomon Islands; and Waisoi (<5 Ma), Fiji) indicate that the fluids from which these minerals precipitated were of mixed magmatic and non-magmatic sources. The non-magmatic component of the fluid from the island arc deposits (Koloula, Waisoi) was ocean water. For Ok Tedi, the non-magmatic component was a meteoric water with an isotopic composition different from that of the present meteoric water in the region. The isotopic signature of the former meteoric water is consistent with a surface elevation of 200 m a.s.l. or less at the time of mineralization. The deposit was later exposed and supergene kaolinitization commenced at approximately 1200 m a.s.l. Uplift and erosion has continued to the present at which time the elevation of the exposed deposit is 1800 m a.s.l. This rate of uplift is consistent with that known from other geological evidence. If the rate of uplift were approximately constant during the last 1.2 Ma, the age of supergene enrichment can be dated at approximately 0.4 Ma B.P. Similarly, influx of meteoric water at Yandera occurred when the ground surface above the deposit was at an elevation of approximately 600 m a.s.l. The deposit's present elevation is 1600 m a.s.l. In this case a total uplift of approximately 2.2 km is indicated, with removal of 1.2 km of overburden by erosion. ?? 1984.

  20. Impact melting early in lunar history

    NASA Technical Reports Server (NTRS)

    Lange, M. A.; Ahrens, T. J.

    1979-01-01

    The total amount of impact melt produced during early lunar history is examined in light of theoretically and experimentally determined relations between crater diameter (D) and impact melt volume. The time dependence of the melt production is given by the time dependent impact rate as derived from cratering statistics for two different crater-size classes. Results show that small scale cratering (D less than or equal to 30 km) leads to melt volumes which fit selected observations specifying the amount of impact melt contained in the lunar regolith and in craters with diameters less than 10 km. Larger craters (D greater than 30 km) are capable of forming the abundant impact melt breccias found on the lunar surface. The group of large craters (D greater than 30 km) produces nearly 10 times as much impact melt as all the smaller craters, and thus, the large impacts dominate the modification of the lunar surface. A contradiction between the distribution of radiometric rock ages and a model of exponentially decreasing cratering rate going back to 4.5 b.y. is reflected in uncertainty in the distribution of impact melt as a function of time on the moon.

  1. Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading

    NASA Astrophysics Data System (ADS)

    Nield, G. A.; Barletta, V. R.; Bordoni, A.; King, M. A.; Whitehouse, P. L.; Clarke, P. J.; Domack, E. W.

    2013-12-01

    Since 1995 several ice shelves in the northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at GPS stations. The previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf failed, being limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to show that non-linear uplift of the Palmer GPS station since 2002 cannot be explained by an elastic-only signal. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995. We vary the thickness of the elastic lithosphere and upper mantle viscosity, and test the fit to the Palmer GPS time series. We find a best fitting Earth model with an upper mantle viscosity of less than 2 x 1018 Pa s, much lower than previously modelled, and limited sensitivity to lithospheric thickness. Comparison to vertical velocities from six GPS stations deployed after 2009 (the LARISSA network) verifies the results from the model with reduction of signal from up to 14 mm/yr to up to 3 mm/yr. These sites have a unique spatial arrangement and are ideally placed to record uplift close to the region of largest mass loss. Including the time series of the newer sites in the model tuning produces a narrower range of lithospheric thickness estimates but with the drawback of needing to assume the pre-2009 background uplift rate. The Palmer GPS time series offers a rare opportunity to study the time-evolution of low-viscosity solid earth response to a well-captured ice unloading event.

  2. Seismic influence in the Quaternary uplift of the Central Chile coastal margin, preliminary results.

    NASA Astrophysics Data System (ADS)

    Valdivia, D.; del Valle, F.; Marquardt, C.; Elgueta, S.

    2017-12-01

    In order to quantify the influence of NW striking potentially seismogenic normal faults over the longitudinal variation of the Central Chile Coastal margin uplift, we measured Quaternary marine terraces, which represent the tectonic uplift of the coastal margin. Movement in margin oblique normal faults occurs by co-seismic extension of major subduction earthquakes and has occurred in the Pichilemu fault, generating a 7.0 Mw earthquake after the 2010 8.8 Mw Maule earthquake.The coastal area between 32° and 34° S was selected due to the presence of a well-preserved sequence of 2 to 5 Quaternary marine terraces. In particular, the margin oblique normal NW-trending, SW-dipping Laguna Verde fault, south of Valparaiso (33° S) puts in contact contrasting morphologies: to the south, a flat coast with wide marine terraces is carved in both, Jurassic plutonic rocks and Neogene semi-consolidated marine sediments; to the north, a steeper scarp with narrower marine terraces, over 120 m above the corresponding ones in the southern coast, is carved in Jurassic plutonic rocks.We have collected over 6 months microseimic data, providing information on seismic activity and underground geometry of the Laguna Verde fault. We collected ca. 100 systematic measurements of fringes at the base of paleo coastal scarps through field mapping and a 5 m digital elevation model. These fringes mark the maximum sea level during the terrace's carving.The heights of these fringes range between 0 and 250 masl. We estimate a 0.7 mm/yr slip rate for the Laguna Verde fault based on the height difference between corresponding terraces north- and southward, with an average uplift rate of 0.3 mm/yr for the whole area.NW striking normal faults, besides representing a potential seismic threat to the near population on one of the most densely populated areas of Chile, heavily controls the spatial variation of the coastal margin uplift. In Laguna Verde, the uplift rate differs more than three times northward

  3. Seismic Reflection Characteristic and Structure Unit Division of Nanwei Uplift in the Nansha Waters, South China Sea

    NASA Astrophysics Data System (ADS)

    Guo, L.; Zhan, W.; Yao, Y.

    2016-12-01

    Nanwei uplift is located in the continent-ocean transition zone at the southern margin of the South China Sea (SCS). It has the structural characteristics in typical passive margin models. Attributed to squeezing action, the anticline and faulted anticline structure were well developed since Oligocene. The development of organic reef and marine mudstone deposit indicated the drifting and subsidence stage. In this area, the structural evolution is not only related to the dynamic systems of rifting, basin spreading and expansion ending, but also to the collisions between different plates. Meanwhile, a large number of continental margin rifting basins with rich oil and gas resources developed in Nanwei uplift. It is meaningful to analyze the characteristics of seismic reflection waves. Also, two main structural unit were divided for studying the special structures and stratigraphic features in this paper. Two high-resolution single-channel seismic Line Nan-1 and Line Nan-2 in the Nansha Waters, acquired by the trial vessel "Shiyan 2" of the South China Sea Institute of Oceanology in 2013, is interpreted and analyzed in this study. The profiles show that there are a lot of normal fault half-garben systems and depressions in NE direction. Five seismic interfaces have been distinguished, named T0,T3,T4,T5 and Tg respectively. It corresponds to different regional unconformities in different geological age which indicated the characteristics of regional tectonics. On the basis of tectonic shape and previous geophysical data, it is believed that the Nanwei uplift zone is mainly composed of two structural units, the southern subsidence belt and northern buried volcanic uplift belt. The general range of zoning is also discussed in this paper. It is considered that the buried volcanic uplift belt mainly involved the marginal area along the southern ocean basin from 63-72 km wide in SE direction, the neighboring subsidence belt in rifting stage is parallel to the buried

  4. Surgical management of early pregnancy failure: history, politics, and safe, cost-effective care.

    PubMed

    Harris, Lisa H; Dalton, Vanessa K; Johnson, Timothy R B

    2007-05-01

    Early pregnancy failure and induced abortion are often managed differently, even though safe uterine evacuation is the goal in both. Early pregnancy failure is commonly treated by curettage in operating room settings in anesthetized patients. Induced abortion is most commonly managed by office vacuum aspiration in awake or sedated patients. Medical evidence does not support routine operating room management of early pregnancy failure. This commentary reviews historical origins of these different care standards, explores political factors responsible for their perpetuation, and uses experience at University of Michigan to dramatize the ways in which history, politics, and biomedicine intersect to produce patient care. The University of Michigan initiated office uterine evacuations for early pregnancy failure treatment. Patients previously went to the operating room. These changes required faculty, staff, and resident education. Our efforts blurred the lines between spontaneous and induced abortion management, improved patient care and better utilized hospital resources.

  5. Rock Uplift above the Yakutat Megathrust on Montague Island, Prince William Sound, Alaska

    NASA Astrophysics Data System (ADS)

    Ferguson, K.; Armstrong, P. A.; Haeussler, P. J.; Arkle, J. C.

    2011-12-01

    The Yakutat microplate is subducting shallowly (~6°) beneath the North American Plate at a rate of approximately 53 mm/yr to the northwest. Deformation from this flat- slab subduction extends >600 km inland and has resulted in regions of focused rock uplift and exhumation in the Alaska Range, central Chugach Mountains, and St. Elias Mountains. Many questions still remain about how strain is partitioned between these regions of focused uplift, particularly in the Prince William Sound (southern Chugach Mountains) on Montague Island. Montague Island (and adjacent Hinchinbrook Island) are ~20 km above the megathrust where there is a large degree of coupling between the subducting Yakutat microplate and overriding North American Plate. Montague Island is of particular interest because it lies between two areas of rapid rock uplift focused in the St. Elias/eastern Chugach Mountains and the western Chugach Mountains. In the St. Elias/eastern Chugach Mountains, faulting related to collisional processes and bending of fault systems causes rapid rock uplift. About 200 km farther northwest in the western Chugach Mountains, recent rock uplift is caused by underplating along the megathrust that is focused within a syntaxial bend of major fault systems and mountain ranges. Montague Island bounds the southern margin of Prince William Sound, and is steep, narrow, and elongate (81 km long and ~15 km wide). The maximum relief is 914 m, making for very steep, mountainous topography considering the narrow width of the island. During the Mw 9.2 earthquake in 1964, the Patton Bay and Hanning Bay reverse faults were reactivated, with 7 and 5 m of vertical offset, respectively. Both faults dip ~60° NW and strike NE-SW parallel to the long-axis of the island and parallel to geomorphic features including lineaments, elongate valleys, and escarpments. Prominent ~450 m high escarpments are present along the SE-facing side of the island, which suggests rapid and sustained uplift. New apatite

  6. Approaches to the History of Patients: From the Ancient World to Early Modern Europe.

    PubMed

    Stolberg, Michael

    2016-01-01

    This chapter looks from an early modernist's perspective at some of the major questions and methodological issues that writing the history of patients in the ancient world shares with similar work on Patientengeschichte in medieval and early modern Europe. It addresses, in particular, the problem of finding adequate sources that give access to the patients' experience of illness and medicine and highlights the potential as well as the limitations of using physicians' case histories for that purpose. It discusses the doctor-patient relationship as it emerges from these sources, and the impact of the patient's point of view on learned medical theory and practice. In conclusion, it pleads for a cautious and nuanced approach to the controversial issue of retrospective diagnosis, recommending that historians consistently ask in which contexts and in what way the application of modern diagnostic labels to pre-modern accounts of illness can truly contribute to a better historical understanding rather than distort it.

  7. Telomere biology in aging and cancer: early history and perspectives.

    PubMed

    Hayashi, Makoto T

    2018-01-20

    The ends of eukaryotic linear chromosomes are protected from undesired enzymatic activities by a nucleoprotein complex called the telomere. Expanding evidence indicates that telomeres have central functions in human aging and tumorigenesis. While it is undoubtedly important to follow current advances in telomere biology, it is also fruitful to be well informed in seminal historical studies for a comprehensive understanding of telomere biology, and for the anticipation of future directions. With this in mind, I here summarize the early history of telomere biology and current advances in the field, mostly focusing on mammalian studies relevant to aging and cancer.

  8. Associations of personal and family preeclampsia history with the risk of early-, intermediate- and late-onset preeclampsia.

    PubMed

    Boyd, Heather A; Tahir, Hassaan; Wohlfahrt, Jan; Melbye, Mads

    2013-12-01

    Preeclampsia encompasses multiple conditions of varying severity. We examined the recurrence and familial aggregation of preeclampsia by timing of onset, which is a marker for severity. We ascertained personal and family histories of preeclampsia for women who delivered live singletons in Denmark in 1978-2008 (almost 1.4 million pregnancies). Using log-linear binomial regression, we estimated risk ratios for the associations between personal and family histories of preeclampsia and the risk of early-onset (before 34 weeks of gestation, which is typically the most severe), intermediate-onset (at 34-36 weeks of gestation), and late-onset (after 36 weeks of gestation) preeclampsia. Previous early-, intermediate-, or late-onset preeclampsia increased the risk of recurrent preeclampsia with the same timing of onset 25.2 times (95% confidence interval (CI): 21.8, 29.1), 19.7 times (95% CI: 17.0, 22.8), and 10.3 times (95% CI: 9.85, 10.9), respectively, compared with having no such history. Preeclampsia in a woman's family was associated with a 24%-163% increase in preeclampsia risk, with the strongest associations for early- and intermediate-onset preeclampsia in female relatives. Preeclampsia in the man's family did not affect a woman's risk of early-onset preeclampsia and was only weakly associated with her risks of intermediate- and late-onset preeclampsia. Early-onset preeclampsia appears to have the largest genetic component, whereas environmental factors likely contribute most to late-onset preeclampsia. The role of paternal genes in the etiology of preeclampsia appears to be limited.

  9. Recent uplift of the Atlantic Atlas (offshore West Morocco): Tectonic arch and submarine terraces

    NASA Astrophysics Data System (ADS)

    Benabdellouahed, M.; Klingelhoefer, F.; Gutscher, M.-A.; Rabineau, M.; Biari, Y.; Hafid, M.; Duarte, J. C.; Schnabel, M.; Baltzer, A.; Pedoja, K.; Le Roy, P.; Reichert, C.; Sahabi, M.

    2017-06-01

    Re-examination of marine geophysical data from the continental margin of West Morocco reveals a broad zone characterized by deformation, active faults and updoming offshore the High Atlas (Morocco margin), situated next to the Tafelney Plateau. Both seismic reflection and swath-bathymetric data, acquired during Mirror marine geophysical survey in 2011, indicate recent uplift of the margin including uplift of the basement. This deformation, which we propose to name the Atlantic Atlas tectonic arch, is interpreted to result largely through uplift of the basement, which originated during the Central Atlantic rifting stage - or even during phases of Hercynian deformation. This has produced a large number of closely spaced normal and reverse faults, ;piano key faults;, originating from the basement and affecting the entire sedimentary sequence, as well as the seafloor. The presence of four terraces in the Essaouira canyon system at about 3500 meters water depth and ;piano key faults; and the fact that these also affect the seafloor, indicate that the Atlantic Atlas is still active north of Agadir canyon. We propose that recent uplift is causing morphogenesis of four terraces in the Essaouira canyon system. In this paper the role of both Canary plume migration and ongoing convergence between the African and Eurasian plates in the formation of the Atlantic Atlas are discussed as possibilities to explain the presence of a tectonic arch in the region. The process of reactivation of passive margins is still not well understood. The region north of Agadir canyon represents a key area to better understand this process.

  10. Renewed uplift at the Yellowstone caldera measured by leveling surveys and satellite radar interferometry

    USGS Publications Warehouse

    Dzurisin, D.; Wicks, Charles; Thatcher, W.

    1999-01-01

    A first-order leveling survey across the northeast part of the Yellowstone caldera in September 1998 showed that the central caldera floor near Le Hardy Rapids rose 24±5 mm relative to the caldera rim at Lake Butte since the previous survey in September 1995. Annual surveys along the same traverse from 1985 to 1995 tracked progressive subsidence near Le Hardy Rapids at an average rate of –19±1 mm/year. Earlier, less frequent surveys measured net uplift in the same area during 1923–1976 (14±1 mm/year) and 1976–1984 (22±1 mm/year). The resumption of uplift following a decade of subsidence was first detected by satellite synthetic aperture radar interferometry, which revealed approximately 15 mm of uplift in the vicinity of Le Hardy Rapids from July 1995 to June 1997. Radar interferograms show that the center of subsidence shifted from the Sour Creek resurgent dome in the northeast part of the caldera during August 1992 to June 1993 to the Mallard Lake resurgent dome in the southwest part during June 1993 to August 1995. Uplift began at the Sour Creek dome during August 1995 to September 1996 and spread to the Mallard Lake dome by June 1997. The rapidity of these changes and the spatial pattern of surface deformation suggest that ground movements are caused at least in part by accumulation and migration of fluids in two sill-like bodies at 5–10 km depth, near the interface between Yellowstone's magmatic and deep hydrothermal systems.

  11. Causes of rapid uplift and exceptional topography of Gongga Shan on the eastern margin of the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Cook, Kristen L.; Hovius, Niels; Wittmann, Hella; Heimsath, Arjun M.; Lee, Yuan-Hsi

    2018-01-01

    Erosion and tectonic uplift are widely thought to be coupled through feedbacks involving orographic precipitation, relief development, and crustal weakening. In many orogenic systems, it can be difficult to distinguish whether true feedbacks exist, or whether observed features are a consequence of tectonic forcing. To help elucidate these interactions, we examine Gongga Shan, a 7556 m peak on the eastern margin of the Tibetan Plateau where cosmogenic 10Be basin-wide erosion rates reach >5 mm/yr, defining a region of localized rapid erosion associated with a restraining bend in the left-lateral Xianshuihe Fault. Erosion rates are consistent with topography, thermochronometry, and geodetic data, suggesting a stable pattern of uplift and exhumation over at least the past 2-3 My. Transpression along the Xianshuihe Fault, orographically enhanced precipitation, thermally weakened crust, and substantial local relief all developed independently in the Gongga region and existed there prior to the uplift of Gongga Shan. However, only where all of these conditions are present do the observed topographic and erosional extremes exist, and their relative timing indicates that these conditions are not a consequence of rapid uplift. We conclude that their collocation at 3-4 Ma set into motion a series of feedbacks between erosion and uplift that has resulted in the exceptionally high topography and rapid erosion rates observed today.

  12. Elastic and viscoelastic model of the stress history of sedimentary rocks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Warpinski, N.R.

    A model has been developed to calculate the elastic and viscoelastic stresses which develop in rocks at depth due to burial, uplift and diagenesis. This model includes the effect of the overburden load, tectonic or geometric strains, thermal strains, varying material properties, pore pressure variations, and viscoeleastic relaxation. Calculations for some simple examples are given to show the contributions of the individual stress components due to gravity, tectonics, thermal effects and pore pressure. A complete stress history for Mesaverde rocks in the Piceance basin is calculated based on available burial history, thermal history and expected pore pressure, material property andmore » tectonic strain variations through time. These calculations show the importance of including material property changes and viscoelastic effects. 15 refs., 48 figs.« less

  13. Coastal uplift and mortality of intertidal organisms caused by the september 1985 Mexico earthquakes.

    PubMed

    Bodin, P; Klinger, T

    1986-09-05

    Coastal uplift associated with the great Mexican earthquake of 19 September 1985 and its principal aftershock produced widespread mortality of intertidal organisms along the coast of the states of Michoacán and Guerrero, Mexico. Measurements of the vertical extent of mortality at ten sites provided estimates of the magnitude of the vertical component of deformation along the coast. Within the affected area, uplift ranged from about 12 centimeters to about 1 meter, and no subsidence was observed. The observations are consistent with models of the tectonic deformation that results from buried slip on a shallow-dipping underthrust fault.

  14. Greenland uplift and regional sea level changes from ICESat observations and GIA modelling

    NASA Astrophysics Data System (ADS)

    Spada, G.; Ruggieri, G.; Sørensen, L. S.; Nielsen, K.; Melini, D.; Colleoni, F.

    2012-06-01

    We study the implications of a recently published mass balance of the Greenland ice sheet (GrIS), derived from repeated surface elevation measurements from NASA's ice cloud and land elevation satellite (ICESat) for the time period between 2003 and 2008. To characterize the effects of this new, high-resolution GrIS mass balance, we study the time-variations of various geophysical quantities in response to the current mass loss. They include vertical uplift and subsidence, geoid height variations, global patterns of sea level change (or fingerprints), and regional sea level variations along the coasts of Greenland. Long-wavelength uplifts and gravity variations in response to current or past ice thickness variations are obtained solving the sea level equation, which accounts for both the elastic and the viscoelastic components of deformation. To capture the short-wavelength components of vertical uplift in response to current ice mass loss, which is not resolved by satellite gravity observations, we have specifically developed a high-resolution regional elastic rebound (ER) model. The elastic component of vertical uplift is combined with estimates of the viscoelastic displacement fields associated with the process of glacial-isostatic adjustment (GIA), according to a set of published ice chronologies and associated mantle rheological profiles. We compare the sensitivity of global positioning system (GPS) observations along the coasts of Greenland to the ongoing ER and GIA. In notable contrast with past reports, we show that vertical velocities obtained by GPS data from five stations with sufficiently long records and from one tide gauge at the GrIS margins can be reconciled with model predictions based on the ICE-5G deglaciation model and the ER associated with the new ICESat-derived mass balance.

  15. Tensions in Constructions of Quality in Australian Early Childhood Education and Care Policy History

    ERIC Educational Resources Information Center

    Logan, Helen

    2017-01-01

    In pronouncements of early childhood education and care (ECEC) policy the importance of quality appears as a seemingly irrefutable concept. Yet, attention to ECEC policy history reveals tensions between discourses that construct quality in ways that endure whereas other ways are ostensibly forgotten. Drawing on a Foucauldian-influenced…

  16. Interpretation of the Seattle uplift, Washington, as a passive-roof duplex

    USGS Publications Warehouse

    Brocher, T.M.; Blakely, R.J.; Wells, R.E.

    2004-01-01

    We interpret seismic lines and a wide variety of other geological and geophysical data to suggest that the Seattle uplift is a passive-roof duplex. A passive-roof duplex is bounded top and bottom by thrust faults with opposite senses of vergence that form a triangle zone at the leading edge of the advancing thrust sheet. In passive-roof duplexes the roof thrust slips only when the floor thrust ruptures. The Seattle fault is a south-dipping reverse fault forming the leading edge of the Seattle uplift, a 40-km-wide fold-and-thrust belt. The recently discovered, north-dipping Tacoma reverse fault is interpreted as a back thrust on the trailing edge of the belt, making the belt doubly vergent. Floor thrusts in the Seattle and Tacoma fault zones, imaged as discontinuous reflections, are interpreted as blind faults that flatten updip into bedding plane thrusts. Shallow monoclines in both the Seattle and Tacoma basins are interpreted to overlie the leading edges of thrust-bounded wedge tips advancing into the basins. Across the Seattle uplift, seismic lines image several shallow, short-wavelength folds exhibiting Quaternary or late Quaternary growth. From reflector truncation, several north-dipping thrust faults (splay thrusts) are inferred to core these shallow folds and to splay upward from a shallow roof thrust. Some of these shallow splay thrusts ruptured to the surface in the late Holocene. Ages from offset soils in trenches across the fault scarps and from abruptly raised shorelines indicate that the splay, roof, and floor thrusts of the Seattle and Tacoma faults ruptured about 1100 years ago.

  17. Non-lethal effects of an invasive species in the marine environment: the importance of early life-history stages.

    PubMed

    Rius, Marc; Turon, Xavier; Marshall, Dustin J

    2009-04-01

    Studies examining the effects of invasive species have focussed traditionally on the direct/lethal effects of the invasive on the native community but there is a growing recognition that invasive species may also have non-lethal effects. In terrestrial systems, non-lethal effects of invasive species can disrupt early life-history phases (such as fertilisation, dispersal and subsequent establishment) of native species, but in the marine environment most studies focus on adult rather than early life-history stages. Here, we examine the potential for an introduced sessile marine invertebrate (Styela plicata) to exert both lethal and non-lethal effects on a native species (Microcosmus squamiger) across multiple early life-history stages. We determined whether sperm from the invasive species interfered with the fertilisation of eggs from the native species and found no effect. However, we did find strong effects of the invasive species on the post-fertilisation performance of the native species. The invasive species inhibited the settlement of native larvae and, in the field, the presence of the invasive species was associated with a ten-fold increase in the post-settlement mortality of the native species, as well as an initial reduction of growth in the native. Our results suggest that larvae of the native species avoid settling near the invasive species due to reduced post-settlement survival in its presence. Overall, we found that invasive species can have complex and pervasive effects (both lethal and non-lethal) across the early life-history stages of the native species, which are likely to result in its displacement and to facilitate further invasion.

  18. The fascinating early history of optics! Archaeological optics 2009: our knowledge of the early history of lenses, mirrors, and artificial eyes!

    NASA Astrophysics Data System (ADS)

    Enoch, Jay M.

    2009-08-01

    The early history of optics and vision science (older term: physiological optics) is indeed fascinating. The earliest known true lenses have been found in "eyes" of Egyptian statues which contain superb, complex, and well-polished eye-lens units. The oldest ones known are dated circa 2575 BCE = BC, Dynasty IV, Old Kingdom. These eye-lens units induce a fascinating and powerful visual illusion, but they are just too good to have been the first lenses, or even the first lenses of this design! So saying, no earlier dateable lenses have been found in Egypt or elsewhere. Recently, at the Boston Museum of Fine Arts, the writer noted a previously undetected lens in this series (a first in the Western Hemisphere). Oddly, dateable simpler magnifying lenses and burning glasses seem to have appeared later in time (?)! Manufactured mirrors are quite a bit older, dating from circa 6000 BCE in atal Hyk, located in south-central modern-day Turkey. Using these ancient mirrors, the image quality obtained is remarkable! Recently discovered ancient artificial eyes, located, in situ, in exhumed corpses, have been dated circa 3000 BCE (one discovered in Iran) 5000 BCE (one found in Spain). On the 3000 BCE artificial eye, there are drawn light rays (the writer believes these to be the oldest known depiction of light rays!) spreading out from (or passing into) the iris/ pupil border! Added interesting aspects associated with the early development of light-rays are considered. Thus, early optics can be readily traced back to the Neolithic era (the new stone age), and in some cases before that time period. We have deep roots indeed!

  19. Accelerated uplift and magmatic intrusion of the Yellowstone caldera, 2004 to 2006

    USGS Publications Warehouse

    Chang, Wu-Lung; Smith, Robert B.; Wicks, Charles; Farrell, J.M.; Puskas, C.M.

    2007-01-01

    The Yellowstone caldera began a rapid episode of ground uplift in mid-2004, revealed by Global Positioning System and interferometric synthetic aperture radar measurements, at rates up to 7 centimeters per year, which is over three times faster than previously observed inflation rates. Source modeling of the deformation data suggests an expanding volcanic sill of ???1200 square kilometers at a 10-kilometer depth beneath the caldera, coincident with the top of a seismically imaged crustal magma chamber. The modeled rate of source volume increase is 0.1 cubic kilometer per year, similar to the amount of magma intrusion required to supply the observed high heat flow of the caldera. This evidence suggests magma recharge as the main mechanism for the accelerated uplift, although pressurization of magmatic fluids cannot be ruled out.

  20. The Processes Producing the Actively Uplifting Mackenzie Mountains in the Yukon and Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Rasmussen, B.; Aster, R. C.; Schutt, D.

    2016-12-01

    The actively uplifting and seismically active Mackenzie Mountains in the Yukon and Northwest Territories of Canada exist nearly 800 km from the Pacific plate subduction zone. As such, it is clear that traditional subduction zone orogenic mechanics are not at play. This mountain range may present a model for uplift of other ranges distant from plate boundaries, such as the Rockies or Ancestral Rockies. Due to its remote location, this region's lithospheric structure is poorly constrained. However, two hypotheses have been developed recently. The first proposes that stress from the Yakutat Indentor as it subducts under North America at the Gulf of Alaska is transferred deep inland through the upper crust, and that the lower crust and mantle lithosphere are very weak. As this weak lithosphere meets the strong Canadian Craton, lateral translation turns into uplift, forming the Mackenzies (Mazzotti and Hyndman, 2002, Geology, v. 30, no.6). Alternatively, it may be that mantle flow from the north is deflected eastward by the Yakutat slab, producing large scale mantle flow and stress which propagates through the crust to uplift the Mackzenzie Mountains without an abnormally weak lithosphere (Finzel, 2015, Geophys. Res. Lett., 42, 4350-4358). Both cases imply distinct isotropic and anisotropic structure that will be constrained through Rayleigh wave tomography. Notably, we will take advantage of the recent deployment of several Earthscope Transportable Array stations nearby, and some preliminary data from the ongoing Mackenzie Mountains Earthscope Project.

  1. A review of noble gas geochemistry in relation to early Earth history

    NASA Technical Reports Server (NTRS)

    Kurz, M. D.

    1985-01-01

    One of the most fundamental noble gas constraints on early Earth history is derived from isotopic differences in (129)Xe/(130)Xe between various terrestrial materials. The short half life (17 m.y.) of extinct (129I, parent of (129)Xe, means that these differences must have been produced within the first 100 m.y. after terrestrial accretion. The identification of large anomalies in (129)Xe/(130)Xe in mid ocean ridge basalts (MORB), with respect to atmospheric xenon, suggests that the atmosphere and upper mantle have remained separate since that time. This alone is a very strong argument for early catastrophic degassing, which would be consistent with an early fractionation resulting in core formation. However, noble gas isotopic systematics of oceanic basalts show that the mantle cannot necessarily be regarded as a homogeneous system, since there are significant variations in (3)He/(4)He, (40)Ar/(36)Ar, and (129)Xe/(130)Xe. Therefore, the early degassing cannot be considered to have acted on the whole mantle. The specific mechanisms of degassing, in particular the thickness and growth of the early crust, is an important variable in understanding present day noble gas inventories. Another constraint can be obtained from rocks that are thought to be derived from near the lithosphere asthenosphere boundary: ultramafic xenoliths.

  2. Tilting, burial, and uplift of the Guadalupe Igneous Complex, Sierra Nevada, California

    USGS Publications Warehouse

    Haeussler, Peter J.; Paterson, Scott R.

    1993-01-01

    It is often incorrectly assumed that plutons have a relatively uneventful structural history after emplacement. The 151 Ma Guadalupe Igneous Complex (GIC) in the Foothills Terrane, California, was involved in three post-emplacement events: (1) ∼30° of southwestside-up tilting during ductile regional faulting and contraction, (2) burial of the pluton from ∼4 to 12 km during crustal thickening of the wall rocks, and (3) uplift with only minor tilting in the Late Cretaceous. Tilting of the pluton is indicated by (1) southwest to northeast gradational changes from layered gabbros and diorites to granites and granophyres; (2) northeastward dips of layering in gabbro, internal contacts, and bedding of overlying coeval(?) volcanic rocks; (3) northeastward decrease in wall-rock metamorphic grade; and (4) paleomagnetic data from 14 localities across the pluton. We argue that tilting occurred between 146-135 Ma during southwest-northeast-directed regional contraction. This contraction is indicated by widespread folds and cleavages and by reverse motion on the Bear Mountains fault zone (BMFZ), a large northeast-dipping shear zone that bounds the GIC on its southwest side. Burial of the GIC, which overlapped in time but outlasted tilting, is suggested by (1) post-emplacement contractional faulting, folding, and cleavage development; (2) analyses of strains associated with widespread cleavage that indicate vertical thickening of ∼100% and (3) microstructural and mineral assemblage data that indicate shallow emplacement of the GIC, in contrast to mineral assemblage and limited geobarometric data from adjacent 120-110 Ma plutons that indicate moderate emplacement levels. Late Cretaceous uplift is indicated by 95-75 Ma sedimentary rocks that unconformably overlie the 120-110 Ma plutons.This geologic history is interesting for several reasons. First, although the GIC participated in extensive post-emplacement deformation, it lacks internal structural evidence of these events

  3. Late Quaternary Uplift Rates and Geomorphology of the Santa Fe Springs and West Coyote Folds, Los Angeles Basin, California

    NASA Astrophysics Data System (ADS)

    Sundermann, S. T.; Mueller, K. J.

    2001-12-01

    We mapped Quaternary aquifers with water wells and 5 m DEM's from IFSAR to define rates of folding along the Puente Hills blind thrust system. A cross section across Santa Fe Springs along Carfax Ave suggests 100 and 165 m of uplift of the 330 ka Gage and 650 ka Lynwood aquifers, yielding uplift rates of 0.2 mm/yr between 330-650 ka and 0.27 mm/yr beween 0-330 ka. For a 27° thrust, this yields a slip rate of 0.44 - 0.59 mm/yr. Surface folding is discernable across the Santa Fe Springs segment in the DEM, to a point 4 km west of the San Gabriel River. Aquifers correlated with reflectors in a USGS seismic profile along Carfax suggests lower relief for the Lynwood (85 m) and the Gage (59 m). We suggest the 1 km-long USGS profile images only part of the fold limb and that additional structural relief is accommodated further north, as defined by our subsurface mapping. Correlation of a shallow reflector in the seismic profile with the 15-20 ka Gaspur aquifer suggests Holocene uplift of 1.0 mm/yr. A similar analysis undertaken for the Coyote fold near Trojan Ave. suggests 85 and 229 m of uplift for the Gage and Lynwood, yielding uplift rates of 0.26 mm/yr between 0-330 ka and 0.45 mm/yr between 330-650 ka. Correlation of the Gage with a reflector on another USGS seismic profile along Trojan suggests equivalent uplift (86 m), indicating the profile images the entire width of the Coyote forelimb at this site.

  4. Cenozoic record of aeolian sediment accumulation and aridification from Lanzhou, China, driven by Tibetan Plateau uplift and global climate

    NASA Astrophysics Data System (ADS)

    Zhang, Yuebao; Sun, Donghuai; Li, Zaijun; Wang, Fei; Wang, Xin; Li, Baofeng; Guo, Feng; Wu, Sheng

    2014-09-01

    Previous work has shown that aeolian Red Clay first appears at around 8 Ma in the main Chinese Loess Plateau and at 25-22 Ma in the western Loess Plateau; however, records of aeolian deposition in the North Pacific suggest that aeolian accumulation occurred throughout the Cenozoic, and that changes in aeolian flux occurred in distinct stages. Tracing the Cenozoic aeolian history of the interior of the Asian continent may help us to understand the history of Asian aridification and its driving forces. In the Lanzhou area on the western margin of the Loess Plateau and the northeastern edge of the Tibetan Plateau, the Cenozoic stratigraphic sequence consists of fluvial-lacustrine sediments in the lower part, aeolian Red Clay with intercalated fluvial layers in the middle part, and predominantly aeolian loess in the upper part. We use high resolution paleomagnetic measurements of this sequence to construct a time scale, and measurements of sediment rock magnetic properties, grain-size, and color reflectance and sedimentary facies analysis to reconstruct the paleoenvironment. The results show that prior to 33 Ma the area was dominantly a fluvial-lacustrine environment, and that subsequently an aridification trend commenced, as indicated by the appearance of aeolian sediment. This change coincided with, and is thus explained as the environmental response to global cooling. A significant increase in aeolian sediments occurred at ~ 26 Ma, suggesting that a large scale arid environment had formed in the Asian interior since the late Oligocene. Stepwise increases of aeolian sediment, and decreases in sediments of hydraulic origin, occurred at ~ 22, ~ 14, ~ 8 and 2.6 Ma and represent important stages in the aridification process. This long-term trend was interrupted by intervals dominated by fluvial sedimentation at 23.6-22 Ma and 17.1-14.1 Ma and which were probably associated with warming of the global climate and the tectonic uplift of the northeastern Tibetan Plateau

  5. Development and Early Usage Patterns of a Consumer-Facing Family Health History Tool

    PubMed Central

    Hulse, Nathan C.; Ranade-Kharkar, Pallavi; Post, Herman; Wood, Grant M.; Williams, Marc S.; Haug, Peter J.

    2011-01-01

    Personalized medicine will require detailed clinical patient profiles, and a particular focus on capturing data that is useful in forecasting risk. A detailed family health history is considered a critical component of these profiles, insomuch that it has been coined as ‘the best genetic test available’. Despite this, tools aimed at capturing this information for use in electronic health records have been characterized as inadequate. In this manuscript we detail the creation of a patient-facing family health history tool known as OurFamilyHealth, whose long-term emphasis is to facilitate risk assessment and clinical decision support. We present the rationale for such a tool, describe its development and release as a component of Intermountain Healthcare’s patient portal, and detail early usage statistics surrounding the application. Data derived from the tool since its release are also compared against family history charting patterns in Intermountain’s electronic health records, revealing differences in data availability. PMID:22195113

  6. Predictions of vertical uplift caused by changing polar ice volumes on a viscoelastic earth

    NASA Technical Reports Server (NTRS)

    Wahr, John; Dazhong, Han; Trupin, Andrew

    1995-01-01

    Measurements of crustal uplift from bedrock around the edges of Antarctica or Greenland could help constrain the mass balance of those ice caps. Present-day changes in ice could cause vertical displacement rates of several mm/yr around Antarctica and up to 10-15 mm/yr around Greenland. Horizontal displacement rates are likely to be about 1/3 the vertical rates. The viscoelastic response of the earth to past changes in ice could cause uplift rates that are several times larger. By measuring both gravity and vertical displacements, it is possible to remove the viscoelastic effects, so that the observations can be used to constrain present-day thickness changes.

  7. Uplift and Subsidence Associated with the Great Aceh-Andaman Earthquake of 2004

    NASA Image and Video Library

    2006-03-01

    The magnitude 9.2 Indian Ocean earthquake of December 26, 2004, produced broad regions of uplift and subsidence. In order to define the lateral extent and the downdip limit of rupture. This image is from NASA Terra spacecraft.

  8. Miocene block uplift and basin formation in the Patagonian foreland: The Gastre Basin, Argentina

    NASA Astrophysics Data System (ADS)

    Bilmes, A.; D'Elia, L.; Franzese, J. R.; Veiga, G. D.; Hernández, M.

    2013-08-01

    The intraplate fault-block mountains and intermontane deposits of the Gastre Basin, which are recorded more than 550 km east of the Andean trench in central Patagonia, Argentina, are analyzed. The Gastre Basin is one of the largest Patagonian intermontane basins, limited by uplifted blocks strongly oblique to the Andean chain. It was originated by reverse faulting and inversion of pre-existing normal faults associated with a Mesozoic rift basin and defined by older crustal heterogeneities. The deformational event occurred during the middle Miocene, related to a short contractional episode (16.1-14.86 Ma), probably in response to an eastward migration of the Andean fold and thrust belt. During Pliocene to Quaternary times, neither younger fault-block uplifts nor reconfigurations of the basin occurred. Similarities between the study area and other parts of the Patagonian foreland - such as the presence of Miocene reverse or inversion tectonics, as well as the accommodation of the Miocene sedimentary successions - suggest that the Gastre Basin is part of a major late early to middle Miocene broken foreland system (i.e. the Patagonian broken foreland) that exhumed discrete fault-block mountains and generated contemporary basins along more than 950 km parallel to the Andean trench (i.e. between 40°00' and 48°00' south latitude). Based on recent studies on the southern Andean Margin, this continental-scale contractional episode may be the result of a flat-slab subduction segment. Nevertheless, such a hypothesis is very difficult to support when analyzing such a large flat subduction segment along the entire Patagonian trench. This suggests the need to consider alternative flat-slab trigger mechanisms or other factors in the generation of broken foreland systems.

  9. The "Starch Wars" and the Early History of DNA Profiling.

    PubMed

    Aronson, J D

    2006-01-01

    Just as the movie Star Wars had a prequel, so did the "DNA Wars"-the series of legal, scientific, and personal battles that took place over the admissibility of forensic DNA evidence from 1989 to 1994. Between the late 1970s and the mid-1980s, another forensic identification technique became mired in controversy: electrophoresis-based blood protein analysis. Although the debates over blood analysis were every bit as rancorous and frustrating to almost everybody involved - so much so that they became known as the "Starch Wars" - their importance has not been adequately appreciated in the recent history of forensic science. After reviewing the early history of blood typing, I will describe the development of the Multi-System approach to blood protein analysis that took place in California from 1977 to 1978. I will then elucidate the history of the Starch Wars, and demonstrate the ways that they shaped subsequent disputes over DNA evidence, especially in California. I will show that: (a) many of the forensic scientists, law enforcement officials, and lawyers who became prominent players in the DNA Wars were deeply involved in the court cases involving protein electrophoresis; and (b) many of the issues that became controversial in the disputes over DNA evidence first emerged in the Starch Wars. In the conclusion, I will suggest various ways to improve the quality of forensic science based on my analysis of the Starch Wars. Copyright © 2006 Central Police University.

  10. A 17-My-old whale constrains onset of uplift and climate change in east Africa

    PubMed Central

    Wichura, Henry; Lin, Andrew; Polcyn, Michael J.; Manthi, Fredrick K.; Winkler, Dale A.; Strecker, Manfred R.; Clemens, Matthew

    2015-01-01

    Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates. PMID:25775586

  11. A 17-My-old whale constrains onset of uplift and climate change in east Africa

    NASA Astrophysics Data System (ADS)

    Wichura, Henry; Jacobs, Louis L.; Lin, Andrew; Polcyn, Michael J.; Manthi, Fredrick K.; Winkler, Dale A.; Strecker, Manfred R.; Clemens, Matthew

    2015-03-01

    Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates.

  12. Relative value of race, family history and prostate specific antigen as indications for early initiation of prostate cancer screening.

    PubMed

    Vertosick, Emily A; Poon, Bing Ying; Vickers, Andrew J

    2014-09-01

    Many guidelines suggest earlier screening for prostate cancer in men at high risk, with risk defined in terms of race and family history. Recent evidence suggests that baseline prostate specific antigen is strongly predictive of the long-term risk of aggressive prostate cancer. We compared the usefulness of risk stratifying early screening by race, family history and prostate specific antigen at age 45 years. Using estimates from the literature we calculated the proportion of men targeted for early screening using family history, black race or prostate specific antigen as the criterion for high risk. We calculated the proportion of prostate cancer deaths that would occur in those men by age 75 years. Screening based on family history involved 10% of men, accounting for 14% of prostate cancer deaths. Using black race as a risk criterion involved 13% of men, accounting for 28% of deaths. In contrast, 44% of prostate cancer deaths occurred in the 10% of men with the highest prostate specific antigen at age 45 years. In no sensitivity analysis for race and family history did the ratio of risk group size to number of prostate cancer deaths in that risk group approach that of prostate specific antigen. Basing decisions for early screening on prostate specific antigen at age 45 years provided the best ratio between men screened and potential cancer deaths avoided. Given the lack of evidence that race or family history affects the relationship between prostate specific antigen and risk, prostate specific antigen based risk stratification would likely include any black men or men with a family history who are destined to experience aggressive disease. Differential screening based on risk should be informed by baseline prostate specific antigen. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  13. Thermal history, exhumation, uplift, and long-term landscape evolution of the Eastern Great and Northern Lesser Caucasus, Azerbaijan

    NASA Astrophysics Data System (ADS)

    Spilger, Tatiana; Glasmacher, Ulrich Anton; Mosar, Jon

    2015-04-01

    The Caucasus orogen (Great and Lesser Caucasus) is the highest mountain range between Asia and Europe, whose growth takes place since the beginning of the Cenozoic (Mosar et al. 2010). The orogen has evolved as a result of the active north directed convergence of the Arabian plate (Nikishin et al. 2001). The Great Caucasus (GC) represents a doubly verging fold-and-thrust belt, with a per-and a retro wedge actively propagating into the foreland sedimentary basins to the south and to the north (Sholpo 1993). Thermochronometric techniques (fission-track, (U-Th-Sm)/He, each on apatite and zircon) are used to reconstruct the thermal evolution of the upper crust, the subsidence, as well as the rock and surface uplift of the Eastern GC and Northern Lesser Caucasus and to connect them with the thrust kinematics of the GC. Samples were taken along different transects in Eastern GC and Northern Lesser Caucasus in Azerbaijan. Most samples of Eastern GC are Lower Jurassic age sandstones (deep marine and slope facies). Several sedimentary rock samples of Cretaceous, Miocene, Pliocene and Quaternary age were taken from the outcrops in the Kura basin and along rivers in the Eastern GC. Samples of the Lesser Caucasus are igneous and sedimentary origin and have Lower Jurassic to Holocene age. The first AFT-data in the Eastern Great Caucasus were investigated. All researched samples show recessed AF-ages. Most dated sedimentary samples have several populations of apatite minerals. Apatite minerals have low U-concentration (up to 10 ppm). Most dated samples taken in Aalenian sandstone have very young AFT-ages (up to 10 Ma). Some samples show Oligocene AF-ages of 23-28Ma. The preliminary data confirm orogeny in the Eastern Great Caucasus since Oligocene and propagation of orogeny since middle Miocene (Mosar et al. 2010). References Mosar, J., Kangarli, T., Bochud, M., Glasmacher, U.A., Rast, A., Brunet, M.-F. & Sosson, M. 2010. Cenozoic-Recent tectonics and uplift in the Greater

  14. Francis Bacon's natural history and the Senecan natural histories of early modern Europe.

    PubMed

    Jalobeanu, Dana

    2012-01-01

    At various stages in his career, Francis Bacon claimed to have reformed and changed traditional natural history in such a way that his new "natural and experimental history" was unlike any of its ancient or humanist predecessors. Surprisingly, such claims have gone largely unquestioned in Baconian scholarship. Contextual readings of Bacon's natural history have compared it, so far, only with Plinian or humanist natural history. This paper investigates a different form of natural history, very popular among Bacon's contemporaries, but yet unexplored by contemporary students of Bacon's works. I have provisionally called this form of natural history'Senecan' natural history, partly because it took shape in the Neo-Stoic revival of the sixteenth-century, partly because it originates in a particular cosmographical reading of Seneca's Naturales quaestiones. I discuss in this paper two examples of Senecan natural history: the encyclopedic and cosmographical projects of Pierre de la Primaudaye (1546-1619) and Samuel Purchas (1577-1626). I highlight a number of similarities between these two projects and Francis Bacon's natural history, and argue that Senecan natural history forms an important aspect in the historical and philosophical background that needs to be taken into consideration if we want to understand the extent to which Bacon's project to reform natural history can be said to be new.

  15. some morphological effects related to a non-uniform uplifting of crustal blocks in Northern Sicily (Central Mediterranean)

    NASA Astrophysics Data System (ADS)

    Nigro, Fabrizio; Renda, Pietro; Favara, Rocco

    2010-05-01

    We can distinguish two morphological evolutions of the drainage basins which develop in the earth's sectors subjected to uplift and tilting, in relationship to their antecedence or subsequence in comparison to the tectonic process. If this process begins in concomitance with a geomorphic cycle the main valleys of the drainage basins will longitudinally be developed according to the tilting direction which the crustal block is subjected. But if the non-uniform vertical movement develops in a sector already characterized by the presence of a idrographic network, this can be influenced in its pattern in various ways. A crustal block contemporarily subject to uplift and tilting will be characterized to its inside, at the end of this process, by more elevated and less elevated sectors. The erosive ground processes suffer this non-uniform vertical movement and since it gradually develops in time, landforms, as valleys of drainage basins, will suffer analogous variations. If pre-existing, the slopes of the valleys will be subjected to tilting also and one of the characteristics in the evolution of the reliefs connected with the uplift and the tilting of crustal blocks are represented by the progressive asymmetry of the slopes of a valley. The uplift and the tilting of the block progressively determines a difference of inclination of the slopes of the incising valley. This effect is given by the progressive incision and migration of the axis of the valley that it determines slopes with crests to different middle elevation between the right side and that left. The erosional process that determines him with the uplift and the tilting of the crustal blocks are characterized by a greater erosion rate in the sectors of head of the slope that is mostly raised. Likewise, the migration of the river consistent with the tilting direction determines a greater rate of erosion along one of the banks. The general morphometric result can be that of the individualization of slopes that

  16. Cumulative Effects of Nutrient Enrichment and Elevated Temperature Compromise the Early Life History Stages of the Coral Acropora tenuis

    PubMed Central

    Noonan, Sam H. C.; Willis, Bette L.; Fabricius, Katharina E.; Negri, Andrew P.

    2016-01-01

    Inshore coral reefs are experiencing the combined pressures of excess nutrient availability associated with coastal activities and warming seawater temperatures. Both pressures are known to have detrimental effects on the early life history stages of hard corals, but studies of their combined effects on early demographic stages are lacking. We conducted a series of experiments to test the combined effects of nutrient enrichment (three levels) and elevated seawater temperature (up to five levels) on early life history stages of the inshore coral Acropora tenuis, a common species in the Indo-Pacific and Red Sea. Gamete fertilization, larval survivorship and larval settlement were all significantly reduced as temperature increased, but only fertilization was further affected by simultaneous nutrient enrichment. Combined high temperatures and nutrient enrichment affected fertilization in an additive manner, whereas embryo abnormalities increased synergistically. Higher than normal temperatures (32°C) increased coral juvenile growth rates 1.6-fold, but mortality also increased by 50%. The co-occurrence of nutrient enrichment with high temperatures reduced juvenile mortality to 36%, ameliorating temperature stress (antagonistic interaction). Overall, the types of effect (additive vs synergistic or antagonistic) and their magnitude varied among life stages. Gamete and embryo stages were more affected by temperature stress and, in some cases, also by nutrient enrichment than juveniles. The data suggest that coastal runoff events might exacerbate the impacts of warming temperatures on fertilization if these events co-occur during corals spawning. The cumulative impacts of simultaneous exposure to nutrient enrichment and elevated temperatures over all early life history stages increases the likelihood for failure of larval supply and recruitment for this coral species. Our results suggest that improving the water quality of river discharges into coastal areas might help to

  17. Building an Evidence-Based Mental Health Program for Children with History of Early Adversity

    ERIC Educational Resources Information Center

    Kroupina, Maria; Vermeulen, Marlous; Moberg, Stephanie

    2015-01-01

    Adoption is a major intervention in a child's life, however internationally adopted (IA) children remain at risk for long-term neurodevelopmental and mental health issues due to the fact that most of them have a history of early adversity prior to their adoption. In the last 20 years, extensive research with this population has increased the…

  18. Early life history pelagic exposure profiles of selected commercially important fish species in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Doyle, Miriam J.; Mier, Kathryn L.

    2016-10-01

    A synthesis of nearly four decades of ichthyoplankton survey data from the Gulf of Alaska was undertaken to provide the most comprehensive information available on the early life history ecology of five focal species: Pacific Cod (Gadus macrocephalus), Walleye Pollock (Gadus chalcogrammus), Pacific Ocean Perch (Sebastes alutus), Sablefish (Anoplopoma fimbria), and Arrowtooth Flounder (Atheresthes stomias). This analysis of historical data, along with information from published studies, is presented here in the form of ecological reviews of the species during their planktonic phase. The reviews include descriptions of temporal and spatial patterns of exposure to the environment, and interpretation regarding associated sensitivities to environmental forcing. On a temporal scale, patterns in abundance of eggs and larvae are synthesized that characterize seasonal exposure to the pelagic environment, and interannual variation that is presumed to incorporate responses to long-term environmental forcing. Spatial patterns are synthesized to identify horizontal and vertical extent of egg and larval distributions, delineate areas of primary larval habitat, and illuminate egg and larval drift pathways. The observed patterns are discussed with respect to characterizing species early life history strategies, identifying long-term adaptations to the Gulf of Alaska environment, and associated resilience and vulnerability factors that may modulate early life responses to environmental forcing in this region. For each species, gaps in knowledge are identified and are concerned primarily with the period of transition between the larval and juvenile stage, and feeding habits and ecology across seasons, habitats and sub-intervals of early ontogeny. These early life history reviews advance our ecological understanding of the pelagic phase, and fine-tune our focus for the investigation of potential response mechanisms to environmental forcing at appropriate, species-specific temporal

  19. Erosive processes after tectonic uplift stimulate vicariant and adaptive speciation: evolution in an Afrotemperate-endemic paper daisy genus

    PubMed Central

    2014-01-01

    Background The role of tectonic uplift in stimulating speciation in South Africa’s only alpine zone, the Drakensberg, has not been explicitly examined. Tectonic processes may influence speciation both through the creation of novel habitats and by physically isolating plant populations. We use the Afrotemperate endemic daisy genus Macowania to explore the timing and mode (geographic versus adaptive) of speciation in this region. Between sister species pairs we expect high morphological divergence where speciation has happened in sympatry (adaptive) while with geographic (vicariant) speciation we may expect to find less morphological divergence and a greater degree of allopatry. A dated molecular phylogenetic hypothesis for Macowania elucidates species’ relationships and is used to address the potential impact of uplift on diversification. Morphological divergence of a small sample of reproductive and vegetative characters, used as a proxy for adaptive divergence, is measured against species’ range distributions to estimate mode of speciation across two subclades in the genus. Results The Macowania crown age is consistent with the hypothesis of post-uplift diversification, and we find evidence for both vicariant and adaptive speciation between the two subclades within Macowania. Both subclades exhibit strong signals of range allopatry, suggesting that geographic isolation was important in speciation. One subclade, associated with dry, rocky environments at high altitudes, shows very little morphological and ecological differentiation but high range allopatry. The other subclade occupies a greater variety of habitats and exhibits far greater morphological differentiation, but contains species with overlapping distribution ranges. Conclusions Species in Macowania are likely to have diversified in response to tectonic uplift, and we invoke uplift and uplift-mediated erosion as the main drivers of speciation. The greater relative morphological divergence in

  20. Using LiDAR to quantify uplift of shoreline angles during late Holocene earthquakes in northwest Washington

    NASA Astrophysics Data System (ADS)

    Sherrod, B. L.

    2014-12-01

    Three reverse faults in northwestern Washington - the Seattle, Tacoma, and Birch Bay faults - experienced late Holocene earthquakes. Warped intertidal platforms in the hanging wall of each fault formed broad anticlines as a result of deformation during these three earthquakes. Estimates of past deformation rely on differencing raised shoreline features and corresponding modern features. I utilized profiles of LiDAR digital elevation models to calculate prehistoric (647 profiles) and modern shoreline angles (507 profiles) and used these angles to quantify the shape and amount of deformation of each anticline. I calculated shoreline angle elevations by visually fitting lines to modern and uplifted intertidal surfaces and adjacent shoreline cliffs. The intersection of the two fitted lines is the shoreline angle. Mean elevations of modern shoreline angles for 6 shoreline areas in northern Puget Sound and the Strait of Georgia (n=507) lie within 2-46 cm of mean tide level. Three additional shoreline areas in southern Puget Sound have modern shoreline angles closer to mean higher high water (within 22-88 cm) and lie in areas with less fetch and greater tidal range than sites in northern Puget Sound and the Straits of Georgia. A M>7 earthquake ~1.1 ka on the Seattle fault lifted a broad platform cut on sedimentary rocks out of the intertidal zone. Profiles of the platform at three locations along the western end of the Seattle fault zone define an anticline 8-10 km wide (orthogonal to the fault) with a maximum uplift during the earthquake of ~5-8 m. Another large earthquake ~1.1 ka uplifted an intertidal platform along the western part of the Tacoma fault. The raised platform formed an anticline ~10 km wide (orthogonal to the fault) with a maximum uplift of ~5 m. An earthquake ~1.2 ka raised shorelines in the hanging wall of the Birch Bay fault above an anticline observed on seismic reflection profiles near Bellingham, WA. Only part of the anticline is expressed in raised

  1. Interview with Paul W. Kruse on the Early History of HgCdTe, Conducted on October 22, 1980

    NASA Astrophysics Data System (ADS)

    Reine, Marion B.

    2015-09-01

    This paper presents an interview with Dr Paul W. Kruse (1927-2012) on the early history of the semiconductor alloy mercury cadmium telluride (HgCdTe or Hg1- x Cd x Te) at the Honeywell Corporate Research Center near Minneapolis, Minnesota. Conducted on October 22, 1980, the interview covers two main areas. One area is the story of how the HgCdTe research effort came about at the Honeywell Research Center in the early 1960s, what technical choices were made and when, and what technical challenges were overcome and how. The other area is the organization, culture, environment and personnel at the Honeywell Research Center that made the early HgCdTe research programs so successful. HgCdTe has emerged as the highest-performance, most widely applicable infrared detector material. HgCdTe continues to satisfy a broad variety of advanced military and space applications. It is illustrative to look back on the early history of this remarkable semiconductor alloy to help to understand why its technological development as an infrared detector has been so successful.

  2. Assessment of Differential Uplift Along South Java, Indonesia from Terrace Elevations Mapped with Structure from Motion Photogrammetry

    NASA Astrophysics Data System (ADS)

    Andreini, J.; Bunds, M. P.; Harris, R. A.; Yulianto, E.; Horns, D. M.; Prasetyadi, C.; Putra, P. S.

    2016-12-01

    Assessment of Differential Uplift Along South Java, Indonesia from Terrace Elevations Mapped with Structure from Motion Photogrammetry Jeremy Andreini, Michael Bunds, Ronald Harris, Eko Yulianto, Carolus Prasetyadi, Daniel Horns, Purna Putra Is differential uplift occurring on the south coast of Java? Java is on the southern edge of the Sunda plate, above the subducting Indo-Australian plate. Its south coast is 300 km north of the Java Trench and south of the volcanic arc that runs the length of Java. We are investigating relations between marine terraces and convergence, normal faulting associated with tectonically induced basin subsidence, eustatic sea level change, and variations in sediment supply from volcanic activity. Exposed bedrock along the coast includes upper Miocene basinal limestone, and localized exposure of underlying Miocene reef deposits and Oligo-miocene volcanic basement. Differential uplift in the past is implied by north-south trending horst-like ridges of Miocene reef sediment and volcanic basement that have been exhumed from greater depth than adjacent upper Miocene strata. We utilized Quaternary terrace elevations at four locations (Pangamalang, Pangandaran, Karanghawu, and Pacitan). Elevations were measured using traverses with handheld GPS units, profiles made with RTK GPS, and digital surface models (DSMs).The DSMs have 5 cm pixels and were constructed using structure-from-motion (SfM) software to process photos collected with quadcopters equipped with a 24 Mpixel Sony A5100 camera; their vertical RMS error relative to checkpoints measured on bare ground is 6 cm. SfM processing was done in the field with a specially built portable workstation. Four sets of terraces (T) with the following elevations were identified: T1 0-.5 m, T2 2 m, T3 17 m, T4 22 m. We interpret T1 to be the modern wave-cut platform, T2 to represent Holocene uplift of a Holocene terrace or possibly modern deposition, T3 to result from Marine Isotope Stage 5e. T4 occurs

  3. The role of the uplift of the Qinghai-Tibetan Plateau for the evolution of Tibetan biotas.

    PubMed

    Favre, Adrien; Päckert, Martin; Pauls, Steffen U; Jähnig, Sonja C; Uhl, Dieter; Michalak, Ingo; Muellner-Riehl, Alexandra N

    2015-02-01

    Biodiversity is unevenly distributed on Earth and hotspots of biodiversity are often associated with areas that have undergone orogenic activity during recent geological history (i.e. tens of millions of years). Understanding the underlying processes that have driven the accumulation of species in some areas and not in others may help guide prioritization in conservation and may facilitate forecasts on ecosystem services under future climate conditions. Consequently, the study of the origin and evolution of biodiversity in mountain systems has motivated growing scientific interest. Despite an increasing number of studies, the origin and evolution of diversity hotspots associated with the Qinghai-Tibetan Plateau (QTP) remains poorly understood. We review literature related to the diversification of organisms linked to the uplift of the QTP. To promote hypothesis-based research, we provide a geological and palaeoclimatic scenario for the region of the QTP and argue that further studies would benefit from providing a complete set of complementary analyses (molecular dating, biogeographic, and diversification rates analyses) to test for a link between organismic diversification and past geological and climatic changes in this region. In general, we found that the contribution of biological interchange between the QTP and other hotspots of biodiversity has not been sufficiently studied to date. Finally, we suggest that the biological consequences of the uplift of the QTP would be best understood using a meta-analysis approach, encompassing studies on a variety of organisms (plants and animals) from diverse habitats (forests, meadows, rivers), and thermal belts (montane, subalpine, alpine, nival). Since the species diversity in the QTP region is better documented for some organismic groups than for others, we suggest that baseline taxonomic work should be promoted. © 2014 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge

  4. Genomic evidence for rod monochromacy in sloths and armadillos suggests early subterranean history for Xenarthra

    PubMed Central

    Emerling, Christopher A.; Springer, Mark S.

    2015-01-01

    Rod monochromacy is a rare condition in vertebrates characterized by the absence of cone photoreceptor cells. The resulting phenotype is colourblindness and low acuity vision in dim-light and blindness in bright-light conditions. Early reports of xenarthrans (armadillos, sloths and anteaters) suggest that they are rod monochromats, but this has not been tested with genomic data. We searched the genomes of Dasypus novemcinctus (nine-banded armadillo), Choloepus hoffmanni (Hoffmann's two-toed sloth) and Mylodon darwinii (extinct ground sloth) for retinal photoreceptor genes and examined them for inactivating mutations. We performed PCR and Sanger sequencing on cone phototransduction genes of 10 additional xenarthrans to test for shared inactivating mutations and estimated the timing of inactivation for photoreceptor pseudogenes. We concluded that a stem xenarthran became an long-wavelength sensitive-cone monochromat following a missense mutation at a critical residue in SWS1, and a stem cingulate (armadillos, glyptodonts and pampatheres) and stem pilosan (sloths and anteaters) independently acquired rod monochromacy early in their evolutionary history following the inactivation of LWS and PDE6C, respectively. We hypothesize that rod monochromacy in armadillos and pilosans evolved as an adaptation to a subterranean habitat in the early history of Xenarthra. The presence of rod monochromacy has major implications for understanding xenarthran behavioural ecology and evolution. PMID:25540280

  5. Ca isotopes reveal weak control of tectonic uplift on long-term climate change

    NASA Astrophysics Data System (ADS)

    Moore, J.; Jacobson, A. D.; Holmden, C. E.; Craw, D.

    2010-12-01

    Ca-Mg silicate weathering consumes atmospheric CO2 over geological timescales (≥106 yr) whereas carbonate weathering has no effect. High Ca fluxes from active orogens have been used to argue that mountain uplift is a disproportionately large CO2 sink. To test this hypothesis, it is essential to determine proportions of Ca from silicate versus carbonate weathering. High precision measurement of Ca isotopes (δ44/40Ca) provides a novel method to directly quantify Ca sources. To this end, we examined δ44/40Ca in rivers draining the Southern Alps of New Zealand. The Southern Alps have large tectonic and climatic gradients but nearly constant bedrock chemistry. West of the main topographic divide, uplift and precipitation rates are high, and steep, fast-flowing rivers drain schist. East of the divide, uplift and precipitation rates are low, and low-gradient, braided rivers drain either schist or greywacke. Both schist and greywacke contain up to 3% hydrothermal and metamorphic calcite. Glaciers feed several schist and greywacke catchments. Examined as δ44/40Ca versus Sr/Ca, values measured for carbonate and silicate end-members define two-component mixing envelopes. Rivers west of the divide plot within the envelope, ruling out isotopic fractionation as a factor for these streams. Several rivers east of the divide are 40Ca enriched relative to the envelope. In-situ fractionation of stream water Ca cannot explain this pattern because fractionation is expected to preferentially remove 40Ca. We measured δ42/44Ca ratios to test if chemical weathering preferentially releases 40Ca. When examined as δ40/44Ca versus δ42/44Ca, the data only display mass-dependent isotope effects. Ca in grass and the exchangeable pool of shallow soils is enriched in 40Ca relative to waters and bedrock. This Ca defines a third mixing end-member that contributes 15-30% of the Ca in rivers east of the divide. Evidence of the plant-fractionated signal likely reflects water residence times

  6. Tectonic history of Sweetgrass Arch, Montana and Alberta-key to finding new hydrocarbons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shepard, W. Shepard, B.

    1985-05-01

    The Sweetgrass arch of northwestern Montana and southern Alberta is a major ancient structural feature. Initial anticlinal emplacement occurred during the early Paleozoic and was parallel with the cratonic margin. Strong uplift followed by peneplanation occurred during the Late Jurassic and basal Cretaceous during the westward drifting of the North American plate following the breakup of Pangea. During Cretaceous and early Tertiary times, the Sweetgrass arch was quiescent, but was rejuvenated in mid to late Tertiary, upwarped by a basement flexure to its present structural configuration: a 200 mi (322 km) long, north-plunging anticline showing 10,000 ft (350 m) ofmore » structural relief. Midway down its plunge, the anticline is offset 30 mi (48 km) by a right-lateral transcurrent fault. During Late Cretaceous and early Tertiary, plutonic uplifts were emplaced on the east flank, forming traps for oil then migrating updip from the Williston and Alberta basins. Oil and gas accumulated in Mississippian, Jurassic, and basal Cretaceous reservoirs in structural and stratigraphic traps around these plutonic uplifts. Subsequent late Tertiary doming of the Sweetgrass arch tilted the earlier structural traps and drained them, resulting in remigration of much of the oil and gas to the crest of the arch. The tilting failed to destroy many of the stratigraphic traps. As a result, down the flanks of the Sweetgrass arch are many frozen stratigraphic traps including Cut Bank field, the largest single-pay stratigraphic trap in the north Rockies. On the crest are large structure accumulations of remigrated oil at Kevin Sunburst and Pondera. Evidence of remigration is recorded by live oil show tracks in the reservoirs and remnant gas caps throughout the area of earlier accumulations. A potential exists for finding new frozen traps on the flanks and remigrated oil accumulations on or near the crest of the Sweetgrass arch.« less

  7. Continental drift and plateau uplift control origination and evolution of Asian and Australian monsoons.

    PubMed

    Liu, Xiaodong; Dong, Buwen; Yin, Zhi-Yong; Smith, Robin S; Guo, Qingchun

    2017-01-13

    Evolutions of Asian and Australian monsoons have important significance for understanding the past global change but are still a controversial subject. Here, we explore systematically the effects of plate movement and plateau uplift on the formation and evolution of the Asian and Australian monsoons by numerical simulations based on land-sea distributions and topographic conditions for five typical geological periods during the Cenozoic. Our results suggest that the timings and causes of formation of the monsoons in South Asia, East Asia and northern Australia are different. The Indian Subcontinent, which was located in the tropical Southern Hemisphere in the Paleocene, was influenced by the austral monsoon system simulated at that time. Once it moved to the tropical Northern Hemisphere in the Eocene, the South Asian monsoon established and remained persistently thereafter. However, the monsoons of East Asia and northern Australia did not appear until the Miocene. The establishment of the simulated low-latitude South Asian (northern Australian) monsoon appeared to have strongly depended on the location of mainland India (Australia), associated with northward plate motion, without much relation to the plateau uplift. On the contrary, the establishment of the mid-latitude East Asian monsoon was mainly controlled by the uplift of Tibetan plateau.

  8. Mega-tsunami deposits or evidence of uplift within the Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Keating, B. H.

    2004-12-01

    For several years there has been a controversy over the origin of coral-bearing deposits on the island of Lanai (Hawaii). Studies underway have expanded the study of marine deposits from Lanai to adjacent islands. Coral-bearing deposits are present at elevations up to 190 m on Lanai, 90 m on Maui, 90 m on Molokai, 30 m Oahu, 30 m on Niihau, roughly 75 m on Kauai (as well as a few m above sea level on the Kohala Volcano on the island of Hawaii). The deposits show a persistent pattern of increased weathering, color change, increasing age and increase in the number of fossils now extinct in Hawaiian waters, with elevation above modern sea level. Changes in slope are also observed reflecting changing relative sea level. A review of radiometric ages suggests in-situ corals as well as marine conglomerates were deposited near sea level and were contemporaneous. The distribution, stratigraphy and age of marine sediments around the islands are consistent with a history of uplift combined with changing sea level. We document the age, rock and fossil characteristics and distribution of sub-aerially exposed marine sediments, in the Hawaiian Island chain. We suggest that the Hawaiian Islands have experienced lithospheric adjustments during the last 500,000 years that have left marine deposits exposed above sea level.

  9. Uplifted Terraces along the Southeastern Coast of Bangladesh Reveal the Extent of 1762 Earthquake Surface Deformation and Potentially Document Prior Earthquakes

    NASA Astrophysics Data System (ADS)

    Mondal, D. R.; McHugh, C.; Steckler, M. S.; Seeber, L.; Akhter, S. H.; Mustaque, S.; Knappett, P. S.

    2016-12-01

    To better understand geohazards for Bangladesh, the surface expression of the 1762 earthquake and previous earthquakes, we surveyed the coast of Teknaf for evidence of uplift with high precision NetR9, RTX GPS. Previous studies by Aung et al. (2006; 2008) and Wang et al. (2013) documented uplifted terraces along the west coast of Myanmar and linked the youngest terrace to the 1762 Arakan earthquake. Previous studies by Mondal et al. (2015) documented 2.5 m uplifted microatoll corals in the Saint Martin anticline, 10 km southwest from the Teknaf coastline, and linked their uplift by U/Th ages to the 1762 earthquake. Along the southeast Bangladesh coastline, we mapped three geomorphic terraces for 70 km from Teknaf to Cox's Bazar. While GPS measured the location and elevation, an optical level (Theodolite) was used to survey across the different terraces from the beach to the Teknaf anticline foothills. The terraces were also characterized by slope analysis using 30 m SRTM DEM to understand the relation between the terrace geomorphology and potential influence from slope aprons derived from the erosion of the anticline. Our results show that the elevation of three terraces is consistent along the coast, and that terrace elevation ranges from 2-5 m, 5 -7 m and 11-13 m for the youngest, intermediate and oldest terrace, respectively. The youngest terrace, previously dated by McHugh et al. (2015) using C-14 from marine shells obtained from the terrace top, is linked to uplift from the 1762 earthquake. Marine fossils are present in the oldest terrace, and we will present the C-14 age results. Results also suggest that the higher terrace is not prominent in those locations where the slope of the anticline aprons is very high, and they are in a close proximity to each other. The present geomorphic evidence suggests that these terraces were uplifted by three paleoearthquakes, and C-14 ages will provide timing for the uplift. Evidence of terrace uplift derived from our GPS

  10. A Literature Survey and Experimental Evaluation of the State-of-the-Art in Uplift Modeling: A Stepping Stone Toward the Development of Prescriptive Analytics.

    PubMed

    Devriendt, Floris; Moldovan, Darie; Verbeke, Wouter

    2018-03-01

    Prescriptive analytics extends on predictive analytics by allowing to estimate an outcome in function of control variables, allowing as such to establish the required level of control variables for realizing a desired outcome. Uplift modeling is at the heart of prescriptive analytics and aims at estimating the net difference in an outcome resulting from a specific action or treatment that is applied. In this article, a structured and detailed literature survey on uplift modeling is provided by identifying and contrasting various groups of approaches. In addition, evaluation metrics for assessing the performance of uplift models are reviewed. An experimental evaluation on four real-world data sets provides further insight into their use. Uplift random forests are found to be consistently among the best performing techniques in terms of the Qini and Gini measures, although considerable variability in performance across the various data sets of the experiments is observed. In addition, uplift models are frequently observed to be unstable and display a strong variability in terms of performance across different folds in the cross-validation experimental setup. This potentially threatens their actual use for business applications. Moreover, it is found that the available evaluation metrics do not provide an intuitively understandable indication of the actual use and performance of a model. Specifically, existing evaluation metrics do not facilitate a comparison of uplift models and predictive models and evaluate performance either at an arbitrary cutoff or over the full spectrum of potential cutoffs. In conclusion, we highlight the instability of uplift models and the need for an application-oriented approach to assess uplift models as prime topics for further research.

  11. Canyon incision chronology based on ignimbrite stratigraphy and cut-and-fill sediment sequences in SW Peru documents intermittent uplift of the western Central Andes

    NASA Astrophysics Data System (ADS)

    Thouret, Jean-Claude; Gunnell, Yanni; Jicha, Brian R.; Paquette, Jean-Louis; Braucher, Régis

    2017-12-01

    Based on an 40Ar/39Ar- and U/Pb-based chronostratigraphy of ignimbrite sheets and the geomorphological features of watersheds, river profiles and slope deposits in the Ocoña-Cotahuasi-Marán (OCM) and Colca valleys of southwest Peru, we reconstruct the valley incision history of the western Central Andes over the last c. 25 Myr. We further document the Pleistocene and Holocene evolution of deep valleys on the basis of 14 10Be surface-exposure ages obtained on debris-avalanche deposits and river straths. The data suggest that uplift was gradual over the past 25 Myr, but accelerated after c. 9 Ma. Valley incision started around 11-9 Ma and accelerated between 5 and 4 Ma. Incision was followed by several pulses of valley cut-and-fill after 2.3 Ma. Evidence presented suggest that the post-5 Ma sequence of accelerated canyon incision probably resulted from a combination of drainage piracy from the Cordilleran drainage divide towards the Altiplano, accentuated flexural tilting of the Western Cordillera towards the SE, and increased rainfall on the Altiplano after late Miocene uplift of the Eastern Cordillera. The valley deepening and slope steepening driven by tectonic uplift gave rise to large occurrences of rockslope failure. The collapsed rock masses periodically obstructed the canyons, thus causing abrupt changes in local base levels and interfering with the steadiness of fluvial incision. As a result, channel aggradation has prevailed in the lower-gradient, U-shaped Pacific-rim canyons, whereas re-incision through landslide deposits has occurred more rapidly across the steeper V-shaped, upper valleys. Existing canyon knickpoints are currently arrested at the boundary between the plutonic bedrock and widespread outcrops of middle Miocene ignimbritic caprock, where groundwater sapping favouring rock collapse may be the dominant process driving headward erosion.

  12. Re-examining the doming uplift model of Emeishan Large Igneous Province (SW China): evidence from high-resolution conodont biostratigraphy and sedimentology

    NASA Astrophysics Data System (ADS)

    Yadong, S.; Wignall, P. B.; Ali, J. R.; Widdowson, M.; Bond, D. P.; Lai, X.

    2010-12-01

    The Middle Permian Emeishan large igneous province of SW China is regard by many as providing the quintessential example of kilometre-scale pre-eruption domal uplift associated with mantle plume impingement on the base of the lithosphere. The key line of evidence for this has been the purported deep erosion profile of the Maokou Formation platform carbonates that lie directly beneath the central and inner parts of the volcanic pile. We have tested this interpretation by carrying out conodont age dating and facies analysis on the uppermost beds of the Maokou Formation across these central regions, together with the limestones that are intercalated within the basal lava flows. The investigated sections (from Yunnan, Sichuan, Guizhou and Guangxi provinces) span locations from directly below the centre of the igneous province, to several hundred kilometres beyond its margins. The results show that eruptions began in the Jinogondolella altudaensis Zone (~263 Ma) of the Middle Capitanian Stage, and subsequently greatly increased in extent and volume in the J. xuanhanensis Zone (~262 Ma) (Sun et al., 2010). Most importantly, at most locations within the terrain, and many locations beyond its margins, there appears to have been platform subsidence (not uplift) with deep-water facies (radiolarian cherts, submarine fans) developing immediately prior to the initial volcanism (J. altudaensis Zone). Accordingly, pre-eruption uplift must have been muted because over large areas of the terrain the basal flows rest conformably on a variety of Maokou sedimentary facies. By contrast, the clearest evidence for an emergence surface occurs around the flanks of the province in the J. xuanhanensis Zone. This is after the initial onset of eruptions, and coincides with the regional eustatic fall (Sun et al., 2010). Furthermore, pillow lavas, hydromagmatic deposits and interflow limestone/reef packages are commonly seen around the terrain indicating a strong marine influence at the early

  13. An early history of the Gestalt factors of organisation.

    PubMed

    Vezzani, Stefano; Marino, Barbara F M; Giora, Enrico

    2012-01-01

    Wertheimer's (1923, Psychologische Forschung 4 301 - 350) idea that the perceptual world is articulated according to factors of organisation is widely acknowledged as one of the most original contributions of Gestalt psychology and stands as a milestone in the history of vision research. An inquiry focused on the forerunners of some of Wertheimer's factors of perceptual organisation is documented here. In fact, in 1900 Schumann described grouping by proximity and by vertical symmetry, and in 1903 G E Müller identified the factors of sameness/similarity and contour. Other authors contributed to the early description of these factors, such as Rubin, who in 1922 originally illustrated grouping by similarity. Even though Wertheimer himself granted these authors due recognition, later psychologists have paid little attention to their contributions. Some possible reasons for this negligence are briefly discussed.

  14. The Role of Residential Early Parenting Services in Increasing Parenting Confidence in Mothers with A History of Infertility.

    PubMed

    Khajehei, Marjan; Finch, Lynette

    2016-01-01

    Mothers with a history of infertility may experience parenting difficulties and challenges. This study was conducted to investigate the role of residential early parenting services in increasing parenting confidence in mothers with a history of infertility. This was a retrospective chart review study using the quantitative data from the clients attending the Karitane Residential Units and Parenting Services (known as Karitane RUs) during 2013. Parenting confidence (using Karitane Parenting Confidence Scale-KPCS), depression, demographics, reproductive and medical history, as well as child's information were assessed from a sample of 27 mothers who had a history of infertility and who attended the Karitane RUs for support and assistance. The data were analyzed using SPSS version 19. More than half of the women (59.3%) reported a relatively low level of parenting confidence on the day of admission. The rate of low parenting confidence, however, dropped to 22.2% after receiving 4-5 days support and training in the Karitane RUs. The mean score of the KPCS increased from 36.9 ± 5.6 before the intervention to 41.1 ± 3.4 after the intervention, indicating an improvement in the parenting confidence of the mothers after attending the Karitane RUs (P<0.0001). No statistically significant association was found between maternal low parenting confidence with parental demographics (including age, country of birth, and employment status), a history of help-seeking, symptoms of depression, as well as child's information [including gender, age, siblings, diagnosis of gastroesophageal reflux disease (GORD) and use of medication]. Having a child after a period of infertility can be a stressful experience for some mothers. This can result in low parenting confidence and affect parent-child attachment. Our findings emphasized on the role of the residential early parenting services in promoting the level of parenting confidence and highlighted the need for early recognition and

  15. The Role of Residential Early Parenting Services in Increasing Parenting Confidence in Mothers with A History of Infertility

    PubMed Central

    Khajehei, Marjan; Finch, Lynette

    2016-01-01

    Background Mothers with a history of infertility may experience parenting difficulties and challenges. This study was conducted to investigate the role of residential early parenting services in increasing parenting confidence in mothers with a history of infertility. Materials and Methods This was a retrospective chart review study using the quantitative data from the clients attending the Karitane Residential Units and Parenting Services (known as Karitane RUs) during 2013. Parenting confidence (using Karitane Parenting Confidence Scale-KPCS), depression, demographics, reproductive and medical history, as well as child’s information were assessed from a sample of 27 mothers who had a history of infertility and who attended the Karitane RUs for support and assistance. The data were analyzed using SPSS version 19. Results More than half of the women (59.3%) reported a relatively low level of parenting confidence on the day of admission. The rate of low parenting confidence, however, dropped to 22.2% after receiving 4-5 days support and training in the Karitane RUs. The mean score of the KPCS increased from 36.9 ± 5.6 before the intervention to 41.1 ± 3.4 after the intervention, indicating an improvement in the parenting confidence of the mothers after attending the Karitane RUs (P<0.0001). No statistically significant association was found between maternal low parenting confidence with parental demographics (including age, country of birth, and employment status), a history of help-seeking, symptoms of depression, as well as child’s information [including gender, age, siblings, diagnosis of gastroesophageal reflux disease (GORD) and use of medication]. Conclusion Having a child after a period of infertility can be a stressful experience for some mothers. This can result in low parenting confidence and affect parent-child attachment. Our findings emphasized on the role of the residential early parenting services in promoting the level of parenting confidence

  16. Ground uplift related to permeability enhancement following the 2011 Tohoku earthquake in the Kanto Plain, Japan

    NASA Astrophysics Data System (ADS)

    Ishitsuka, Kazuya; Matsuoka, Toshifumi; Nishimura, Takuya; Tsuji, Takeshi; ElGharbawi, Tamer

    2017-06-01

    We investigated the post-seismic surface displacement of the 2011 Tohoku earthquake around the Kanto Plain (including the capital area of Japan), which is located approximately 400 km from the epicenter, using a global positioning system network during 2005-2015 and persistent scatterer interferometry of TerraSAR-X data from March 2011 to November 2012. Uniform uplift owing to viscoelastic relaxation and afterslip on the plain has been reported previously. In addition to the general trend, we identified areas where the surface displacement velocity was faster than the surrounding areas, as much as 7 mm/year for 3 years after the earthquake and with a velocity decay over time. Local uplift areas were 30 × 50 km2 and showed a complex spatial distribution with an irregular shape. Based on an observed groundwater level increase, we deduce that the local ground uplift was induced by a permeability enhancement and a pore pressure increase in the aquifer system, which is attributable to mainshock vibration.[Figure not available: see fulltext.

  17. Women's experiences of hassles and uplifts in their everyday patterns of occupations.

    PubMed

    Erlandsson, Lena-Karin; Eklund, Mona

    2003-01-01

    The aim of this study was to investigate experiences of hassles and uplifts among women. One hundred working mothers were interviewed using the Target Complaints instrument. Content analysis, resulting in both qualitative categories and quantitative variables, was used. Working mothers' hassles were mainly generated by their social, temporal and doing contexts and illustrate the importance of considering women's total patterns of everyday occupations and not focusing one-sidedly on the work situation when treating occupation-related ill-health. Women's uplifts were experienced through the social context and by doing such different occupations as going to the movies, cleaning the house, or attending a class. This indicates the appropriateness of using a client-centred approach in interventions with openness to the client's unique situation. Unexpected occupations were identified almost exclusively among the hassles. This is important knowledge for occupational therapists since women will continue to be dual workers and at potential risk of developing unbalanced and detrimental patterns of occupations, in turn causing ill health.

  18. Evidence for Late Pleistocene uplift at the Somma-Vesuvius apron near Pompeii

    NASA Astrophysics Data System (ADS)

    Marturano, Aldo; Aiello, Giuseppe; Barra, Diana

    2011-05-01

    Detailed stratigraphic and micropalaeontological analyses of samples from boreholes at the Somma-Vesuvius apron, between Pompeii and the sea, allowed reconstruction of Late Quaternary palaeoenvironmental evolution of the Sarno coastal plain. In all, 116 samples were recovered from seven boreholes drilled from 2-10 m a.s.l. to 16.5-26 m b.s.l. Microfossil assemblages, with special regard to benthic foraminifers and ostracods, were used to reconstruct the depositional palaeoenvironment. Fossil remains show that all the pre-79 AD fossiliferous sediments from 2 to - 24 m a.s.l. were deposited in shallow marine waters for a long time despite an appreciable sea level rise. The data indicate alternation of both shallow marine and subaerial conditions during the last ~ 15 kyr, evidencing ground uplift of the area of about 75 m at a rate of ~ 5 mm/year. Marine sediment accumulation (~ 6 m/kyr) and tectonic uplift long offset the sea level rise, and as a consequence, submerged areas remained the same as well.

  19. Late Quaternary uplift rate inferred from marine terraces, Shimokita Peninsula, northeastern Japan: A preliminary investigation of the buried shoreline angle

    NASA Astrophysics Data System (ADS)

    Matsu'ura, Tabito; Kimura, Haruo; Komatsubara, Junko; Goto, Norihisa; Yanagida, Makoto; Ichikawa, Kiyoshi; Furusawa, Akira

    2014-03-01

    After estimating tectonic uplift rates along the northern part of the northeast Japan forearc (the overriding plate in the northeast Japan subduction zone) by mapping the elevation of the inner edges of marine terrace surfaces, we refined this estimate through elevation measurements of the buried shoreline angle beneath well-dated marine terrace surfaces, from which we could derive more accurate paleo-sea levels. The uplift rate initially inferred from the inner edge of marine terrace T4, correlated with marine isotope stage MIS 5e by tephrochronology, increases eastward from 0.11-0.22 m ky- 1 around the backarc volcanic front to 0.17-0.32 m ky- 1 in the forearc on the peninsula of Shiriyazaki. We refined the uplift rates for T4, on the basis of the shoreline angle elevation, from the reconstructed profile of the paleo-sea cliff and wave-cut platform on a rocky coast and the reconstructed profile of the swash zone sediments and terrace deposits on a sandy coast. The refined uplift rates were 0.14-0.25 m ky- 1 on the rocky coast and 0.14-0.23 m ky- 1 on the sandy coast, slightly slower than the rates we inferred from the height of T4 and about one-half to three-fourths of previously reported rates. By extrapolation from the example of the sandy coast, the refined uplift rate around the volcanic front was 0.09-0.18 m ky- 1. The vertical deformation across the forearc of the Shimokita Peninsula since MIS 5e is possibly associated with regional isostatic uplift of 0.09-0.18 m ky- 1 and anticlinal deformation by an offshore fault, interpreted from acoustic profiles, of 0.05-0.07 m ky- 1.

  20. Late Eocene Uplift of the Al Hajar Mountains, Oman, Supported by Stratigraphy and Low-Temperature Thermochronology

    NASA Astrophysics Data System (ADS)

    Hansman, Reuben J.; Ring, Uwe; Thomson, Stuart N.; den Brok, Bas; Stübner, Konstanze

    2017-12-01

    Uplift of the Al Hajar Mountains in Oman has been related to either Late Cretaceous ophiolite obduction or the Neogene Zagros collision. To test these hypotheses, the cooling of the central Al Hajar Mountains is constrained by 10 apatite (U-Th)/He (AHe), 15 fission track (AFT), and four zircon (U-Th)/He (ZHe) sample ages. These data show differential cooling between the two major structural culminations of the mountains. In the 3 km high Jabal Akhdar culmination AHe single-grain ages range between 39 ± 2 Ma and 10 ± 1 Ma (2σ errors), AFT ages range from 51 ± 8 Ma to 32 ± 4 Ma, and ZHe single-grain ages range from 62 ± 3 Ma to 39 ± 2 Ma. In the 2 km high Saih Hatat culmination AHe ages range from 26 ± 4 to 12 ± 4 Ma, AFT ages from 73 ± 19 Ma to 57 ± 8 Ma, and ZHe single-grain ages from 81 ± 4 Ma to 58 ± 3 Ma. Thermal modeling demonstrates that cooling associated with uplift and erosion initiated at 40 Ma, indicating that uplift occurred 30 Myr after ophiolite obduction and at least 10 Myr before the Zagros collision. Therefore, this uplift cannot be related to either event. We propose that crustal thickening supporting the topography of the Al Hajar Mountains was caused by a slowdown of Makran subduction and that north Oman took up the residual fraction of N-S convergence between Arabia and Eurasia.

  1. Marine Terrace Deposits along the Mediterranean Coast on the Southeastern Turkey and Their Implications for Tectonic Uplift and Sea Level Change

    NASA Astrophysics Data System (ADS)

    Tari, U.; Tüysüz, O.; Blackwell, B. A. B.; Genç, Ş. C.; Florentin, J. A.; Mahmud, Z.; Li, G. L.; Blickstein, J. I. B.; Skinner, A. R.

    2016-12-01

    Tectonic movements among the African, Arabian and Anatolian Plates have deformed the eastern Mediterranean. These movements caused transtensional opening of the NE-trending Antakya Graben since the late Pliocene. Tectonic uplift coupled with Quaternary sealevel fluctuations has produced several stacked marine terraces along the Mediterranean coasts on the graben. Here, marine terrace deposits that sit on both flanks of the graben at elevations between 3 and 175 m were dated using electron spin resonance (ESR) method in order to calculate uplift rates. The ESR ages range from 12 ka in late MIS 2 to 457 ka in MIS 9-11, but most of the terraces contain molluscs reworked from several earlier deposits due to successive tectonic movements and sealevel fluctuations. By dating in situ fossils, along the basal contacts of the marine terraces, uplift rates were calculated on both sides of the Antakya Graben. Results indicate that these deposits were mainly uplifted by local active faults rather than regional movements.

  2. On the early history of the Finnish Meteorological Institute

    NASA Astrophysics Data System (ADS)

    Nevanlinna, H.

    2014-03-01

    This article is a review of the foundation (in 1838) and later developments of the Helsinki (Finland) magnetic and meteorological observatory, today the Finnish Meteorological Institute (FMI). The main focus of the study is in the early history of the FMI up to the beginning of the 20th century. The first director of the observatory was Physics Professor Johan Jakob Nervander (1805-1848). He was a famous person of the Finnish scientific, academic and cultural community in the early decades of the 19th century. Finland was an autonomously part of the Russian Empire from 1809 to 1917, but the observatory remained organizationally under the University of Helsinki, independent of Russian scientific institutions, and funded by the Finnish Government. Throughout the late-19th century the Meteorological Institute was responsible of nationwide meteorological, hydrological and marine observations and research. The observatory was transferred to the Finnish Society of Sciences and Letters under the name the Central Meteorological Institute in 1881. The focus of the work carried out in the Institute was changed gradually towards meteorology. Magnetic measurements were still continued but in a lower level of importance. The culmination of Finnish geophysical achievements in the 19th century was the participation to the International Polar Year programme in 1882-1883 by setting up a full-scale meteorological and magnetic observatory in Sodankylä, Lapland.

  3. EARLY IMPACT MELTING AND SPACE EXPOSURE HISTORY OF THE PAT91501 LCHONDRITE

    NASA Technical Reports Server (NTRS)

    Bogard, Donald D.; Garrison, D. H.; Herzog, G. F.; Xue, S.; Klein, J.; Middleton, R.

    2004-01-01

    Collisions probably occurred frequently in the early history of the asteroid belt. Their effects, which should be recorded in meteorites, must have included heating and melting along with shock alteration of mineral textures. Some non-chondritic meteorite types e.g., eucrites and IIE and IAB irons - do indeed give evidence of extensive impact heating more than 3.4 Gyr ago. The ordinary chondrites, in contrast, show little evidence of early impact heating. The Ar-Ar and Rb-Sr ages of ordinary chondrites that experienced intense shock are for the most part relatively young, many less than 1.5 Gyr. The numerous L-chondrites with Ar- Ar ages clustering near 0.5 Gy are a well-known example. One of them, the 105-kg Chico Lchondrite, shows the effects of unusually intense heating. It is approximately 60% impact melt and likely formed as a dyke beneath a large crater when the L-chondrite parent body underwent a very large impact approximately 0.5 Gyr ago. In rare instances, older shock dates are indicated for ordinary chondrites. Dixon et al show early impact resetting of Ar-Ar ages of a few LL-chondrites including MIL 99301 at 4.23 0.03 Gyr, but in none of these stones did shock lead to extensive melting. As of 2003, searches for chondritic melts attributable to early shock had turned up only the Shaw L-chondrite, which has an Ar-Ar age of approximately 4.42 Gyr. PAT91501 is an 8.55-kg L-chondrite containing vesicles and metal-troilite nodules. It is a unique, near-total impact melt, unshocked, depleted in siderophile and chalcophile elements, and contains only approximately 10% relic chondritic material. The authors conclude that PAT91501 crystallized rapidly and from a much more homogeneous melt than did Shaw. They suggest that PAT resembles Chico and likely formed as an impact melt vein within an impact crater. To define the history of PAT, we have determined its Ar-39-Ar-40 age and measured several radioactive and stable nuclides produced during its space exposure to

  4. Differential uplift and incision of the Yakima River terraces, central Washington State

    USGS Publications Warehouse

    Bender, Adrian M.; Amos, Colin B.; Bierman, Paul R.; Rood, Dylan; Staisch, Lydia; Kelsey, Harvey M.; Sherrod, Brian

    2016-01-01

    The fault-related Yakima folds deform Miocene basalts and younger deposits of the Columbia Plateau in central Washington State. Geodesy implies ~2 mm/yr of NNE directed shortening across the folds, but until now the distribution and rates of Quaternary deformation among individual structures has been unclear. South of Ellensburg, Washington, the Yakima River cuts a ~600 m deep canyon across several Yakima folds, preserving gravel-mantled strath terraces that record progressive bedrock incision and related rock uplift. Here we integrate cosmogenic isochron burial dating of the strath terrace gravels with lidar analysis and field mapping to quantify rates of Quaternary differential incision and rock uplift across two folds transected by the Yakima River: Manastash and Umtanum Ridge. Isochron burial ages from in situ produced 26Al and 10Be at seven sites across the folds date episodes of strath terrace formation over the past ~2.9 Ma. Average bedrock incision rates across the Manastash (~88 m/Myr) and Umtanum Ridge (~46 m/Myr) anticlines are roughly 4 to 8 times higher than rates in the intervening syncline (~14 m/Myr) and outside the canyon (~10 m/Myr). These contrasting rates demonstrate differential bedrock incision driven by ongoing Quaternary rock uplift across the folds at rates corresponding to ~0.13 and ~0.06 mm/yr shortening across postulated master faults dipping 30 ± 10°S beneath the Manastash and Umtanum Ridge anticlines, respectively. The reported Quaternary shortening across the anticlines accounts for ~10% of the ~2 mm/yr geodetic budget, suggesting that other Yakima structures actively accommodate the remaining contemporary deformation.

  5. Early volcanic history of the Rabaul area

    NASA Astrophysics Data System (ADS)

    McKee, Chris O.; Duncan, Robert A.

    2016-04-01

    We conducted an extensive program of 40Ar-39Ar age determinations on a suite of 27 volcanic rock samples from key stratigraphic units at Rabaul, Papua New Guinea in order to improve understanding of the early eruption history of the multiple volcanic systems present in the area. Analyses of whole rock, plagioclase and groundmass separates yielded statistically significant ages for 24 samples. Replicate analyses (groundmass, plagioclase) for 17 of the samples provided concordant ages. The oldest systems in the Rabaul area (>1 Ma to ≈300 ka) are in the south, associated with the caldera-like Varzin Depression, and in the north, at the stratovolcanoes Watom and Tovanumbatir. The earliest known activity of the Rabaul system occurred between about 330 and 200 ka and involved emplacement of lava flows and scoria deposits. Major explosive activity at the Rabaul system commenced at about 200 ka and produced a sequence of dacitic ignimbrites that culminated with the emplacement of the large-volume Malaguna Pyroclastics at about 160 ka. Calderas may have been formed as a consequence of the large volumes of tephra produced during some of these eruptions. Products of the early activity are found in the northern and northeastern walls of Rabaul Caldera and on the northeastern flank of Tovanumbatir. This leads to the conclusion that the source of the early activity at Rabaul probably was located in the northern part of the present caldera complex. A shift in the focus of activity at the Rabaul system took place between about 160 and 125 ka. All of the younger (<125 ka) major pyroclastic formations, including the Karavia Welded Tuff, the Barge Tunnel Ignimbrite and the Latlat Pyroclastics, which make up the bulk of the exposure in the southern and western walls of Rabaul Caldera, were erupted from a source or sources in the south-central part of the complex. The stratovolcanoes Palangiangia and Kabiu, which flank the northeastern part of the complex, had commenced activity by

  6. CHROMOSOME 11 ABERRATIONS IN SMALL COLONY L5178Y TK-/-MUTANTS EARLY IN THEIR CLONAL HISTORY

    EPA Science Inventory

    The authors have developed a cytogenetic technique that allows observation of chromosome rearrangements associated with TK-/- mutagenesis of the L5178Y/TK+/-3.7.2C cell line early in mutant clonal history. For a series of mutagenic treatments they show that the major proportion (...

  7. Variations in the long-term uplift rate due to the Altiplano-Puna magma body observed with Sentinel-1 interferometry

    NASA Astrophysics Data System (ADS)

    Lau, Nicholas; Tymofyeyeva, Ekaterina; Fialko, Yuri

    2018-06-01

    We present new Interferometric Synthetic Aperture Radar (InSAR) observations of surface deformation in the Altiplano-Puna region (South America) where previous studies documented a broad uplift at an average rate of ∼10 mm/yr. We use data from the Sentinel-1 satellite mission to produce high-resolution velocity maps and time series of surface displacements between years 2014-2017. The data reveal that the uplift has slowed down substantially compared to the 1992-2010 epoch and is characterized by short-term fluctuations on time scales of months to years. The observed variations in uplift rate may indicate a non-steady supply of melt and/or volatiles from the partially molten Altiplano-Puna Magma Body (APMB) into an incipient diapir forming in the roof of the APMB.

  8. The interaction of prehistoric human settlement, sea level change and tectonic uplift of the Coastal Range, eastern Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, H.; Chen, W. S.

    2017-12-01

    The late Cenozoic mountain belt of Taiwan, resulting from the collision between the Eurasian and Philippine Sea plates, is known for its rapid tectonic uplift. As postglacial sea level rose ca. 15,000 yr ago, the eastern coast of Taiwan, due to the rapid tectonic uplift rate, displayed a totally different scenario comparing with most of the coastal plains around the world. At the beginning of postglacial era, the sea level rising rate was greater than the tectonic uplift rate which induced the original piedmont alluvial fan or coastal plain to be overwhelmed by sea water rapidly. Around 13.5 ka, the tectonic uplift rate caught up with the sea level rising and broad wave-cut platform formed. The approximation of tectonic uplift and sea level rising rates was lasting from 13.5 to 5ka, but shoreline progradation may have been enhanced by increased slope erosion which resulted in the alluvial fan forming at the later time of this period. As soon as the eustasy stabilized, the landmass continued to uplift which might have enhanced the river incising and wave erosion rapidly. Therefore the topographic expression along the eastern fringing of Coastal Range forms extended alluvial-fan, stream, and marine terraces and are covered by late Holocene colluvium and marine deposits. 88 archaeological sites were chosen in this study based on surface survey where the archaeological chronology of cultural stage is established primarily through examining pottery series and associated manual excavation. It is interesting that most of the archaeological sites were located on the alluvial fan although the Holocene marine terraces have formed after 5ka. There are no clear evidences to support a shore-oriented settlement, but the abundant alluvial depositional structures observed from the overlaying formation reveals the stream depositional system was still active at this time. If the Neolithic people wanted to come to the "new born" coastal region for the abundant ocean resources, they

  9. The known knowns, the known unknowns, and beyond: early life history perspective for the Laurentian Great Lakes

    EPA Science Inventory

    Early life history research has been crucial for understanding and managing fisheries in the Laurentian Great Lakes and beyond. Much is known about spawning sites, temperatures at spawning, incubation periods, spawning substrates, and other factors surrounding reproduction for ma...

  10. Reflexivity, the role of history, and the case of mesmerism in early Victorian Britain.

    PubMed

    Lamont, Peter

    2010-11-01

    As part of a wider argument that history is essential to psychological understanding because of the reflexive nature of psychological knowledge, this article examines the case of mesmerism in early Victorian Britain as an example of how psychological knowledge is both constructive and constructed. It is argued that the shift from "mesmerism" to "hypnotism" was a change in understanding that created a new kind of psychological experience. It is also argued that demonstrations of mesmerism, far from being self-evident facts, could be framed as evidence either for or against the central claims of mesmerism. It is concluded that the case of mesmerism in early Victorian Britain provides a further example of the need for historical understanding within Psychology.

  11. New insights on multiple seismic uplift on the Main Frontal Thrust near the Ratu river, Eastern Nepal using high-resolution topography

    NASA Astrophysics Data System (ADS)

    Karakas, Cagil; Tapponnier, Paul; Nath Sapkota, Soma; Coudurier Curveur, Aurelie; Ildefonso, Sorvigenaleon; Gao, Mingxing; Bollinger, Laurent; Klinger, Yann

    2016-04-01

    The number of localities along the Main Frontal Thrust, between 85°49' to 86°27' E, where new data corroborates the surface emergence of the great M ≈ 8.4, 1934 Bihar-Nepal and 1255 AD earthquakes has increased over the past years. Here we show new high-resolution, quantitative evidences of surface rupture and co-seismic uplift near the Ratu river area. We present a refined map of uplifted terrace surfaces and abandoned paleo-channels truncated by the MFT, obtained by the combination of newly acquired high resolution Digital Elevation Models from Total station, Terrestrial Lidar Scanner (TLS), Unmanned Aerial Vehicle (UAV) and kinematic GPS surveys. In the Ratu valley, using these new high-resolution topographic datasets, we identify six and possibly seven distinct terrace levels uplifted parallel to the riverbed, lying unconformably on top of folded Siwaliks. Several sets of measurements may be taken to imply broadly characteristic increments of throw during sequences of at least six to seven events of riverbed abandonment related to co-seismic uplifts. Newly collected detrital charcoals from several pits and from a rejuvenated paleoseismological wall will help assess more precisely uplift and shortening rates over the length of segments of the MFT east and west of Bardibas. A regional comparison of comparable long-term paleoseismological data at other sites along the 1934 rupture length is in progress.

  12. Density-dependent coral recruitment displays divergent responses during distinct early life-history stages

    PubMed Central

    Evensen, Nicolas R.; Gómez-Lemos, Luis A.; Babcock, Russell C.

    2017-01-01

    Population growth involves demographic bottlenecks that regulate recruitment success during various early life-history stages. The success of each early life-history stage can vary in response to population density, interacting with intrinsic (e.g. behavioural) and environmental (e.g. competition, predation) factors. Here, we used the common reef-building coral Acropora millepora to investigate how density-dependence influences larval survival and settlement in laboratory experiments that isolated intrinsic effects, and post-settlement survival in a field experiment that examined interactions with environmental factors. Larval survival was exceptionally high (greater than 80%) and density-independent from 2.5 to 12 days following spawning. By contrast, there was a weak positive effect of larval density on settlement, driven by gregarious behaviour at the highest density. When larval supply was saturated, settlement was three times higher in crevices compared with exposed microhabitats, but a negative relationship between settler density and post-settlement survival in crevices and density-independent survival on exposed surfaces resulted in similar recruit densities just one month following settlement. Moreover, a negative relationship was found between turf algae and settler survival in crevices, whereas gregarious settlement improved settler survival on exposed surfaces. Overall, our findings reveal divergent responses by coral larvae and newly settled recruits to density-dependent regulation, mediated by intrinsic and environmental interactions. PMID:28573015

  13. TEACHERS' GUIDES. WORLD HISTORY FOR THE ACADEMICALLY TALENTED. ADVANCED PLACEMENT EUROPEAN HISTORY.

    ERIC Educational Resources Information Center

    AUGSPURGER, EVERETT F.; AND OTHERS

    PREPARED BY TEACHERS AND SUPERVISORS WORKING WITH A 2-YEAR DEMONSTRATION PROJECT, THIS DOCUMENT CONTAINS GUIDES FOR A WORLD HISTORY COURSE (PREHISTORY TO EARLY 20TH CENTURY) FOR THE GIFTED AND AN ADVANCED PLACEMENT COURSE IN EUROPEAN HISTORY (ANCIENT CIVILIZATION TO EARLY 20TH CENTURY). STUDENTS ARE EXPECTED TO STUDY HISTORICAL ISSUES AND DEVELOP…

  14. The early history of ideas on brief interventions for alcohol

    PubMed Central

    McCambridge, Jim; Cunningham, John A

    2014-01-01

    Aims This study explores the early development of brief interventions for alcohol using a history of ideas approach with a particular focus on intervention content. Methods The source publications of the key primary studies published from approximately 1962 to 1992 were examined, followed by a brief review of the earliest reviews in this field. These studies were placed in the context of developments in alcohol research and in public health. Results After early pioneering work on brief interventions, further advances were not made until thinking about alcohol problems and their treatment, most notably on controlled drinking, along with wider changes in public health, created new conditions for progress. There was then a golden era of rapid advance in the late 1980s and early 1990s, when preventing the development of problem drinking became important for public health reasons, in addition to helping already problematic drinkers. Many research challenges identified at that time remain to be met. The content of brief interventions changed over the period of study, although not in ways well informed by research advances, and there were also obvious continuities, with a renewed emphasis on the facilitation of self-change being one important consequence of the development of internet applications. Conclusions Ideas about brief interventions have changed in important ways. Brief interventions have been studied with different populations of drinkers, with aims embracing both individual and population-level perspectives, and without well-specified contents. The brief intervention field is an appropriate target for further historical investigations, which may help thinking about addressing alcohol and other problems. PMID:24354855

  15. Last interglacial (MIS5e) sea-levels and uplift along the north-east Gulf of Aqaba

    NASA Astrophysics Data System (ADS)

    BAR (KOHN), N.; Stein, M.; Agnon, A.; Yehudai, M.; Lazar, B.; Shaked, Y.

    2014-12-01

    An uplifted flight of coral reef terraces, extending along the north-east margin of the Gulf of Aqaba (GOA), provides evidence for uplift rates and sea level high stands. GOA fills a narrow and deep tectonic depression lying along the southern sector of the Dead Sea Transform where it meets the Red Sea. This special configuration of the GOA and its latitude turn it into a dependable paleo-sea level monitor, sensitive only to global eustatic changes and local tectonic movements. A sequence of five uplifted coral reef terraces were mapped and characterized on basis of morphology and reef-facies, and their elevation above the present sea level was determined. The fossil reefs studied comprise fringing reefs, some with clear reef-structure that includes a reef flat and a shallow back lagoon. Most outcrops in the study area represent a transgressive sequence in which, during its highest stand, formed fringing reef terraces. We use U-Th ages of fossil corals samples found in growth position at various terraces. Corals from three uplifted reef terraces, R1, R2, and R3 were dated to the last interglacial period particularly to marine isotope stage (MIS) 5e. These ages were achieved from mainly calcitic corals (recrystallized in a freshwater phreatic environment). A few ages were derived from aragonite corals. The three terraces represent three sub-stages within MIS5e: R3 formed during a short standstill at ~130 ka BP; R2 formed during a long and steady standstill between ~128 to ~121 ka BP; and R1 represents a short standstill at ~117 ka BP. Assuming that terrace reef flats represent past sea level high stands, we calculated the coast average uplift rate and constrained the original terraces elevations. The reconstructed eustatic sea level variation during MIS 5e at GOA resembles observations from reef terraces in other locations. Combined, all indicate a significant sea-level rise from the MIS 6 low stand at ~134-130 ka and followed by a long and stable sea level high

  16. Neogene Uplift and Magmatism of Anatolia: Insights From Drainage Analysis and Basaltic Geochemistry

    NASA Astrophysics Data System (ADS)

    McNab, F.; Ball, P. W.; Hoggard, M. J.; White, N. J.

    2018-01-01

    It is agreed that mantle dynamics have played a role in generating and maintaining the elevated topography of Anatolia during Neogene times. However, there is debate about the relative importance of subduction zone and asthenospheric processes. Key issues concern onset and cause of regional uplift, thickness of the lithospheric plate, and the presence/absence of temperature and/or compositional anomalies within the convecting mantle. Here, we tackle these interlinked issues by analyzing and modeling two disparate suites of observations. First, a drainage inventory of 1,844 longitudinal river profiles is assembled. This database is inverted to calculate the variation of Neogene regional uplift through time and space by minimizing the misfit between observed and calculated river profiles subject to independent calibration. Our results suggest that regional uplift commenced at 20 Ma in the east and propagated westward. Second, we have assembled a database of geochemical analyses of basaltic rocks. Two different approaches have been used to quantitatively model this database with a view to determining the depth and degree of asthenospheric melting across Anatolia. Our results suggest that melting occurs at depths as shallow as 60 km in the presence of mantle potential temperatures as high as 1400°C. There is evidence that temperatures are higher in the east, consistent with the pattern of subplate shear wave velocity anomalies. Our combined results are consistent with isostatic and admittance analyses and suggest that elevated asthenospheric temperatures beneath thinned Anatolian lithosphere have played a first-order role in generating and maintaining regional dynamic topography and basaltic magmatism.

  17. Noachian Faulting: What Do Faults Tell Us About the Tectonic History of Tharsis?

    NASA Technical Reports Server (NTRS)

    Anderson, R. C.; Dohm, J. M.

    2001-01-01

    The western hemisphere of Mars is dominated by the formation of Tharsis, which is an enormous high-standing region (roughly 25% of the surface area of the planet) capped by volcanics, including the solar system's largest shield volcanoes. Tharsis is surrounded by an enormous radiating system of grabens and a circumferential system of wrinkle ridges that extends over the entire western hemisphere of Mars. This region is perhaps the largest and most long lived tectonic and volcanic province of any of the terrestrial planets with a well-preserved history of magmatic-driven activity that began in the Noachian and has lasted throughout Martian geologic time. Tharsis and the surrounding regions comprise numerous components, including volcanic constructs of varying sizes and extensive lava flow fields, large igneous plateaus, fault and ridge systems of varying extent and relative age of formation, gigantic outflow channel systems, vast system of canyons, and local and regional centers of tectonic activity. Many of these centers are interpreted to be the result of magmatic-related activity, including uplift, faulting, dike emplacement, volcanism, and local hydrothermal activity. Below we present a summary of our work for Tharsis focusing primarily on the earliest stage of development, the Noachian period. Here we hone in on the early centers and how they relate to the early development of the Tharsis Magmatic Complex (TMC).

  18. Note on seismic hazard assessment using gradient of uplift velocities in the Turan block (Central Asia)

    NASA Astrophysics Data System (ADS)

    Jaboyedoff, M.; Derron, M.-H.; Manby, G. M.

    2005-01-01

    Uplift gradients can provide the location of highly strained zones, which can be considered to be seismic. The Turan block (Central Asia) contains zones with high gradient of uplift velocities, above the threshold 0.04mm km-1year-1. Some of these zones are associated with important seismic activity and others are not correlated with any recent important recorded earthquakes, however, recent faults scarps as well as diverted rivers may indicate a recent tectonic activity. This threshold of gradient is probably a significant rheologic property of the upper crust. On the basis of these considerations the Uzboy river area is proposed as a potential high seismic hazard zone.

  19. Uplifting of palsa peatlands by permafrost identified by stable isotope depth profiles

    NASA Astrophysics Data System (ADS)

    Krüger, Jan Paul; Conen, Franz; Leifeld, Jens; Alewell, Christine

    2015-04-01

    Natural abundances of stable isotopes are a widespread tool to investigate biogeochemical processes in soils. Palsas are peatlands with an ice core and are common in the discontinuous permafrost region. Elevated parts of palsa peatlands, called hummocks, were uplifted by permafrost out of the influence of groundwater. Here we used the combination of δ15N values and C/N ratio along depth profiles to identify perturbation of these soils. In the years 2009 and 2012 we took in total 14 peat cores from hummocks in two palsa peatlands near Abisko, northern Sweden. Peat samples were analysed in 2 to 4 cm layers for stable isotope ratios and concentrations of C and N. The uplifting of the hummocks by permafrost could be detected by stable isotope depth patterns with the highest δ15N value at permafrost onset, a so-called turning point. Regression analyses indicated in 11 of 14 peat cores increasing δ15N values above and decreasing values below the turning point. This is in accordance with the depth patterns of δ13C values and C/N ratios in these palsa peatlands. Onset of permafrost aggradation identified by the highest δ15N value in the profile and calculated from peat accumulation rates show ages ranging from 80 to 545 years and indicate a mean (±SD) peat age at the turning points of 242 (±66) years for Stordalen and 365 (±53) years for Storflaket peatland. The mean peat ages at turning points are within the period of the Little Ice Age. Furthermore, we tested if the disturbance, in this case the uplifting of the peat material, can be displayed in the relation of δ15N and C/N ratio following the concept of Conen et al. (2013). In unperturbed sites soil δ15N values cover a relatively narrow range at any particular C/N ratio. Changes in N cycling, i.e. N loss or gain, results in the loss or gain of 15N depleted forms. This leads to larger or smaller δ15N values than usual at the observed C/N ratio. All, except one, turning point show a perturbation in the depth

  20. [Evaluation of quality of life in school children with a history of early severe malnutrition].

    PubMed

    De Grandis, E S; Armelini, P A; Cuestas, E

    2014-12-01

    Severe malnutrition in young children may lead to long-term complications, in particular learning and psychosocial disorders linked to health related quality of life (HRQOL). The aim of this study was to evaluate HRQOL in children whit a history of severe malnutrition before 2 years of life, expecting to find lower scores in these patients. A comparative study was performed on schoolchildren between 5 and 12 years with a history of early severe malnutrition, excluding those with chronic diseases. The Controls were healthy siblings of patients. The sample size was estimated as 26 subjects per group (Total=52). Sociodemographic variables were recorded and the HRQOL was assessed with PedsQL4.0. Chi square and Student t test were applied. Significance level: P<.05. A total of 25 patients and 28 controls were studied. The HRQOL scores obtained from PedsQL for children with history of malnutrition, compared with their healthy siblings, were: Total: 80.82±1.94 vs 89.18±1.84 P<.0001), physical health/dimension: 87.75±3.37 vs 94.75±1.87 (P<.0001), psychosocial health: 77.77±2.90 vs 86.57±1.42 (P<.0001), emotional dimension: 67.80±4.40 vs 78.75±2.96 (P<.0001), social dimension: 88.80±3.05 vs 95.71±1.52 (P<.0001), and school dimension: 74.58±3.80 vs 85.00±3.51 (P<.0001). Patients with a history of early severe malnutrition, showed significantly lower HRQOL scores compared with controls. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  1. Uplift-driven sediment redness decrease at ~16.5 Ma in the Yumen Basin along the northeastern Tibetan Plateau

    PubMed Central

    Wang, Weitao; Zhang, Peizhen; Zheng, Wenjun; Zheng, Dewen; Liu, Caicai; Xu, Hongyan; Zhang, Huiping; Yu, Jingxing; Pang, Jianzhang

    2016-01-01

    Significant climate shifts in the northeastern Tibetan Plateau have taken place during the Cenozoic, but the reasons behind them remain unclear. In order to unravel the mechanisms driving these climate changes, proxy data with accurate age constraint are needed. Here we present magnetostratigraphy, sediment color (redness a*, and lightness L*) and grain-size analysis from an early to middle Miocene (~20–15.3 Ma) sediment sequence preserved in the Yumen Basin on the northeastern Tibetan Plateau. In this basin, remarkable increase in lightness, decreases in redness and in ratio of hematite (Hm) to goethite (Gt) took place at ~16.5 Ma. We suggest that these changes result from shorter duration of weathering, climatic wetting, and cooling associated with rapid uplift of the Qilian Shan at the middle Miocene. PMID:27411593

  2. Glacial uplift: fluid injection beneath an elastic sheet on a poroelastic substrate

    NASA Astrophysics Data System (ADS)

    Neufeld, Jerome; Hewitt, Duncan; Chini, Greg

    2016-11-01

    Supraglacial lakes can drain to the base of glaciers extremely rapidly, causing localised uplift of the surrounding glacier and affecting its sliding velocity. The means by which large volumes of drained water interact with and leak into the subglacial hydrological system is unclear, as is the role of the basal till. A theoretical study of the spread of fluid injected below an elastic sheet (the ice) is presented, where the ice lies above, and initially compresses, a deformable poroelastic layer. As pressurized fluid is injected, the deformable layer swells to accommodate more fluid. If sufficient fluid is injected, a 'blister' of fluid forms above the layer, causing the overburden to lift off the base. The flow is controlled by the local pressure drop across the tip of this blister, which depends subtly on both the flow of fluid through the porous layer below the tip, and on poroelastic deformation in the till ahead of the tip. The spreading behaviour and dependence on key parameters is analysed. Predictions of the model are compared to field measurements of uplift from draining glacial lakes in Greenland.

  3. Caregiving burden and uplifts: a contradiction or a protective partnership for the quality of life of parents and their children with asthma?

    PubMed

    Silva, Neuza; Carona, Carlos; Crespo, Carla; Canavarro, Maria Cristina

    2015-04-01

    Parental caregiving in the context of pediatric chronic conditions is a multifaceted experience that encompasses negative (burdens) and positive dimensions (uplifts), which may support risk and protective processes that influence family adaptation. This study aimed to examine the caregiving experience of parents caring for a child with asthma and the moderating role of caregiving uplifts on the associations between caregiving burden and quality of life (QoL) of parents and their children. Participants were 180 dyads of children/adolescents with asthma between 8 and 18 years of age and one of their parents. The parents reported on caregiving burden and uplifts and on their QoL, and the children/adolescents completed a self-report measure of generic QoL. Results showed that although parents of children with intermittent asthma and parents of younger children presented higher levels of caregiving burden, noncontrolled asthma was the only clinical variable representing a significant risk factor for decreased QoL in children. Significant negative and positive associations were found between burden dimensions and QoL and between caregiving uplifts and QoL, respectively, in parents and children. Additionally, caregiving uplifts moderated the negative link between relationship burden and parents' QoL. These results suggest that, far from being contradictory, caregiving uplifts may co-occur with high levels of burden and may constitute a protective factor against the deleterious effect of the caregiving burden on parents' QoL and a resource that directly contributes to children's QoL. This risk-resistance approach to family caregiving may contribute to operationalizing strength-based interventions in the context of pediatric asthma. (c) 2015 APA, all rights reserved).

  4. Role of erosion and isostasy in the Cordillera Blanca uplift: insights from Low-T thermochronology and landscape evolution modeling (northern Peru, Andes)

    NASA Astrophysics Data System (ADS)

    Margirier, A.; Robert, X.; Braun, J.; Laurence, A.

    2017-12-01

    The uplift and exhumation of the highest Peruvian peaks seems closely linked to the Cordillera Blanca normal fault that delimits and shape the western flank of the Cordillera Blanca. Two models have been previously proposed to explain the occurrence of extension and the presence of this active normal fault in a compression setting but the Cordillera Blanca normal fault and the uplift and exhumation of the Cordillera Blanca remain enigmatic. Recent studies suggested an increase of exhumation rates during the Quaternary in the Cordillera Blanca and related this increase to a change in climate and erosion process (glacial erosion vs. fluvial erosion). The Cordillera Blanca granite has been significantly eroded since its emplacement (12-5 Ma) indicating a significant mass of rocks removal. Whereas it has been demonstrated recently that the effect of eroding denser rocks can contribute to an increase of uplift rate, the impact of erosion and isostasy on the increase of the Cordillera Blanca uplift rates has never been explored. Based on numerical modeling of landscape evolution we address the role of erosion and isostasy in the uplift and exhumation of the Cordillera Blanca. We performed inversions of the present-day topography, total exhumation and thermochronological data using a landscape evolution model (FastScape). Our results evidence the contribution of erosion and associated flexural rebound to the uplift of the Cordillera Blanca. Our models suggest that the erosion of the Cordillera Blanca dense intrusion since 3 Ma could also explain the Quaternary exhumation rate increase in this area. Finally, our results allow to question the previous models proposed for the formation of the Cordillera Blanca normal fault.

  5. Paleokarst on the top of the Maokou Formation: Further evidence for domal crustal uplift prior to the Emeishan flood volcanism

    NASA Astrophysics Data System (ADS)

    He, Bin; Xu, Yi-Gang; Guan, Jun-Peng; Zhong, Yu-Ting

    2010-09-01

    The ~ 260 Ma Emeishan Large Igneous Province (ELIP) in southwest China has previously been demonstrated to provide compelling evidence for pre-volcanic crustal doming in support of the mantle plume hypothesis. However this has been questioned by Ukstins-Peate and Bryan (2008) by showing hydrothermal magmatic activity at the Daqiao section. To solve this argument, a detailed characterization of the contact between the Emeishan basalts and the Maokou Formation was carried out. The contact is shown to be an unconformity, which is characterized by paleokarst on top of the Maokou Formation, including paleokarst relief, sinkholes, caves, tower karst and its corresponding rocks (such as kaolinite, bauxite and ferruginous duricrust and collapsed breccias, etc.). This paleokarst unconformity was in turn covered or infilled by the Emeishan basalts and tuffs, suggesting that uplift and erosion occurred prior to the eruption of the ELIP. The extent of erosion of the Maokou Formation indicates the ELIP can be divided into three roughly concentric zones: the inner, intermediate, and outer zones. The paleokarst features on the top of Maokou Formation vary across the ELIP. In the inner zone, a likely sinkhole and an incision valley with 450 m relief in height are found. In the intermediate zone, various paleokarst landforms such as karst relief, sinkholes and tower karsts are well developed. Some sinkholes that developed in the Qixia Formation below the Maokou Formation imply that the paleorelief is more than 350 m in height. In the outer zone, the paleokarstic surface is a paleo-weathering layer with minor karstification and development of caves at 10-50 m. This spatial variation of the paleokarst reflects variation of uplift height across the ELIP. The extent of minimal uplift is estimated to be at least 450 m in the inner zone, 350 m in the intermediate zone, whereas uplift is minor (tens-50 m) in the outer zone. The magnitude and shape of the uplift is roughly consistent with

  6. Social Confidence in Early Adulthood Among Young People With and Without a History of Language Impairment

    PubMed Central

    Durkin, Kevin; Toseeb, Umar; Botting, Nicola; Pickles, Andrew

    2017-01-01

    Purpose The purposes of this study were to test the predictions that lower self-esteem and higher shyness in individuals with a history of language impairment (LI) would continue from adolescence into early adulthood and that those with LI would have lower social self-efficacy in early adulthood. Method Participants were young people with a history of LI and a comparison group of age-matched peers. Both groups were tested at ages 17 and 24 years. Participants completed measures of language ability, nonverbal IQ, shyness, global self-esteem, and (at age 24 years only) social self-efficacy. Results Young adults with LI scored lower than age-matched peers on self-esteem, higher on shyness, and lower on social self-efficacy (medium to large effect sizes). In line with expectations, in the group with LI, language ability in adolescence predicted shyness in young adulthood, which, in turn, was negatively associated with self-esteem. There was also a direct association between language ability in adolescence and self-esteem in young adulthood. Conclusions Young people with a history of LI are likely to be entering adulthood less socially confident than their peers. Interventions may be desirable for young adults with LI, and the present findings indicate social self-efficacy as a key area of social confidence that calls for practitioners' attention. PMID:28586830

  7. Burial history of Upper Cretaceous and Tertiary rocks interpreted from vitrinite reflectance, northern Green River basin, Wyoming

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dickinson, W.W.; Law, B.E.

    1985-05-01

    The burial history of Upper Cretaceous and Tertiary rocks in the northern Green River basin is difficult to reconstruct for three reasons: (1) most of these rocks do not crop out, (2) there are few stratigraphic markers in the subsurface, and (3) regional uplift beginning during the Pliocene caused erosion that removed most upper Tertiary rocks. To understand better the burial and thermal history of the basin, published vitrinite reflectance (R/sub o/) data from three wells were compared to TTI (time-temperature index) maturation units calculated from Lopatin reconstructions. For each well, burial reconstructions were made as follows. Maximum depth ofmore » burial was first estimated by stratigraphic and structural evidence and by extrapolation to a paleosurface intercept of R/sub o/ = 0.2%. This burial was completed by early Oligocene (35 Ma), after which there was no net deposition. The present geothermal gradient in each well as used because there is no geologic evidence for elevated paleotemperature gradients. Using these reconstructions, calculated TTI units agreed with measured R/sub o/ values when minor adjustments were made to the estimated burial depths. Reconstructed maximum burials were deeper than present by 2500-3000 ft (762-914 m) in the Pacific Creek area, by 4000-4500 ft (1219-1372 m) in the Pinedale area, and by 0-1000 ft (0-305 m) in the Merna area. However, at Pinedale geologic evidence can only account for about 3000 ft (914 m) of additional burial. This discrepancy is explained by isoreflectance lines, which parallel the Pinedale anticline and indicate that approximately 2000 ft (610 m) of structural relief occurred after maximum burial. In other parts of the basin, isoreflectance lines also reveal significant structural deformation after maximum burial during early Oligocene to early Pliocene time.« less

  8. Surface uplift and time-dependent seismic hazard due to fluid injection in eastern Texas.

    PubMed

    Shirzaei, Manoochehr; Ellsworth, William L; Tiampo, Kristy F; González, Pablo J; Manga, Michael

    2016-09-23

    Observations that unequivocally link seismicity and wastewater injection are scarce. Here we show that wastewater injection in eastern Texas causes uplift, detectable in radar interferometric data up to >8 kilometers from the wells. Using measurements of uplift, reported injection data, and a poroelastic model, we computed the crustal strain and pore pressure. We infer that an increase of >1 megapascal in pore pressure in rocks with low compressibility triggers earthquakes, including the 4.8-moment magnitude event that occurred on 17 May 2012, the largest earthquake recorded in eastern Texas. Seismic activity increased even while injection rates declined, owing to diffusion of pore pressure from earlier periods with higher injection rates. Induced seismicity potential is suppressed where tight confining formations prevent pore pressure from propagating into crystalline basement rocks. Copyright © 2016, American Association for the Advancement of Science.

  9. Exhumation History Of Brasilian Highlands After Late Cretaceous Alcaline Magmatism

    NASA Astrophysics Data System (ADS)

    Doranti Tiritan, Carolina; Hackspacher, Peter Christian; Carina Siqueira Ribeiro, Marli; Glasmacher, Ulrich Anton; Françoso de Godoy, Daniel

    2017-04-01

    The southeast Brazilian margin recorded a long history of tectonic and magmatic events after the Gondwana continent break up. The drifting of the South American Platform over a thermal anomaly generated a series of alkaline intrusions that are distributed from the interior to the coast from west to east. Several exhumation events are recorded on the region and we are providing insights on the landscape evolution of the region since Late Cretaceous, comparing low temperature thermochronology results from two alkaline intrusions regions. Poços de Caldas Alkaline Massif (PCAM), is lied in the interior, 300km from the coastline, covering over 800km2 intruding the Precambrian basement around 83Ma, nepheline syenites, phonolites and tinguaites intruded in a continuous and rapid sequence lasting between 1 to 2 Ma. São Sebastião Island (SSI) on the other hand is located at the coast, 200 km southeast of São Paulo. It is characterized by an intrusion in Precambrian/Brazilian orogen and intruded by Early Cretaceous sub-alkaline basic and acid dykes, as well as by Late Cretaceous alkaline stocks (syenites) and dykes (basanite to phonolite). Will be presenting the apatite fission track (AFT) and (U-Th)/He results that shows the main difference between the areas is that PCAM region register older history then the coastal area of SSI, where thermal history starts register cooling event after the South Atlantic rifting process, while in the PCAM area register a previous history, since Carboniferous. The results are giving support to studies that indicate the development of the relief in Brazil being strongly influenced by the local and regional tectonic movements and the lithological and structural settings. The landscape at the Late Cretaceous was witness of heating process between 90 and 60Ma due the intense uplift of South American Platform. The elevation of the isotherms is associated with the mantellic plumes and the crustal thickness that caused thermal anomalies due

  10. Late Quaternary uplift rate inferred from marine terraces, Muroto Peninsula, southwest Japan: Forearc deformation in an oblique subduction zone

    NASA Astrophysics Data System (ADS)

    Matsu'ura, Tabito

    2015-04-01

    Tectonic uplift rates across the Muroto Peninsula, in the southwest Japan forearc (the overriding plate in the southwest Japan oblique subduction zone), were estimated by mapping the elevations of the inner edges of marine terrace surfaces. The uplift rates inferred from marine terraces M1 and M2, which were correlated by tephrochronology with marine isotope stages (MIS) 5e and 5c, respectively, include some vertical offset by local faults but generally decrease northwestward from 1.2-1.6 m ky- 1 on Cape Muroto to 0.3-0.7 m ky- 1 in the Kochi Plain. The vertical deformation of the Muroto Peninsula since MIS 5e and 5c was interpreted as a combination of regional uplift and folding related to the arc-normal offshore Muroto-Misaki fault. A regional uplift rate of 0.46 m ky- 1 was estimated from terraces on the Muroto Peninsula, and the residual deformation of these terraces was attributed to fault-related folding. A mass-balance calculation yielded a shortening rate of 0.71-0.77 m ky- 1 for the Muroto Peninsula, with the Muroto-Misaki fault accounting for 0.60-0.71 m ky- 1, but these rates may be overestimated by as much as 10% given variations of several meters in the elevation difference between the buried shoreline angles and terrace inner edges in the study area. A thrust fault model with flat (5-10° dip) and ramp (60° dip) components is proposed to explain the shortening rate and uplift rate of the Muroto-Misaki fault since MIS 5e. Bedrock deformation also indicates that the northern extension of this fault corresponds to the older Muroto Flexure.

  11. Tectonic Uplift of the Danba Area in the Eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Chang, C. P.; Ho, H. P.; Horng, C. S.; Hsu, Y. C.; Tan, X. B.

    2017-12-01

    The Danba anticline in the eastern Tibetan Plateau is located between the Longmenshan orogen to the east and the Xianshuihe sinistral fault zone to the west. This anticline has been recognized as an area with extreme exhumation by previous studies. The Tibetan plateau was built by the convergence between Indo-Australian plate and Eurasian plate since early Cenozoic. The eastward lower crustal flow under the plateau obstructed by the Yangtze craton soon after this convergence generated a very complex structural situation in the southeastern side of the Tibetan plateau. In this study, in order to understand the processes and mechanisms of the structural complexity of the Danba area, we apply two methods: stress analysis and magnetic measurement. By measuring the brittle deformation recorded in the strata, we carry out a series of stress analysis to demonstrate the stress field of this area. In addition, due to comprehend the magnetic characteristics of low-grade metamorphic rocks and volcanic rocks in this area, we process the rock magnetic measurement of hysteresis loop and X-ray diffraction analysis. The occurrence of pyrrhotite can be taken as an important isograd in low-grade metamorphic rocks, which is helpful for stratigraphic and structural studies. Based on our results, we try to explain the mechanism of this rapid uplift, which involves material, structural, and kinematic interaction.

  12. Accidental inflation from Kähler uplifting

    NASA Astrophysics Data System (ADS)

    Ben-Dayan, Ido; Jing, Shenglin; Westphal, Alexander; Wieck, Clemens

    2014-03-01

    We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Käahler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ``left-rolling" ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ``inflation by deflation" (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running α ~ 0.012 and enhanced tensor-to-scalar ratio r ~ 10-5. The latter results differ significantly from many string inflation models.

  13. The early history of ideas on brief interventions for alcohol.

    PubMed

    McCambridge, Jim; Cunningham, John A

    2014-04-01

    This study explores the early development of brief interventions for alcohol using a history of ideas approach with a particular focus on intervention content. The source publications of the key primary studies published from approximately 1962 to 1992 were examined, followed by a brief review of the earliest reviews in this field. These studies were placed in the context of developments in alcohol research and in public health. After early pioneering work on brief interventions, further advances were not made until thinking about alcohol problems and their treatment, most notably on controlled drinking, along with wider changes in public health, created new conditions for progress. There was then a golden era of rapid advance in the late 1980s and early 1990s, when preventing the development of problem drinking became important for public health reasons, in addition to helping already problematic drinkers. Many research challenges identified at that time remain to be met. The content of brief interventions changed over the period of study, although not in ways well informed by research advances, and there were also obvious continuities, with a renewed emphasis on the facilitation of self-change being one important consequence of the development of internet applications. Ideas about brief interventions have changed in important ways. Brief interventions have been studied with different populations of drinkers, with aims embracing both individual and population-level perspectives, and without well-specified contents. The brief intervention field is an appropriate target for further historical investigations, which may help thinking about addressing alcohol and other problems. © 2013 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

  14. East Antarctic rifting triggers uplift of the Gamburtsev Mountains

    USGS Publications Warehouse

    Ferraccioli, F.; Finn, Carol A.; Jordan, Tom A.; Bell, Robin E.; Anderson, Lester M.; Damaske, Detlef

    2011-01-01

    The Gamburtsev Subglacial Mountains are the least understood tectonic feature on Earth, because they are completely hidden beneath the East Antarctic Ice Sheet. Their high elevation and youthful Alpine topography, combined with their location on the East Antarctic craton, creates a paradox that has puzzled researchers since the mountains were discovered in 1958. The preservation of Alpine topography in the Gamburtsevs may reflect extremely low long-term erosion rates beneath the ice sheet, but the mountains’ origin remains problematic. Here we present the first comprehensive view of the crustal architecture and uplift mechanisms for the Gamburtsevs, derived from radar, gravity and magnetic data. The geophysical data define a 2,500-km-long rift system in East Antarctica surrounding the Gamburtsevs, and a thick crustal root beneath the range. We propose that the root formed during the Proterozoic assembly of interior East Antarctica (possibly about 1 Gyr ago), was preserved as in some old orogens and was rejuvenated during much later Permian (roughly 250 Myr ago) and Cretaceous (roughly 100 Myr ago) rifting. Much like East Africa, the interior of East Antarctica is a mosaic of Precambrian provinces affected by rifting processes. Our models show that the combination of rift-flank uplift, root buoyancy and the isostatic response to fluvial and glacial erosion explains the high elevation and relief of the Gamburtsevs. The evolution of the Gamburtsevs demonstrates that rifting and preserved orogenic roots can produce broad regions of high topography in continental interiors without significantly modifying the underlying Precambrian lithosphere.

  15. The Pleistocene rivers of the English Channel region

    NASA Astrophysics Data System (ADS)

    Antoine, Pierre; Coutard, Jean-Pierre; Gibbard, Philip; Hallegouet, Bernard; Lautridou, Jean-Pierre; Ozouf, Jean-Claude

    2003-02-01

    The Pleistocene history of river systems that enter the English Channel from northern France and southern England is reviewed. During periods of low sea-level (cold stages) these streams were tributaries of the Channel River. In southern England the largest, the River Solent, is an axial stream that has drained the Hampshire Basin from the Early Pleistocene or late Pliocene. Other streams of southern England may be of similar antiquity but their records are generally short and their sedimentary history have been destroyed, as in northern Brittany, by coastal erosion and valley deepening as a consequence of tectonic uplift. In northern France, the Seine and Somme rivers have very well developed terrace systems recording incision that began at around 1 Ma. The uplift rate, deduced from the study of these terrace systems, is of 55 to 60 m myr-1 since the end of the Early Pleistocene. Generally the facies and sedimentary structures indicate that the bulk of the deposits in these rivers accumulated in braided river environments under periglacial climates in all the area around the Channel. Evolution of the rivers reflects their responses to climatic change, local geological structure and long-term tectonic activity. In this context the Middle Somme valley is characterised by a regular pattern in which incision occurs at the beginning of each glacial period within a general background of uplift. Nevertheless the response of the different rivers to climatic variations, uplift and sea-level changes is complex and variable according to the different parts of the river courses.

  16. Post-breakup tectonics in southeast Brazil from thermochronological data and combined inverse-forward thermal history modeling

    NASA Astrophysics Data System (ADS)

    Cogné, Nathan; Gallagher, Kerry; Cobbold, Peter R.; Riccomini, Claudio; Gautheron, Cecile

    2012-11-01

    The continental margin of southeast Brazil is elevated. Onshore Tertiary basins and Late Cretaceous/Paleogene intrusions are good evidence for post breakup tectono-magmatic activity. To constrain the impact of post-rift reactivation on the geological history of the area, we carried out a new thermochronological study. Apatite fission track ages range from 60.7 ± 1.9 Ma to 129.3 ± 4.3 Ma, mean track lengths from 11.41 ± 0.23 μm to 14.31 ± 0.24 μm and a subset of the (U-Th)/He ages range from 45.1 ± 1.5 to 122.4 ± 2.5 Ma. Results of inverse thermal history modeling generally support the conclusions from an earlier study for a Late Cretaceous phase of cooling. Around the onshore Taubaté Basin, for a limited number of samples, the first detectable period of cooling occurred during the Early Tertiary. The inferred thermal histories for many samples also imply subsequent reheating followed by Neogene cooling. Given the uncertainty of the inversion results, we did deterministic forward modeling to assess the range of possibilities of this Tertiary part of the thermal history. The evidence for reheating seems to be robust around the Taubaté Basin, but elsewhere the data cannot discriminate between this and a less complex thermal history. However, forward modeling results and geological information support the conclusion that the whole area underwent cooling during the Neogene. The synchronicity of the cooling phases with Andean tectonics and those in NE Brazil leads us to assume a plate-wide compressional stress that reactivated inherited structures. The present-day topographic relief of the margin reflects a contribution from post-breakup reactivation and uplift.

  17. Distribution of physical properties and timing of relative uplift in upper plate off Costa Rica: IODP Expedition 344

    NASA Astrophysics Data System (ADS)

    Saiki, A.; Hashimoto, Y.

    2015-12-01

    Evolution of physical properties in subduction zone is a key to understand lithification processes, location of decollement, and stress distribution. In this study, we examined the physical properties of sediments using on-board data and laboratory experimental data on sediments obtained off Costa Rica margin. Target sites are in the Integrate Ocean Drilling Program (IODP) Expedition 344 off Costa Rica, including reference sites (U1381 and U1414), mid-slope site (U1378, U1380) and upper-slope site (U1413). Seven samples from reference sites were analyzed. Laboratory experiments for velocity and porosity measurements were conducted with variation of effective pressure. Velocity-porosity relationships from on-board data and from laboratory experiments are comparable. The porosity-effective pressure curves under isotropic condition were converted to the curves under uniaxial condition (Teeuw, 1971). Using the normal consolidation curves under uniaxial stress conditions, we converted onboard porosity to effective pressure and fluid pressure. In reference sites, hydrostatic fluid pressure was estimated as expected as a reference sites, suggesting that porosity-effective pressure relationship was obtained correctly by experiments and it can be adapted to estimation of fluid pressure for the wedge sites. The porosity-effective pressure relationship under isotropic conditions were used for the estimation in wedge sites. In wedge sites, estimated pore pressures show lower than hydrostatic pressure, suggesting that onboard porosity was lower than that under normal compaction. The lower porosity can be caused by relative uplift from deeper portion. The amount of relative uplift can be estimated by differences in porosity-depth relationships between onboard data and experimental data. The amount of relative uplift for each site shows more than ~1000m up to ~5000m. The small error in porosity depth curve from experimental data makes relative uplift larger or smaller

  18. Does slab-window opening cause uplift of the overriding plate? A case study from the Gulf of California

    NASA Astrophysics Data System (ADS)

    Mark, Chris; Chew, David; Gupta, Sanjeev

    2017-11-01

    Complete subduction of an oceanic plate results in slab-window opening. A key uncertainty in this process is whether the higher heat flux and asthenospheric upwelling conventionally associated with slab-window opening generate a detectable topographic signature in the overriding plate. We focus on the Baja California Peninsula, which incorporates the western margin of the Gulf of California rift. The topography and tectonics of the rift flank along the peninsula are strongly bimodal. North of the Puertecitos accommodation zone, the primary drainage divide attains a mean elevation of ca. 1600 m above sea level (asl), above an asthenospheric slab-window opened by Pacific-Farallon spreading ridge subduction along this section of the trench at ca. 17-15 Ma. To the south, mean topography decreases abruptly to ca. 800 m asl (excluding the structurally distinct Los Cabos block at the southern tip of the peninsula), above fragments of the oceanic Farallon slab which stalled following slab tear-off at ca. 15-14 Ma. Along the peninsula, a low-relief surface established atop Miocene subduction-related volcaniclastic units has been incised by a west-draining canyon network in response to uplift. These canyons exhibit cut-and-fill relationships with widespread post-subduction lavas. Here, we utilise LANDSAT and digital elevation model (DEM) data, integrated with previously published K-Ar and 40Ar/39Ar lava crystallisation ages, to constrain the onset of rift flank uplift to ca. 9-5 Ma later than slab-window formation in the north and ca. 11-10 Ma later in the south. These greatly exceed response time estimates of ca. 2 Ma or less for uplift triggered by slab-window opening. Instead, uplift timing of the high-elevation northern region is consistent with lower-lithospheric erosion driven by rift-related convective upwelling. To the south, stalled slab fragments likely inhibited convective return flow, preventing lithospheric erosion and limiting uplift to the isostatic response

  19. Late Quaternary uplift along the North America-Caribbean plate boundary: Evidence from the sea level record of Guantanamo Bay, Cuba

    NASA Astrophysics Data System (ADS)

    Muhs, Daniel R.; Schweig, Eugene S.; Simmons, Kathleen R.; Halley, Robert B.

    2017-12-01

    The tectonic setting of the North America-Caribbean plate boundary has been studied intensively, but some aspects are still poorly understood, particularly along the Oriente fault zone. Guantanamo Bay, southern Cuba, is considered to be on a coastline that is under a transpressive tectonic regime along this zone, and is hypothesized to have a low uplift rate. We tested this by studying emergent reef terrace deposits around the bay. Reef elevations in the protected, inner part of the bay are ∼11-12 m and outer-coast, wave-cut benches are as high as ∼14 m. Uranium-series analyses of corals yield ages ranging from ∼133 ka to ∼119 ka, correlating this reef to the peak of the last interglacial period, marine isotope stage (MIS) 5.5. Assuming a span of possible paleo-sea levels at the time of the last interglacial period yields long-term tectonic uplift rates of 0.02-0.11 m/ka, supporting the hypothesis that the tectonic uplift rate is low. Nevertheless, on the eastern and southern coasts of Cuba, east and west of Guantanamo Bay, there are flights of multiple marine terraces, at higher elevations, that could record a higher rate of uplift, implying that Guantanamo Bay may be anomalous. Southern Cuba is considered to have experienced a measurable but modest effect from glacial isostatic adjustment (GIA) processes. Thus, with a low uplift rate, Guantanamo Bay should show no evidence of emergent marine terraces dating to the ∼100 ka (MIS 5.3) or ∼80 ka (MIS 5.1) sea stands and results of the present study support this.

  20. Late Quaternary uplift along the North America-Caribbean plate boundary: Evidence from the sea level record of Guantanamo Bay, Cuba

    USGS Publications Warehouse

    Muhs, Daniel; Schweig, Eugene S.; Simmons, Kathleen; Halley, Robert B.

    2017-01-01

    The tectonic setting of the North America-Caribbean plate boundary has been studied intensively, but some aspects are still poorly understood, particularly along the Oriente fault zone. Guantanamo Bay, southern Cuba, is considered to be on a coastline that is under a transpressive tectonic regime along this zone, and is hypothesized to have a low uplift rate. We tested this by studying emergent reef terrace deposits around the bay. Reef elevations in the protected, inner part of the bay are ∼11–12 m and outer-coast, wave-cut benches are as high as ∼14 m. Uranium-series analyses of corals yield ages ranging from ∼133 ka to ∼119 ka, correlating this reef to the peak of the last interglacial period, marine isotope stage (MIS) 5.5. Assuming a span of possible paleo-sea levels at the time of the last interglacial period yields long-term tectonic uplift rates of 0.02–0.11 m/ka, supporting the hypothesis that the tectonic uplift rate is low. Nevertheless, on the eastern and southern coasts of Cuba, east and west of Guantanamo Bay, there are flights of multiple marine terraces, at higher elevations, that could record a higher rate of uplift, implying that Guantanamo Bay may be anomalous. Southern Cuba is considered to have experienced a measurable but modest effect from glacial isostatic adjustment (GIA) processes. Thus, with a low uplift rate, Guantanamo Bay should show no evidence of emergent marine terraces dating to the ∼100 ka (MIS 5.3) or ∼80 ka (MIS 5.1) sea stands and results of the present study support this.

  1. Plio-Pleistocene paleo-erosion rates as a recorder of orographic barrier uplift in the NW-Argentine Andes (Humahuaca Basin)

    NASA Astrophysics Data System (ADS)

    Pingel, Heiko; Schildgen, Taylor; Wittmann, Hella

    2017-04-01

    As an integral part of the Eastern Cordillera, the intermontane Humahuaca Basin in the NW Argentine Andes is located in transition between the arid and internally drained Puna Plateau to the west and the humid broken foreland to the east. In combination with moisture-bearing air masses sourced in the Atlantic Ocean and the Amazon Basin, the present-day topographic gradient of the eastern Andean margin comprises an efficient orographic barrier that results in a strong precipitation gradient, with rainfall of more than 2,000 mm/a along the eastern flanks and <200 mm/a on the plateau. Ultimately, variable moisture availability affects surface processes, such as fluvial erosion and transport of eroded material, with decreasing erosion rates towards the orogenic hinterland. Paleoenvironmental reconstructions of the Humahuaca Basin suggest that this region became disconnected from the foreland during the Mio-Pliocene by the growth of fault-bounded mountain ranges. This led to an increase in accommodation space and enabled the trapping of largely fluvial, late Miocene to Quaternary basin filling units. Subsequently, the basin was uplifted and internally deformed. Fossil records, sedimentologic evidence, and stable-isotopes (δD from volcanic glass) moreover imply that the re-routing of the fluvial network, an initial increase in precipitation, and, as the windward ranges attained threshold elevations to incoming moisture, reduced moisture availability by ca. 3 Ma, were all a consequence of the Mio-Pliocene uplift. In this study, we present first results of terrestrial cosmogenic nuclide-derived paleo-erosion rates from quartz-bearing fluvial sands and gravels of known stratigraphic age. In most cases, the age control is based on previously published U-Pb zircon data of intercalated volcanic ash deposits, but also utilizes new OSL and AMS14C ages. A reassessment of the sediment-accumulation history of the basin highlights important changes of the depositional system

  2. Recycling an uplifted early foreland basin fill: An example from the Jaca basin (Southern Pyrenees, Spain)

    NASA Astrophysics Data System (ADS)

    Roigé, M.; Gómez-Gras, D.; Remacha, E.; Boya, S.; Viaplana-Muzas, M.; Teixell, A.

    2017-10-01

    In the northern Jaca basin (Southern Pyrenees), the replacement of deep-marine by terrestrial environments during the Eocene records a main drainage reorganization in the active Pyrenean pro-wedge, which leads to recycling of earlier foreland basin sediments. The onset of late Eocene-Oligocene terrestrial sedimentation is represented by four main alluvial fans: Santa Orosia, Canciás, Peña Oroel and San Juan de la Peña, which appear diachronously from east to west. These alluvial fans are the youngest preserved sediments deposited in the basin. We provide new data on sediment composition and sources for the late Eocene-Oligocene alluvial fans and precursor deltas of the Jaca basin. Sandstone petrography allows identification of the interplay of axially-fed sediments from the east with transversely-fed sediments from the north. Compositional data for the alluvial fans reflects a dominating proportion of recycled rock fragments derived from the erosion of a lower to middle Eocene flysch depocentre (the Hecho Group), located immediately to the north. In addition, pebble composition allows identification of a source in the North Pyrenean Zone that provided lithologies from the Cretaceous carbonate flysch, Jurassic dolostones and Triassic dolerites. Thus we infer this zone as part of the source area, located in the headwaters, which would have been unroofed from turbidite deposits during the late Eocene-Oligocene. These conclusions provide new insights on the response of drainage networks to uplift and topographic growth of the Pyrenees, where the water divide migrated southwards to its present day location.

  3. Everyday hassles and uplifts among women on long-term sick-leave due to stress-related disorders.

    PubMed

    Johansson, Gun; Eklund, Mona; Erlandsson, Lena-Karin

    2012-05-01

    A balance between different experiences of occupations in everyday life is important for well-being. The study aim was to describe hassles and uplifts in everyday occupations among women on long-term sick-leave due to stress-related disorders. The sample consisted of 77 women and experiences were collected by the THU-5 instrument. The statements were analysed using quantitative content analysis. Data were categorized into three domains of hassles concerning oneself, doings, and social and physical context. The same domains occurred among the uplifts. Hassles were mostly generated by disturbing people around the women and by their limited body functions. The women were uplifted by supportive social relationships and by performing relaxing and calming occupations. The study illuminates the strong need for social support among women on sick-leave, as well as their low level of energy, which was an obvious obstacle for performing occupations. It is suggested that, in order to increase well-being in the target group, the occupational therapist should meet their need for occupations that match their current level of energy. The challenge for the client is to avoid remaining in a pattern of low-demand occupations without exceeding her/his capacity and returning to an unhealthy pattern of occupations.

  4. Rapid uplift during 2007-2012 at Laguna del Maule volcanic field, Andean Southern Volcanic Zone, Chile

    NASA Astrophysics Data System (ADS)

    Le Mevel, H.; Feigl, K.; Ali, T.; Cordova V., M. L.; DeMets, C.; Singer, B. S.

    2012-12-01

    obtained using a rectangular sill model (Okada, 1985) for which the free parameters include the tensile opening, the location, depth, and dimensions of the source. In total, the volume increase is about 60 million cubic meters since inflation began, for the modeled sill at a depth of approximately 5 km. In early 2012, this trend persists in the InSAR data. Three continuous GPS stations installed in April 2012 around the lake confirm this extraordinarily high vertical uplift rate of more than 280 mm/yr, among the fastest deformation signal measured geodetically for any volcano that is not erupting.

  5. The Positive Event Scale: Measuring Uplift Frequency and Intensity in an Adult Sample

    ERIC Educational Resources Information Center

    Maybery, D. J.; Jones-Ellis, Jenny; Neale, Jason; Arentz, Alexandra

    2006-01-01

    Of the limited number of studies employing positive event (uplift) measures none have published detailed psychometric information about the scale that was used (Maybery and Graham, 2001, Stress and Health 17, pp. 91-104). Building on previous work with university students and employing conceptually distinct measurement strategies (i.e. measuring…

  6. Thermal maturation history of the Wilcox group (Paleocene-Eocene), Texas: Results of regional-scale multi-1D modeling

    USGS Publications Warehouse

    Rowan, E.L.; Warwick, Peter D.; Pitman, Janet K.; Kennan, Lorcan; Pindell, James; Rosen, Norman C.

    2007-01-01

    The thermal maturation history of the Paleocene-Eocene Wilcox Group has been reconstructed based on burial history models of 53 wells in the Texas coastal plain. This modeling study has been conducted in conjunction with a geologically based assessment of the oil and gas resources in Cenozoic strata of the Gulf of Mexico coastal plain and state waters. In the onshore Texas coastal plain, coals and organic-rich shales, predominantly of terrestrial origin, within the Wilcox Group are the primary source of oil (Wenger et al., 1994) as well as a source of gas. The Wilcox, however, is modeled as a single unit, without subdivision into source rock and non-source rock intervals.Generation of oil from Type III kerogen within the Wilcox Group is modeled using hydrous pyrolysis reaction kinetic parameters (Lewan, M.D., written communication, 2006). Gas generation from Type III kerogen is represented using calculated Ro values. The models are calibrated with bottom hole temperature (BHT), and vitrinite reflectance (Ro %) data for the Wilcox Group. Ro data from near-coastal sites have been selected to minimize the possible effects of uplift and erosion and then composited to give a regional Rodepth trend.Model calculations for the study area, the onshore Texas coastal plain, indicate that downdip portions of the basal Wilcox had reached sufficient thermal maturity to generate hydrocarbons by early Eocene (~50 Ma). This relatively early maturation is explained by rapid sediment accumulation in the early Tertiary combined with the reaction kinetic parameters used in the models. Thermal maturation increases through time with increasing burial depth and temperature, gradually moving the maturation front updip. At present day, hydrocarbon generation is complete in the downdip Wilcox within the study area but is currently ongoing in the updip portions of the formation.

  7. Geologic Map of the Snegurochka Planitia Quadrangle (V-1): Implications for the Volcanic History of the North Polar Region of Venus

    NASA Technical Reports Server (NTRS)

    Hurwitz, D. M.; Head, J. W.

    2010-01-01

    Geologic mapping of Snegurochka Planitia (V-1) reveals a complex stratigraphy of tectonic and volcanic features that can provide insight into the geologic history of Venus and Archean Earth [1,2], including 1) episodes of both localized crustal uplift and mantle downwelling, 2) shifts from local to regional volcanic activity, and 3) a shift back to local volcanic activity. We present our interpretations of the volcanic history of the region surrounding the north pole of Venus and explore how analysis of new data support our interpretations

  8. Seafloor Uplift in Middle Valley, Juan de Fuca Ridge: New High-Resolution Pressure Data

    NASA Astrophysics Data System (ADS)

    Inderbitzen, K. E.; Becker, K.; Davis, E. E.

    2011-12-01

    Currently, in-situ seafloor and basement pressures are continuously monitored and recorded by an ODP subseafloor hydrogeological observatory (CORK) located in Middle Valley, Juan de Fuca Ridge. Hole 857D was drilled in 1991 in thickly sedimented crust to a depth of 936 mbsf and instrumented with an original CORK that was replaced in 1996. A large hydrothermal field (Dead Dog) lies roughly 1.7 km north of the hole, and two isolated chimneys and several diffuse flow sites are located ~800 meters northeast. The borehole and the vent fields have been visited periodically by submersible/ROV since 1999. Recent results from the CORK at 857D have shown apparent seafloor uplift, supported by depth records from the submersible Alvin. A constant rate of pressure change of ~6 kPa/yr, from its initiation in 2005 to the visit in 2010, has reduced mean seafloor pressure by ~28 kPa, equivalent to nearly 3 meters of head. This uplift rate is several times the typical pre-eruption inflation rates observed at Axial Seamount further south along the Juan de Fuca Ridge. Initially, the apparent uplift at 857D did not seem to have any effect on local high-temperature hydrothermal venting, however recent operations in Middle Valley revealed distinct changes at not only the hydrothermal field to the northeast, but also a shutdown of high-temperature venting to the north of 857D. We will present new data from Middle Valley, including the first year of data collected by a high-resolution pressure data logger deployed at 857D in June, 2010.

  9. Rheology of the lithosphere inferred from postseismic uplift following the 1959 Hebgen Lake earthquake

    USGS Publications Warehouse

    Nishimura, T.; Thatcher, W.

    2003-01-01

    We have modeled the broad postseismic uplift measured by geodetic leveling in the epicentral area of the 1959 Mw = 7.3 Hebgen Lake, Montana earthquake, a normal faulting event in the northern Basin and Range province. To fit the observed uplift we calculate synthetic postseismic deformation using the relaxation response of a gravitational viscoelastic Earth to the earthquake. For a model with an elastic plate overlying a viscoelastic half-space, we find that the elastic thickness is 38 ?? 8 km, which isclose to the local crustal thickness. The half-space viscosity is estimated at 4 ?? 1018??0.5 Pa s. The leveling data do not require a viscous lower crust but permit a lower bound viscosity of 1020 Pa s. The observed broad uplift cannot be explained by physically plausible afterslip on and below the coseismic fault. However, local deformation across the coseismic surface rupture requires shallow afterslip reaching the surface. The postseismic deformation induced by the estimated viscoelastic structure decays exponentially with a time constant of ???15 years. Because of coupling between the elastic layer and the viscoelastic substrate, this relaxation time is significantly longer than the 2 year Maxwell relaxation time of the viscous half-space itself. Our result suggests the importance of postseismic relaxation in interpreting high-precision global positioning system velocities. For example, our model results suggest that postseismic transient velocities from both the 1959 Hebgen Lake and the 1983 Mw = 6.9 Borah Peak earthquakes are currently as large as 1-2 mm/yr.

  10. Dwarf galaxy populations in present-day galaxy clusters - II. The history of early-type and late-type dwarfs

    NASA Astrophysics Data System (ADS)

    Lisker, Thorsten; Weinmann, Simone M.; Janz, Joachim; Meyer, Hagen T.

    2013-06-01

    How did the dwarf galaxy population of present-day galaxy clusters form and grow over time? We address this question by analysing the history of dark matter subhaloes in the Millennium II cosmological simulation. A semi-analytic model serves as the link to observations. We argue that a reasonable analogue to early morphological types or red-sequence dwarf galaxies are those subhaloes that experienced strong mass-loss, or alternatively those that have spent a long time in massive haloes. This approach reproduces well the observed morphology-distance relation of dwarf galaxies in the Virgo and Coma clusters, and thus provides insight into their history. Over their lifetime, present-day late types have experienced an amount of environmental influence similar to what the progenitors of dwarf ellipticals had already experienced at redshifts above 2. Therefore, dwarf ellipticals are more likely to be a result of early and continuous environmental influence in group- and cluster-size haloes, rather than a recent transformation product. The observed morphological sequences of late-type and early-type galaxies have developed in parallel, not consecutively. Consequently, the characteristics of today's late-type galaxies are not necessarily representative for the progenitors of today's dwarf ellipticals. Studies aiming to reproduce the present-day dwarf population thus need to start at early epochs, model the influence of various environments, and also take into account the evolution of the environments themselves.

  11. Uplifted Yellow river terraces across the Haiyuan fault, China and their implications to geometrical complexity of strike-slip fault system

    NASA Astrophysics Data System (ADS)

    Liu, J.; van der Woerd, J.; Li, Z.; Klinger, Y.; Matrau, R.; Shao, Y.; Zhang, J.; Wang, P.

    2016-12-01

    Geometrical complexities and discontinues, such as fault bends, splays and step-overs, are common along large strike-slip faults. Numerical and observational studies show that geometrical complexities above some threshold degree may inhibit thoroughgoing rupture, limiting rupture length and the size of the resulting earthquake. Studying the fine structure and long-term evolution of fault step-overs would help us better understand their effect on earthquake ruptures. In this study, we focus on a prominent geometrical "knot" on the left-lateral Haiyuan fault, where the fault curves with multi-strand splays bounding the Mijia Shan-Hasi Shan ranges. Incidentally, the Yellow river flows between the Mijia Shan and Hasi Shan and cuts a deep gorge when crossing the fault. On the western bank of the river, a series of at least twelve levels of fluvial strath terraces perch above river bed, and are capped with no more than 5 meters of alluvial deposits. We measured the terrace heights above river bed, using RTK and UAV surveys. We collected quartz-rich pebbles of yellow river gravel for cosmogenic radio nuclide (CRN), and silt layers within gravel and the overlying loess cap for optimally stimulated luminescence (OSL) dating to constrain the terrace formation ages. Quartz-rich pebbles were sampled both in hand-dug pit for depth-profile method and surface samples on terrace surfaces. The CRN age results were corrected in terms of inheritance and shielding by loess. The dates and heights of serial terraces yielded an average uplift rate of 2±0.34 mm/yr, which represents the late Quaternary uplifting rate of the Mijia Shan. The uplift of the Mijia Shan-Hasi Shan may result from the oblique shear of positive flower in the deep crust of the left-lateral Haiyuan fault. We further speculate that with progressively uplifted mountain ranges, the active fault trace shifts with time among the multi-strands of the fault system. In addition, the coincidence of prominent uplifted

  12. InSAR Time Series Analysis and Geophysical Modeling of City Uplift Associated with Geothermal Drillings in Staufen im Breisgau, Germany

    NASA Astrophysics Data System (ADS)

    Motagh, M.; Lubitz, C.

    2014-12-01

    Geothermal energy is of increasing importance as alternative, environmentally friendly technology for heat management. Direct interaction with the subsurface requires careful implementation, in particular in geological complex regions. The historical city Staufen im Breisgau, SW Germany, has attracted national attention as a case of implementation failure with severe consequences, causing debates on the applicability and security of this sustainable technique. Located at the eastern transition zone of the Upper Rhine Graben and the Schwarzwald massif, the geothermal potential is high at Staufen due to strong temperature gradients. In September 2007, seven boreholes for geothermal probes were drilled up to a depth of 140 m to provide a new heat management for the city hall. Within five years an uplift phenomenon has been observed in Staufen reaching more than 40 cm in places and 269 buildings were damaged. Hydro-chemical driven anhydrite-gypsum transformation in the subsurface was identified as the cause leading to volume increase that is observable as surface uplift. This process is associated with the geothermal drilling activities that have crossed several groundwater levels. In this work, we summarize and present the findings of spaceborne Synthetic Aperture Radar Interferometry (InSAR) analysis of the uplift in Staufen over the last five years from July 2008 through July 2013. By applying the Small Baseline Subset (SBAS) method, we find a localized elliptical-shaped deformation field in NE-SW orientation. Area of maximum uplift is located 50 m NNE of the drilling zone. At this location, we observe a cumulative uplift of approx. 13.7 cm ± 0.34 cm (mean value within an area of 30 m by 30 m) from July 2008 to July 2009, which reduced to cumulative uplift of 3 cm ± 0.25 cm from July 2012 to July 2013. The deceleration can be related to applied countermeasures as borehole sealing and groundwater pumping. The observed ground surface response was compared to

  13. The relevance of the early history of probability theory to current risk assessment practices in mental health care.

    PubMed

    Large, Matthew

    2013-12-01

    Probability theory is at the base of modern concepts of risk assessment in mental health. The aim of the current paper is to review the key developments in the early history of probability theory in order to enrich our understanding of current risk assessment practices.

  14. Interferograms showing land subsidence and uplift in Las Vegas Valley, Nevada, 1992-99

    USGS Publications Warehouse

    Pavelko, Michael T.; Hoffmann, Jörn; Damar, Nancy A.

    2006-01-01

    The U.S. Geological Survey, in cooperation with the Nevada Department of Conservation and Natural Resources-Division of Water Resources and the Las Vegas Valley Water District, compiled 44 individual interferograms and 1 stacked interferogram comprising 29 satellite synthetic aperture radar acquisitions of Las Vegas Valley, Nevada, from 1992 to 1999. The interferograms, which depict short-term, seasonal, and long-term trends in land subsidence and uplift, are viewable with an interactive map. The interferograms show that land subsidence and uplift generally occur in localized areas, are responsive to ground-water pumpage and artificial recharge, and, in part, are fault controlled. Information from these interferograms can be used by water and land managers to mitigate land subsidence and associated damage. Land subsidence attributed to ground-water pumpage has been documented in Las Vegas Valley since the 1940s. Damage to roads, buildings, and other engineered structures has been associated with this land subsidence. Land uplift attributed to artificial recharge and reduced pumping has been documented since the 1990s. Measuring these land-surface changes with traditional benchmark and Global Positioning System surveys can be costly and time consuming, and results typically are spatially and temporally sparse. Interferograms are relatively inexpensive and provide temporal and spatial resolutions previously not achievable. The interferograms are viewable with an interactive map. Landsat images from 1993 and 2000 are viewable for frames of reference to locate areas of interest and help determine land use. A stacked interferogram for 1992-99 is viewable to visualize the cumulative vertical displacement for the period represented by the individual interferograms. The interactive map enables users to identify and estimate the magnitude of vertical displacement, visually analyze deformation trends, and view interferograms and Landsat images side by side. The

  15. Retaining Meanings of Quality in Australian Early Childhood Education and Care Policy History: Perspectives from Policy Makers

    ERIC Educational Resources Information Center

    Logan, Helen

    2018-01-01

    This paper presents lesser known accounts from policy makers whose experiences as elite informants span 40 or so years in Australian early childhood education and care (ECEC) policy history between 1972 and 2009. Drawing on a post-structuralist theoretical frame, this paper employs a Foucauldian-influenced approach to discourse analysis. Given the…

  16. Preliminary Gravity and Ground Magnetic Data in the Arbuckle Uplift near Sulphur, Oklahoma

    USGS Publications Warehouse

    Scheirer, Daniel S.; Aboud, Essam

    2008-01-01

    Improving knowledge of the geology and geophysics of the Arbuckle Uplift in south-central Oklahoma is a goal of the Framework Geology of Mid-Continent Carbonate Aquifers project sponsored by the United States Geological Survey (USGS) National Cooperative Geologic Mapping Program (NCGMP). In May 2007, we collected ground magnetic and gravity observations in the Hunton Anticline region of the Arbuckle Uplift, near Sulphur, Oklahoma. These observations complement prior gravity data collected for a project sponsored by the National Park Service and helicopter electromagnetic (HEM) and aeromagnetic data collected in March 2007 for the NCGMP project. This report describes the instrumentation and processing that was utilized in the May 2007 geophysical fieldwork, and it presents preliminary results as gravity anomaly maps and magnetic anomaly profiles. Digital tables of gravity and magnetic observations are provided as a supplement to this report. Future work will generate interpretive models of these anomalies and will involve joint analysis of these ground geophysical measurements with airborne and other geophysical and geological observations, with the goal of understanding the geological structures influencing the hydrologic properties of the Arbuckle-Simpson aquifer.

  17. Late Pliocene Depositional History and Paleoclimate Reconstructions of the Southwest Pacific

    NASA Astrophysics Data System (ADS)

    Royce, B.; Patterson, M. O.; Pietras, J.

    2017-12-01

    Drift deposits off the eastern margin of New Zealand are important archives for the paleoclimate and paleoceanographic history of the southwest Pacific. Ocean Drilling Program (ODP) Site 1123 is located on the North Chatham rise drift just North of the westerly wind driven Subtropical Front (STF) and provides a record of near continuous sediment deposition since the Miocene along the southwest Pacific deep western boundary current (DWBC). While the Miocene and Late Pleistocene portion of this record have been well studied, the Late Pliocene record is less well developed. Southern Ocean geological records demonstrate that Late Pliocene cooling is the transient time bracketing the warmer than present Early Pliocene and bipolar glaciation at 2.7 Ma. A newly developed, robust, and astronomically tuned long-term record of benthic δ13C from ODP Site 1123 spanning the Early to Late Pliocene implies a reduction in Southern Ocean ventilation and lowering of preformed values from waters sourced along the Antarctic margin during the Late Pliocene. Thus, Late Pliocene Southern Hemisphere cooling and sea ice expansion may have drastically reduced outgassing and increased the burial of heat into the deep ocean. South Atlantic records off the west coast of Africa demonstrate an increase in the flux of iron to the open ocean during this time potentially enhancing surface ocean productivity and providing an additional cooling mechanism. Currently, atmospheric transport of dust to the Southern Ocean is dominated by persistent mid-latitude circumpolar westerly winds; this is particularly relevant for dust sourced from New Zealand. The Late Pliocene to Early Pleistocene uplift of the North Island axial ranges and South Island southern alps potentially provided a greater amount of not only sediment to the deep ocean, but also wind blow dust to the Pacific sector of the Southern Ocean. We will present a detailed high-resolution sedimentological study on the development of the Chatham

  18. Post-orogenic subsidence and uplift of the Carpathian belt: An integrated approach

    NASA Astrophysics Data System (ADS)

    Bertotti, G.; Matenco, L.; Drijkonigen, G.; Krijgsman, W.; Tarapoanca, M.; Panea, I.; Vasiliev, I.; Milea, M.; Cloetingh, S.

    2003-04-01

    Several hundred metres thick Pliocene to Quaternary sequences outcropping along the Carpathian front steeply dip away from the mountain belt towards the Carpathian foredeep. They overly the Carpathian fold-and-thrust belt and document that, following the main contractional stages, the orogenic wedge first subsided and was then uplifted. Uplift occurred coeval with substantial subsidence in the basin adjacent to the E, the Focsani Depression. To define the precise kinematics of such movements and thereby constrain these vertical movements taking place in the "wrong" place and in the "wrong" time, the Netherlands Research Center for Integrated Solid Earth Science has launched a large campaign of geological and geophysical investigation. The main components of the project are as follows: 1) acquisition of nearly 100km of seismic data designed to image the uppermost hundred metres of the Earth's crust and thereby making a precise connection between features visible in Industry lines and at the surface 2) paleomagnetic investigations in order to constrain the age of the poorly dated continental to lacustrine sediments 3) A seismic experiment designed to detect 3-D effects on 2-D acquisition 4) Structural work to determine the stress/strain conditions during subsidence and subsequent uplift At a larger scale, these activities are embedded in the effort made by ISES and connected groups to precisely constrain the kinematics of the Pannonian-Carpathian system. Seismic acquisition has been performed during the summer 2002 and has been technically very successful thanks also to the effort of the prospecting company Prospectiunii SA. Lines have been processed and are currently being interpreted. The most apparent feature is the lack of localized deformation demonstrating that subsidence and tilting affected areas of several tens of kilometers and are not related to single faults. Sampling for paleomagnetic studies has been carried out in 2002 along the same section where

  19. Shelf width and river base level on active margins controlled by a combination of eustasy and local uplift rate, illustration from the Pacific NW of the United States.

    NASA Astrophysics Data System (ADS)

    Malatesta, L. C.; Finnegan, N. J.; Kushwaha, G.

    2017-12-01

    Sea level defines the elevation where wave-base erosion is the dominant erosive process. Hence, submarine erosion of the margin and creation of a continental shelf depend on the time distribution of sea level relative to bedrock by correcting eustasy for local rock uplift. Eustasy and wave-base erosion also impact most fluvial systems on Earth by affecting the vertical and lateral position of their lower boundary condition, the coastline. When uplift rate is slow, the concentration of wave-base erosion on a restricted range of elevation promotes the creation of wide shelves and of a relatively stable average base level for coastal rivers. While interfluves above the shelf are steep, fluvial valleys in slow uplift regions grade into the shelf and form estuaries that trap sediment at high stand. Alternatively, a fast coastal uplift rate distributes wave-base erosion over a wide range of bedrock elevations that are quickly uplifted above the eustatic range, preventing the beveling of a shelf and the establishment of a river profile equilibrated around an average sea-level. In that case, river base level is highly dependent on the gradient of the continental slope. We show that the width of the shelf is inversely correlated with the uplift rate along the Oregon and northern California coast. The extent of the shelf can be a valuable counterpart to (often absent) marine terraces that provides a record for coastline retreat, local uplift rate and river base level.

  20. Early life history and spatiotemporal changes in distribution of the rediscovered Suwannee moccasinshell Medionidus walkeri (Bivalvia: Unionidae)

    USGS Publications Warehouse

    Johnson, Nathan A.; Mcleod, John; Holcomb, Jordan; Rowe, Matthew T.; Williams, James D.

    2016-01-01

    Accurate distribution data are critical to the development of conservation and management strategies for imperiled species, particularly for narrow endemics with life history traits that make them vulnerable to extinction. Medionidus walkeri is a rare freshwater mussel endemic to the Suwannee River Basin in southeastern North America. This species was rediscovered in 2012 after a 16-year hiatus between collections and is currently proposed for listing under the Endangered Species Act. Our study fills knowledge gaps regarding changes in distribution and early life history requirements of M. walkeri. Spatiotemporal changes in M. walkeri distribution were displayed using a conservation status assessment map incorporating metadata from 98 historical (1916–1999) and 401 recent (2000–2015) site surveys from museums and field notes representing records for 312 specimens. Recent surveys detected M. walkeri only in the middle Suwannee subbasin (n = 86, 22 locations) and lower Santa Fe subbasin (n = 2, 2 locations), and it appears the species may be extirpated from 67% of historically occupied 10-digit HUCs. In our laboratory experiments, M. walkeri successfully metamorphosed on Percina nigrofasciata (56.2% ± 8.9) and Etheostoma edwini (16.1% ± 7.9) but not on Trinectes maculatus, Lepomis marginatus, Notropis texanus, Noturus leptacanthus, Etheostoma fusiforme, or Gambusia holbrooki. We characterize M. walkeri as a lure-displaying host fish specialist and a long-term brooder (bradytictic), gravid from fall to early summer of the following year. The early life history and distribution data presented here provide the baseline framework for listing decisions and future efforts to conserve and recover the species.

  1. Evidence for an agitated-aggressive syndrome in early-onset psychosis correlated with antisocial personality disorder, forensic history, and substance use disorder.

    PubMed

    Huber, Christian G; Hochstrasser, Lisa; Meister, Klara; Schimmelmann, Benno G; Lambert, Martin

    2016-08-01

    Agitation, aggression, and violence are increased in psychotic disorders. Additionally, an earlier age at onset may be associated with aggressive behavior. However, the relationship of age at onset, an agitated-aggressive syndrome as measured with the Positive And Negative Syndrome Scale for Schizophrenia - Excited Component (PANSS-EC), and its potential correlates in first-episode psychosis (FEP) has not been studied. This study assessed the association between age at onset, an agitated-aggressive syndrome, and its potential correlates in a prospective sample of 52 FEP patients with early-onset and adult-onset followed up for 12months. Twenty-six patients conformed to the criteria of early-onset psychosis. Early age at onset was associated with antisocial personality disorder (p=0.004; φc=0.39), a history of legal involvement (p=0.005; φc=0.39), and higher rates of lifetime substance use disorder (SUD; p=0.002; φc=0.42). Early-onset patients had significantly higher PANSS-EC scores over the course of observation (F(1,44.4)=5.39; p=0.025; d=0.656), but no significant group differences emerged for the remaining PANSS subscores. PANSS-EC scores were correlated positively with antisocial personality disorder and forensic history at 6weeks, 3months, 6months, and 12months, and with lifetime substance use disorder at 3months and 6months. Patients with early onset psychosis may have increased levels of agitation/aggressiveness, and, more likely, antisocial personality disorder, forensic history, and lifetime substance use disorder. These variables were linked to suicidality, aggressiveness, and involuntary treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Accidental inflation from Kähler uplifting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ben-Dayan, Ido; Westphal, Alexander; Wieck, Clemens

    2014-03-01

    We analyze the possibility of realizing inflation with a subsequent dS vacuum in the Käahler uplifting scenario. The inclusion of several quantum corrections to the 4d effective action evades previous no-go theorems and allows for construction of simple and successful models of string inflation. The predictions of several benchmark models are in accord with current observations, i.e., a red spectral index, negligible non-gaussianity, and spectral distortions similar to the simplest models of inflation. A particularly interesting subclass of models are ''left-rolling'' ones, where the overall volume of the compactified dimensions shrinks during inflation. We call this phenomenon ''inflation by deflation''more » (IBD), where deflation refers to the internal manifold. This subclass has the appealing features of being insensitive to initial conditions, avoiding the overshooting problem, and allowing for observable running α ∼ 0.012 and enhanced tensor-to-scalar ratio r ∼ 10{sup −5}. The latter results differ significantly from many string inflation models.« less

  3. Origins of the Asian-Australian monsoons related to Cenozoic plate movement and Tibetan Plateau uplift - A modeling study

    NASA Astrophysics Data System (ADS)

    Liu, X.; Dong, B.; Yin, Z. Y.; Smith, R. S.; Guo, Q.

    2017-12-01

    The origin of monsoon is a subject that has attracted much attention in the scientific community and even today it is still controversial. According to geological records, there is conflicting evidence regarding the timings of establishment of the monsoon climates in South Asia, East Asia, and northern Australia. Additionally, different explanations for the monsoon origins have been derived from various numerical simulations. To further investigate the origin and evolution of the Asian and Australian monsoons, we designed a series of numerical experiments using a coupled atmospheric-oceanic general circulation model. Since the Indian-Australian plate has shifted its position significantly during the Cenozoic, together with the large-scale uplift of the Tibetan Plateau (TP), in these experiments we considered the configurations of ocean-land masses and large topographic features based on geological evidence of plate motion and TP uplift in 5 typical Cenozoic geological periods: mid-Paleocene ( 60Ma), late-Eocene ( 40Ma), late-Oligocene ( 25Ma), late-Miocene ( 10Ma), and present day. These experiments allowed us to examine the combined effects of the changes in the land-ocean configuration due to plate movement and TP uplift, they also provided insight into the effects of the high CO2 levels during the Eocene. The simulations revealed that during the Paleocene, the Indian Subcontinent was still positioned in the Southern Hemisphere (SH) and, therefore, its climate behaved as the SH tropical monsoon. By the late Eocene, it moved into the tropical Northern Hemisphere, which allowed the establishment of the South Asian monsoon. In contrast, the East Asian and Australian monsoon did not exist in the late Oligocene. These monsoon systems were established in the Miocene and then enhanced thereafter. Establishments of the low-latitude monsoons in South Asia and Australia were entirely determined by the position of the Indian-Australian plate and not related to the TP uplift

  4. Stochastic simulation of Venice land uplift by seawater injection in deep heterogeneous aquifers

    NASA Astrophysics Data System (ADS)

    Ferronato, M.; Gambolati, G.; Teatini, P.; Bau, D. A.; Putti, M.

    2010-12-01

    In recent years, several geo-mechanical modeling studies have indicated that seawater injection into deep formations underneath the city of Venice, Italy, may produce a land uplift sufficient to significantly mitigate the effects of the acqua alta, that is, the exceptional tide peaks that periodically occur in the northern Adriatic Sea. However, of major concern is the differential vertical displacement at the ground surface, which must not exceed prescribed regulatory thresholds to guarantee structural preservation of the city historical buildings. In this work, we focus on the hydraulic conductivity, K, which - due to its inherent spatial heterogeneity - is often one of the most difficult hydrogeological parameters to characterize, and analyze the effects that spatially heterogeneous aquifer K distributions may have on the uniformity of the induced land uplift. This study relies on a series of stochastic geomechanical simulations performed using an uncoupled 3D finite-element model poro-elastic model and refers to a pilot project devised to address the feasibility and sustainability of an actual full-scale injection program. The pilot project considers the recharge of about 3,100 m3/day seawater over three years from three injection wells installed into six aquifers comprised between depths of 600 and 800 meters. The K field is modeled geostatistically according to an unconditional, second-order, stationary random process characterized by an exponential covariance function. The stochastic geomechanical simulations are structured into a sensitivity analysis in order to investigate the impact of the variance, σ2, and the horizontal correlation scale, λ, of the K field on the spatial distributions of the ground surface uplift and its horizontal gradient ρz. The results indicate that, irrespective of the σ2 and λ values, properly selected within the ranges 0.2-1.0 and 20-1000 m, respectively, typical of normally consolidated sedimentary basins, the predicted

  5. Ogaden Basin subsidence history: Another key to the Red Sea-Gulf of Aden tectonic puzzle

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pigott, J.D.; Neese, D.; Carsten, G.

    1995-08-01

    Previous work has attempted to understand the tectonic evolution of the Red Sea-Gulf of Aden region through a focus upon plate kinematics and reconstruction of plate interactions in a two dimensional sense. A significant complement to the three dimensional puzzle can be derived from a critical examination of the vertical component, tectonic subsidence analysis. By removing the isostatic contributions of sediment loading and unloading, and fluctuations in sea level, the remaining thermal-mechanical contribution to a basin`s subsidence can be determined. Such an analysis of several Ogaden Basin wells reveals multiple pulses of tectonic subsidence and uplift which correspond to far-fieldmore » tectonic activities in the Red Sea and Gulf of Aden. One of the more dramatic is a Jurassic tectonic pulse circa 145-130 m.a., and a later extensional event which correlates to a major subsidence event ubiquitous through-out the Gulf of Aden, related to Gondwana Land breakup activities. Tectonic uplift during the Tertiary coincides with early Red Sea rifting episodes. Such activities suggest the Ogaden Basin has been a relatively stable East African cratonic basin, but with heating-extension events related to nearby plate interactions. In terms of hydrocarbon generation, the use of steady state present day geothermal gradients, coupled with subsidence analysis shows that potential Paleozoic and Mesozoic source rocks initiated generation as early as the Jurassic. The generating potential of Paleozoic source rocks would only be exacerbated by later heating events. Furthermore, cooling and tectonic uplift during the Tertiary would tend to arrest on-going hydrocarbon generation for Jurassic source rocks in the Ogaden area.« less

  6. Late Cenozoic Uplift of the Chinese South Tian Shan: Insight from Magnetostratigraphy and Sedimentology

    NASA Astrophysics Data System (ADS)

    Chen, X.; Chen, H.; Cheng, X. G.; Zhongyue, S.; Lin, X.

    2016-12-01

    The South Tian Shan in the Central Asia is an intracontinental orogeny reactivated in the late Cenozoic by far-field effect of continuous India-Aisa convergence. However, its uplift time and process remains controversial. Here, Magnetostratigraphic and Sedimentological work in the Cenozoic Tierekesazi Profile in the South Tian Shan foreland was taken to figure out these problems. The Cenozoic sediment reveals a section of generally upwardly increasing particle sizes triggered by uplift of Tian Shan. Based on increasing particle size and water power, the Cenozoic succession could be divided into four lithofacies: (i) Paleogene marine lithofacies from the Paleogene Aertashi to Eocene-Oligocene Bashibulake Formation, (ii) lacustrine to fluvial (plain) lithofacies from the early Miocene Keziluoyi Formation to the middle of middle Miocene Pakabulake Formations, (iii) alluvial sand-gravel sheet lithofacies in the upperpart of middle Miocene Pakabulake Formation, and (iv) conglomerate lithofacies from the Neogene Atushi to Quaternary Xiyu Formation. Our magnetostratigraphic results, combined with biostratigraphic correlations, provide the chronologic constraints for each lithofacies and also the sediment accumulation rates (SAR). These results indicate lithofacies (i) aged ca. 65-34 Ma, lithofacies (ii) aged ca. 22.1-12 Ma, lithofacies (iii) aged ca. 12-5.2 Ma, and lithofacies (iv) aged ca. 5.2 Ma-present (?), with SARs increasing from lithofacies (i) to (iv). Regional correlation of SAR from foreland of South Tian Shan has suggested a linkage of the sedimentary event to the tectonic activity along South Tian Shan. We propose that the earliest Miocene event may represent the initial response of the far-field effect of Indian-Eurasian convergence, but more directly and likely marks the initial underthrusting of the Tarim block beneath the South Tian Shan. The mid-Miocene and Mio-Pliocene boundary events have different structural expression in the opposite regions east and

  7. Thermochronologic constraints on post-Paleozoic tectonic evolution of the central Transantarctic Mountains, Antarctica

    NASA Astrophysics Data System (ADS)

    Fitzgerald, Paul G.

    1994-08-01

    Built upon the roots of a compressive orogenic belt of late Proterozoic-early Paleozoic age and once adjacent to North America, the present-day Transantarctic Mountains (TAM) represent a rift flank, resulting from episodic uplift in the Cretaceous and Cenozoic. Fault blocks are discernible in present-day topography and subglacial morphology. Fission track results give information on differential block movement (uplift and denudation) and are important in constraining models for the uplift of the range. Apatite fission track thermochronology on samples collected from the central TAM record a complex thermotectonic history for this region over the past 350 m.y. Apatite ages in the Miller Range vary from ˜250 to ˜350 Ma and are from an exhumed apatite partial annealing zone formed following cooling of Cambro-Ordovician granitoids. A period of Cretaceous denudation (≲2 km), beginning at ˜115 Ma, is recorded at Moody Nunatak on the inland side of the TAM. Near the coast, samples along the Beardmore Glacier record rapid cooling indicative of denudation initiated in the early Cenozoic (˜50 Ma). The amount of uplift ˜70 km inland of the coast in the Queen Alexandra Range since the early Cenozoic is ˜7 km, with the likelihood of an additional ˜3 km at the coast. Eastward facing topographic escarpments in the Queen Alexandra Range mark the likely position of steeply dipping normal faults, which offset the apatite ages. Apatite ages on the east side of the Beardmore Glacier mouth are generally younger (average 27 Ma) than on the west side (average 33 Ma), reflecting greater denudation. Assumptions made regarding the use of an assumed paleogeothermal gradient are tested with available geologic evidence. The fission track data neither conflict with nor confirm paleobotanical evidence from the Sirius Group in the central TAM which suggests significant surface uplift (2-3 km) of the TAM since the Pliocene. Results build upon the available fission track database along the

  8. Influencing factors for early acute cerebrovascular accidents in patients with stroke history following off-pump coronary artery bypass grafting.

    PubMed

    Wang, Bin; Jia, Ming; Jia, Shijie; Wan, Jiuhe; Zhou, Xiao; Luo, Zhimin; Zhou, Ye; Zhang, Jianqun

    2014-06-01

    To analyse risk factors for early acute cerebrovascular accidents following off-pump coronary artery bypass grafting (OPCAB) in patients with stroke history, and to propose preventive measures to reduce the incidence of these events. A total of 468 patients with a history of stroke underwent OPCAB surgery in Beijing Anzhen Hospital of China from January 2010 to September 2012. They were retrospectively divided into two groups according to the occurrence of early acute cerebrovascular accidents within 48 hours following OPCAB. Multivariate logistic regression analysis was used to find risk or protective factors for early acute cerebrovascular accidents following the OPCAB. Fifty-two patients (11.1%) suffered from early acute cerebrovascular accidents in 468 patients, including 39 cases of cerebral infarction, two cases of cerebral haemorrhage, 11 cases of transient ischaemic attack (TIA). There were significant differences between the two groups in preoperative left ventricular ejection fraction ≤ 35%, severe bilateral carotid artery stenosis, poorly controlled hypertension, intraoperative application of Enclose® II proximal anastomotic device, postoperative acute myocardial infarction, atrial fibrillation, hypotension, ventilation time > 48h, ICU duration >48h and mortality. Multivariate logistic regression analysis showed that preoperative severe bilateral carotid stenosis (OR=6.378, 95%CI: 2.278-20.987) and preoperative left ventricular ejection fraction ≤ 35% (OR=2.737, 95%CI: 1.267-6.389), postoperative acute myocardial infarction (OR=3.644, 95%CI: 1.928-6.876), postoperative atrial fibrillation (OR=3.104, 95%CI:1.135∼8.016) and postoperative hypotension (OR=4.173, 95%CI: 1.836∼9.701) were independent risk factors for early acute cerebrovascular accidents in patients with a history of stroke following OPCAB procedures, while intraoperative application of Enclose® II proximal anastomotic device was protective factor (OR=0.556, 95%CI: 0.337-0.925). This

  9. Class Climate Moderates Peer Relations and Emotional Adjustment in Children with an Early History of Anxious Solitude: A Child x Environment Model

    ERIC Educational Resources Information Center

    Gazelle, Heidi

    2006-01-01

    Classroom emotional climate was hypothesized to moderate psychosocial adjustment in 1st grade for children with an early childhood history of anxious solitude. Participants were 1,364 children in the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and their mothers, child-care providers, and teachers.…

  10. Respite Care, Stress, Uplifts, and Marital Quality in Parents of Children with Down Syndrome

    ERIC Educational Resources Information Center

    Norton, Michelle; Dyches, Tina Taylor; Harper, James M.; Roper, Susanne Olsen; Caldarella, Paul

    2016-01-01

    Parents of children with disabilities are at risk for high stress and low marital quality; therefore, this study surveyed couples (n = 112) of children with Down syndrome (n = 120), assessing whether respite hours, stress, and uplifts were related to marital quality. Structural equation modeling indicated that respite hours were negatively related…

  11. Advancement Staff and Alumni Advocates: Cultivating LGBTQ Alumni by Promoting Individual and Community Uplift

    ERIC Educational Resources Information Center

    Garvey, Jason C.; Drezner, Noah D.

    2013-01-01

    Using a constructivist case-study analysis, we explore philanthropy toward higher education among lesbian, gay, bisexual, transgender, and queer (LGBTQ) alumni, examining the role of advancement staff and alumni advocates in engaging LGBTQ alumni to promote individual and community uplift. Data come from focus groups with 37 advancement staff and…

  12. Geologic Map of the Snegurochka Planitia Quadrangle (V-1): Implications for Tectonic and Volcanic History of the North Polar Region of Venus

    NASA Technical Reports Server (NTRS)

    Hurwitz, D. M.; Head, J. W.

    2009-01-01

    Geologic mapping of Snegurochka Planitia (V-1) reveals a complex stratigraphy of tectonic and volcanic features that can provide insight into the geologic history of Venus and Archean Earth [1,2], including 1) episodes of both localized crustal uplift and mantle downwelling, 2) shifts from local to regional volcanic activity, and 3) a shift back to local volcanic activity. We present our progress in mapping the spatial and stratigraphic relationships of material units and our initial interpretations of the tectonic and volcanic history of the region surrounding the north pole of Venus

  13. Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading

    NASA Astrophysics Data System (ADS)

    Nield, Grace A.; Barletta, Valentina R.; Bordoni, Andrea; King, Matt A.; Whitehouse, Pippa L.; Clarke, Peter J.; Domack, Eugene; Scambos, Ted A.; Berthier, Etienne

    2014-07-01

    Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, invoking a solid Earth response that has been recorded at continuous GPS (cGPS) stations. A previous attempt to model the observation of rapid uplift following the 2002 breakup of Larsen B Ice Shelf was limited by incomplete knowledge of the pattern of ice unloading and possibly the assumption of an elastic-only mechanism. We make use of a new high resolution dataset of ice elevation change that captures ice-mass loss north of 66°S to first show that non-linear uplift of the Palmer cGPS station since 2002 cannot be explained by elastic deformation alone. We apply a viscoelastic model with linear Maxwell rheology to predict uplift since 1995 and test the fit to the Palmer cGPS time series, finding a well constrained upper mantle viscosity but less sensitivity to lithospheric thickness. We further constrain the best fitting Earth model by including six cGPS stations deployed after 2009 (the LARISSA network), with vertical velocities in the range 1.7 to 14.9 mm/yr. This results in a best fitting Earth model with lithospheric thickness of 100-140 km and upper mantle viscosity of 6×1017-2×1018 Pa s - much lower than previously suggested for this region. Combining the LARISSA time series with the Palmer cGPS time series offers a rare opportunity to study the time-evolution of the low-viscosity solid Earth response to a well-captured ice unloading event.

  14. The Early History of Life

    NASA Astrophysics Data System (ADS)

    Nisbet, E. G.; Fowler, C. M. R.

    2003-12-01

    ago, for the most part the planet was peaceful. Even the most active volcanoes are mostly quiet; meteorites large enough to extinguish all dinosaurs may have hit as often as every few thousand years, but this is not enough to be a nuisance to a bacterium (except when the impact boiled the ocean); while to the photosynthesizer long-term shifts in the solar spectrum may be less of a problem than cloudy hazy days. Though, admittedly, green is junk light to biology, the excretion from the photosynthetic antennae, nevertheless even a green sky would have had other wavelengths also in its spectrum.Most important of all, like all good houses, this planet had location: Earth was just in the right spot. Not too far from the faint young Sun (Sagan and Chyba, 1997), it was also far enough away still to be in the comfort zone ( Kasting et al., 1993) when the mature Sun brightened. As many have pointed out, when Goldilocks arrived, she found everything just right. But what is less obvious is that as she grew and changed, and the room changed too, she commenced to rearrange the furniture to make it ever righter for her. Thus far, the bears have not arrived, though they may have reclaimed Mars from Goldilocks's sister see ( Figure 1). (3K)Figure 1. The habitable zone (Kasting et al., 1993). Too close to the Sun, a planet's surface is too hot to be habitable; too far, it is too cold. Early in the history of the solar system, the Sun was faint and the habitable zone was relatively close; 4.5 Ga later, with a brighter Sun, planets formerly habitable are now too hot, and the habitable zone has shifted out. Note that boundaries can shift. By changing its albedo and by altering the greenhouse gas content of the air, the planet can significantly widen the bounds of the habitable zone (Lovelock, 1979, 1988).

  15. Family Caregiver Uplift and Burden: Associations with Aggressive Behavior in Adults with Intellectual Disability

    ERIC Educational Resources Information Center

    Unwin, Gemma; Deb, Shoumitro

    2011-01-01

    The purpose of this study was to investigate the experience of family caregivers caring for adults with intellectual disabilities (ID) who display aggressive behavior in terms of associations with caregiver burden and uplift. The family caregivers of 44 people with ID and aggressive behavior were interviewed using a suite of questionnaires and…

  16. Upper-plate splay fault earthquakes along the Arakan subduction belt recorded by uplifted coral microatolls on northern Ramree Island, western Myanmar (Burma)

    NASA Astrophysics Data System (ADS)

    Shyu, J. Bruce H.; Wang, Chung-Che; Wang, Yu; Shen, Chuan-Chou; Chiang, Hong-Wei; Liu, Sze-Chieh; Min, Soe; Aung, Lin Thu; Than, Oo; Tun, Soe Thura

    2018-02-01

    Upper-plate structures that splay out from the megathrusts are common features along major convergent plate boundaries. However, their earthquake and tsunami hazard potentials have not yet received significant attention. In this study, we identified at least one earthquake event that may have been produced by an upper-plate splay fault offshore western Myanmar, based on U-Th ages of uplifted coral microatolls. This event is likely an earthquake that was documented historically in C.E. 1848, with an estimated magnitude between 6.8 and 7.2 based on regional structural characteristics. Such magnitude is consistent with the observed co-seismic uplift amount of ∼0.5 m. Although these events are smaller in magnitude than events produced by megathrusts, they may produce higher earthquake and tsunami hazards for local coastal communities due to their proximity. Our results also indicate that earthquake events with co-seismic uplift along the coast may not necessarily produce a flight of marine terraces. Therefore, using only records of uplifted marine terraces as megathrust earthquake proxies may overlook the importance of upper-plate splay fault ruptures, and underestimate the overall earthquake frequency for future seismic and tsunami hazards along major subduction zones of the world.

  17. A history of early life parental loss or separation is associated with successful cognitive-behavioral therapy in major depressive disorder.

    PubMed

    Niciu, Mark J; Abdallah, Chadi G; Fenton, Lisa R; Fasula, Madonna K; Black, Anne; Anderson, George M; Sanacora, Gerard

    2015-11-15

    There is a clinical need for evidence-based psychotherapy response biomarkers in major depressive disorder (MDD). Based on previous studies, we hypothesized that lower 24-h urinary cortisol levels and a history of early life stress/trauma would predict an improved antidepressant response to cognitive-behavioral therapy (CBT). 50 currently depressed MDD subjects were enrolled. 24-h urine was collected and measured for cortisol levels by radioimmunoassay (RIA). Subjects were also administered early life stress/trauma measures at baseline: Global Perceived Early-Life Stress (GPELS), The Early Life Trauma Inventory (ELTI) and Klein Loss Scale (KLS). The efficacy of a twelve-week course of once-weekly CBT was evaluated by the primary outcome measure, the 24-item Hamilton Depression Rating Scale (HDRS24), at baseline and every four weeks, and the Beck Depression Inventory at baseline and weekly thereafter. 42 subjects had at least one complete follow-up visit (≥4 weeks of CBT), and 30 subjects completed the full 12-week course. Baseline 24-h urinary cortisol levels did not correlate with CBT's antidepressant response. Higher KLS scores, a measure of early life parental loss or separation, correlated with delta HDRS24 (rs=-0.39, padjusted=0.05). Complementary general linear model analysis revealed enhanced CBT efficacy in patients with a history of early life parental loss or separation [F(1,35)=6.65, p=0.01]. Small sample size, Treatment-naïve population. Early life parental separation or loss positively correlated with CBT's antidepressant efficacy in our sample and may warrant further study in larger clinical samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The central uplift of Elorza Crater: Insights into its geology and possible relationships to the Valles Marineris and Tharsis regions

    NASA Astrophysics Data System (ADS)

    Hopkins, R. T.; Tornabene, L. L.; Osinski, G. R.

    2017-03-01

    The majority of hydrated silicate occurrences on Mars are associated with impact craters (Ehlmann et al., 2011; Carter et al., 2013). Three formation mechanisms have been suggested to account for this correlation: (1) aqueous alteration occurred pre-impact, and was subsequently exposed via the impact (pre-impact; Bibring et al., 2006; Ehlmann et al., 2011), (2) heat generated from the impact facilitated the formation of a hydrothermal system, leading to alteration products (syn-impact; e.g. Marzo et al., 2010; Osinski et al., 2013), and/or (3) altered materials were deposited after crater formation, or formed within the crater well after the impact had taken place (post-impact). In this study, we analyze the central uplift of Elorza Crater, a ∼40 km diameter impact crater located ∼300 km north of Valles Marineris. To determine whether hydrated minerals found within the uplift were generated pre-, syn-, or post-impact, we used a data synthesis approach, utilizing High Resolution Imaging Science Experiment (HiRISE), Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), Context Camera (CTX), and Thermal Emission Imaging System (THEMIS) imagery. Opaline silica is observed in two locations on the southwestern side of the uplift and is interpreted to have been pre-existing or formed via hydrothermal alteration due to stratigraphic relationships with the overlying impact melt unit. Both Fe/Mg smectite and low-calcium pyroxene (LCP) are found throughout the uplift. Bedrock exposures on the northern wall of Coprates Chasma containing Fe/Mg smectite and LCP suggest an uplifted origin for these units. In all cases, although a pre-existing origin is probable, it is difficult to rule out the possibility of an impact-generated hydrothermal origin. Using the observed stratigraphy exposed in Coprates Chasma and bedrock exposures analyzed in nearby craters, we were able to constrain the pre-impact stratigraphy around Elorza. The near-subsurface consists of Hesperian

  19. Maternal dental history and child’s birth outcome and early cognitive development

    PubMed Central

    Daniels, JL; Rowland, AS; Longnecker, MP; Crawford, P; Golding, J

    2013-01-01

    Summary Prenatal exposure to high levels of mercury, radiation, and inflammation have been associated with adverse reproductive outcomes such as increases in preterm delivery, low birthweight, and delayed neurodevelopment. Few data are available to evaluate the potential effects of prenatal low-level exposure to these factors as might occur during dental care. We evaluated maternal dental history prior to and during pregnancy in relation to birth outcomes and early communicative development among offspring in a large cohort (n=7375) of British children born in 1991–1992. Dental history was assessed by questionnaire. The child’s communicative development was assessed using the MacArthur Communicative Development Inventory at 15 months of age. Total mercury was measured in umbilical cord tissue for a subset of the children. Overall, dental care, including amalgam fillings, was not associated with birth outcomes or language development. Having x-rays taken during pregnancy was not associated with birthweight measured continuously (β=14.7, p=0.4), but was associated with slightly increased odds of having a term, low birthweight baby (OR 1.9, 95%CI 1.0–3.4). More detailed evaluation of the potential adverse effects of elective dental treatment during pregnancy, particularly dental x-rays, may be warranted. PMID:17697075

  20. Integrated approaches to terminal Proterozoic stratigraphy: an example from the Olenek Uplift, northeastern Siberia

    NASA Technical Reports Server (NTRS)

    Knoll, A. H.; Grotzinger, J. P.; Kaufman, A. J.; Kolosov, P.

    1995-01-01

    In the Olenek Uplift of northeastern Siberia, the Khorbusuonka Group and overlying Kessyusa and Erkeket formations preserve a significant record of terminal Proterozoic and basal Cambrian Earth history. A composite section more than 350 m thick is reconstructed from numerous exposures along the Khorbusuonka River. The Khorbusuonka Group comprises three principal sedimentary sequences: peritidal dolomites of the Mastakh Formation, which are bounded above and below by red beds; the Khatyspyt and most of the overlying Turkut formations, which shallow upward from relatively deep-water carbonaceous micrites to cross-bedded dolomitic grainstones and stromatolites; and a thin upper Turkut sequence bounded by karst surfaces. The overlying Kessyusa Formation is bounded above and below by erosional surfaces and contains additional parasequence boundaries internally. Ediacaran metazoans, simple trace fossils, and vendotaenids occur in the Khatyspyt Formation; small shelly fossils, more complex trace fossils, and acritarchs all appear near the base of the Kessyusa Formation and diversify upward. The carbon-isotopic composition of carbonates varies stratigraphically in a pattern comparable to that determined for other terminal Proterozoic and basal Cambrian successions. In concert, litho-, bio-, and chemostratigraphic data indicate the importance of the Khorbusuonka Group in the global correlation of terminal Proterozoic sedimentary rocks. Stratigraphic data and a recently determined radiometric date on basal Kessyusa volcanic breccias further underscore the significance of the Olenek region in investigations of the Proterozoic-cambrian boundary.

  1. Integrated approaches to terminal Proterozoic stratigraphy: an example from the Olenek Uplift, northeastern Siberia.

    PubMed

    Knoll, A H; Grotzinger, J P; Kaufman, A J; Kolosov, P

    1995-01-01

    In the Olenek Uplift of northeastern Siberia, the Khorbusuonka Group and overlying Kessyusa and Erkeket formations preserve a significant record of terminal Proterozoic and basal Cambrian Earth history. A composite section more than 350 m thick is reconstructed from numerous exposures along the Khorbusuonka River. The Khorbusuonka Group comprises three principal sedimentary sequences: peritidal dolomites of the Mastakh Formation, which are bounded above and below by red beds; the Khatyspyt and most of the overlying Turkut formations, which shallow upward from relatively deep-water carbonaceous micrites to cross-bedded dolomitic grainstones and stromatolites; and a thin upper Turkut sequence bounded by karst surfaces. The overlying Kessyusa Formation is bounded above and below by erosional surfaces and contains additional parasequence boundaries internally. Ediacaran metazoans, simple trace fossils, and vendotaenids occur in the Khatyspyt Formation; small shelly fossils, more complex trace fossils, and acritarchs all appear near the base of the Kessyusa Formation and diversify upward. The carbon-isotopic composition of carbonates varies stratigraphically in a pattern comparable to that determined for other terminal Proterozoic and basal Cambrian successions. In concert, litho-, bio-, and chemostratigraphic data indicate the importance of the Khorbusuonka Group in the global correlation of terminal Proterozoic sedimentary rocks. Stratigraphic data and a recently determined radiometric date on basal Kessyusa volcanic breccias further underscore the significance of the Olenek region in investigations of the Proterozoic-cambrian boundary.

  2. Habitat shifts in the evolutionary history of a Neotropical flycatcher lineage from forest and open landscapes

    PubMed Central

    2008-01-01

    Background Little is known about the role ecological shifts play in the evolution of Neotropical radiations that have colonized a variety of environments. We here examine habitat shifts in the evolutionary history of Elaenia flycatchers, a Neotropical bird lineage that lives in a range of forest and open habitats. We evaluate phylogenetic relationships within the genus based on mitochondrial and nuclear DNA sequence data, and then employ parsimony-based and Bayesian methods to reconstruct preferences for a number of habitat types and migratory behaviour throughout the evolutionary history of the genus. Using a molecular clock approach, we date the most important habitat shifts. Results Our analyses resolve phylogenetic relationships among Elaenia species and confirm several species associations predicted by morphology while furnishing support for other taxon placements that are in conflict with traditional classification, such as the elevation of various Elaenia taxa to species level. While savannah specialism is restricted to one basal clade within the genus, montane forest was invaded from open habitat only on a limited number of occasions. Riparian growth may have been favoured early on in the evolution of the main Elaenia clade and subsequently been deserted on several occasions. Austral long-distance migratory behaviour evolved on several occasions. Conclusion Ancestral reconstructions of habitat preferences reveal pronounced differences not only in the timing of the emergence of certain habitat preferences, but also in the frequency of habitat shifts. The early origin of savannah specialism in Elaenia highlights the importance of this habitat in Neotropical Pliocene and late Miocene biogeography. While forest in old mountain ranges such as the Tepuis and the Brazilian Shield was colonized early on, the most important colonization event of montane forest was in conjunction with Pliocene Andean uplift. Riparian habitats may have played an important role in

  3. Statistical distribution of the vacuum energy density in racetrack Kähler uplift models in string theory

    NASA Astrophysics Data System (ADS)

    Sumitomo, Yoske; Tye, S.-H. Henry; Wong, Sam S. C.

    2013-07-01

    We study a racetrack model in the presence of the leading α'-correction in flux compactification in Type IIB string theory, for the purpose of getting conceivable de-Sitter vacua in the large compactified volume approximation. Unlike the Kähler Uplift model studied previously, the α'-correction is more controllable for the meta-stable de-Sitter vacua in the racetrack case since the constraint on the compactified volume size is very much relaxed. We find that the vacuum energy density Λ for de-Sitter vacua approaches zero exponentially as the volume grows. We also analyze properties of the probability distribution of Λ in this class of models. As in other cases studied earlier, the probability distribution again peaks sharply at Λ = 0. We also study the Racetrack Kähler Uplift model in the Swiss-Cheese type model.

  4. Uplift of the Transantarctic Mountains and the bedrock beneath the East Antarctic ice sheet

    USGS Publications Warehouse

    ten Brink, Uri S.; Hackney, R.I.; Bannister, S.; Stern, T.A.; Makovsky, Y.

    1997-01-01

    In recent years the Transantarctic Mountains (TAM), the largest noncontractional mountain belt in the world, have become the focus of modelers who explained their uplift by a variety of isostatic and thermal mechanisms. A problem with these models is a lack of available data to compare with model predictions. We report here the results of a 312-km-long geophysical traverse conducted in 1993/1994 in the hinterland of the TAM. Using detailed subglacial topography and gravity measurements, we confirm the origin of the TAM as a flexural uplift of the edge of East Antarctica. Using an elastic model with a free edge, we can jointly fit the topography and the gravity with a plate having an elastic thickness of 85 ?? 15 km and a preuplift elevation of 700 ?? 50 m for East Antarctica. Using a variety of evidence, we argue that the uplift is coincident with a relatively minor tectonic event of transtensional motion between East and West Antarctica during the Eocene rather than the Late Cretaceous rifting event that created the Ross Embayment. We suggest that this transtensional motion caused the continuous plate to break, which created an escarpment that significantly increased the rates of erosion and exhumation. Results from the geophysical traverse also extend our knowledge of the bedrock geology from the exposures within the TAM to the ice covered interior. Our interpretation suggests that the Ferrar flood basalts extend at least 100 km westward under the ice. The Beacon Supergroup of Paleozoic and Mesozoic sediments thins gradually under the ice and its reconstructed thickness is reminiscent of profiles of foreland basins. Finally, there is no indication in the gravity field for an incomplete rebound due to significant melting of the East Antarctic ice sheet since the last glacial period.

  5. Early Lactation and Infant Feeding Practices Differ by Maternal Gestational Diabetes History.

    PubMed

    Oza-Frank, Reena; Moreland, Jennifer J; McNamara, Kelly; Geraghty, Sheela R; Keim, Sarah A

    2016-11-01

    Detailed data on lactation practices by gestational diabetes mellitus (GDM) history are lacking, precluding potential explanations and targets for interventions to improve lactation intensity and duration and, ultimately, long-term maternal and child health. This study aimed to examine breastfeeding practices through 12 months postpartum by GDM history. Women who delivered a singleton, liveborn infant at The Ohio State University Wexner Medical Center (Columbus, OH), in 2011 completed a postal questionnaire to assess lactation and infant feeding practices and difficulties. Bivariate and multivariate associations between GDM history and lactation and infant feeding practices were examined. The sample included 432 women (62% response rate), including 7.9% who had GDM during the index pregnancy. Women with GDM initiated breastfeeding (at-the-breast or pumping) as often as women without any diabetes but were more likely to report introduction of formula within the first 2 days of life (79.4% vs 53.8%, P < .01; adjusted odds ratio: 3.48; 95% confidence interval, 1.47-8.26). Women with GDM initiated pumping 4 days earlier than women without diabetes ( P < .05), which was confirmed in adjusted analyses. There was no difference in the proportion of women reporting breastfeeding difficulty (odds ratio: 2.08; 95% confidence interval, 0.78-5.52). However, there was a trend toward women with GDM reporting more formula feeding and less at-the-breast feeding as strategies to address difficulty compared with women without diabetes. Additional research is needed to understand why women with GDM engage in different early lactation and infant feeding practices, and how best to promote and sustain breastfeeding among these women.

  6. Oxygenation history of the Neoproterozoic to early Phanerozoic and the rise of land plants

    NASA Astrophysics Data System (ADS)

    Wallace, Malcolm W.; Hood, Ashleigh vS.; Shuster, Alice; Greig, Alan; Planavsky, Noah J.; Reed, Christopher P.

    2017-05-01

    There has been extensive debate about the history of Earth's oxygenation and the role that land plant evolution played in shaping Earth's ocean-atmosphere system. Here we use the rare earth element patterns in marine carbonates to monitor the structure of the marine redox landscape through the rise and diversification of animals and early land plants. In particular, we use the relative abundance of cerium (Ceanom), the only redox-sensitive rare earth element, in well-preserved marine cements and other marine precipitates to track seawater oxygen levels. Our results indicate that there was only a moderate increase in oceanic oxygenation during the Ediacaran (average Cryogenian Ceanom = 1.1, average Ediacaran Ceanom = 0.62), followed by a decrease in oxygen levels during the early Cambrian (average Cryogenian Ceanom = 0.90), with significant ocean anoxia persisting through the early and mid Paleozoic (average Early Cambrian-Early Devonian Ceanom = 0.84). It was not until the Late Devonian that oxygenation levels are comparable to the modern (average of all post-middle Devonian Ceanom = 0.55). Therefore, this work confirms growing evidence that the oxygenation of the Earth was neither unidirectional nor a simple two-stage process. Further, we provide evidence that it was not until the Late Devonian, when large land plants and forests first evolved, that oxygen levels reached those comparable to the modern world. This is recorded with the first modern-like negative Ceanom (values <0.6) occurring at around 380 Ma (Frasnian). This suggests that land plants, rather than animals, are the 'engineers' responsible for the modern fully oxygenated Earth system.

  7. The association of daily hassles and uplifts with family and life satisfaction: does cultural orientation make a difference?

    PubMed

    Lavee, Yoav; Ben-Ari, Adital

    2008-03-01

    The study examined similarities and differences between people having individualist and collectivist cultural orientations in terms of what they perceive as stressful and uplifting experiences in their daily lives, and the relation between daily experiences and family and life satisfaction. Data were collected from two representative community samples (697 Jews and 303 Arabs). Each sample was grouped into individualist and collectivist cultural orientations. The two cultural orientation groups differed with respect to the appraisal of positive and negative daily experiences. A structural equation modeling (SEM) multi-group analysis indicated a similar factor structure for hassles and uplifts in both groups. However, the two groups differed in the effects of positive and negative daily occurrences on family and life satisfaction.

  8. Recent uplift and hydrothermal activity at Tangkuban Parahu volcano, west Java, Indonesia

    USGS Publications Warehouse

    Dvorak, J.; Matahelumual, J.; Okamura, A.T.; Said, H.; Casadevall, T.J.; Mulyadi, D.

    1990-01-01

    Tangkuban Parahu is an active stratovolcano located 17 km north of the city of Bandung in the province west Java, Indonesia. All historical eruptive activity at this volcano has been confined to a complex of explosive summit craters. About a dozen eruptions-mostly phreatic events- and 15 other periods of unrest, indicated by earthquakes or increased thermal activity, have been noted since 1829. The last magmatic eruption occurred in 1910. In late 1983, several small phreatic explosions originated from one of the summit craters. More recently, increased hydrothermal and earthquake activity occurred from late 1985 through 1986. Tilt measurements, using a spirit-level technique, have been made every few months since February 1981 in the summit region and along the south and east flanks of the volcano. Measurements made in the summit region indicated uplift since the start of these measurements through at least 1986. From 1981 to 1983, the average tilt rate at the edges of the summit craters was 40-50 microradians per year. After the 1983 phreatic activity, the tilt rate decreased by about a factor of five. Trilateration surveys across the summit craters and on the east flank of the volcano were conducted in 1983 and 1986. Most line length changes measured during this three-year period did not exceed the expected uncertainty of the technique (4 ppm). The lack of measurable horizontal strain across the summit craters seems to contradict the several years of tilt measurements. Using a point source of dilation in an elastic half-space to model tilt measurements, the pressure center at Tangkuban Parahu is located about 1.5 km beneath the southern part of the summit craters. This is beneath the epicentral area of an earthquake swarm that occurred in late 1983. The average rate in the volume of uplift from 1981 to 1983 was 3 million m3 per year; from 1983 to 1986 it averaged about 0.4 million m3 per year. Possible causes for this uplift are increased pressure within a very

  9. Miocene tectono-stratigraphic history of La Mision basin, northwestern Baja California: implications for early tectonic development of southern California continental borderland

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ashby, J.R.; Minch, J.

    1988-03-01

    The middle Miocene La Mision basin in northwestern Baja California, Mexico, provides a rare opportunity to study an onshore portion of the southern California continental borderland. Stratigraphy, geometry of dispersal, and a variety of lithotypes within the volcanic and volcaniclastic sediments of the Rosarito Beach Formation provide clues to the nature of early tectonic evolution of this area during the Miocene. The elongated, trough-shaped La Mision basin formed in response to peninsular basement uplifts and the formation of volcanic highlands west of the present coastline. Lithologies and depositional environments represented within the basin sediments include: subaerial basalt flows and airfallmore » tuffs, submarine muddy- and sandy-matrix mudflow breccias, lapilli tuffs, crystal tuffs, tuffaceous sandstones,d diatomites, and conglomerates. The environments of deposition range from fluvatile to intertidal to shallow marine. Early basin infilling is characterized by sediments and basalts, with a western source terrane, that were deposited against the faulted seacliffs. progressive infilling against the seacliff resulted in the formation of an extensive eastward-sloping basaltic platform extending eastward to the foothill coastal belt of the Peninsular Ranges. Marine transgression and subsequent regression are recorded by diverse marine volcaniclastic lithologies. Abundant fossils, K-Ar dates, and paleomagnetic data obtained from the La Mision basin allow precise correlation with other areas in the continental borderland and provide conclusive evidence that this block of the borderland was formed and in its present position by 16-14 Ma.« less

  10. Double-difference tomography velocity structure in Northern Oklahoma: Evidence for reduced basement velocity in the Nemaha Uplift

    NASA Astrophysics Data System (ADS)

    Stevens, N. T.; Keranen, K. M.; Lambert, C.

    2016-12-01

    Induced seismicity in northern Oklahoma presents risk for infrastructure, but also an opportunity to gain new insights to earthquake processes [Petersen et al., 2016]. Here we present a double-difference tomographic study using TomoDD [Zhang and Thurber, 2003] in northern Oklahoma utilizing records from a dense broadband network over a 1-year period, constituting a catalog of over 10,000 local seismic events. We image a shallow (depth < 4 km) high-velocity structure consistent with the Nemaha uplift [Gay, 2003a], bounded by shallow, lower-velocity regions on either side, likely sedimentary strata at this depth bounding uplifted basement. Velocities within the uplift are lower than expected in subjacent crystalline basement rock (depth > 4 km). We suggest that this low velocity anomaly stems from enhanced fracturing and/or weathering of the basement in the Nemaha uplift in northern Oklahoma. This velocity anomaly is not observed in basement off the shoulders of the structure, particularly to the southeast of the Nemaha bounding fault. Enhanced fracturing, and related increases to permeability, would ease pressure migration from injection wells linked to increased seismicity in the region, and may explain the relative absence of seismicity coincident with this structure compared to it periphery. References Gay, S. Parker, J. (2003), The Nemaha Trend-A System of Compressional Thrust-Fold, Strike-Slilp Structural Features in Kansas and Oklahoma, Part 1, Shale Shak., 9-49. Petersen, M. D., C. S. Mueller, M. P. Moschetti, S. M. Hoover, A. L. Llenos, W. L. Ellsworth, A. J. Michael, J. L. Rubinstein, A. F. McGarr, and K. S. Rukstales (2016), 2016 One-Year Seismic Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes, Open-File Rep., doi:10.3133/OFR20161035. Zhang, H., and C. H. Thurber (2003), Double-difference tomography: The method and its application to the Hayward Fault, California, Bull. Seismol. Soc. Am., 93(5), 1875-1889, doi

  11. Mapping Early American History: Beyond What Happened Where

    ERIC Educational Resources Information Center

    Milson, Andrew J.

    2014-01-01

    American history demands to be mapped. The stories of exploration, the colonies, the Louisiana Purchase, and so on are incomplete without maps to locate historical places, events, and conflicts. Yet maps can do more for the history teacher than simply illustrating what happened where or what territory was acquired when. Maps also provide clues…

  12. An Hour in History

    NASA Image and Video Library

    2011-03-22

    John C. Stennis Space Center historian Marco Giardino speaks to center employees during the first An Hour in History session March 22. The Stennis History Office launched the series as part of the rocket engine test facility's yearlong 50th anniversary celebration. The inaugural session focused on Stennis history during the early 1960s. Subsequent sessions will focus on other aspects of Stennis history as part of the '50 Years of Powering Dreams' anniversary theme.

  13. Constraining the age and magnitude of uplift in the northern National Petroleum Reserve in Alaska (NPRA)-apatite fission-track analysis of samples from three wells

    USGS Publications Warehouse

    Houseknecht, David W.; Bird, Kenneth J.; O'Sullivan, Paul

    2011-01-01

    A broad, post-mid-Cretaceous uplift is defined in the northern National Petroleum Reserve in Alaska (NPRA) by regional truncation of Cretaceous strata, thermal maturity patterns, and amounts of exhumation estimated from sonic logs. Apatite fission-track (AFT) analysis of samples from three wells (South Meade No. 1, Topagoruk No. 1, and Ikpikpuk No. 1) across the eastern flank of the uplift indicates Tertiary cooling followed by Quaternary heating. Results from all three wells indicate that cooling, presumably caused by uplift and erosion, started about 75-65 Ma (latest Cretaceous-earliest Tertiary) and continued through the Tertiary Period. Data from South Meade indicate more rapid cooling after about 35-15 Ma (latest Eocene-middle Miocene) followed by a significant increase in subsurface temperature during the Quaternary, probably the result of increased heat flow. Data from Topagoruk and Ikpikpuk include subtle evidence of accelerated cooling starting in the latest Eocene-middle Miocene and possible evidence of increased temperature during the Quaternary. Subsurface temperature perturbations related to the insulating effect of permafrost may have been responsible for the Quaternary temperature increase at Topagoruk and Ikpikpuk and may have been a contributing factor at South Meade. Multiple lines of geologic evidence suggest that the magnitude of exhumation resulting from uplift and erosion is 5,000-6,500 ft at South Meade, 4,000-5,500 ft at Topagoruk, and 2,500-4,000 ft at Ikpikpuk. The results from these wells help to define the broad geometry of the uplift, which increases in magnitude from less than 1,000 ft at the Colville River delta to perhaps more than 7,000 ft along the northwestern coast of NPRA, between Point Barrow and Peard Bay. Neither the origin nor the offshore extent of the uplift, west and north of the NPRA coast, have been determined.

  14. Bichordites from the early Eocene of Cuba: significance in the evolutionary history of the spatangoids

    NASA Astrophysics Data System (ADS)

    Villegas-Martín, Jorge; Netto, Renata Guimarães

    2017-12-01

    The trace fossil Bichordites monastiriensis is found in early Eocene turbiditic sandstones of the upper-slope deposits from the Capdevila Formation in Los Palacios Basin, Pinar del Río region, western Cuba. The potential tracemakers of B. monastiriensis include fossil spatangoids from the family Eupatagidae. The record of Bichordites in the deposits from Cuba allows to suppose that Eupatagidae echinoids were the oldest potential tracemakers of Bichordites isp. and reinforce the hypothesis that the ichnological record are relevant in envisaging the evolutionary history of the spatangoids.

  15. Measuring the Timing, Magnitude, and Rate of Rock uplift of Sierra Madre Mountains with CRN Analysis of Relict Landscapes and Strath Terraces

    NASA Astrophysics Data System (ADS)

    Schoettle, E.; Burbank, D. W.; Bookhagen, B.

    2014-12-01

    California's Sierra Madre Mountains lie at the junction of the Coast and Transverse Ranges, where they form an arcuate range crest with peak elevations of nearly 1,800 m. Near the range crest, a gently sloping paleovalley in the Southern Sierra Madre is being consumed by the headward migration of a prominent knickpoint, with an ~250-m-high headwall abutting below the gently sloped paleovalley. This paleovalley at 1400 m elevation and other low-relief, high-elevation remnants in the Sierra Madres at elevations from 800-1400 m show that the range is young enough to have regions not yet in equilibrium with the modern base level and uplift rate. Toward the western end of the Sierra Madre, the Cuyama River cuts a bedrock canyon through the range. The canyon planform describes a meandering river that has now incised ~400 m into the range. The combination of (i) high-altitude, low-relief surfaces in the Sierra Madre including the paleovalley with (ii) a meandering planform that has been incised into bedrock by a transverse river suggests (1) a low-altitude meandering proto-Cuyama river preceded significant rock uplift, and (2) the river's incision records the rock uplift of the range. Using cosmogenic nuclides to measure both the bedrock-lowering rate of the high-elevation paleovalley and the erosion rate of the steep catchment eroding into it, we can place some limits on the timing and magnitude of rock uplift in the range. By dating bedrock straths along the river canyon's walls, we can directly quantify the pace of channel incision. Together these new estimates will yield an improved reconstruction of the timing, magnitude, and rate of rock uplift of the Sierra Madre.

  16. Neogene-Quaternary slow coastal uplift of Western Europe through the perspective of sequences of strandlines from the Cotentin Peninsula (Normandy, France)

    NASA Astrophysics Data System (ADS)

    Pedoja, K.; Jara-Muñoz, J.; De Gelder, G.; Robertson, J.; Meschis, M.; Fernandez-Blanco, D.; Nexer, M.; Poprawski, Y.; Dugué, O.; Delcaillau, B.; Bessin, P.; Benabdelouahed, M.; Authemayou, C.; Husson, L.; Regard, V.; Menier, D.; Pinel, B.

    2018-02-01

    The Cotentin Peninsula (Normandy, France) displays sequences of marine terraces and rasas, the latter being wide Late Cenozoic coastal erosion surfaces, that are typical of Western European coasts in Portugal, Spain, France and southern England. Remote sensing imagery and field mapping enabled reappraisal of the Cotentin coastal sequences. From bottom to top, the N Cotentin sequence includes four previously recognized Pleistocene marine terraces (T1 to T4) at elevations < 40 m as well as four higher and older rasas (R1 to R4) reaching 200 ± 5 m in elevation. Low-standing marine terraces are not observed in the central part of the Peninsula and a limited number of terraces are described to the south. The high-standing rasas are widespread all over the peninsula. Such strandline distributions reveal major changes during the Late Cenozoic. Progressive uplift of an irregular sea-floor led to subaerial exposure of bathymetric highs that were carved into rocky platforms, rasas and marine terraces. Eventually, five main islands coalesced and connected to the mainland to the south to form the Cotentin Peninsula. On the basis of previous dating of the last interglacial maximum terrace (i.e. Marine Isotopic Stage, MIS 5e), sequential morphostratigraphy and modelling, we have reappraised uplift rates and derived: (i) mean Upper Pleistocene (i.e. since MIS 5e 122 +/- 6 ka, i.e. kilo annum) apparent uplift rates of 0.04 ± 0.01 mm/yr, (ii) mean Middle Pleistocene eustasy-corrected uplift rates of 0.09 ± 0.03 mm/yr, and (iii) low mean Pleistocene uplift rates of 0.01 mm/yr. Extrapolations of these slow rates combined with geological evidence implies that the formation of the sequences from the Cotentin Peninsula occurred between 3 Ma (Pliocene) and 15 Ma (Miocene), which cannot be narrowed down further without additional research. Along the coasts of Western Europe, sequences of marine terraces and rasas are widespread (169 preserve the MIS 5e benchmark). In Spain, Portugal, S

  17. Characterizing the early life history of an imperiled freshwater mussel (Ptychobranchus jonesi) with host-fish determination and fecundity estimation

    USGS Publications Warehouse

    Mcleod, John; Jelks, Howard L.; Pursifull, Sandra; Johnson, Nathan A.

    2017-01-01

    Conservation of imperiled species is frequently challenged by insufficient knowledge of life history and environmental factors that affect various life stages. The larvae (glochidia) of most freshwater mussels in the family Unionidae are obligate ectoparasites of fishes. We described the early life history of the federally endangered Southern Kidneyshell Ptychobranchus jonesi and compared methods for estimating fecundity and conducting host trials on this conglutinate-producing mussel species. Glochidial inoculation baths and direct feeding of conglutinates to Percina nigrofasciata, Etheostoma edwini, and Etheostoma fusiforme resulted in successful metamorphosis to the juvenile life stage. Ptychobranchus jonesi glochidia did not metamorphose on 25 other species of fishes tested representing 11 families. Three juveniles were recovered from Gambusia holbrooki resulting in a metamorphosis rate <1%. We characterize P. jonesi as a host-fish specialist that fractionally releases conglutinates from late January to early June. Intact P. jonesi conglutinates resemble simuliid fly larvae attached to an egg-like structure, but most conglutinates were released as segments representing separate egg or larva mimics. Viability of glochidia encased within a conglutinate was >90% for ≥5 d. Feeding conglutinates directly to fishes allowed us to estimate seminatural infestation rates and calculate average numbers of juveniles produced per conglutinate, unlike the traditional approach of infesting fish hosts in an inoculation bath. Regressions based on the physical dimensions of each conglutinate or conglutinate segment were the most practical method used to estimate fecundity. Species distribution information, early life-history description, and methods developed for determining fecundity and conducting host trials may assist in the conservation of P. jonesi during recovery options that include captive propagation, augmentation, and reestablishment.

  18. Using slope-area and apatite fission track analysis to decipher the rock uplift pattern of the Yumu Shan: New insights into the growth of the NE Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Wang, Yizhou; Zheng, Dewen; Pang, Jianzhang; Zhang, Huiping; Wang, Weitao; Yu, Jingxing; Zhang, Zhuqi; Zheng, Wenjun; Zhang, Peizhen; Li, Youjuan

    2018-05-01

    Studies have shown that the growth of the Qilian Shan, the northeastern margin of the Tibetan Plateau, started 10 Ma ago. However, when and how it expanded northwards is still under debate. Here we focus on the rock uplift pattern of the Yumu Shan, an active fault-related fold in the Hexi Corridor north to the Qilian Shan. Normalized channel steepness achieved from the analysis of river longitudinal profiles shows a spatially variant rock uplift pattern, with higher rates in the middle part and lower rates towards the west and east tips. The compression of the mountain is typically accommodated by fault-fold related shortening and vertical thickening. Apatite fission track thermochronology reveals that the growth of the Yumu Shan started 4 Ma ago, similar to the work on active tectonics. Combining the onset ages of the growth of the Qilian Shan (10 Ma), Laojunmiao anticline (3-4 Ma), Baiyanghe anticline (3-4 Ma), Wenshu Shan (4.5 Ma) and Heli Shan (2 Ma), we draw an conclusion that the NE margin of the Tibetan Plateau initiated growth in the mid-Miocene and expanded to the Hexi Corridor and to the south of the Alxa block in the early Pleistocene.

  19. Flow of material under compression in weak lower continental crust can cause post-rift uplift of passive continental margins

    NASA Astrophysics Data System (ADS)

    Chalmers, James

    2014-05-01

    There are mountain ranges up to more than 2 km high along many passive continental margins (e.g. Norway, eastern Australia, eastern Brazil, SE and SW Africa, east and west Greenland etc.), dubbed Elevated Passive Continental Margins (EPCMs). EPCMs contain several features in common and observations indicate that uplift of these margins took place after continental break-up. There are many explanations for their formation but none that satisfy all the observations. Lack of a geodynamical mechanism has meant that there has been difficulty in getting the community to accept the observational evidence. Formation of a passive continental margin must take place under conditions of tension. After rifting ceases, however, the margin can come under compression from forces originating elsewhere on or below its plate, e.g. orogeny elsewhere in the plate or sub-lithospheric drag. The World Stress Map (www.world-stress-mp.org) shows that, where data exists, all EPCMs are currently under compression. Under sufficient compression, crust and/or lithosphere can fold, and Cloetingh & Burov (2010) showed that many continental areas may have folded in this way. The wavelengths of folding observed by Cloetingh & Burov (2010) imply that the lower crust is likely to be of intermediate composition; granitic lower crust would fold with a shorter wavelength and basic lower crust would mean that the whole lithosphere would have to fold as a unit resulting in a much longer wavelength. Continental crust more than 20 km thick would be separated from the mantle by a weak layer. However, crust less thick than that would contain no weak layers would become effectively annealed to the underlying strong mantle. Under sufficient horizontal compression stress, material can flow in the lower weak layer towards a continental margin from the continental side. The annealed extended crust and mantle under the rift means, however, that flow cannot continue towards the ocean. Mid- and lower crustal material

  20. Early history of Vesta: implications for the surface morphology and composition

    NASA Astrophysics Data System (ADS)

    Turrini, D.; Coradini, A.; Formisano, M.; Carli, C.; Magni, G.

    2011-12-01

    The Dawn mission inserted into orbit around Vesta on 15 July 2011 and is presently gathering data on the morphology and the composition of the asteroid. In order to fully exploit the data that the Dawn mission is supplying to probe the ancient past of our Solar System, we need to be able to understand how the present state of Vesta is linked to its origin and its secular evolution. The spectral connection between Vesta and the Howardite-Eurcrite-Diogenite (HED) suite of meteorites suggests that Vesta formed very early in the history of the Solar System and differentiated on a Ma-long timescale due to the decay of short-lived radioactive nuclides (see Keil 2002 and references therein). Short after the differentiation process ended, Vesta started to cool down quickly, so that on a 10 Ma timescale its molten mantle would be topped by a thick solid layer (Formisano et al. 2011). Across the same timespan, Jupiter and the other giant planets would form in the outer Solar System and trigger a primordial phase of bombardment on the other already formed planetary bodies (Turrini et al. 2011, Coradini et al. 2011). Such primordial bombardment is expected to excavate the solid crust of Vesta and to cause local to regional effusive phenomena (Turrini et al. 2011). Moreover, due to the relatively high escape speed from Vesta, most of the excavated material would fall back on the asteroid as an ejecta blanket. Here we discuss the timescale of the formation and evolution of Vesta and the implications for the interpretation of the data that the Dawn mission is collecting while orbiting the asteroid. Bibliography 1. Coradini A., Turrini D., Federico C., Magni G. (2011). Vesta and Ceres: crossing the history of the Solar System. Space Science Reviews, DOI: 10.1007/s11214-011-9792-x. 2. Formisano M., Federico C., Coradini A. (2011). Vesta Thermal Models. EPSC-DPS Joint Meeting 2011, Nantes, France. 3. Keil K. (2002). Geological History of Asteroid 4 Vesta: The Smallest Terrestrial

  1. Calculation of regional geomorphic indices to constrain the mechanisms of tectonic uplift and active deformation of the Island of Puerto Rico

    NASA Astrophysics Data System (ADS)

    Martinez, S.

    2016-12-01

    The island of Puerto Rico in the northern Caribbean covers an area of about 14,000 km2 and is 180 km long and 65 km wide and is densely populated by 3.4 million persons. The island is mountainous with an east-west-trending, central mountain range with its highest point of 1338 m in the geographic center of the island. Previous workers have suggested that the origin of this east-west, Central Cordillera is active uplift and folding of a large, east-west-trending anticline whose fold axis is coincident with the topographic crest of the Cordillera Central. The folding mechanism has been attributed by previous workers to obliquely-subducting slabs of the North American and Caribbean plates beneath the island. To test the hypothesis that this topographic and structural axis is also the axis of active topographic uplift, I created a knickpoint density map for the island based on over 50 different river systems to reveal areas of active uplift. The knickpoint map shows an excellent correlation with the proposed arch both in width and trend of the axis and supports the conclusion that the arch is the main axis of active uplift on the Island. I also calculated geomorphic indices for 21 different watersheds of the island that include the Hypsometric Integral and a Stream Length Gradient Index that both assess tectonic activity based on stream and watershed behaviors. The Hack index and Hypsometric Integral show that the most active area of uplift is located in the central and north-central parts of the island that include about one half of the length of the proposed, east-west-trending arch. The two topographically-elevated ends of the arch in the western and eastern parts of the island are less active, according to the indices. Lower values in these areas may be influenced by higher amounts of precipitations in these areas.

  2. Onset of uplift and environmental change in East Africa: paleoaltimetry constraints from a 17 Ma beaked whale fossil from northern Kenya

    NASA Astrophysics Data System (ADS)

    Wichura, H.; Jacobs, L. L.; Strecker, M. R.; Lin, A. S.; Polcyn, M. J.; Manthi, F. K.; Winkler, D. A.; Clemens, M.

    2014-12-01

    Deciphering the timing and magnitude of vertical crustal motions is key to understanding the impact of tectonic uplift on changes in atmospheric circulation, rainfall, and environmental conditions. Uplift of the East African Plateau (EAP) of Kenya has been linked to mantle processes, but paleoaltimetry data are still too scarce to unambiguously constrain plateau evolution and subsequent vertical motions associated with late Cenozoic rifting. Here we assess the fossil remains of a beaked whale (Ziphiidae) from the Turkana region of Kenya, 700 km inland from the present-day coastline of the Indian Ocean. The whale fossil was found at an elevation of 650 m and helps constraining the uplift of the northeastern flanks of the EAP. The Kenyan ziphiid was discovered in fluvio-lacustrine sediments of the extensional Oligo-Miocene Lokichar basin (Mead, 1975) along with terrestrial mammals and freshwater mollusks below a basalt dated at 17.1 ± 1.0 Ma (Boschetto et al., 1992). The unifying characteristics of riverine occurrences of modern marine mammals include sufficient discharge in low-gradient rivers to maintain pathways deep enough to facilitate migration, and the absence of shallow bedrock, rapids and waterfalls. The most likely route, which may have had these characteristics is a fluvial corridor controlled by thermal subsidence of the Cretaceous Anza Rift, which once linked extensional processes in Central and East Africa with the continental margin. The fossil locality and analogies with present-day occurrences of marine mammals in terrestrial realms suggest that the ziphiid stranded slightly above sea level. In combination with 13.5. Ma phonolite flows that utilized eastward-directed drainages away from the EAP the fossil find thus provides the older of only two empirical paleoelevation points that constrain the onset of uplift of the EAP to the interval between approximately 17 and 13 Ma. Topographic uplift of the EAP induced paleoclimatic change from a low

  3. Vertical forearc tectonic displacements offer insights into underlying interplate thrust zone processes: 104-105 yr uplift/subsidence cycles in Southwest Pacific arcs may represent recoverable plastic deformation that is often falsely attributed to other causes

    NASA Astrophysics Data System (ADS)

    Taylor, F. W.; Lavier, L. L.; Frohlich, C.; Thirumalai, K.; Papabatu, A. K.

    2015-12-01

    In the forearcs of subduction zones, the characteristics of both short-term (temporary earthquake cycle) and longer-term permanent vertical deformation offer insights into processes by which plates subduct. But permanent vertical deformation may be a product of several simultaneous processes, including tectonic erosion/underplating, changing dip of the slab, upward displacement due to buoyancy or bathymetric features, and plastic shortening/extension of the forearc wedge. Here we note the rarely recognized, but possibly common, phenomenon of intermediate time scale transient vertical movements (TVM's). Both the central New Hebrides and Western Solomon forearcs have uplifted ≥500 m over time scales of 105 yr. Uplift started abruptly (over ≤10 ky) and proceeded at localized rates up to 7-8 mm/yr. Both initial uplifts terminated preceding rapid subsidence of similar dimensions and rates that, in turn, had followed yet older uplift. However, these uplifts and subsidences are superimposed on a yet longer-term trend of uplift on time scales >105 yr. The most recent uplifts extended 100-200 km along-arc and 60-90 km cross-arc while plate convergence was <10 km. These 105 yr vertical oscillations are most likely due to plastic shortening/extension driven by strong horizontal forces related to rugged seafloor bathymetry impinging on the outer forearc. Subsidence follows uplift when horizontal force abates temporarily and uplift is no longer supported by enhanced interplate coupling. Over the 105 yr time frame when interplate slip is <10 km, it is difficult to account for the timing, geography, and amounts of up and down motion by processes such as buoyancy or volumetric displacement of downgoing bathymetric features or by tectonic underplating/erosion. Instead, ~1% of shortening within the upper plate is sufficient to account for up to several hundred m of uplift across a large area of the forearc.

  4. [An early history of Japanese amyotrophic lateral sclerosis (ALS)-related diseases and the current development].

    PubMed

    Abe, Koji

    2018-03-28

    The present review focuses an early history of Japanese amyotrophic lateral sclerosis (ALS)-related diseases and the current development. In relation to foreign previous reports, five topics are introduced and discussed on ALS with dementia, ALS/Parkinsonism dementia complex (ALS/PDC), familial ALS (FALS), spinal bulbar muscular atrophy (SBMA), and multisystem involvement especially in cerebellar system of ALS including ALS/SCA (spinocerebellar ataxia) crossroad mutation Asidan. This review found the great contribution of Japanese reports on the above five topics, and confirmed the great development of ALS-related diseases over the past 120 years.

  5. Societal Uplift and Productive Efficiency: Corporate Use of Vocational Education in Ellsworth, Pennsylvania, 1900-1915.

    ERIC Educational Resources Information Center

    Hyser, Raymond M.

    About 1900, James W. Ellsworth created the educational system of Ellsworth, Pennsylvania. His aim was to have the system serve a dual purpose: the societal uplift of foreign miners to make them better citizens and the improvement of the company's productive efficiency. Ellsworth's school offered traditional courses along with training in English…

  6. Stress, coping, uplifts, and quality of life in subtypes of depression: a conceptual frame and emerging data.

    PubMed

    Ravindran, Arun V; Matheson, Kimberly; Griffiths, Jenna; Merali, Zul; Anisman, Hymie

    2002-09-01

    Depressive illness is associated with several functional disturbances, including increased stress perception and reliance on emotion focused coping styles, reduced perception of uplifting events, and impairment of several aspects of quality of life. Inasmuch as different subtypes of depression may be accompanied by differing neuroendocrine profiles, it was of interest to establish whether they could also be distinguished from one another on the basis of functional behavioral indices. Major stressors, day-to-day stressors and uplift perception, coping styles, and quality of life were assessed in control participants, as well as in acute or chronically (dysthymia) depressed patients exhibiting either typical or atypical features, and in treatment resistant major depressive patients. Relative to controls, the depressive groups had higher perceptions of day-to-day stressors (hassles), reduced perception of uplifting events, excessive reliance on emotion-focused coping strategies, and diminished quality of life. Among depressed patients the hassles, coping styles and some elements of quality of life were related to symptom severity, as well as treatment-resistance. Data concerning stress, coping and quality of life were collected retrospectively, and the number of subjects in each condition was small. Hence, the relationship of the outcome measures to depression need to be considered cautiously. Quality of life represents a functional index of the behavioral and cognitive impact of depression. This outcome measure is sensitive to differences as a function of depressive characteristics, and may prove to be a useful assessment tool in evaluating treatment efficacy.

  7. Heat flow and thermal history of the Anadarko basin, Oklahoma

    USGS Publications Warehouse

    Carter, L.S.; Kelley, S.A.; Blackwell, D.D.; Naeser, N.D.

    1998-01-01

    New heat-flow values for seven sites in the Anadarko basin, Oklahoma, were determined using high-precision temperature logs and thermal conductivity measurements from nearly 300 core plugs. Three of the sites are on the northern shelf, three sites are in the deep basin, and one site is in the frontal fault zone of the northern Wichita Mountains. The heat flow decreased from 55 to 64 mW/m2 in the north, and from 39 to 54 mW/m2 in the south, due to a decrease in heat generation in the underlying basement rock toward the south. Lateral lithologic changes in the basin, combined with the change in heat flow across the basin, resulted in an unusual pattern of thermal maturity. The vitrinite reflectance values of the Upper Devonian-Lower Mississippian Woodford formation are highest 30-40 km north-northwest of the deepest part of the basin. The offset in highest reflectance values is due to the contrast in thermal conductivity between the Pennsylvanian "granite wash" section adjacent to the Wichita uplift and the Pennsylvanian shale section to the north. The geothermal gradient in the low-conductivity shale section is elevated relative to the geothermal gradient in the high-conductivity "granite wash" section, thus displacing the highest temperatures to the north of the deepest part of the basin. Apatite fission-track, vitrinite reflectance, and heat-flow data were used to constrain regional aspects of the burial history of the Anadarko basin. By combining these data sets, we infer that at least 1.5 km of denudation has occurred at two sites in the deep Anadarko basin since the early to middle Cenozoic (40 ?? 10 m.y.). The timing of the onset of denudation in the southern Anadarko basin coincides with the period of late Eocene erosion observed in the southern Rocky Mountains and in the northern Great Plains. Burial history models for two wells from the deep Anadarko basin predict that shales of the Woodford formation passed through the hydrocarbon maturity window by the

  8. Impact History of the Moon

    NASA Astrophysics Data System (ADS)

    Cohen, B. A.; Bottke, W. F.; Norman, M. V.; van der Bogert, C. H.; Fassett, C. I.; Hiesinger, H.; Joy, K. H.; Mazrouei, S. A.; Nemchin, A.; Neumann, G. A.; Zellner, N. E. B.

    2018-04-01

    Establishing an absolute planetary chronology has important ramifications for understanding the early structure of the solar system and the geologic history of the planets. The Moon is the cornerstone for understanding this impact history.

  9. Earthquakes and Uplift At Somma-vesuvius Before The 79 A.d. Eruption

    NASA Astrophysics Data System (ADS)

    Marturano, A.

    In the morning of 24 August of the year 79 A. D. the famous eruption of Pompei be- gan with a phreatomagmatic manifestation. For several years a number of earthquakes are likely to have occurred at Vesuvius together with unrest episodes. The event of 5 February 62 A.D., which is the best known and the strongest earthquake ever gener- ated by the Vesuvius, and that of 64, are the only events that can be historiographically dated. However, a number of historical epigraphical and archeological evidences ad- vocate the view that several seismic crisis occurred, characterized by strong enough earthquakes to damage the building structures. At Pompei, plenty of evidence of gener- alized, sometimes hasty, reconstructions (even of refined buildings), had erroneously validated the view of a decaying town; more likely, people were only suspiciously waiting for more imminent dangers to come. In 79 A.D. several restoration works were under way to repair the damage caused by an earthquake which had occurred shorty time before. Probably the seismicity was particularly intense in the early years of sixth decad, as well as in the early and in the end of the seventh, just before the erup- tion. At this same time the civic aqueduct of Pompei was out of use. Deep trenches ran along most of the streets for the layng of new tubes. From the 43 fountains of the town didnSt gush a drop of water, and the Castellum aquae was not supplied by regional aqueduct coming from near Apennines crossing the Campanian Plain from North to South. Two different chemical calcareous deposits in the roman water main attest two sources and two water supply stops at least. This phenomenon is interpreted with a relative uplift of the volcano respect to the external areas begun several years before 79 eruption in according with the sensible seismic precursors observed for long a time.

  10. The early history of the lunar inclination. [effect of tidal friction

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1973-01-01

    The effect of tidal friction on the inclination of the lunar orbit to the earth's equator for earth-moon distances of less than 10 earth radii is examined. The results obtained bear on a conclusion drawn by Gerstenkorn and others which has been raised as a fatal objection to the fission hypothesis of lunar origin, namely, that the present nonzero inclination of the moon's orbit to the ecliptic implies a steep inclination of the moon's orbit to the earth's equatorial plane in the early history of the earth-moon system. This conclusion is shown to be valid only for particular rheological models of the earth. The earth is assumed to behave like a highly viscous fluid in response to tides raised in it by the moon. The moon is assumed to be tideless and in a circular orbit about the earth. The equations of tidal friction are integrated numerically to give inclination of the lunar orbit as a function of earth-moon distance.

  11. Uplift sequence of the Andes at 30°S: Insights from sedimentology and U/Pb dating of synorogenic deposits

    NASA Astrophysics Data System (ADS)

    Suriano, J.; Mardonez, D.; Mahoney, J. B.; Mescua, J. F.; Giambiagi, L. B.; Kimbrough, D.; Lossada, A.

    2017-04-01

    The South Central Andes at 30°S represent a key area to understand the Andes geodynamics as it is in the middle of the flat slab segment and all the morphotectonic units of the Central Andes are well developed. This work is focused in the proximal synorogenic deposits of the Western Precordillera, in the La Tranca valley, in order to unravel the uplift sequence of this belt. Nine facies associations were recognized; most of them represent piedmont facies with local provenance from Precordillera and were deposited in the wedge-top depozone, as is expected for proximal sinorogenic deposits. However there are intercalations of transference fluvial systems, which show mixed provenance indicating that Permo-Triassic igneous rocks were already exposed to the west (Frontal Cordillera). There are also lacustrine deposits which are interpreted as the result of damming by fault activity at east of the studied basin. Finally, two maximum depositional ages at ca. 11 Ma and 8 Ma of these deposits indicate that the onset of uplift of the Precordillera at 30°S is little older than 11 Ma. These data change two previous ideas about the evolution of the Precordillera: its uplift at 30° S is younger than proposed by previous works and it is nearly synchronous along strike.

  12. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary.

    PubMed

    Amarilla, Leonardo D; Anton, Ana M; Chiapella, Jorge O; Manifesto, María M; Angulo, Diego F; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species' range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2-1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity.

  13. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary

    PubMed Central

    Amarilla, Leonardo D.; Anton, Ana M.; Chiapella, Jorge O.; Manifesto, María M.; Angulo, Diego F.; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species’ range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2–1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity. PMID:26110533

  14. The role of uplift and erosion in the persistence of saline groundwater in the shallow subsurface

    NASA Astrophysics Data System (ADS)

    Yager, R. M.; McCoy, K. J.; Voss, C. I.; Sanford, W. E.; Winston, R. B.

    2017-04-01

    In many regions of the world, the shallow (<300 m) subsurface is replenished with meteoric recharge within a few centuries or millennia, but in some regions saline groundwater persists despite abundant rainfall. Analyses of the flushing rate of shallow groundwater usually consider the permeability and recharge rate and a static landscape. The influence of landscape evolution can become important over millions of years, however. Here we present numerical simulations of fluid flow and transport in the top 1 km of a sedimentary foreland basin dominated by aquitards, where the rate of uplift and erosion (20 m Ma-1) balances that of meteoric flushing. Paleozoic age saline groundwater and brine persist at shallow depths that might otherwise have contained potable water. Similar hydrogeologic conditions, and uplift and erosion rates, likely exist in many other regions of the world, where a moving landscape has probably never been considered as an important contributor to groundwater quality.

  15. The role of uplift and erosion in the persistence of saline groundwater in the shallow subsurface

    USGS Publications Warehouse

    Yager, Richard M.; McCoy, Kurt J.; Voss, Clifford I.; Sanford, Ward E.; Winston, Richard B.

    2017-01-01

    In many regions of the world, the shallow (<300 m) subsurface is replenished with meteoric recharge within a few centuries or millennia, but in some regions saline groundwater persists despite abundant rainfall. Analyses of the flushing rate of shallow groundwater usually consider the permeability and recharge rate and a static landscape. The influence of landscape evolution can become important over millions of years, however. Here we present numerical simulations of fluid flow and transport in the top 1 km of a sedimentary foreland basin dominated by aquitards, where the rate of uplift and erosion (20 m Ma−1) balances that of meteoric flushing. Paleozoic age saline groundwater and brine persist at shallow depths that might otherwise have contained potable water. Similar hydrogeologic conditions, and uplift and erosion rates, likely exist in many other regions of the world, where a moving landscape has probably never been considered as an important contributor to groundwater quality.

  16. Making History Local: The Efficacy of Local History for Student Interest, Success, and Multicultural Awareness

    ERIC Educational Resources Information Center

    Paysinger, Christopher Browning

    2012-01-01

    This study was an action research design which examined the effects of infusing the local history of North Alabama into the traditional Early American History curriculum to assess the effect on student interest, multicultural awareness, and success on the Alabama High School Graduation Exam history portion. This study found no significance when…

  17. Parents' and Teachers' Views on the Psychosocial Adjustment of Students with and without a History of Early Grade Retention

    ERIC Educational Resources Information Center

    Anastasiou, Andri I.; Papachristou, Eleni M.; Diakidoy, Irene-Anna N.

    2017-01-01

    The study compared teachers' and parents' views about elementary school children's psychosocial adjustment with and without a history of early grade retention. The sample included retained and non-retained students currently in Grades Two and Four (age range 7.5 to 11.6 years) in Cypriot public schools. The retained students experienced early…

  18. Early life history and survival of natural subyearling fall chinook salmon in the Snake and Clearwater rivers in 1995

    USGS Publications Warehouse

    Connor, William P.; Bjornn, Theodore C.; Burge, Howard L.; Garcia, Aaron P.; Rondorf, Dennis W.

    1997-01-01

    The objectives of this segment of our study were to (1) describe the early life history characteristics of naturally produced subyearling fall chinook salmon in the Snake and Clearwater rivers, and (2) estimate survival for juvenile fall chinook salmon emigrating from the Snake and Clearwater rivers to the tail race of Lower Granite Dam.

  19. Influences of spawning timing, water temperature, and climatic warming on early life history phenology in western Alaska sockeye salmon

    USGS Publications Warehouse

    Sparks, Morgan M.; Falke, Jeffrey A.; Quinn, Thomas P.; Adkison, Milo D.; Schindler, Daniel E.; Bartz, Krista K.; Young, Daniel B.; Westley, Peter A. H.

    2018-01-01

    We applied an empirical model to predict hatching and emergence timing for 25 western Alaska sockeye salmon (Oncorhynchus nerka) populations in four lake-nursery systems to explore current patterns and potential responses of early life history phenology to warming water temperatures. Given experienced temperature regimes during development, we predicted hatching to occur in as few as 58 d to as many as 260 d depending on spawning timing and temperature. For a focal lake spawning population, our climate-lake temperature model predicted a water temperature increase of 0.7 to 1.4 °C from 2015 to 2099 during the incubation period, which translated to a 16 d to 30 d earlier hatching timing. The most extreme scenarios of warming advanced development by approximately a week earlier than historical minima and thus climatic warming may lead to only modest shifts in phenology during the early life history stage of this population. The marked variation in the predicted timing of hatching and emergence among populations in close proximity on the landscape may serve to buffer this metapopulation from climate change.

  20. Phylogeny and biogeography of Primula sect. Armerina: implications for plant evolution under climate change and the uplift of the Qinghai-Tibet Plateau.

    PubMed

    Ren, Guangpeng; Conti, Elena; Salamin, Nicolas

    2015-08-16

    The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section. We sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns. Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic