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Sample records for plant strata

  1. Deciphering evolutionary strata on plant sex chromosomes and fungal mating-type chromosomes through compositional segmentation.

    PubMed

    Pandey, Ravi S; Azad, Rajeev K

    2016-03-01

    Sex chromosomes have evolved from a pair of homologous autosomes which differentiated into sex determination systems, such as XY or ZW system, as a consequence of successive recombination suppression between the gametologous chromosomes. Identifying the regions of recombination suppression, namely, the "evolutionary strata", is central to understanding the history and dynamics of sex chromosome evolution. Evolution of sex chromosomes as a consequence of serial recombination suppressions is well-studied for mammals and birds, but not for plants, although 48 dioecious plants have already been reported. Only two plants Silene latifolia and papaya have been studied until now for the presence of evolutionary strata on their X chromosomes, made possible by the sequencing of sex-linked genes on both the X and Y chromosomes, which is a requirement of all current methods that determine stratum structure based on the comparison of gametologous sex chromosomes. To circumvent this limitation and detect strata even if only the sequence of sex chromosome in the homogametic sex (i.e. X or Z chromosome) is available, we have developed an integrated segmentation and clustering method. In application to gene sequences on the papaya X chromosome and protein-coding sequences on the S. latifolia X chromosome, our method could decipher all known evolutionary strata, as reported by previous studies. Our method, after validating on known strata on the papaya and S. latifolia X chromosome, was applied to the chromosome 19 of Populus trichocarpa, an incipient sex chromosome, deciphering two, yet unknown, evolutionary strata. In addition, we applied this approach to the recently sequenced sex chromosome V of the brown alga Ectocarpus sp. that has a haploid sex determination system (UV system) recovering the sex determining and pseudoautosomal regions, and then to the mating-type chromosomes of an anther-smut fungus Microbotryum lychnidis-dioicae predicting five strata in the non

  2. Specialization and interaction strength in a tropical plant-frugivore network differ among forest strata.

    PubMed

    Schleuning, Matthias; Blüthgen, Nico; Flörchinger, Martina; Braun, Julius; Schaefer, H Martin; Böhning-Gaese, Katrin

    2011-01-01

    The degree of interdependence and potential for shared coevolutionary history of frugivorous animals and fleshy-fruited plants are contentious topics. Recently, network analyses revealed that mutualistic relationships between fleshy-fruited plants and frugivores are mostly built upon generalized associations. However, little is known about the determinants of network structure, especially from tropical forests where plants' dependence on animal seed dispersal is particularly high. Here, we present an in-depth analysis of specialization and interaction strength in a plant-frugivore network from a Kenyan rain forest. We recorded fruit removal from 33 plant species in different forest strata (canopy, midstory, understory) and habitats (primary and secondary forest) with a standardized sampling design (3447 interactions in 924 observation hours). We classified the 88 frugivore species into guilds according to dietary specialization (14 obligate, 28 partial, 46 opportunistic frugivores) and forest dependence (50 forest species, 38 visitors). Overall, complementary specialization was similar to that in other plant-frugivore networks. However, the plant-frugivore interactions in the canopy stratum were less specialized than in the mid- and understory, whereas primary and secondary forest did not differ. Plant specialization on frugivores decreased with plant height, and obligate and partial frugivores were less specialized than opportunistic frugivores. The overall impact of a frugivore increased with the number of visits and the specialization on specific plants. Moreover, interaction strength of frugivores differed among forest strata. Obligate frugivores foraged in the canopy where fruit resources were abundant, whereas partial and opportunistic frugivores were more common on mid- and understory plants, respectively. We conclude that the vertical stratification of the frugivore community into obligate and opportunistic feeding guilds structures this plant

  3. Evolutionary Strata on the X Chromosomes of the Dioecious Plant Silene latifolia: Evidence From New Sex-Linked Genes

    PubMed Central

    Bergero, Roberta; Forrest, Alan; Kamau, Esther; Charlesworth, Deborah

    2007-01-01

    Despite its recent evolutionary origin, the sex chromosome system of the plant Silene latifolia shows signs of progressive suppression of recombination having created evolutionary strata of different X–Y divergence on sex chromosomes. However, even after 8 years of effort, this result is based on analyses of five sex-linked gene sequences, and the maximum divergence (and thus the age of this plant's sex chromosome system) has remained uncertain. More genes are therefore needed. Here, by segregation analysis of intron size variants (ISVS) and single nucleotide polymorphisms (SNPs), we identify three new Y-linked genes, one being duplicated on the Y chromosome, and test for evolutionary strata. All the new genes have homologs on the X and Y chromosomes. Synonymous divergence estimated between the X and Y homolog pairs is within the range of those already reported. Genetic mapping of the new X-linked loci shows that the map is the same in all three families that have been studied so far and that X–Y divergence increases with genetic distance from the pseudoautosomal region. We can now conclude that the divergence value is saturated, confirming the cessation of X–Y recombination in the evolution of the sex chromosomes at ∼10–20 MYA. PMID:17287532

  4. Rhizoctonia Species Associated With Bark Media and Plant Strata of Container-Grown Azalea

    USDA-ARS?s Scientific Manuscript database

    Symptoms of Rhizoctonia web blight, caused predominantly by binucleate Rhizoctonia (BNR) anastomosis group U, develops annually from late-June to mid-September on container-grown azaleas (Rhododendron spp.) in the southern United States. In 2005 and 2006, ‘Gumpo White’ azalea plants with a disease ...

  5. A review of WIPP (Waste Isolation Pilot Plant) repository clays and their relationship to clays of adjacent strata

    SciTech Connect

    Krumhansl, J.L.; Kimball, K.M.; Stein, C.L.

    1990-12-01

    The Salado Formation is a thick evaporite sequence located in the Permian Delaware Basin of southeastern New Mexico. This study focuses on the intense diagenetic alteration that has affected the small amounts of clay, feldspar, and quartz washed into the basin during salt deposition. These changes are of more than academic interest since this formation also houses the WIPP (Waste Isolation Pilot Plant). Site characterization concerns warrant compiling a detailed data base describing the clays in and around the facility horizon. An extensive sampling effort was undertaken to address these programmatic issues as well as to provide additional insight regarding diagenetic mechanisms in the Salado. Seventy-five samples were collected from argillaceous partings in halite at the stratigraphic level of the Waste Isolation Pilot Plant (WIPP). These were compared with twenty-eight samples from cores of the Vaca Triste member of the Salado, a thin clastic unit at the top of the McNutt potash zone, and with a clay-rich sample from the lower contact of the Culebra Dolomite (in the overlying Rustler Formation). These settings were compared to assess the influence of differences in brine chemistry (i.e., halite and potash facies, normal to hypersaline marine conditions) and sediment composition (clays, sandy silt, dolomitized limestone) on diagenetic processes. 44 refs., 11 figs., 5 tabs.

  6. Sequence stratigraphy, paleoclimate, and tectonics of coal-bearing strata

    SciTech Connect

    Jack C. Pashin; Robert A. Gastaldo

    2004-07-15

    The origin of coal-bearing strata has been debated vigorously for more than a century, and with the emergence of coalbed methane as a major energy resource and the possibility of sequestering greenhouse gas in coal, this debate has never been more relevant. This volume contains 10 chapters on coal-bearing strata of Carboniferous through Tertiary age and is based on a special session that was held at an AAPG Annual Meeting in New Orleans. Contributors have employed a multitude of approaches ranging from basin analysis to plant taphonomy to support a variety of views on the sequence stratigraphy, paleoclimate, and tectonics of coal-bearing strata.

  7. On Paleozoic plants from marine strata: Trivena arkansana (Lyginopteridaceae) gen. et sp. nov., a lyginopterid from the Fayetteville Formation (middle Chesterian/Upper Mississippian) of Arkansas, USA.

    PubMed

    Dunn, Michael T; Rothwell, Gar W; Mapes, Gene

    2003-08-01

    Five permineralized seed fern stems from the Fayetteville Formation (middle Chesterian/Upper Mississippian) of Arkansas conform to the concept of lyginopterid seed ferns. However, these specimens are unlike all previously reported lyginopterids, and the name Trivena arkansana (Lyginopteridaceae) gen. et sp. nov. is proposed. The stems are up to 30 by 19 mm in diameter and have pentagonal pith and eustele of five cryptic sympodia. Secondary tissues include abundant xylem with numerous wide rays and phloem surrounded by a periderm. The cortex is parenchymatous with abundant sclerotic clusters: some clusters are randomly dispersed and some are in discontinuous rows. Sclerenchyma bands form the "Dictyoxylon"-type outer cortex. Leaf traces diverge in a 2/5 phyllotaxy. Traces, accompanied by concentric secondary xylem, increase in size as they extend through the secondary xylem of the stem. The trace assumes a squat C shape at the outer margin of the secondary xylem and in the cortex divides into three discrete bundles, each surrounded by secondary xylem. Galleries within the phloem contain arthropod coprolites and exhibit wound response, suggesting plant-arthropod coevolution. The discovery of this new lyginopterid stem adds to the growing list of unique taxa described from the Fayetteville Formation and further solidifies its reputation as one of the most important Upper Mississippian plant fossil sites in North America.

  8. Aeromagnetic anomalies over faulted strata

    USGS Publications Warehouse

    Grauch, V.J.S.; Hudson, Mark R.

    2011-01-01

    High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.).

  9. Monoclinal bending of strata over laccolithic intrusions

    USGS Publications Warehouse

    Koch, F.G.; Johnson, A.M.; Pollard, D.D.

    1981-01-01

    Sedimentary strata on top of some laccolithic intrusions are nearly horizontal and little deformed, but are bent into steeply dipping monoclinal flexures over the peripheries of these intrusions. This form of bending is not explained by previous theories of laccolithic intrusion, which predict either horizontal undeformed strata over the center and faulted strata around the periphery, or strata bent continuously into a dome. However, a slight generalization of these theories accomodates the observed form and contains the previous forms as special cases. A critical assumption is that the strength of contacts within a multilayered overburden is overcome locally by layer-parallel shear. If this strength is less than the strength of the layers themselves, then layers over the center remain bonded together and display negligible bending, whereas layers over the periphery slip over one another and are readily bent into a monoclinal flexure. ?? 1981.

  10. Thermal maturity of carboniferous strata, Ouachita Mountains

    SciTech Connect

    Houseknecht, D.W.; Matthews, S.M.

    1985-03-01

    The Ouachita Mountains, a relatively untested, potential hydrocarbon province, contain a thick Paleozoic section of apparently favorable source beds, reservoir beds, and trap configurations. To estimate the thermal maturity of these strata, vitrinite reflectance was measured on 89 samples collected mostly from Carboniferous rocks from throughout the Ouachita outcrop area.

  11. Supraregional seismites in Triassic - Jurassic boundary strata

    NASA Astrophysics Data System (ADS)

    Lindström, Sofie; Pedersen, Gunver K.; van de Schootbrugge, Bas; Johansson, Leif; Petersen, Henrik I.; Dybkjær, Karen; Weibel, Rikke; Hansen, Katrine H.; Erlström, Mikael; Alwmark, Carl; Nielsen, Lars Henrik; Oschmann, Wolfgang; Tegner, Christian

    2014-05-01

    The end-Triassic mass extinction event (201.564 Ma) was synchronous with the earliest volcanic phase during the emplacement of the Central Atlantic Magmatic Province (CAMP), a large igneous province (LIP) formed during the initial breakup of Pangea. Volcanic degassing of CO2 and other volatile gases, and/or thermogenic methane, from the CAMP is generally regarded as the main cause of the end-Triassic biotic crisis. However, discrepancies in the durations of the ETE (50 Kyrs) and the CAMP volcanism (600 Kyrs) as well as temporal offsets between carbon cycle perturbations and biotic turnovers suggest a more complex scenario that require further studies of the temporal succession of events in Triassic-Jurassic (TJ) boundary strata. Here, we present and examine multiple episodes of soft-sediment deformation (seismite) within uppermost Rhaetian marine and terrestrial strata of Denmark, Sweden and Germany. These seismites are stratigraphically constrained by palynology and C-isotopes to the latest Rhaetian, and are synchronous to the single seismite layer from the UK, which similarly predates the T/J boundary, and has been explained by an extraterrestrial bolide impact. Instead, we argue that the multiple episodes of soft-sediment deformation, interbedded by undisturbed strata, were formed from repeated intense earthquake activity restricted to an interval within the latest Rhaetian bracketed by two negative excursions in δ13C and also containing palynological evidence for deforestation and fern proliferation. The fact that these biotic changes coincide with repeated seismic activity has implications for the end-Triassic extinction and the CAMP scenario. We discuss the temporal position of the seismites in regards to other end-Triassic events, and argue that their supraregional distribution in pre-TJ-boundary strata of NW Europe may be linked to intensified earthquake activity during CAMP emplacement, rather than an extraterrestrial impact.

  12. Oligocene terrestrial strata of northwestern Ethiopia : a preliminary report on paleoenvironments and paleontology

    Treesearch

    Bonnie F. Jacobs; Neil Tabor; Mulugeta Feseha; Aaron Pan; John Kappelman; Tab Rasmussen; William Sanders; Michael Wiemann; Jeff Crabaugh; Juan Leandro Garcia Massini

    2005-01-01

    The Paleogene record of Afro-Arabia is represented by few fossil localities, most of which are coastal. Here we report sedimentological and paleontological data from continental Oligocene strata in northwestern Ethiopia. These have produced abundant plant fossils and unique assemblages of vertebrates, thus filling a gap in what is known of Paleogene interior Afro-...

  13. Paleoecology of Early eocene strata near Buffalo, Wyoming

    SciTech Connect

    Durkin, T.V.; Rich, F.J.

    1986-08-01

    Palynological investigation has helped illustrate the paleoecology of a vertical section of strata from the Wasatch Formation between the Healy and Walters coal burns near Buffalo, Wyoming. Numerous silicified logs and stumps of cypress and sequoia have been preserved at the site and drew initial attention to it. Flood-basin deposits enclose the trees and include sandstones, siltstones, shale, and coal beds that accumulated as channel, levee, crevasse-splay, and swamp/marsh sediments. Detrital sediments were probably derived from the Bighorn Mountains and accumulated as they were carried into the Powder River basin fluvial system. One hundred five polynomorph taxa have been distinguished, as well as 10 types of fungal spores. Platycarya, Tilia, Sparganium, and Platanus pollen indicate an early Eocene age for the strata. Other pollen, as well as the genera of trees and megafossil remains from a clinker bed several miles from the study area, reinforce the interpretation of a warm-temperature or subtropical climate at the time of deposition. The megafossil assemblage includes pinnae of the aquatic fern Marsilea, never before described from the fossil record. Variations in the species composition of the polynomorph assemblages show that several plant communities existed in succession at the site. These varied from pond or marsh types to mature forests.

  14. The Formation of Sedimentary Strata on Continental Margins

    DTIC Science & Technology

    1997-09-30

    provides data needed to understand strata formation and allows specifically for better interpretation of long cores recording the environmental ... history of the Eel margin. Because much of the insight gained about strata formation is generic in nature, this work interfaces at the short and

  15. Identification of canopy strata in Allegheny hardwood stands

    Treesearch

    David W. McGill; Stephen B. Jones; Christopher A. Nowak

    1995-01-01

    Allegheny hardwood stands typically develop vertical canopy layers, or strata, due to differential species-specific growth rates and tolerance to shade. Across the Allegheny Plateau, black cherry dominates the main canopy, while sugar maple, American beech, and red maple are relegated to subcanopy strata.

  16. Strata mechanics of hydraulic sub-level coal mining

    SciTech Connect

    Jeremic, M.L.

    1982-06-01

    Strata mechanics have been studied by monitoring and observing underground mines, and by means of digital and physical models. On the basis of these integrated investigations three principal phenomena have been evaluated: Coal strata are displaced by roof movement along planes of stratification and differential shearing of coal pillars, and floor strata mainly by heave deformations. Within sub-level structures are stress-concentration zones, stress-relaxed zones with pushes of abutment stress of more than 50 m, and the influence of mining stresses for 150-300m. Bed separation and sagging, and strata breaks, are caused by caving of the immediate roof by block rotation, and the main roof by block crushing. Strata mechanics of sub-level hydraulic coal mining still are not well understood and require further investigation.

  17. Strata at Base of Mount Sharp

    NASA Image and Video Library

    2015-10-08

    A view from the Kimberly formation on Mars taken by NASA Curiosity rover. The strata in the foreground dip towards the base of Mount Sharp, indicating the ancient depression that existed before the larger bulk of the mountain formed. The colors are adjusted so that rocks look approximately as they would if they were on Earth, to help geologists interpret the rocks. This "white balancing" to adjust for the lighting on Mars overly compensates for the absence of blue on Mars, making the sky appear light blue and sometimes giving dark, black rocks a blue cast. This image was taken by the Mast Camera (Mastcam) on Curiosity on the 580th Martian day, or sol, of the mission. Malin Space Science Systems, San Diego, built and operates Curiosity's Mastcam. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, built the rover and manages the project for NASA's Science Mission Directorate, Washington. http://photojournal.jpl.nasa.gov/catalog/PIA19839

  18. Evaporites and strata-bound tungsten mineralization

    SciTech Connect

    Ririe, G.T. )

    1989-02-01

    Discoidal gypsum crystal cavities occur in quartzites that host varying amounts of strata-bound scheelite mineralization near Halls Creek in Western Australia. The host quartzites have been regionally metamorphosed to greenschist facies and are contained within a Middle Proterozoic sequence that includes pelites, mafic and felsic volcanics, and volcaniclastic rocks. Textural, fluid inclusion, and oxygen isotope data indicate that scheelite was present in the host quartzites prior to regional metamorphism. The presence of crystal cavities after gypsum in the quartzites implies an evaporitic origin for this sequence. The continental-sabkha playa basins of the Mojave Desert, California, are suggested to be possible modern analogs-e.g., Searles Lake, where the tungsten content is up to 70 ppm WO{sub 3} in brines and 118 ppm in muds, and exceeds the amount of tungsten in all known deposits in the United States. Metamorphism of a continental evaporitic sequence containing tungsten could produce an assemblage of rocks very similar to those reported from several stratabound tungsten deposits. Some of these, such as at Halls Creek, may be related to original accumulations of tungsten in nonmarine evaporitic environments.

  19. Geochronology of Early Eocene strata, Baja California

    SciTech Connect

    Flynn, J.J.; Cipolletti, R.M.

    1985-01-01

    Recent discoveries clearly indicate a Wasatchian (Early Eocene) land mammal age for fossil vertebrates from the Punta Prieta area, Baja California North, Mexico. This fauna provides a rare test for discriminating the temporal significance of mammalian faunas over a broad geographic area. The authors sampled intertonguing, fossiliferous terrestrial and marine strata for paleomagnetic and biostratigraphic analyses to provide an independent age determination for the Punta Prieta area mammal fauna. The marine macroinvertebrate assemblage is most likely upper Meganos to lower Capay West Coast Molluscan Stage based on the temporal ranges of all the taxa; also, none of the taxa occur in pre-Meganos stages. Two genera of planktonic forams indicate a probably Eocene age. They sampled seventeen paleomagnetic sites over 50 meters in the terrestrial mammal-bearing section, and thirteen sites over 25 meters in the marine section. The entire terrestrial sequence is reversely magnetized; initial results indicate the marine sequence probably also is reversely magnetized. Based on all the available biochronologic evidence this reversed sequence most likely should be correlated with the long reversed polarity Chron C24R. Clarkforkian to Early Wasatchian faunas in Wyoming also are associated with Chron C24R. All the available biostratigraphic and magnetostratigraphic evidence strongly supports an Early Eocene age for the Punta Prieta mammalian fauna and temporal equivalence of the Punta Prieta Wasatchian fauna with Wasatchian faunas from the Western United States. Land mammal ages are synchronous and applicable across broad geographic areas.

  20. Palynology of the Vermillion Creek coal bed and associated strata

    SciTech Connect

    Nichols, D.J.

    1987-01-01

    Fifty-four species of spores, pollen, fungi, and algal palynomorphs were identified from the Vermillion Creek coal bed and associated strata, including underlying and overlying deposits and partings within the coal. The stratigraphic distribution and relative abundances of these plant microfossils were determined in samples from three cores. The palynomorph assemblage, which is late early Eocene in age, includes 8 species of pterophyte spores, 4 species of gymnosperm pollen, 39 species of angiosperm pollen, 2 species of algal coenobia or cysts, and 1 species of fungal spore. The assemblage is dominated by the pollen species Platycarya paltycaryoides and Arecipites tenuiexinous. Ten species appear to have biostratigraphic importance, based on their stratigraphic ranges in the Rocky Mountain region. The record of their occurrence in a well-dated stratigraphic section is a contribution to Tertiary biostratigraphy in the central Rockies. Palynologic evidence supplements stratigraphic, sedimentologic, geochemical, coal petrographic and other paleontologic evidence on the nature of the depositional environment. The Vermillion Creek coal was deposited in a paludal environment adjacent to a nonsaline lacustrine system. Evidence from botanical affinities of palynomorph species and habitats of living relatives indicates that the region had a moist subtropical climate in late early Eocene time.

  1. Investigation of deep permeable strata in the permian basin for future geothermal energy reserves

    SciTech Connect

    Erdlac, Richard J., Jr.; Swift, Douglas B.

    1999-09-23

    This project will investigate a previously unidentified geothermal energy resource, opening broad new frontiers to geothermal development. Data collected by industry during oil and gas development demonstrate deep permeable strata with temperatures {ge} 150 C, within the optimum window for binary power plant operation. The project will delineate Deep Permeable Strata Geothermal Energy (DPSGE) assets in the Permian Basin of western Texas and southeastern New Mexico. Presently, geothermal electrical power generation is limited to proximity to shallow, high-temperature igneous heat sources. This geographically restricts geothermal development. Delineation of a new, less geographically constrained geothermal energy source will stimulate geothermal development, increasing available clean, renewable world energy reserves. This proposal will stimulate geothermal reservoir exploration by identifying untapped and unrealized reservoirs of geothermal energy. DPSGE is present in many regions of the United States not presently considered as geothermally prospective. Development of this new energy source will promote geothermal use throughout the nation.

  2. The Strata-1 Experiment on Microgravity Regolith Segregation

    NASA Astrophysics Data System (ADS)

    Fries, M.; Abell, P.; Brisset, J.; Britt, D.; Colwell, J.; Durda, D.; Dove, A.; Graham, L.; Hartzell, C.; John, K.; Leonard, M.; Love, S.; Sanchez, D. P.; Scheeres, D. J.

    2016-08-01

    The Strata-1 experiment exposes four regolith simulants to microgravity for an extended period to study regolith dynamics on small bodies. The experiment is currently operational on the International Space Station for a one-year mission.

  3. Relation of Middle and Late Triassic strata of N-C Nevada to contemporaneous strata of southern Nevada and Utah

    SciTech Connect

    Elison, M.W.

    1993-04-01

    Middle and Late Triassic shelf strata in north-central Nevada comprising dominantly carbonate rocks of the Star Peak Group and overlying siliciclastic and carbonate rocks are overlain tectonically by predominantly siliciclastic basinal strata. Late Triassic slope strata are preserved in the East and Humboldt Ranges. At present, these Triassic rocks are separated from contemporaneous deposits of Utah by roughly 300 km over which time-equivalent ( ) strata are limited to a small, isolated outcrop near Currie, NV. Mesozoic and Cenozoic tectonics and widespread absence of Triassic rocks immediately to the east complicate the relation between the north-central Nevada section and Triassic rocks of southern Nevada and Utah. The gap in Triassic rocks may have resulted from erosion of intervening strata or from tectonic separation of originally contiguous stratal sequences. Some depositional facies of the shelf uniformly cover the preserved outcrop area and do not constrain the scale of the depositional system. Where facies variations are present, they suggest sediment sources to the east and north and deeper water to the west. Facies patterns, however, were influenced by local tectonics and changes in sediment source and supply. Late Triassic strata of N-C Nevada probably are the shallow-marine equivalents of fluvial and lacustrine rocks to the east. Local tectonics and changes in sediment influx require caution regarding interpretation of the original proximity of preserved stratal sequences.

  4. Perspective on the sequence stratigraphy of continental strata

    SciTech Connect

    Shanley, K.W. ); McCabe, P.J. )

    1994-04-01

    This report is the result of a working group on continental sequence stratigraphy that was set up at the 1991 NUNA conference in Banff, Canada. To data, sequence stratigraphic concepts have been applied mainly to the marine realm, but unconformity-bounded units have long been recognized in nonmarine strata. Successful application of sequence stratigraphic concepts to continental strata requires careful consideration of controls on base level and sediment supply. As with shallow marine environments, relative sea level can be considered as the stratigraphic as well as the geomorphic base level for coastal nonmarine settings. Farther inland, stratigraphic base level, which determines accomodation space, is more complex and takes various forms, such as the graded profile for fluvial strata, groundwater tables for some eolian strata, and lake level for some intermontane sediments. Sediment supply is also generally a more complex variable for nonmarine environments than in the marine realm because of the proximity to the source area. The influence of climate and tectonism on sediment supply can clearly be seen in many continental sediments. Although in its infancy, sequence stratigraphy concepts have been applied to a wide variety of continental settings in attempts to explain variations in facies architecture. Future advances in this field promise tools for more precise correlation of nonmarine strata and better prediction of the location and geometry of facies from a limited knowledge of the stratigraphic relationships within a basin. This would be useful in the exploration for fluvial and eolian sandstone reservoirs and coalbeds. 135 refs., 13 figs.

  5. Short-term dynamics of second-growth mixed mesophytic forest strata in West Virginia

    Treesearch

    Cynthia C. Huebner; Steven L. Stephenson; Harold S. Adams; Gary W. Miller

    2007-01-01

    The short-term dynamics of mixed mesophytic forest strata in West Virginia were examined using similarity analysis and linear correlation of shared ordination space. The overstory tree, understory tree, shrub/vine, and herb strata were stable over a six year interval, whereas the tree seedling and sapling strata were unstable. All strata but the shrub/vine and tree...

  6. Inventory of Neoproterozoic and Paleozoic strata in Sonora, Mexico

    USGS Publications Warehouse

    Stewart, John H.; Poole, Forrest G.

    2002-01-01

    This compilation is an inventory of all known outcrops of Neoproterozoic and Paleozoic strata in Sonora, Mexico. We have not attempted an interpretation of the regional stratigraphic or structural setting of the strata. Brief summaries of the stratigraphic setting of the Sonora rocks are given in Poole and Hayes (1971), Rangin (1978), Stewart and others (1984, 1990), and Poole and Madrid (1986; 1988b). More specific information on the setting of strata of specific ages are given by Stewart and others (2002) for the Neoproterozoic and Cambrian; by Poole and others (1995a) for Ordovician shelf strata; by Poole and others (1995b) for Ordovician deep-water openbasin strata; by Poole and others (1997, 1998, 2000a) for Silurian strata; and by Poole and others (2000a) for Mississippian strata. Other reports that discuss regional aspects of Paleozoic stratigraphy include López-Ramos (1982), Peiffer-Rangin, (1979, 1988), Pérez-Ramos (1992), and Stewart and others (1997, 1999a). Structurally, the major Paleozoic feature of Sonora is the Sonora allochthon, consisting of deep-water (eugeoclinal) strata emplaced in the Permian over shelf (miogeoclinal) deposits (Poole and others, 1995a,b; Poole and Perry, 1997; 1998). The emplacement structure is generally considered to be a major Permian continental margin thrust fault that emplaced the deep-water rocks northward over shelf (miogeoclinal) deposits. An alternate interpretation has been presented by Stewart and others (2002). He proposed that the emplacement of the Sonora allochthon was along a major Permian transpressional structure that was primarily a strike-slip fault with only a minor thrust component . The Mojave-Sonora megashear has been proposed to disrupt Neoproterozoic and Paleozoic trends in Sonora. This feature is a hypothetical, left-lateral, northwest-striking fault extending across northern Sonora and the southwestern United States (Silver and Anderson, 1974; Anderson and Schmidt, 1983). It is proposed to have

  7. Reservoir potential in Lower Devonian strata of Illinois

    SciTech Connect

    Whitaker, S.T. )

    1989-08-01

    Lower Devonian strata have considerable potential for hydrocarbon reserves in the Illinois basin; however, there has not yet been a major exploration effort for Lower Devonian reservoirs in the basin, nor has an adequate model been developed to explain distribution of these reservoirs. Due to the lack of exploration, production from these strata is presently limited to a few fields in south-central and southwestern Illinois. A review of data available at the Illinois State Geological Survey indicates that most Lower Devonian production in Illinois is from dolomitized cherty limestones in the Clear Creek Formation and Grassy Knob Chert. Minor production has also been noted in similar facies in the Bailey Limestone. Reservoir development within these strata is caused by dolomitization of slightly porous limestone beds and occurs in proximity to the beds' subcrop at the sub-Kaskaskia (pre-Middle Devonian) unconformity. The best reservoir development appears to be along paleotopographic highs on the Lower Devonian surface. Traps are most commonly formed where porous dolomitic beds, truncated at the sub-Kaskaskia unconformity are underlain by tight cherty limestones and overlain by tight Middle Devonian carbonates. Traps may also be formed downdip from porosity truncations where trends of porous Lower Devonian strata coincide with structural closures. The geometry and distribution of known reservoirs and traps in Lower Devonian carbonates indicate there may be several productive fairways in the basin. Exploration for and exploitation of these plays will depend on an increased understanding of Lower Devonian strata utilizing exploration models such as the one presented here.

  8. Coal and coal-bearing strata: recent advances

    SciTech Connect

    Scott, A.C.

    1987-01-01

    This volume contains keynote papers presented at the International Symposium on Coal and Coal-bearing Strata held at the University of London, April 1986. The authors reviewed progress in their fields over the past 15 years. Nine keynote lectures plus seven other invited contributions by experts in geology, geochemistry, sedimentology and biology are included in the volume. Coal, a major fossil fuel, is of broad interest to geologists and technological professionals alike. Topics in this volume include the formation of peat, coalification, coal geochemistry, palaeobotanical and palynological studies, sedimentology, coal exploration, oil-prone coals, and numerous coal basins. This volume is of interest not only to workers in the coal, oil, and gas industries, but also to survey geologists, lecturers, and students alike who are concerned with recent advances in the study of coal and coal-bearing strata.

  9. Sequence stratigraphic framework of Neogene strata in offshore Nigeria

    SciTech Connect

    Pacht, J.A.; Bowen, B.E.; Hall, D.J.

    1996-08-01

    The western portion of the Nigerian continental margin (Dahomey Basin) exhibits stable to moderately unstable progradation. Systems tracts are similar to those described by Vail for stable progradational margins. In contrast, strata off the central and eastern portions of the Nigerian coast (Niger Delta Complex) exhibit highly unstable progradation, and systems tracts are similar to those in Neogene strata of the offshore Gulf of Mexico. Lowstand basin floor fans in both areas are defined by a well-developed upper reflection. This reflection downlaps along the sequence boundary or abuts against the downthrown side of a growth fault surface. Most lower lowstand (slope fan) strata exhibit discontinuous to semi-continuous subparallel reflections. However, this systems tract also contains channel complexes characterized by chaotic bedding with small bright spots and less common large channels, which exhibit concave-upward reflections. In the western portion of the study area, lower lowstand deposits commonly pinch out on the slope. Deposition occurred largely from point sources. In contrast, contemporaneous shallow-water facies are developed in lower lowstand systems tracts in the Niger Delta Complex. Deposition occurred along a line source. Large amplitude anomalies in the upper lowstand (prograding wedge) suggest well-developed sheet sands occur in shallow-water and deep-water in the Niger Delta complex. However, in the Dahomey Basin there is little evidence of deep-water sands in this interval. The transgressive and highstand systems tracts are usually very thin in outer shelf to basin floor strata in both areas. Both the Dahomey Basin and Niger Delta Complex exhibit different stratigraphic geometries, and therefore, require different exploration strategies.

  10. Correlations among stand ages and forest strata in mixed-oak forests of southeastern Ohio

    Treesearch

    P. Charles Goebel; David M. Hix

    1997-01-01

    Many models of landscape ecosystem development, as well as of forest stand dynamics, are based upon spatial and temporal changes in the species composition and structure of various forest strata. However, few document the interrelationships among forest strata, or the response of different strata to alterations of natural disturbance regimes. To examine how...

  11. Geospatial Database for Strata Objects Based on Land Administration Domain Model (ladm)

    NASA Astrophysics Data System (ADS)

    Nasorudin, N. N.; Hassan, M. I.; Zulkifli, N. A.; Rahman, A. Abdul

    2016-09-01

    Recently in our country, the construction of buildings become more complex and it seems that strata objects database becomes more important in registering the real world as people now own and use multilevel of spaces. Furthermore, strata title was increasingly important and need to be well-managed. LADM is a standard model for land administration and it allows integrated 2D and 3D representation of spatial units. LADM also known as ISO 19152. The aim of this paper is to develop a strata objects database using LADM. This paper discusses the current 2D geospatial database and needs for 3D geospatial database in future. This paper also attempts to develop a strata objects database using a standard data model (LADM) and to analyze the developed strata objects database using LADM data model. The current cadastre system in Malaysia includes the strata title is discussed in this paper. The problems in the 2D geospatial database were listed and the needs for 3D geospatial database in future also is discussed. The processes to design a strata objects database are conceptual, logical and physical database design. The strata objects database will allow us to find the information on both non-spatial and spatial strata title information thus shows the location of the strata unit. This development of strata objects database may help to handle the strata title and information.

  12. 43 CFR 2806.32 - How does BLM determine the population strata served?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How does BLM determine the population... does BLM determine the population strata served? (a) BLM determines the population strata served as follows: (1) If the site or facility is within a designated RMA, BLM will use the population strata of the...

  13. 43 CFR 2806.32 - How does BLM determine the population strata served?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false How does BLM determine the population... does BLM determine the population strata served? (a) BLM determines the population strata served as follows: (1) If the site or facility is within a designated RMA, BLM will use the population strata of the...

  14. 43 CFR 2806.32 - How does BLM determine the population strata served?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How does BLM determine the population... does BLM determine the population strata served? (a) BLM determines the population strata served as follows: (1) If the site or facility is within a designated RMA, BLM will use the population strata of the...

  15. 43 CFR 2806.32 - How does BLM determine the population strata served?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How does BLM determine the population... does BLM determine the population strata served? (a) BLM determines the population strata served as follows: (1) If the site or facility is within a designated RMA, BLM will use the population strata of the...

  16. Sandstone units of the Lee Formation and related strata in eastern Kentucky

    USGS Publications Warehouse

    Rice, Charles L.

    1984-01-01

    sandstone and conglomerate. The Dark Ridge and Hensley Members are mostly shale, siltstone, thin-bedded silty sandstone, and coal. The lower three of these members, the Pinnacle Overlook, Chadwell, and White Rocks Sandstone, are assigned to the Upper Mississippian Series because they intertongue with marine reddish or greenish shale and siltstone of the Pennington Formation or equivalent strata that contain a Late Mississippian fauna. The overlying quartzose sandstone members of the Lee commonly have coalified plant remains and impressions of plants and are Early to Middle Pennsylvanian in age; they are generally associated with terrestrial shale and siltstone containing coal beds and pinch out eastward into subgraywacke, siltstone, and shale. Although marine members commonly are bimodal, resultant transport directions for both marine and terrestrial members are southwesterly as determined by crossbedding. Thickness variations of the Middlesboro Member in the Cumberland overthrust sheet suggest that it represents tills of at least three major southwesterly trending paleovalleys. Thickness variations of the Bee Rock Sandstone Member east of Rocky Face fault and the combined Bee Rock and Naese Sandstone Members west of Rocky Face fault suggest that these members represent tills of at least two major southwesterly trending paleovalleys. East of Rocky Face fault, the Bee Rock is generally the uppermost member of the Lee; west of the fault, the overlying Naese is at the top. The Naese may range in age from Early to Middle Pennsylvanian and is partly or wholly equivalent to the Rockcastle Sandstone member of the Lee Formation in the area of the Pottsville Escarpment. The Mississippian-Pennsylvanian systemic boundary in the area of the Cumberland overthrust sheet in most places has been placed at an unconformity at the base of the Middlesboro Member; locally it is projected at the base of shales of the underlying Dark Ridge Member or equivalent strata in the Penningto

  17. The Strata-l Experiment on Microgravity Regolith Segregation

    NASA Technical Reports Server (NTRS)

    Fries, M.; Abell, P.; Brisset, J.; Britt, D.; Colwell, J.; Durda, D.; Dove, A.; Graham, L.; Hartzell, C.; John, K.; Leonard, M.; Love, S.; Sanchez, D. P.

    2016-01-01

    The Strata-1 experiment studies the segregation of small-body regolith through long-duration exposure of simulant materials to the microgravity environment on the International Space Station (ISS). Many asteroids feature low bulk densities, which implies high values of porosity and a mechanical structure composed of loosely bound particles, (i.e. the "rubble pile" model), a prime example of a granular medium. Even the higher-density, mechanically coherent asteroids feature a significant surface layer of loose regolith. These bodies will evolve in response to very small perturbations such as micrometeoroid impacts, planetary flybys, and the YORP effect. A detailed understanding of asteroid mechanical evolution is needed in order to predict the surface characteristics of as-of-yet unvisited bodies, to understand the larger context of samples from sample return missions, and to mitigate risks for both manned and unmanned missions to asteroidal bodies. Due to observation of rocky regions on asteorids such as Eros and Itokawa, it has been hypothesized that grain size distribution with depth on an asteroid may be inhomogeneous: specifically, that large boulders have been mobilized to the surface. In terrestrial environments, this size-dependent sorting to the surface of the sample is called the Brazil Nut Effect. The microgravity and acceleration environment on the ISS is similar that of a small asteroid. Thus, Strata-1 investigates size segregation of regolith in an environment analogous to that of small bodies. Strata-1 consists of four regolith simulants in evacuated tubes, as shown in Figure 1 (Top and Middle). The simulants are (1) a crushed and sieved ordinary chondrite meteorite to simulate an asteroidal surface, (2) a carbonaceous chondrite simulant with a mixture of fine and course particles, and two simplified silicate glass simulants; (3) one with angular and (4) another with spherical particles. These materials were chosen to span a range of granular

  18. Field Testing the STRATA Ground Penetrating Radar for Mars

    NASA Astrophysics Data System (ADS)

    Williams, K. K.; Grant, J. A.; Leuschen, C. J.; Schutz, A. E.

    2005-12-01

    With the MARSIS and SHARAD orbital radar sounders now in operation at and in transit to Mars, respectively, radar investigation of the deep structure of Mars down to several kilometers is underway. By contrast, optical and thermal instruments both in orbit and on the surface have provided information about the top several millimeters and the Mars Exploration Rovers have dug to several cm with their wheels. Nevertheless, little is known about the shallow subsurface of Mars to depths of meters except at locations where continuation of outcrop into the subsurface can be extrapolated. As the methods for exploring Mars evolve, the utility of ground penetrating radar (GPR) for investigating the shallow subsurface of that planet is being considered. GPR has been used for several decades on Earth as a non-invasive tool for studying subsurface structures and stratigraphy for applications in geology, engineering, and archaeology. The STRATA GPR for Mars has been developed as an adaptable, low power, compact, rover-mounted instrument capable of penetrating 10-20 m to reveal subsurface information. Field-testing of this instrument has taken place in volcanic, cratered, permafrost, and deltaic settings, and data collected at 400 MHz possess vertical resolutions of a few cm, sufficient to interpret the subsurface geologic setting. Results from the permafrost environment showed detection of buried massive ground ice as well as the base of the active layer. GPR analysis of this ice distribution was confirmed by resistivity measurements. The fine vertical resolution and good penetration in a variety of geologic settings show that the STRATA instrument provides data quality indistinguishable from commercial systems used on Earth. Most recently, the STRATA instrument has been tested in aeolian and filled crater environments. Data were collected over a sand dune overlying a basalt lava flow near St. Anthony, ID, and at the Campo del Cielo impact crater field in Chaco Province

  19. Distribution and Origin of Iridium in Upper Triassic-Lower Jurassic Continental Strata of the Fundy, Deerfield and Hartford Basins, Newark Supergroup

    NASA Astrophysics Data System (ADS)

    Tanner, L. H.; Kyte, F. T.

    2015-12-01

    To date, elevated Ir levels in continental sediments proximal to the Triassic-Jurassic boundary (TJB) have been reported only from Upper Triassic strata of the Newark and Fundy basins, below the basal extrusive units of the Central Atlantic Magmatic Province. We report here the first occurrence of elevated Ir above the oldest volcanic units, as well as additional horizons of Ir enrichment from other basins of the Newark Supergroup. In the Fundy Basin (Nova Scotia, Canada), lacustrine sediments of the Scots Bay Member of the McCoy Brook Formation that directly overlie the North Mountain Basalt contain Ir up to 413 pg/g in fish-bearing strata very close to the palynological TJB. Higher in the formation the strata lack significant Ir enrichment. Similarly, sedimentary strata from between flows of North Mount Basalt show no Ir appreciable enrichment. The Deerfield Basin (Massachusetts) extension of the Hartford Basin contains only one CAMP extrusive unit, the Lower Jurassic Deerfield Basalt. Very modest Ir enrichment, up to 90 pg/g, occurs in the Fall River Beds of the Sugarloaf Formation, several meters below the basalt, and up to 70 pg/g in the Turners Falls Formation less than 2 meters above the basalt. The uppermost New Haven Formation (Upper Triassic) at the Silver Ridge locality (Guilford, CT) in the Hartford Basin contains abundant plant debris, but no evidence of elevated Ir. At the Clathopteris locality to the north (Holyoke, MA), potentially correlative strata that are fine grained and rich in plant remains have Ir enriched to 542 pg/g, an order of magnitude higher than in the coarser-grained strata in direct stratigraphic contact. The high-Ir beds also have elevated REEs relative to other Hartford Basin samples, although there is no evidence of HREE enrichment. We consider the basalts of the Central Atlantic Magmatic Province, widely accepted as the driver of Late Triassic extinctions, as the origin of the elevated Ir levels in the Newark Supergroup.

  20. Baseline characteristics of different strata of astronaut corps

    NASA Technical Reports Server (NTRS)

    Hamm, Peggy B.; Pepper, L. J.

    1993-01-01

    The Longitudinal Study of Astronaut Health (LSAH) is an epidemiological study designed to study the effects of the occupational exposures incurred by astronauts in health outcomes and changes in physiological variables. Between 1959 and 1991, 195 individuals were selected for the program. The medical standards for selection have remained essentially unchanged since the Mercury Program, but the range and stringency of these criteria have been modified. Demographic and physiological variables identified during the selection year are examined for various strata of the Astronaut Corps. Specifically, age, sex, race, education, usual occupation, military affiliation, medical history, family medical history, visual and hearing measurements, physical exam variables, and specific laboratory values are investigated. Differences are examined in astronauts for the following criteria: (1) were selected prior to 1970 (n = 73) versus those selected after 1970 (n = 122); (2) have flown multiple missions versus those who have flown less than two missions; (3) have walked in space versus all others; (4) have more than 500 hours of mission time versus all others; and (5) have gone to the Moon versus all others. Length of time served in the Astronaut Corps is examined for each of these strata.

  1. Segmentation of skin strata in reflectance confocal microscopy depth stacks

    NASA Astrophysics Data System (ADS)

    Hames, Samuel C.; Ardigò, Marco; Soyer, H. Peter; Bradley, Andrew P.; Prow, Tarl W.

    2015-03-01

    Reflectance confocal microscopy is an emerging tool for imaging human skin, but currently requires expert human assessment. To overcome the need for human experts it is necessary to develop automated tools for automatically assessing reflectance confocal microscopy imagery. This work presents a novel approach to this task, using a bag of visual words approach to represent and classify en-face optical sections from four distinct strata of the skin. A dictionary of representative features is learned from whitened and normalised patches using hierarchical spherical k-means. Each image is then represented by extracting a dense array of patches and encoding each with the most similar element in the dictionary. Linear discriminant analysis is used as a simple linear classifier. The proposed framework was tested on 308 depth stacks from 54 volunteers. Parameters are tuned using 10 fold cross validation on a training sub-set of the data, and final evaluation was performed on a held out test set. The proposed method generated physically plausible profiles of the distinct strata of human skin, and correctly classified 81.4% of sections in the test set.

  2. Prehistory of Zodiac Dating: Three Strata of Upper Paleolithic Constellations

    NASA Astrophysics Data System (ADS)

    Gurshtein, Alex A.

    A pattern of archaic proto-constellations is extracted from Aratus' "The Phaenomena" didactic poem list according to a size criterion elaborated earlier, and their symbolism is analyzed. As a result of this approach three celestial symbolical strata are discovered to be probably a reflection of the symbols for the Lower, the Middle and the Upper Worlds; the Under-World creatures have a water character, the Middle World ones are mostly anthropomorphic and flying beings are for the Upper World. The strata excerpted from Aratus' sky seems to be in agreement with the well-known Babylonian division into three god pathways for Ea (Enki), Anu and Enlil. There is a possibility of dating the pattern discovered because of precession's strong influence as far back as 16 thousand years, the result being supported by the comparison of different star group mean sizes. The archaic constellation pattern under consideration is a reasonable background of symbolical meanings for the first Zodiacal generation quartet (7.5 thousand years old) examined by the author previously. The enormous size of the Argo constellation (Ship of Argo and his Argonauts) as well as the large sizes of other southern constellations are explained as due to the existence of an accumulation zone near the South celestial pole. Some extra correlations between the reconstruction proposed and cultural data available are discussed. The paper is the second part of the investigation "On the Origin of the Zodiacal constellations" published in Vistas in Astronomy, vol.36, pp.171-190, 1993.

  3. Middle Jurassic strata link Wallowa, Olds Ferry, and Izee terranes in the accreted Blue Mountains island arc, northeastern Oregon

    SciTech Connect

    White, J.D.L. ); Vallier, T. ); Stanley, G.D. Jr. ); Ash, S.R. ); White, D.L.

    1992-08-01

    Middle Jurassic strata atop the Wallowa terrane in northeastern Oregon link the Wallowa, Izee, and Olds Ferry terranes as related elements of a single long-lived and complex oceanic feature, the Blue Mountains island arc. Middle Jurassic strata in the Wallowa terrane include a dacitic ash-flow deposit and contain fossil corals and bivalves of North American affinity. Plant fossils in fluvial sandstones support a Jurassic age and indicate a seasonal temperate climate. Corals in a transgressive sequence traditionally overlying the fluvial units are of Bajocian age and are closely related to endemic varieties of the Western Interior embayment. They are unlike Middle Jurassic corals in other Cordilleran terranes; their presence suggests that the Blue Mountains island arc first approached the North American craton at high paleolatitudes in Middle Jurassic time. The authors consider the Bajocian marine strata and underlying fluvial volcaniclastic units to be a basin-margin equivalent of the Izee terrane, a largely Middle Jurassic (Bajocian) succession of basinal volcaniclastic and volcanic rocks known to overlie the Olds Ferry and Baker terranes.

  4. Reliability Considerations in 3D Stacked Strata Systems

    NASA Astrophysics Data System (ADS)

    Pozder, Scott; Jain, Ankur; Jones, Robert; Huang, Zhihong; Justison, Patrick; Chatterjee, Ritwik

    2009-06-01

    The bonding of multiple silicon strata to form stacked circuits with high bandwidth connections, increased circuit densities, decreased latency and the capability to stack disparate technologies is increasingly gaining interest in the microelectronics industry. Stacking has been demonstrated using bom dielectric-to-dielectric and metal-to-metal bonds for die and wafer stratum bonding. The considerable thermal, mechanical and electromigration reliability challenges resulting from such bonding has been the focus of some recently reported work. In mis paper, the bond reliability of various bonding types, including wafer-to-wafer dielectric bond, die-to-wafer Cu/Sn-to-Cu bond and a simultaneous organic adhesive with Cu/Sn-to-Cu bond is discussed. Thermomechanical and electromigration characterization of the die-to-wafer 3D structures is also discussed. Results indicate that the intrinsic reliability of these structures can be as robust as current 2D technologies.

  5. Shales and other argillaceous strata in the United States

    SciTech Connect

    Gonzales, S.; Johnson, K.S.

    1985-03-01

    This report presents detailed geologic and hydrologic data that describe shales and other argillaceous rocks; data are from the open literature. These data are intended to be used in the future to aid in assessment of various strata and their potential for repository siting. No observations, conclusions, or recommendations are made by the authors of this report relative to the suitability of various argillaceous rocks for waste disposal. There are, however, other published reports that contain technical data and evaluative statements regarding the suitability of various argillaceous rocks for repository siting. Where appropriate, the authors of this report have referenced this previously published literature and have summarized the technical data. 838 refs., 121 figs., 6 tabs.

  6. Resistivity imaging of strata and faults in Bangladesh

    NASA Astrophysics Data System (ADS)

    Hosain, A.; Steckler, M. S.; Akhter, S. H.

    2015-12-01

    The Ganges-Brahmaputra-Meghna Delta, the largest in the world, is subject to deformation by active tectonics and dynamic river systems. It lies near the juncture of the Indian, Eurasian and Burmese plates and is being overthrust by both the Shillong Massif and the Indo-Burman Ranges. There are multiple major and minor active faults in Bangladesh, many of which are buried by the sedimentation. For example, the Madhupur tract is a Pleistocene upland in the middle part of Bengal Basin. Whether it is a passive interfluve of the river system or a tilted and tectonically uplifted block has been debated for decades. The Tippera Surface, in Comilla at the eastern part of the basin, is composed of uplifted and oxidized Holocene strata and overlies buried anticlines of the Indo-Burman fold belt. Furthermore, the rivers are subject to migrations, avulsions and other changes in course. The last major avulsion of the Brahmaputra River was only ~200 years ago. During the sea level fall in the last glaciation the major rivers created large incised valleys. In much of the exposed uplands there was the development of a weathered clay surface. This now forms a clay layer separating the Pleistocene and Holocene strata in large parts of Bangladesh. We use electrical resistivity surveying and hand-drilled borehole lithological data to better understand the subsurface discontinuities and structures. The resistivity system consists of an 84 electrode array powered by 2 car batteries and is capable of imaging lithologies to ~100m depth, similar to the depths of the boreholes used to calibrate the data. We extend our previous work on the western margin of the Madhupur Tract with additional lines on the eastern flank of Madhupur. Resistivity lines along the exposed Lalmai anticline in Comilla image the now tilted Holocene-Pleistocene clay layer. Additional lines along the subsurface continuation of the anticline provide additional information on the subsurface lithologies associated with

  7. Post-stratified estimation: with-in strata and total sample size recommendations

    Treesearch

    James A. Westfall; Paul L. Patterson; John W. Coulston

    2011-01-01

    Post-stratification is used to reduce the variance of estimates of the mean. Because the stratification is not fixed in advance, within-strata sample sizes can be quite small. The survey statistics literature provides some guidance on minimum within-strata sample sizes; however, the recommendations and justifications are inconsistent and apply broadly for many...

  8. New interpretation of the so-called Nubian strata in northeast Africa

    SciTech Connect

    Klitzsch, E.H.; Squyres, C.H.

    1988-08-01

    Stratigraphical interpretation of the so-called Nubian Sandstone of Egypt and northern Sudan have led to new ideas on the structural and paleogeographical development of northeast Africa. The strata formerly comprised under the term Nubian Sandstone include sediments from Cambrian to Paleocene age. Based on field work and paleontological investigations during the last 10 years, these strata can be subdivided into three major cycles, each characterizing a certain structural situation of northeast Africa. The first or Paleozoic cycle comprises strata of Cambrian to Early Carboniferous age. These strata were deposited during a period of generally northern dip of northeast Africa; continental sediments transported northward interfinger with marine strata resulting from southward transgressions. Sediments of the second cycle were deposited during and after Gondwana and northern continents collided, which caused updoming of large areas of Egypt and bordering areas to the west and east. As a result, most of Egypt became subject to erosion; transgressions remained near the present northern edge of the continent, and purely continental deposition took place in northern Sudan and bordering areas in Chad and Libya. The resulting strata are similar to the Karroo of East Africa. Strata of the third cycle were deposited after Pangea began to disintegrate. Northeast Africa now had a generally northern dip again, and consequently deposition was controlled - as during the first cycle - by northward drainage and southward transgressions. This last cycle began during Late Jurassic time.

  9. Fossil ghost ranges are most common in some of the oldest and some of the youngest strata

    PubMed Central

    Wills, M.A

    2007-01-01

    Biologists routinely compare inferences about the order of evolutionary branching (phylogeny) with the order in which groups appear in the fossil record (stratigraphy). Where they conflict, ghost ranges are inferred: intervals of geological time where a fossil lineage should exist, but for which there is no direct evidence. The presence of very numerous and/or extensive ghost ranges is often believed to imply spurious phylogenies or a misleadingly patchy fossil record, or both. It has usually been assumed that the frequency of ghost ranges should increase with the age of rocks. Previous studies measuring ghost ranges for whole trees in just a small number of temporal bins have found no significant increase with antiquity. This study uses a much higher resolution approach to investigate the gappiness implied by 1000 animal and plant cladograms over 77 series and stages of the Phanerozoic. It demonstrates that ghost ranges are indeed relatively common in some of the oldest strata. Surprisingly, however, ghost ranges are also relatively common in some of the youngest, fossil-rich rocks. This pattern results from the interplay between several complex factors and is not a simple function of the completeness of the fossil record. The Early Palaeozoic record is likely to be less organismically and stratigraphically complete, and its fossils—many of which are invertebrates—may be more difficult to analyse cladistically. The Late Cenozoic is subject to the pull of the Recent, but this accounts only partially for the increased gappiness in the younger strata. PMID:17652067

  10. Depositional Environment of Mio-Pliocene Siwalik Sedimentary Strata from the Darjeeling Himalayan Foothills, India: A Palynological Approach.

    PubMed

    More, Sandip; Paruya, Dipak Kumar; Taral, Suchana; Chakraborty, Tapan; Bera, Subir

    2016-01-01

    A rich and diverse palynoassemblage recovered from the Churanthi River section (26°53' 59.3" N, 88°34' 17.2" E), Darjeeling foothills Eastern Himalaya, has yielded 87 species assigned to 69 genera. The palynoassemblage is rich in angiosperm taxa (45.63%) followed by gymnosperms (0.45%), pteridophytes (18.49%) and fungal remains (23.88%). Based on their nearest living relatives, a wet evergreen to semi-evergreen forest under a humid tropical to sub-tropical environment during the Mio-Pliocene age has been suggested. A lot of angiosperms such as Palaeosantalaceaepites, Araliaceoipollenites, Malvacearampollis, Zonocostites, Neocouperipollis, Dicolpopollis, Palmidites, Palmaepollenites, isolated salt glands of mangrove plant leaves (Heliospermopsis) and Mediaverrunites type of fungal spores, along with ichnofossils like Planolites, Palaeophycus, Skolithos, Rosselia, Ophiomorpha and Teichichnus associated with rippled mudstone-siltstone suggest an environment strongly influenced by brackish water. Primary sedimentary structures in the associated strata indicate strong wave agitation common in shallow marine setting. Some high elevation components (5.14%) such as Alnipollenites, cf. Corylus (Betulaceae), Juglanspollenites, Engelhardtioipollenites (Juglandaceae), Quercoides, Cupuliferoidaepollenites, Lithocarpus, Castanopsis (Fagaceae), Abietineaepollenites (Pinaceae) represent hinterland vegetation possibly transported to the prograding deltaic coastline by the rivers. Reworked palynotaxa (Striatopodocarpites sp., Striatites sp., Faunipollenites sp., Circumstriatites sp., Crescentipollenites sp., Cuneatisporites sp., Parasaccites sp., Scheuringipollenites sp., Rhizomaspora sp., Marsupipollenites sp., Lophotriletes sp.) of Permian age have also been recorded in the palynoassemblage (11.55%) indicating the abundance of Permian Gondwana strata in the source area.

  11. Depositional Environment of Mio-Pliocene Siwalik Sedimentary Strata from the Darjeeling Himalayan Foothills, India: A Palynological Approach

    PubMed Central

    More, Sandip; Paruya, Dipak Kumar; Taral, Suchana; Chakraborty, Tapan; Bera, Subir

    2016-01-01

    A rich and diverse palynoassemblage recovered from the Churanthi River section (26°53' 59.3" N, 88°34' 17.2" E), Darjeeling foothills Eastern Himalaya, has yielded 87 species assigned to 69 genera. The palynoassemblage is rich in angiosperm taxa (45.63%) followed by gymnosperms (0.45%), pteridophytes (18.49%) and fungal remains (23.88%). Based on their nearest living relatives, a wet evergreen to semi-evergreen forest under a humid tropical to sub-tropical environment during the Mio-Pliocene age has been suggested. A lot of angiosperms such as Palaeosantalaceaepites, Araliaceoipollenites, Malvacearampollis, Zonocostites, Neocouperipollis, Dicolpopollis, Palmidites, Palmaepollenites, isolated salt glands of mangrove plant leaves (Heliospermopsis) and Mediaverrunites type of fungal spores, along with ichnofossils like Planolites, Palaeophycus, Skolithos, Rosselia, Ophiomorpha and Teichichnus associated with rippled mudstone-siltstone suggest an environment strongly influenced by brackish water. Primary sedimentary structures in the associated strata indicate strong wave agitation common in shallow marine setting. Some high elevation components (5.14%) such as Alnipollenites, cf. Corylus (Betulaceae), Juglanspollenites, Engelhardtioipollenites (Juglandaceae), Quercoides, Cupuliferoidaepollenites, Lithocarpus, Castanopsis (Fagaceae), Abietineaepollenites (Pinaceae) represent hinterland vegetation possibly transported to the prograding deltaic coastline by the rivers. Reworked palynotaxa (Striatopodocarpites sp., Striatites sp., Faunipollenites sp., Circumstriatites sp., Crescentipollenites sp., Cuneatisporites sp., Parasaccites sp., Scheuringipollenites sp., Rhizomaspora sp., Marsupipollenites sp., Lophotriletes sp.) of Permian age have also been recorded in the palynoassemblage (11.55%) indicating the abundance of Permian Gondwana strata in the source area. PMID:26930664

  12. Impact and Aqueous Strata in Holden Crater, Mars

    NASA Astrophysics Data System (ADS)

    Grant, J. A.; Irwin, R. P.; Grotzinger, J. P.; Milliken, R. E.; Tornabene, L. L.; McEwen, A. S.

    2007-12-01

    were deposited during a relatively short second wet phase. The aqueous strata in Holden crater indicates a more clement, wet climate characterized some of the Noachian Period and provide the first clear context for phyllosilicates in an alluvial/lacustrine environment. Emplacement of the beds comprising the lower unit likely requires stable wet conditions and a setting likely to preserve geochemical or lithological signatures related to habitability. Hence, the possibility of evaluating the changing potential for habitability over part of Noachian Mars makes Holden crater a priority for future landed missions.

  13. CarboCAT: A cellular automata model of heterogeneous carbonate strata

    NASA Astrophysics Data System (ADS)

    Burgess, Peter M.

    2013-04-01

    CarboCAT is a new numerical model of carbonate deposystems that uses a cellular automata to calculate lithofacies spatial distributions and hence to calculate the accumulation of heterogeneous carbonate strata in three dimensions. CarboCAT includes various geological processes, including tectonic subsidence, eustatic sea-level oscillations, water depth-dependent carbonate production rates in multiple carbonate factories, lateral migration of carbonate lithofacies bodies, and a simple representation of sediment transport. Results from the model show stratigraphically interesting phenomena such as heterogeneous strata with complex stacking patterns, laterally discontinuous subaerial exposure surfaces, nonexponential lithofacies thickness distributions, and sensitive dependence on initial conditions whereby small changes in the model initial conditions have a large effect on the final model outcome. More work is required to fully assess CarboCAT, but these initial results suggest that a cellular automata approach to modeling carbonate strata is likely to be a useful tool for investigating the nature and origins of heterogeneity in carbonate strata.

  14. Strata behavior at fully-mechanized coal mining and solid backfilling face.

    PubMed

    Yin, Wei; Chen, Zhiwei; Quan, Kai; Mei, Xiancheng

    2016-01-01

    Taking Ping Dingshan Coal Mine Group 12 as an example, this paper explains the system layout, key equipment and backfilling technology in detail. It probes into the characteristic of rock strata movement behavior and surface deformation above the gob area through in-site measurement method. The results show that as the overburden strata are effectively supported by the backfill body in mined out areas, there were no evident phenomena as first weighting or periodic weighting during mining process. Besides, influencing scope of advanced support pressure and the strata behavior degree were much smaller than that of the traditional methods of caving mining. Since overburden strata had been well supported by backfill body, it shows the posture of sinking slowly, only resulting in bending zone and minor fracture zone.

  15. Rational Use of Land Resource During the Implementation of Transportless System of Coal Strata Surface Mining

    NASA Astrophysics Data System (ADS)

    Gvozdkova, T.; Tyulenev, M.; Zhironkin, S.; Trifonov, V. A.; Osipov, Yu M.

    2017-01-01

    Surface mining and open pits engineering affect the environment in a very negative way. Among other pollutions that open pits make during mineral deposits exploiting, particular problem is the landscape changing. Along with converting the land into pits, surface mining is connected with pilling dumps that occupy large ground. The article describes an analysis of transportless methods of several coal seams strata surface mining, applied for open pits of South Kuzbass coal enterprises (Western Siberia, Russia). To improve land-use management of open pit mining enterprises, the characteristics of transportless technological schemes for several coal seams strata surface mining are highlighted and observed. These characteristics help to systematize transportless open mining technologies using common criteria that characterize structure of the bottom part of a strata and internal dumping schemes. The schemes of transportless systems of coal strata surface mining implemented in South Kuzbass are given.

  16. Strata-1: A Planetary Science Experiment on the Behavior of Asteroid Regolith in Microgravity

    NASA Astrophysics Data System (ADS)

    John, K. K.; Abell, P.; Brisset, J.; Britt, D.; Colwell, J.; Durda, D.; Dove, A.; Fries, M.; Graham, L.; Hartzell, C.; Leonard, M.; Love, S.; Sanchez, D. P.; Scheeres, D. J.

    2016-10-01

    Strata-1 is an experiment studying asteroid regolith in the microgravity environment of ISS. The prolonged microgravity and vibrational conditions of ISS are analogous to those on small Solar System bodies.

  17. Effects of mine strata thermal behavior and mine initial temperatures on mobile refuge alternative temperature

    PubMed Central

    Yantek, D.S.; Yan, L.; Bissert, P.T.; Klein, M.D.

    2017-01-01

    Federal regulations require the installation of refuge alternatives (RAs) in underground coal mines. Mobile RAs have a limited ability to dissipate heat, and heat buildup can lead to a life-threatening condition as the RA internal air temperature and relative humidity increase. The U.S. National Institute for Occupational Safety and Health (NIOSH) performed heat testing on a 10-person tent-type training RA and contracted ThermoAnalytics Inc. to develop a validated thermal simulation model of the tested RA. The model was used to examine the effects of the constant mine strata temperature assumption, initial mine air temperature, initial mine strata surface temperature (MSST), initial mine strata temperature at depth (MSTD) and mine strata thermal behavior on RA internal air temperature using 117 W (400 Btu/h) of sensible heat input per simulated miner. For the studied RA, when the mine strata temperature was treated as a constant, the final predicted RA internal air temperature was 7.1°C (12.8°F) lower than it was when the mine strata thermal behavior was included in the model. A 5.6°C (10.0°F) increase in the initial MSST resulted in a 3.9°C (7.1°F) increase in the final RA internal air temperature, whereas a 5.6°C (10°F) increase in the initial MSTD yielded a 1.4°C (2.5°F) increase in the final RA internal air temperature. The results indicate that mine strata temperature increases and mine strata initial temperatures must be accounted for in the physical testing or thermal simulations of RAs. PMID:28867830

  18. Evidence for long-term climate change in Upper Devonian strata of the central Appalachians

    USGS Publications Warehouse

    Brezinski, D.K.; Cecil, C.B.; Skema, V.W.; Kertis, C.A.

    2009-01-01

    precipitation that washed progressively higher amounts of terrestrial organic matter into the local marine environments. The late Famennian climate changes identified within the Appalachian basin strata have been recognizable globally, and appear to have had both positive and negative effects on the Earth's biota. Some marine groups exhibit sharp diversity drops or even extinction coincident with the maximum development of the late Famennian ice age. Conversely, terrestrial biota appears to have been more positively affected by the late Famennian increased wetness that accompanied this progressive climate change. Marked diversification and evolutionary innovation, which appear to coincide with this climatic deviation, can be recognized within terrestrial plant communities and early tetrapod amphibians. ?? 2009 Elsevier B.V. All rights reserved.

  19. Nutrient-limited biodegradation of PAH in various soil strata at a creosote contaminated site.

    PubMed

    Breedveld, G D; Sparrevik, M

    2000-01-01

    The effects of nutrient addition on the in situ biodegradation of polycyclic aromatic hydrocarbons in creosote contaminated soil were studied in soil columns taken from various soil strata at a wood preserving plant in Norway. Three samples were used: one from the topsoil (0-0.5 m), one from an organic rich layer (2-2.5 m) and one from the sandy aquifer (4.5-5 m). The addition of inorganic nitrogen and phosphorous stimulated the degradation of polycyclic aromatic hydrocarbons (PAHs) in the top soil and the aquifer sand. These two soils, which differed strongly in contamination levels, responded similarly to nutrient addition with the corresponding degradation of 4-ring PAHs. The ratio between available nitrogen (N) and phosphorous (P) might explain the degree of degradation observed for the 4-ring PAHs. However, the degree of degradation of 3-ring PAHs did not significantly increase after nutrient addition. An increase in the respiration rate, after nutrient addition, could only be observed in the topsoil. In the aquifer sand, 4-ring PAH degradation was not accompanied by an increase in the respiration rate or the number of heterotrophic micro-organisms. PAH degradation in the organic layer did not respond to nutrient addition. This was probably due to the low availability of the contaminants for micro-organisms, as a result of sorption to the soil organic matter. Our data illustrate the need for a better understanding of the role of nutrients in the degradation of high molecular weight hydrocarbons for the successful application of bioremediation at PAH contaminated sites.

  20. Complete exposure of Jurassic strata from the Newark Basin, New Jersey

    SciTech Connect

    Fedosh, M.S.

    1985-01-01

    Exploratory drilling in 1985 has been undertaken along the right-of-way of a proposed flood diversion tunnel in northern New Jersey. The 21.8 kilometer long tunnel route is across the strike of Late Triassic and Early Jurassic rocks of the Newark Basin in an area where rock exposures are few due to glaciation. Approximately 2400 meters of the 6300 meter thick northern portion of the Newark Basin is represented in rock cores. The uppermost 870 meters of Late Triassic strata have been drilled and show an increased percentage of gravel toward the Jurassic contact. Approximately 1620 meters of Early Jurassic strata have been drilled including the three Watchung basalt flows. The oldest basalt flow at the Triassic-Jurassic contact has undergone extensive faulting with high angle normal and reverse oblique slip faults extending into the underlying Triassic rocks. Lacustrine deposits sandwiched between the basalt flows are cyclic with the entire transgressive-regressive sequences up to 12 meters thick and deep water shales and algal mats up to 4 meters thick. What emerges for the first time is a continuous picture of the Newark Basin Jurassic strata. These strata, containing kerogen-rich layers, are some of the youngest found in any of the Mesozoic rift basins. These rock cores represent the western most Mesozoic strata which extend eastward to similar-aged deposits found in outer continental shelf drill holes.

  1. Hippocampal strata theta oscillations change their frequency and coupling during spatial learning.

    PubMed

    Hernández-Pérez, J Jesús; Gutiérrez-Guzmán, Blanca E; Olvera-Cortés, María E

    2016-11-19

    The theta rhythm is necessary for hippocampal-dependent spatial learning. It has been proposed that each hippocampal stratum can generate a current theta dipole. Therefore, considering that each hippocampal circuit (CA1, CA3, and Dentate Gyrus (DG)) contributes differently to distinct aspects of a spatial memory, the theta oscillations on each stratum and their couplings may exhibit oscillatory dynamics associated with different stages of learning. To test this hypothesis, the theta oscillations from five hippocampal strata were recorded in the rat during different stages of learning in a Morris maze. The peak power, the relative power (RP) and the coherence between hippocampal strata were analyzed. The early acquisition stage of the Morris task was characterized by the predominance of slow frequency theta activity and high coupling between specific hippocampal strata at slow frequencies. However, on the last training day, the theta oscillations were faster in all hippocampal strata, with tighter coupling at fast frequencies between the CA3 pyramidal stratum and other strata. Our results suggest that modifications to the theta frequency and its coupling can be a means by which the hippocampus differentially operates during acquisition and retrieval states.

  2. Selenium Concentrations in Middle Pennsylvanian Coal-Bearing Strata in the Central Appalachian Basin

    USGS Publications Warehouse

    Neuzil, Sandra G.; Dulong, Frank T.; Cecil, C. Blaine; Fedorko, Nick; Renton, John J.; Bhumbla, D.K.

    2007-01-01

    Introduction This report provides the results of a reconnaissance-level investigation of selenium (Se) concentrations in Middle Pennsylvanian coal-bearing strata in the central Appalachian basin. Bryant and others (2002) reported enrichments of Se concentrations in streams draining areas disturbed by surface mining relative to Se concentrations in streams that drain undisturbed areas; the study was conducted without the benefit of data on Se concentrations in coal-bearing strata prior to anthropogenic disturbance. Thus, the present study was conducted to provide data on Se concentrations in coal-bearing strata prior to land disturbance. The principal objectives of this work are: 1) determine the stratigraphic and regional distribution of Se concentrations in coal-bearing strata, 2) provide reconnaissance-level information on relations, if any, between Se concentrations and lithology (rock-type), and 3) develop a cursory evaluation of the leachability of Se from disturbed strata. The results reported herein are derived from analyses of samples obtained from three widely-spaced cores that were collected from undisturbed rock within a region that has been subjected to extensive land disturbance principally by either coal mining or, to a lesser extent, highway construction. The focus was on low-organic-content lithologies, not coal, within the coal-bearing interval, as these lithologies most commonly make up the fill materials after coal mining or in road construction.

  3. Tidal influence in fluvial strata - A key element in high-resolution sequence stratigraphic correlation

    SciTech Connect

    Shanley, K.W. ); McCabe, P.J. )

    1990-05-01

    Recognition of tidal influence in fluvial, estuarine, and alluvial strata is critical to establishing of high-resolution sequence stratigraphic correlations between marine and nonmarine strata. In Turonian through Campanian strata of the Kaiparowits Plateau of southern Utah, tidally influenced facies were deposited during at least two periods of relatively rapid base level rise. These facies form part of transgressive systems tracts. Landward of the transgressive maxima, these tidal facies are present in channels that are otherwise encased in alluvial strata. Recognition of subtle sedimentary structures resulting from tidal processes allows an accurate chronostratigraphic framework to be developed between marine deposits and strata deposited up to 50 km inland. Tidally influenced channel deposits near the shoreline are sandstone dominated. They have well-developed sigmoidal bedding, thin mudstone drapes, and contain multiple reactivation surfaces and scattered marine trace fossils. Thirty kilometers inland, channel deposits contain wavy to lenticular bedded fine-grained sandstones and mudstones interbedded with thin sigmoidal cross-stratified sandstones. Teredolites, bidirectional current orientations, and the heterolithic nature suggest a tidally influenced system. Twenty kilometers farther inland lateral accretion deposits consisting of alternating ripple cross-laminated sandstones and mudstones are interpreted as meandering river deposits. The persistence of many mud drapes from the base to the top of lateral accretion surfaces, the presence of lenticular bedded sandstones, and trace fossil evidence suggest a tidal influence. Tidal facies landward of transgressive maxima are correlated to condensed sections representing periods of maximum flooding in the marine shales.

  4. Capture-recapture studies for multiple strata including non-markovian transitions

    USGS Publications Warehouse

    Brownie, C.; Hines, J.E.; Nichols, J.D.; Pollock, K.H.; Hestbeck, J.B.

    1993-01-01

    We consider capture-recapture studies where release and recapture data are available from each of a number of strata on every capture occasion. Strata may, for example, be geographic locations or physiological states. Movement of animals among strata occurs with unknown probabilities, and estimation of these unknown transition probabilities is the objective. We describe a computer routine for carrying out the analysis under a model that assumes Markovian transitions and under reduced parameter versions of this model. We also introduce models that relax the Markovian assumption and allow 'memory' to operate (i.e., allow dependence of the transition probabilities on the previous state). For these models, we sugg st an analysis based on a conditional likelihood approach. Methods are illustrated with data from a large study on Canada geese (Branta canadensis) banded in three geographic regions. The assumption of Markovian transitions is rejected convincingly for these data, emphasizing the importance of the more general models that allow memory.

  5. Arenig volcanic and sedimentary strata, central New Brunswick and eastern Maine

    USGS Publications Warehouse

    Poole, W.H.; Neuman, R.B.

    2002-01-01

    Arenig strata in the Napadogan area of the Miramichi Highlands of west-central New Brunswick are similar to those of the Lunksoos anti-clinorial area of eastern Maine. Strata from both areas were deposited in a volcanic back-arc setting upon Cambrian-Tremadoc, deep-water, turbiditic quartzose strata on the northwest-facing Gander margin of Gondwana. Tremadoc southeastward obduction of the Penobscot Arc, formed in the lapetus Ocean to the northwest of the margin, was followed by local uplift, rift faulting, erosion, and finally by local deposition of late Arenig gravel within the early stages of a subsiding back-arc basin that was related to a younger, northwest-facing, early Arenig-Llanvirn Popelogan Arc lying to the northwest. These strata became overlain by late Arenig marine felsic tuff, sandy and silty tuff and mudstone, coarse textured and many hundreds of metres thick in the Lunksoos area but much finer and only a few metres thick farther from the volcanic centres, in the Napadogan area. During Llanvirn, the strata became covered with deep-water, commonly manganiferous, ferruginous shale-chert in a basin shielded from currents carrying coarse detritus. Arenig strata of the Napadogan area probably developed to the southeast of the main rift-volcanism zone that perhaps extended between the Lunksoos and northeastern Miramichi Highlands during the Arenig. Brachiopods of the Celtic paleogeographic assemblage colonized newly formed shelves flanking islands along the zone. Shell beds developed upon fresh layers of ash in a nutrient-rich environment between episodes of volcanism. These Celtic brachiopods developed in cool waters of high southern latitudes off Gondwana, different from those on the Laurentian margin in warm waters of low southern latitudes.

  6. Analysis of safety precautions for coal and gas outburst-hazardous strata

    SciTech Connect

    Hudecek, V.

    2008-09-15

    The author analyses coal and gas outbursts and generalizes the available data on the approaches to solving the problematics of these gas-dynamic events in the framework of Czech Republic Grant 'Estimate of the Safety Precautions for Coal and Gas Outburst Hazardous Strata'.

  7. 76 FR 69295 - Strata Energy, Inc.; Establishment of Atomic Safety and Licensing Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... COMMISSION Strata Energy, Inc.; Establishment of Atomic Safety and Licensing Board Pursuant to delegation by... is hereby given that an Atomic Safety and Licensing Board (Board) is being established to preside..., Chair, Atomic Safety and Licensing Board Panel, U.S. Nuclear Regulatory Commission, Washington, DC...

  8. Modeling of multi-strata forest fire severity using Landsat TM data

    Treesearch

    Q. Meng; R.K. Meentemeyer

    2011-01-01

    Most of fire severity studies use field measures of composite burn index (CBI) to represent forest fire severity and fit the relationships between CBI and Landsat imagery derived differenced normalized burn ratio (dNBR) to predict and map fire severity at unsampled locations. However, less attention has been paid on the multi-strata forest fire severity, which...

  9. Correlation of upper Triassic strata between southern Colorado Plateau and southern High Plains, New Mexico

    SciTech Connect

    Lucas, S.G. )

    1989-09-01

    Almost 600 m of Upper Triassic strata are exposed in the Hagan basin. They pertain to the basal Agua Zarca member of the Chinle Formation (as much as 80 m), overlain by about 500 m of mud-rock-dominated red beds of the Petrified Forest Member of the Chinle Formation. The top of the Triassic section here is the 5.5-24 m-thick Correo Sandstone Bed of Chinle Formation, which is disconformably overlain by the medial silty member of the Middle Jurassic Entrada Sandstone. At Lamy, approximately 370 m of Upper Triassic strata represent the westernmost outcrops of the Triassic section typical of the Tucumcari basin. This Triassic section consists of about 140 m of Santa Rosa Formation (divisible into three members) overlain by a mud-rock-dominated section (Chinle Formation) split by a medial sandy interval, the Cuervo member (Trujillo Formation of the Palo Duro basin). The youngest Triassic strata near Lamy are rhythmically bedded sediments of the Redonda Member. Based on lithologic similarity, stratigraphic position, and limited paleontological data, the central New Mexico Upper Triassic strata support for the following correlations (from west to east): (1) Shinarump = Agua Zarca = Santa Rosa; (2) lower Petrified Forest = lower shale member of the Chinle = Tecovas; (3) Sonsela = Poleo = Cuervo = Trujillo; (4) upper Petrified Forest = upper shale member of the Chinle; and (5) Owl Rock = Redonda = Correo. These correlations reflect homotaxis of sedimentary cycles across a broad region of the southern Western Interior during the Late Triassic.

  10. Neogene marine isotopic evolution and the erosion of Lesser Himalayan strata: Implications for Cenozoic tectonic history

    NASA Astrophysics Data System (ADS)

    Myrow, Paul M.; Hughes, Nigel C.; Derry, Louis A.; Ryan McKenzie, N.; Jiang, Ganqing; Webb, A. Alexander G.; Banerjee, Dhiraj M.; Paulsen, Timothy S.; Singh, Birendra P.

    2015-05-01

    An extensive, northward deepening blanket of Neoproterozoic and Cambrian sedimentary rocks once extended from the Himalayan margin far onto the Indian craton. Cambrian deposits of this "upper Lesser Himalayan" succession, which include deposits of the "outer" Lesser Himalaya tectonic unit, are enriched in radiogenic 187Os. They make up part of a proximal marine facies belt that extends onto the craton and along strike from India to Pakistan. By contrast, age-equivalent facies in the Tethyan Himalaya are more distal in nature. Neoproterozoic to Cambrian strata of the upper Lesser Himalayan succession are now missing in much of the Lesser Himalaya, with their erosion exposing older Precambrian Lesser Himalayan strata. We suggest that exhumation and weathering of the upper Lesser Himalaya and related strata caused dramatic changes in the 187Os/188Os and 87Sr/86Sr Neogene record of seawater starting at ∼ 16 Ma. First-order estimates for the volume of upper Himalayan strata, as well as the volume of all LH rock eroded since this time, and geochemical box modeling, support this idea. Exhumation at 16 Ma is a fundamental event in the evolution of the Himalayan orogeny and the geochemical evolution of the oceans, and will be a critical part of the construction of future models of Himalayan thrust belt evolution.

  11. Determination of the Optimal Number of Strata for Bias Reduction in Propensity Score Matching

    ERIC Educational Resources Information Center

    Akers, Allen

    2010-01-01

    Previous research implementing stratification on the propensity score has generally relied on using five strata, based on prior theoretical groundwork and minimal empirical evidence as to the suitability of quintiles to adequately reduce bias in all cases and across all sample sizes. This study investigates bias reduction across varying number of…

  12. Use of lumboperitoneal shunts with the Strata NSC valve: a single-center experience.

    PubMed

    Toma, Ahmed K; Dherijha, Muhammad; Kitchen, Neil D; Watkins, Laurence D

    2010-12-01

    The lumboperitoneal (LP) shunt with the adjustable PS Medical Strata NSC LP valve and small lumen peritoneal catheter was introduced in the authors' unit in 2007. The object of this study was to audit the unit's experience with this new shunt system. The authors performed a retrospective review of the clinical records of patients who underwent Strata NSC LP shunt insertion. Demographic and clinical data as well as information about complications and revisions were reported. Between August 2007 and November 2009, 20 patients underwent placement of an LP shunt with an adjustable Strata NSC valve and small lumen peritoneal catheter at the authors' institution. Their mean age was 40.3 years and the mean duration of follow-up was 12 months. Preoperatively, 18 patients had headache and 15 patients had visual signs and symptoms. Fourteen of the 18 patients with preoperative headache did not complain of headache postoperatively, and 4 had headache that was found not to be related to shunt function. Two of the patients with preoperative visual complaints had ongoing visual problems postoperatively. None of the patients had infection or subdural hematoma. The only overdrainage symptoms occurred in association with spontaneous readjustment of the valve and resolved when the valve was reset. Thirteen patients (65%) did not require shunt revision. Seven patients (35%) required 13 shunt exploration or revision procedures, mainly due to distal obstruction. Placement of an LP shunt failed to completely resolve the raised intracranial pressure problem in 2 patients. The use of the Strata NSC valve and small lumen peritoneal catheter is effective in treating pseudotumor cerebri and is beneficial in terms of markedly reducing overdrainage complications compared with other reported series of cases in which an LP shunt has been placed. However, the use of the Strata NSC valve and small lumen peritoneal catheter did not have a marked impact on other causes of shunt failure, particularly

  13. Lithostratigraphy and paleoenvironmental reconstructions for Devonian strata in the Michigan Basin

    SciTech Connect

    Harrison, W.B. III . Dept. of Geology)

    1994-04-01

    Devonian strata in the Michigan Basin are represented by variably thick sequences of open shelf, tidal flat and sabhka carbonates, interbedded with basin-centered and sabhka evaporites (anhydrite and halite). Although there are isolated outcrops around the margins of the basin, the lithofacies relationships of these strata can be best studied from subsurface data of cores, wireline logs, and drill cutting samples. This database is compiled from over 25,000 oil and gas wells that enter or entirely penetrate Devonian strata in Michigan. Most of the strata in the Michigan Basin Devonian are part of the Kaskaskia cratonic depositional sequence (Sloss, 1963). The sequence begins with the southeast to northwest transgression of a quartz arenite (Sylvania Ss.) sandstone facies onto a weathered, cherty carbonate (Bois Blanc Fm.) surface developed on Lower Devonian strata exposed during the post-Tippecanoe unconformity. With rising sea level, the basin sediments became dominated by open shelf, biohermal and locally restricted lagoon carbonates (Amherstberg Fm.). Much of the Middle Devonian is represented by thick basin-centered sabhka and salina evaporates and restricted-environment carbonates (Lucas Fm.). These interbedded and laterally gradational evaporite/carbonate facies are cyclic, showing gradual salinity changes during accumulation. Stratigraphically important K-Bentonite marker beds are prevalent in this part of the Michigan section. Overlying this restricted sequence are again open shelf, biohermal, and local restricted sabhka carbonate deposits (Dundee Fm.). Thin, but widespread and eastwardly thickening, terrigenous shales and mudstones are intercalated within another shelf carbonate package (Traverse Group). Devonian deposits in the Michigan Basin are capped by thick black shales and interbedded carbonates (Antrim Fm.).

  14. Preliminary basin analysis of late Proterozoic-Cambrian post-rift strata, southeast Idaho thrust belt

    SciTech Connect

    Link, P.K.; Jansen, S.T.; Halimdihardja, P.; Lande, A.C.; Zahn, P.D.

    1987-08-01

    Strata of the Brigham Group in the Paris-Putnam plate of the southeastern Idaho thrust belt span the late Proterozoic-Cambrian boundary and consist of quartzose sandstone with subordinate pebble conglomerate and siltstone. The Brigham Group is overlain by fossiliferous Cambrian carbonate units that represent the transition from siliciclastic to carbonate deposition in the Cordilleran miogeocline. The Brigham Group contains four stratigraphic sequences bounded by regional disconformities. The lower sequence includes strata below the Brigham group (upper member, Pocatello Formation), plus the Papoose Creek Formation and most of the overlying Caddy Canyon Quartzite. This sequence is dominantly marine with shoreface and braided fluvial strata at the top. The first sequence is overlain disconformably by offshore sub-wave base marine strata of the upper Caddy Canyon Quartzite and Inkom Formation. This second sequence is entirely marine and is composed dominantly of siltstone with sandstone-filled channels. The third sequence comprises the Mutual Formation, an entirely braided fluvial and lacustrine unit. The fourth sequence (Sauk sequence) locally overlies the Mutual Formation with an erosional unconformity and consists of dominantly marine strata of the Camelback Mountain Quartzite, Gibson Jack Formation, Windy Pass Argillite, Twin Knobs Formation, and Sedgwick peak Quartzite. Correlations of these sequences to the McCoy Creek Group of eastern Nevada suggests uniform conditions of sea level and subsidence across the late Proterozoic-Cambrian Cordilleran miogeocline. This preliminary synthesis suggests the Brigham and McCoy Creek Groups are post-rift deposits, as indicated by regional persistence of facies, paleocurrents, and quartzose petrology.

  15. 78 FR 56944 - Strata Energy, Inc. (Ross In Situ Recovery Uranium Project); Notice of Atomic Safety and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-16

    ... COMMISSION Strata Energy, Inc. (Ross In Situ Recovery Uranium Project); Notice of Atomic Safety and Licensing... (Board) in the above-captioned Strata Energy, Inc. case is hereby reconstituted by appointing Administrative Judge Craig M. White to serve on the Board in place of Administrative Judge Kenneth L. Mossman...

  16. Detrital zircon geochronology of pre- and syncollisional strata, Acadian orogen, Maine Appalachians

    USGS Publications Warehouse

    Bradley, Dwight C.; O'Sullivan, Paul B.

    2017-01-01

    The Central Maine Basin is the largest expanse of deep-marine, Upper Ordovician to Devonian metasedimentary rocks in the New England Appalachians, and is a key to the tectonics of the Acadian Orogeny. Detrital zircon ages are reported from two groups of strata: (1) the Quimby, Rangeley, Perry Mountain and Smalls Falls Formations, which were derived from inboard, northwesterly sources and are supposedly older; and (2) the Madrid, Carrabassett and Littleton Formations, which were derived from outboard, easterly sources and are supposedly younger. Deep-water deposition prevailed throughout, with the provenance shift inferred to mark the onset of foredeep deposition and orogeny. The detrital zircon age distribution of a composite of the inboard-derived units shows maxima at 988 and 429 Ma; a composite from the outboard-derived units shows maxima at 1324, 1141, 957, 628, and 437 Ma. The inboard-derived units have a greater proportion of zircons between 450 and 400 Ma. Three samples from the inboard-derived group have youngest age maxima that are significantly younger than the nominal depositional ages. The outboard-derived group does not share this problem. These results are consistent with the hypothesised provenance shift, but they signal potential problems with the established stratigraphy, structure, and (or) regional mapping. Shallow-marine deposits of the Silurian to Devonian Ripogenus Formation, from northwest of the Central Maine Basin, yielded detrital zircons featuring a single age maximum at 441 Ma. These zircons were likely derived from a nearby magmatic arc now concealed by younger strata. Detrital zircons from the Tarratine Formation, part of the Acadian foreland-basin succession in this strike belt, shows age maxima at 1615, 980 and 429 Ma. These results are consistent with three episodes of zircon recycling beginning with the deposition of inboard-derived strata of the Central Maine Basin, which were shed from post-Taconic highlands located to the

  17. Applications of sequence stratigraphy to Pennsylvanian strata in the Illinois Basin

    USGS Publications Warehouse

    Weibel, C.P.; ,

    1996-01-01

    Sequence stratigraphy concepts have been applied previously to the interpretation of Pennsylvanian strata in the Illinois Basin with the use of the 'cycle' by J.A. Udden in 1912 and the cyclothem by H. Wanless and J. Weller in 1932. The unconformity-bounded cyclothem was recognized in Pennsylvanian strata throughout the basin and is a small-scale version of the cratonic sequence of L.L. Sloss. Recent applications indicate that the transgressive-regressive unit, a genetic succession bounded by marine-flooding surfaces, is a more practical stratigraphic unit that has applications for stratigraphic control, structural control, sedimentology, and hydrostratigraphy. Transgressive-regressive units conveniently fit within a sequence stratigraphic framework.

  18. Dynamics on strata of trigonal Jacobians and some integrable problems of rigid body motion

    NASA Astrophysics Data System (ADS)

    Braden, H. W.; Enolski, V. Z.; Fedorov, Yu N.

    2013-07-01

    We present an algebraic geometrical and analytical description of the Goryachev case of rigid body motion. It belongs to a family of systems sharing the same properties: although completely integrable, they are not algebraically integrable, their solution is not meromorphic in the complex time and involves dynamics on the strata of the Jacobian varieties of trigonal curves. Although the strata of hyperelliptic Jacobians have already appeared in the literature in the context of some dynamical systems, the Goryachev case is the first example of an integrable system whose solution involves a more general curve. Several new features (and formulae) are encountered in the solution given in terms of sigma-functions of such a curve.

  19. Study on Strata Behavior Regularity of 1301 Face in Thick Bedrock of Wei - qiang Coal Mine

    NASA Astrophysics Data System (ADS)

    Gu, Shuancheng; Yao, Boyu

    2017-09-01

    In order to ensure the safe and efficient production of the thick bedrock face, the rule of the strata behavior of the thick bedrock face is discussed through the observation of the strata pressure of the 1301 first mining face in Wei qiang coal mine. The initial face is to press the average distance of 50.75m, the periodic weighting is to press the average distance of 12.1m; during the normal mining period, although the upper roof can not be broken at the same time, but the pressure step is basically the same; the working face for the first weighting and periodical weighting is more obvious to the change of pressure step change, when the pressure of the working face is coming, the stent force increased significantly, but there are still part of the stent work resistance exceeds the rated working resistance, low stability, still need to strengthen management.

  20. The Strata-1 Regolith Dynamics Experiment: Class 1E Science on ISS

    NASA Technical Reports Server (NTRS)

    Fries, Marc; Graham, Lee; John, Kristen

    2016-01-01

    The Strata-1 experiment studies the evolution of small body regolith through long-duration exposure of simulant materials to the microgravity environment on the International Space Station (ISS). This study will record segregation and mechanical dynamics of regolith simulants in a microgravity and vibration environment similar to that experienced by regolith on small Solar System bodies. Strata-1 will help us understand regolith dynamics and will inform design and procedures for landing and setting anchors, safely sampling and moving material on asteroidal surfaces, processing large volumes of material for in situ resource utilization (ISRU) purposes, and, in general, predicting the behavior of large and small particles on disturbed asteroid surfaces. This experiment is providing new insights into small body surface evolution.

  1. Overpressure and hydrocarbon accumulations in Tertiary strata, Gulf Coast of Louisiana

    USGS Publications Warehouse

    Nelson, Philip H.

    2012-01-01

    Many oil and gas reservoirs in Tertiary strata of southern Louisiana are located close to the interface between a sand-rich, normally pressured sequence and an underlying sand-poor, overpressured sequence. This association, recognized for many years by Gulf Coast explorationists, is revisited here because of its relevance to an assessment of undiscovered oil and gas potential in the Gulf Coast of Louisiana. The transition from normally pressured to highly overpressured sediments is documented by converting mud weights to pressure, plotting all pressure data from an individual field as a function of depth, and selecting a top and base of the pressure transition zone. Vertical extents of pressure transition zones in 34 fields across southern onshore Louisiana range from 300 to 9000 ft and are greatest in younger strata and in the larger fields. Display of pressure transition zones on geologic cross sections illustrates the relative independence of the depth of the pressure transition zone and geologic age. Comparison of the depth distribution of pressure transition zones with production intervals confirms previous findings that production intervals generally overlap the pressure transition zone in depth and that the median production depth lies above the base of the pressure transition zone in most fields. However, in 11 of 55 fields with deep drilling, substantial amounts of oil and gas have been produced from depths deeper than 2000 ft below the base of the pressure transition zone. Mud-weight data in 7 fields show that "local" pressure gradients range from 0.91 to 1.26 psi/ft below the base of the pressure transition zone. Pressure gradients are higher and computed effective stress gradients are negative in younger strata in coastal areas, indicating that a greater potential for fluid and sediment movement exists there than in older Tertiary strata.

  2. Preliminary numerical simulation for shallow strata stability of coral reef in South China Sea

    NASA Astrophysics Data System (ADS)

    Tang, Qinqin; Zhan, Wenhuan; Zhang, Jinchang

    2017-04-01

    Coral reefs are the geologic material and special rock and soil, which live in shallow water of the tropic ocean and are formed through biological and geological action. Since infrastructure construction is being increasingly developed on coral reefs during recent years, it is necessary to evaluate the shallow strata stability of coral reefs in the South China Sea. The paper is to study the borehole profiles for shallow strata of coral reefs in the South China Sea, especially in the hydrodynamic marine environment?, and to establish a geological model for numerical simulation with Geo-Studio software. Five drilling holes show a six-layer shallow structure of South China Sea, including filling layer, mid-coarse sand, coral sand gravel, fine sand, limestone debris and reef limestone. The shallow coral reef profile next to lagoon is similar to "layers cake", in which the right side close to the sea is analogous to "block cake". The simulation results show that coral reef stability depends on wave loads and earthquake strength, as well as the physical properties of coral reefs themselves. The safety factor of the outer reef is greater than 10.0 in the static condition, indicating that outer reefs are less affected by the wave and earthquake. However, the safety factor next to lagoon is ranging from 0.1 to 4.9. The main reason for the variations that the strata of coral reefs close to the sea are thick. For example, the thickness of reef limestone is more than 10 m and equivalent to the block. When the thickness of inside strata is less than 10 m, they show weak engineering geological characteristics. These findings can provide useful information for coral reef constructions in future. This work was funded by National Basic Research Program of China (contract: 2013CB956104) and National Natural Science Foundation of China (contract: 41376063).

  3. 2×Nr MIMO ARQ Scheme Using Multi-Strata Space-Time Codes

    NASA Astrophysics Data System (ADS)

    Ko, Dongju; Lee, Jeong Woo

    We propose a 2×Nr MIMO ARQ scheme that uses multi-strata space-time codes composed of two layers. The phase and transmit power of each layer are assigned adaptively at each transmission round to mitigate the inter-layer interference and improve the block error rate by retransmission. Simulation results show that the proposed scheme achieves better performance than the conventional schemes in terms of the throughput and the block error rate.

  4. Stratigraphy and correlation of Upper Triassic strata between west Texas and eastern New Mexico

    SciTech Connect

    Lucas, S.G. ); Anderson, O.J. )

    1992-04-01

    Lithostratigraphy and vertebrate biochronology allow precise correlation of Upper Triassic strata between west Texas and eastern New Mexico. Upper Triassic strata are well exposed in west Texas from Oldham to Scurry counties, and are assigned to the Dockum Formation of the Chinle Group. Fossil vertebrates from the Camp Springs and Tecovas Members are of late Carnian age, whereas those from the Copper Member are of early Norian age. Upper Triassic strata in east-central New Mexico, across the Llano Estacado from the west Texas outcrops, correlate as follows: Camper Springs = lower Santa Rose; Tecovas = upper Santa Rosa/Garita Creek; Trujillo = Trujillo ('Cuervo'); Cooper = lower Bull Canyon. Upper Triassic strata in southeastern New Mexico and in Howard and adjacent counties in Texas are the lower Santa Rosa/Camper Springs overlain by mudstones and sandstones that contain late Carnian vertebrates and are informally termed upper member of Dockum Formation. Available data refute several long-held ideas about the Upper Triassic of west Texas. These data demonstrate that: (1) there is a pervasive unconformity at the base of the Dockum Formation that represents much of Triassic time; (2) the Trujillo Member is not correlative with the Santa Rosa of eastern New Mexico: Trujillo is a medial Dockum unit, whereas Santa Rosa is at the base of the Upper Triassic section; (3) very little Dockum mudrock was deposited in lakes; and (4) Dockum rivers flowed almost exclusively to the north, northwest, and west, so there was no closed depositional basin in west Texas during the Late Triassic.

  5. On the palynomorph-based biozones in paleogene strata of rocky mountain basins

    USGS Publications Warehouse

    Nichols, D.J.

    2009-01-01

    In a paper published in this journal, and in five previous papers published elsewhere, Lillegraven and McKenna (2008) criticize the research of Nichols and Ott (1978) and Nichols and Flores (2006). They attempt to cast doubt on the validity of the palynomorph-based biozones (the "P- zone" system) applied in strata of Paleocene age throughout the Rocky Mountain region. Their conclusions are without merit.

  6. Detrital zircon geochronology of Cordilleran retroarc foreland basin strata, western North America

    NASA Astrophysics Data System (ADS)

    Laskowski, Andrew K.; DeCelles, Peter G.; Gehrels, George E.

    2013-09-01

    present a compilation of 8717 U-Pb analyses from 95 detrital zircon samples of Jurassic-Eocene North American Cordillera foreland basin strata. Of these samples, 30 are new and previously unpublished. Variation in detrital zircon age spectra between samples records erosion or recycling of basement and cover rocks within the Cordilleran orogenic wedge. Each sample can be classified into one of six major provenance groups, whose age spectra suggest derivation from (1) Mesozoic eolianites of the western United States, (2) Paleozoic passive margin strata of the western United States, (3) Paleozoic passive margin strata of western Canada, (4) the Mogollon Highlands, (5) the Cordilleran magmatic arc, or (6) Yavapai-Mazatzal Province crystalline basement rocks. Referencing these provenance interpretations to their location and stratigraphic deposition age produces a detailed spatial and temporal record of sediment dispersal within the foreland basin system. Late Jurassic provenance is dominated by recycling of Mesozoic eolianites from sources in the Sevier thrust belt. Cretaceous-Eocene provenance is dominated by recycling of the passive margin, with increasing complexity upsection. We interpret that this provenance transition records a basin-wide unroofing sequence. A composite age-probability plot of 1539 young (<250 Ma) detrital zircons reveals at least four age-abundance peaks that we interpret to represent periodic high-flux magmatism in the Cordilleran arc.

  7. Numerical and experimental study of strata behavior and land subsidence in an underground coal gasification project

    NASA Astrophysics Data System (ADS)

    Sirdesai, N. N.; Singh, R.; Singh, T. N.; Ranjith, P. G.

    2015-11-01

    Underground Coal Gasification, with enhanced knowledge of hydrogeological, geomechanical and environmental aspects, can be an alternative technique to exploit the existing unmineable reserves of coal. During the gasification process, petro-physical and geomechanical properties undergo a drastic change due to heating to elevated temperatures. These changes, caused due to the thermal anisotropy of various minerals, result in the generation of thermal stresses; thereby developing new fracture pattern. These fractures cause the overhead rock strata to cave and fill the gasification chamber thereby causing subsidence. The degree of subsidence, change in fluid transport and geomechanical properties of the rock strata, in and around the subsidence zone, can affect the groundwater flow. This study aims to predict the thermo-geomechanical response of the strata during UCG. Petro-physical and geomechanical properties are incorporated in the numerical modelling software COMSOL Multiphysics and an analytical strength model is developed to validate and further study the mechanical response and heat conduction of the host rock around the gasification chamber. Once the problems are investigated and solved, the enhanced efficiency and the economic exploitation of gasification process would help meet country's energy demand.

  8. Global CO2 storage potential of self-sealing marine sedimentary strata

    NASA Astrophysics Data System (ADS)

    Eccles, Jordan K.; Pratson, Lincoln

    2012-10-01

    One potential way to geologically sequester captured CO2 emissions is to inject them below the seafloor into marine sedimentary strata where pressures and temperatures would trap the CO2 through “self-sealing” gravitational and hydrate-formation mechanisms. Here we map out the worldwide distribution and thicknesses of such self-sealing strata using a comprehensive, global dataset of deep-sea sediment cores in combination with digital grids of ocean floor heat flow, bathymetry, and sediment thickness. Based on our mapping, we estimate that the total bulk sediment volume of self-sealing strata is 63 million cubic kilometers, 0.8-1.4 km3 (or ˜1.3-2.7%) of which are sands with intrinsic permeability suitable for storing CO2. This is enough storage capacity to hold between 1,260-28,500 gigatonnes of CO2, or about 40-1,000 y of total global CO2 emissions. However, the storage capacity is unevenly distributed where it lies within the Exclusive Economic Zones (EEZ) of the world's largest CO2 emitting economies. The United States and India respectively release 16% and 62% of their annual CO2 emissions (or 1 Bt/y and 800 Mt/y) within 500 km of self-sealing sands located in their EEZs, while only 6% of the annual emissions from China and the European Union (or 330 Mt/y and 250 Mt/y, respectively) occur within this distance.

  9. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata

    PubMed Central

    Han, C. J.

    2015-01-01

    This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines. PMID:26103460

  10. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata.

    PubMed

    Zhang, J; Liang, Z; Han, C J

    2015-01-01

    This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

  11. The Strata Ground Penetrating Radar for Rover Based Exploration of the Martian Subsurface

    NASA Astrophysics Data System (ADS)

    Leuschen, C. J.; Grant, J. A.; Schutz, A. E.; Williams, K. K.

    2005-12-01

    Ground-penetrating radar (GPR) provides a mature and efficient means of identifying the near-surface stratigraphy by mapping the electromagnetic reflectivity of subsurface layering and structure. Typical investigation depths range from less than a meter to tens of meters at spatial resolutions of tens of centimeters to meters, respectively, depending on the system configuration and electrical characteristics of the local geophysical setting. On Mars, a rover-based GPR will define geologically interesting areas for surface in-situ point measurements and can help extrapolate local ground truth to better define the extent and form of a specific deposit, structure, or layer. GPR can also help locate shallow deposits of water or ice, define geological setting based on signatures from analog environments, and help to target and orient rover-based or follow-on drilling operations. Terrestrial GPR systems have been commercially developed to provide optimal performance regarding dynamic range, clutter and sidelobe suppression, and timing stability; while also retaining a high level usability for non-experts in a wide variety of environments. Strata is a similar high-performance GPR that has been tailored for the specific application of Mars exploration from a rover-based platform. It is a 400 MHz impulsive system that can easily be to be mounted on a range of rover platforms. With its high dynamic range of 110 dB, Strata will be capable of probing tens of meters into the subsurface of Mars with a nominal resolution of less than 20 cm. The Strata instrument consists of a low mass and low power digital processor unit and a set of loaded dipole antennas whose specific design and frequency is adaptable to almost any rover configuration. The Strata design is optimized for geologic applications that include definition of geologic setting and detection of water and draws from the maturity of commercial systems developed by Geophysical Survey Systems Inc., which are being adapted

  12. Aromatized arborane/fernane hydrocarbons as molecular indicators of floral changes in Upper Carboniferous/Lower Permian strata of the Saar-Nahe Basin, southwestern Germany

    NASA Astrophysics Data System (ADS)

    Vliex, M.; Hagemann, H. W.; Püttmann, W.

    1994-11-01

    Thirty-seven coal samples of Upper Carboniferous and Lower Permian age from three boreholes in the Saar-Nahe Basin, Germany, have been studied by organic geochemical and coal petrological methods. The investigations were aimed at the recognition of floral changes in the Upper Carboniferous and Lower Permian strata. The results show that compositional changes in the extracts are only partly caused by variations in coalification. Specific aromatic hydrocarbons appear in Upper Westphalian D coal seams and increase in concentration up to the Rotliegendes. The dominant compound has been identified by mass spectrometry and NMR-spectroscopy as 5-methyl-10-(4-methylpentyl)-des- A-25-norarbora(ferna)-5,7,9-triene (MATH) and always occurs associated with 25-norarbora(ferna)-5,7,9-triene. Both compounds are thought to originate from isoarborinol, fernene-3β-ol, or fernenes. The strongly acidic conditions during deposition of the coals might have induced the 4,5-cleavage combined with a methyl-shift in an arborane/fernane-type pentacyclic precursor yielding the MATH. Based on petrological investigations, palynomorphs related to early Gymnospermopsida such as Pteridospermales and Coniferophytes ( Cordaitales and Coniferales) increased in abundance in the strata beginning with the Upper Westphalian D concomitant with the above mentioned biomarkers. The results suggest the arborane/fernane derivatives originate from the plant communities producing these palynomorphs.

  13. Distribution of throughfall and stemflow in multi-strata agroforestry, perennial monoculture, fallow and primary forest in central Amazonia, Brazil

    NASA Astrophysics Data System (ADS)

    Schroth, Götz; Ferreira da Silva, Luciana; Wolf, Marc-Andree; Geraldes Teixeira, Wenceslau; Zech, Wolfgang

    1999-07-01

    The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi-strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open-area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for

  14. Study of the strata formation during the explosion of foils in vacuum

    NASA Astrophysics Data System (ADS)

    Zhigalin, A. S.; Rousskikh, A. G.; Oreshkin, V. I.; Chaikovsky, S. A.; Ratakhin, N. A.; Khishchenko, K. V.; Baksht, R. B.

    2015-11-01

    The formation of the strata during fast explosion of metal foils at current densities of 0.1 GA/cm2 has been studied experimentally. To observe the strata, the soft x-ray radiation generated by an X-pinch was used. The study of the process of stratification during the foil explosion was carried out with a setup consisting of three generators. One of the generators (WEG-2), was operated to initiate the explosion of the foils, while the others (XPG radiographs) were used for diagnostics. The generator WEG-2 has the capacitance of 250 nF, the charge voltage of 20 kV, and the current rate of 16 A/ns. The radiographs XPG have the capacitance of 1 μF, the charge voltage of 43 kV, the current of 300 kA, and the current rise time of 180 ns. X-pinch produced by four Mo wires was a load for the radiographs. The delay between the operation of the WEG-2 and XPG generators was set using a DPG trigger pulse generator. We performed the experiments with the Al and Cu foils. The length of foil was 2 cm, the foil width was 1 mm, and the foil thickness was 6 μm. It has been revealed that strata were formed early in the explosion, i.e. at the stage when the metal melted. Analysis of the experimental results suggests that the most probable reason for the stratification is the thermal instability developing because of the increase in resistivity of the foil metal with temperature.

  15. Propagation and effects of monsoonal seasonally intense rainfall signal in river strata

    NASA Astrophysics Data System (ADS)

    Plink-Bjorklund, P.

    2014-12-01

    Climatic forcing signals in river systems tend to be modified on different temporal and spatial scales due to inherent signal buffering, re-routing, and a complex mixing of multiple autogenic and allogenic signals. Thus climate forcing response is generally assumed inherently non-linear with significant hysteresis effects. This paper explores propagation and effects of monsoonal, seasonally intense rainfall signal in river strata in the monsoonal and bordering subtropical domains. Some such rivers occur completely within the monsoon climate zone. Others have parts of their drainages in temperate climate zones, or on high elevations and receive some of their water discharge from other sources. Yet others, have their upstream drainages in the tropical monsoon climates, but flow through bordering subtropical drylands. Yet, all these rivers characteristically experience seasonal high magnitude floods as the effect of intense monsoon precipitation. Many rivers in the bordering subtropical zone receive monsoon rain and transmit discharge only during abnormal or strengthened monsoon seasons and associated cyclonic flow. Field datasets, comparison to modern river deposits and a literature review of monsoonal and bordering subtropical domain rivers reveal that the effects of the intense seasonal monsoon rain and the resultant flooding are readily recognizable in modern and ancient fluvial strata. This paper argues that this distinct and dominant climate signal propagation occurs because it is the monsoon discharge that is commonly responsible for up to 100% of sediment erosion, transport and deposition, creating a system wide flushing or splash effect on a single season to multi-million year time scale. The distinct monsoon flood deposits are interbedded with other types of fluvial strata in systems where significant deposition also occurs from low-magnitude flood or non-flood discharges.

  16. Paleogeographic and structural setting of Miocene strata in central western Nevada

    SciTech Connect

    Stewart, J.H. )

    1993-04-01

    Late Cenozoic sedimentary rocks as old as 19 Ma are widely distributed in central western Nevada. They are greatly more abundant than older Cenozoic strata and are commonly interpreted to have formed in fault-bounded basins that mark the onset of widespread extension in the Basin and Range Province. Miocene strata are largely coeval with a magmatic arc that extended south southeast near the boundary of the Basin and Range and Sierra Nevada Provinces. This arc produced voluminous andesitic flows and lahars that locally interfinger with the Miocene strata. Miocene depositional basins apparently varied greatly in size. The largest that can be defined clearly is the Esmeralda Basin that was at least 65 km long and 45 km wide. Other basins may have been larger but are difficult to reconstruct; still other basins may be small and isolated, particularly within the magmatic arc. Lacustrine deposits and minor interfingering deltaic and distal fluvial units predominate; near-source, coarse alluvial-fan and megabreccia landslide deposits are locally conspicuous. coarse near-source deposits, particularly landslide deposits, are interpreted to be adjacent to basin-bounding normal faults. The Esmeralda, Coal Valley, and Gabbs Valley-Stewart Valley-Tonopah Basins are interpreted to be related to large-scale Miocene extension. Other basins may be (1) pull-apart structures related to strike-slip faults, (2) downdropped blocks in areas of cross-cutting normal and/or strike-slip faults related to changes in the extension direction or (3) grabens or half-grabens related to uniform extension. Younger Cenozoic basins, including present-day basins, overprint and cut across the Miocene basins.

  17. Strata reinforcement with bolting and wire-rope systems - a comparative study

    SciTech Connect

    Raju, N.M.; Ghose, A.K.

    1982-04-01

    A strata reinforcement system which has been used on an experimental basis in some 60 Indian coal mines over the past 6 years is described. It consists of a system of 'rope stitching' in which wire rope is stretched across the roof of the roadway and the ends are grouted into 1.8 m drill holes. For spans exceedng 3.6 m, grouted bolts with eye hooks are used for additional reinforcement at mid-span. This paper presents the results of a model study to evaluate the relative reinforcement actions of wire-rope and bolting systems.

  18. The Occurrence of Knickpoints in Soluble Strata in the Buffalo River Basin, Arkansas

    NASA Astrophysics Data System (ADS)

    Thaler, E.; Covington, M. D.; Myre, J. M.; Perne, M.; Holcomb, G.

    2014-12-01

    Prior field and theoretical work has suggested that bedrock channels adjust to lower stream power when encountering highly soluble strata, exhibiting an increase in channel width and/or a decrease in channel slope. However, in apparent contradiction to this expectation, many channels within the Buffalo River Basin, Arkansas, contain knickpoints, in the form of waterfalls and slot canyons, that are developed at the contact between the Mississippian Batesville Sandstone and the underlying Boone Limestone. To improve understanding of bedrock channel response to contrasts in rock solubility, longitudinal surveys were conducted in three channels that cross the Boone Limestone. Additionally, channel widths and a profile were obtained for the main stem of the Buffalo River using aerial photography and a digital elevation model. Schmidt scores for the Boone and Batesville suggest that the two strata have similar compressive strengths, which is a measure of relative resistance to mechanical erosion. Two of the four studied reaches show significant knickpoint development, and in both cases the basin area above the knickpoint is less than 3 km2. One possible explanation is that these knickpoints have been arrested at a critical threshold basin area. However, at least four other such knickpoints are known from the area, and in all cases the knickpoint is highly correlated to the contact rather than a specific basin area, suggesting that the properties of the strata are an important factor. We identify three potential mechanisms that may often act in concert to develop knickpoints at contacts with underlying soluble rocks. (1) If chemical erosion in the soluble reach outpaces uplift, and knickpoint retreat through the overlying layer is sufficiently slow, then a knickpoint will develop. (2) Karstification can divert geomorphic work to the subsurface, resulting in a steep surface channel and possible stalling of upstream knickpoint migration within the soluble strata. (3) The

  19. Regional structural cross sections, mid-permian to quaternary strata, Texas Panhandle and Eastern New Mexico

    SciTech Connect

    McGookey, D.A.; Gustavson, T.C.; Hoadley, A.D.

    1989-01-01

    Twelve regional cross sections (with text) of the Palo Duro, Dalhart, and Anadarko Basins illustrating the tabular geometry of Permian evaporite beds, areas where salt has been lost by dissolution, and the effects of dissolution-induced subsidence on Permian and post-Permian strata. The authors identify areas of dissolution beneath the High Plains, the Caprock Escarpment, the Rolling Plains, the Pecos Plains, and along the Canadian River valley. The cross sections are printed at a vertical scale of 1 inch equals 400 feet and a horizontal scale of 1 inch equals approximately 8 miles and were constructed using geophysical logs, sample logs, and surficial geologic data.

  20. Integrated depositional model for the Cenomanian Turonian organic-rich strata in North Africa

    NASA Astrophysics Data System (ADS)

    Lüning, S.; Kolonic, S.; Belhadj, E. M.; Belhadj, Z.; Cota, L.; Barić, G.; Wagner, T.

    2004-01-01

    During the Late Cenomanian-Early Turonian (C/T) Oceanic Anoxic Event (OAE2), organic-rich strata was deposited in rift shelf basins and slopes across North Africa and in deep-sea basins of the adjacent oceans. Based on a review of published and unpublished information, this paper documents the distribution and organic-richness of C/T strata across the whole region within a palaeogeographic framework and systematically analyses the conditions and processes, which controlled their deposition. Previously, the C/T in North Africa has been most intensively studied in southern Morocco (Tarfaya) and Tunisia. Only little data is availabe for other parts of North Africa, namely Algeria, Libya and Egypt, because distribution of C/T Corg strata there becomes more patchy. A general decrease in peak organic richness and black shale thickness occurs from west to east, partly as a result of upwelling along the Moroccan Atlantic coast and the absence of upwelling in the eastern Mediterranean area. Furthermore, in the confined central Atlantic, the oxygen minimum zone (OMZ) in many places reached down to the deep-sea floor (3-4 km), while the lower limit of the OMZ along the North African Tethys was much shallower and underlain by oxic water masses. As documented by high resolution biostratigraphic and chemostratigraphic data, C/T black shale deposition in most areas outside the upwelling zone are restricted to a strong, eustatic, latest Cenomanian transgressive phase. Triggered by this sea-level rise, the OMZ impinged onto the North African continental shelf and the margins of intrashelf basins, which mostly formed during the Early Cretaceous as halfgrabens. Important units containing C/T organic-rich strata in the region are the Atlantic Tarfaya black shales (Morocco, Western Sahara), black shales and phtanites in the Moroccan and Algerian Atlas, the Bahloul Fm. in the SE Constantine Basin and in northern and central Tunisia, the Etel Fm. in the Sirte Basin, the Al Hilal Fm. in

  1. The geology and palynology of lower and Middle Pennsylvanian strata in the Western Kentucky Coal Field

    USGS Publications Warehouse

    Eble, C.F.; Greb, S.F.; Williams, D.A.

    2001-01-01

    The Western Kentucky Coal Field is the southern tip of the Eastern Interior, or Illinois Basin. Pennsylvanian rocks in this area, which include conglomerate, sandstone, shale, limestone and coal, were deposited primarily in coastal-deltaic settings at a time when western Kentucky was located close to the equator. This paper discusses temporal changes in regional sedimentation patterns and coal-forming floras of Lower and Middle Pennsylvanian strata in the Western Kentucky Coal Field. Lower Pennsylvanian strata of the Caseyville Formation are characterized by paleovalley-filling sedimentation patterns and extabasinal quartz pebbles. Caseyville Formation coals are characterized thin and discontinuous and were strongly influenced by subsidence within underlying paleovalleys, and the dissected lower Pennsylvanian paleotopography. Caseyville coals are commonly dominated by Lycospora, but can also have variable palynofloras, which probably reflects variable edaphic conditions and edge effects within small, patchy paleomires. Tradewater Formation strata show increased marine influences and tidal-estuarine sedimentation, especially in the middle and upper parts. Coal beds in the lower part of the Tradewater typically are thin and discontinuous, although some economically important beds are present. Coals become thicker, more abundant and more laterally persistent towards the top of the formation. Palynologically, lower and middle Tradewater Formation coals are dominated by Lycospora, but begin to show increased amounts of tree fern spores. Middle and upper Tradewater coals are thicker and more continuous, and contain high percentages of tree fern spores. In addition, cordaite pollen is locally abundant in this interval. Carbondale and Shelburn (Desmoinesian) strata are much more laterally continuous, and occur within classic cyclothems that can be traced across the coal field. Cyclothems have long been interpreted as being eustatically driven, and glacio-eustacy controlled

  2. The Alabama, U.S.A., seismic event and strata collapse of May 7, 1986

    USGS Publications Warehouse

    Long, L.T.; Copeland, C.W.

    1989-01-01

    On May 7, 1986, the residents of Tuscaloosa, Alabama, felt a seismic event of local magnitude 3.6 that occurred at the same time as a rock burst and roof collapse in an active longwall coal mine. Visual inspection of the seismograms reveals a deficiency in energy at frequencies above 20 Hz compared to tectonic earthquakes or surface blasts. The predominance of energy below 5 Hz may explain reports of body wave magnitudes (mb) greater than 4.2. Also, 1.0 Hz surface waves were more strongly excited than body waves and may explain local felt effects more typically associated with greater epicentral distances. All recorded first motions were dilatational. The concentration of stations in the northern hemisphere allows reverse motion on an east-trending near-vertical plane or strike-slip motion on northwest or southeast trending planes. The reverse focal mechanism is preferred, because the area of roof collapse and the area of active longwall mining are located between two east-striking loose vertical fracture zones. The characteristics of the seismic event suggest that it might have been sudden shear failure resulting from accumulated strain energy in overlying strata behind an active longwall. Although an alternate interpretation of the focal mechanism as an implosion or shear failure in the strata above previously mined out areas is also allowed by the first motion data, this alternate intepretation is not supported by geological data. ?? 1989 Birkha??user Verlag.

  3. Idiosyncrasies of Cherokee genetic sequence of strata, north-central Oklahoma

    SciTech Connect

    O'brien, J.E.

    1987-08-01

    In plan view, the individual genetic increments of strata that comprise the Cherokee genetic sequence of strata are, for the most part, a complex maze of anastomosing fluvial channels generally trending north-south. This picture is further complicated by many isolated pods, splays, and partially preserved minor channels between and outside of the main channels. When viewed in cross section, a few of the individual thick sandstone deposits (50-100 ft) are the result of a single depositional event. Most of these deposits are the result of the stacking of two or three individual channels. An additional complication occurs when downcutting into an underlying interval results in younger sandstones being stacked on older sandstones or occupying an interval that would appear to correlate with the older unit. The rigid use of stereotype principles, such as type electric log signatures (e.g., bell shaped indicating a channel, inverted bell a bar, etc), unimaginative isopach contouring, computer generated data and/or maps, and scout card or other published information will yield erroneous interpretations. Electric logs need to be intelligently examined and interpreted. Numerous cross sections need to be constructed to show proper stratigraphic relationships. Well cuttings need to be examined microscopically. Isopach maps must be constructed with interpretive imagination, not by rote, in order to yield valid oil-finding interpretations.

  4. Automated Segmentation of Skin Strata in Reflectance Confocal Microscopy Depth Stacks.

    PubMed

    Hames, Samuel C; Ardigò, Marco; Soyer, H Peter; Bradley, Andrew P; Prow, Tarl W

    2016-01-01

    Reflectance confocal microscopy (RCM) is a powerful tool for in-vivo examination of a variety of skin diseases. However, current use of RCM depends on qualitative examination by a human expert to look for specific features in the different strata of the skin. Developing approaches to quantify features in RCM imagery requires an automated understanding of what anatomical strata is present in a given en-face section. This work presents an automated approach using a bag of features approach to represent en-face sections and a logistic regression classifier to classify sections into one of four classes (stratum corneum, viable epidermis, dermal-epidermal junction and papillary dermis). This approach was developed and tested using a dataset of 308 depth stacks from 54 volunteers in two age groups (20-30 and 50-70 years of age). The classification accuracy on the test set was 85.6%. The mean absolute error in determining the interface depth for each of the stratum corneum/viable epidermis, viable epidermis/dermal-epidermal junction and dermal-epidermal junction/papillary dermis interfaces were 3.1 μm, 6.0 μm and 5.5 μm respectively. The probabilities predicted by the classifier in the test set showed that the classifier learned an effective model of the anatomy of human skin.

  5. Automated Segmentation of Skin Strata in Reflectance Confocal Microscopy Depth Stacks

    PubMed Central

    Hames, Samuel C.; Ardigò, Marco; Soyer, H. Peter; Bradley, Andrew P.; Prow, Tarl W.

    2016-01-01

    Reflectance confocal microscopy (RCM) is a powerful tool for in-vivo examination of a variety of skin diseases. However, current use of RCM depends on qualitative examination by a human expert to look for specific features in the different strata of the skin. Developing approaches to quantify features in RCM imagery requires an automated understanding of what anatomical strata is present in a given en-face section. This work presents an automated approach using a bag of features approach to represent en-face sections and a logistic regression classifier to classify sections into one of four classes (stratum corneum, viable epidermis, dermal-epidermal junction and papillary dermis). This approach was developed and tested using a dataset of 308 depth stacks from 54 volunteers in two age groups (20–30 and 50–70 years of age). The classification accuracy on the test set was 85.6%. The mean absolute error in determining the interface depth for each of the stratum corneum/viable epidermis, viable epidermis/dermal-epidermal junction and dermal-epidermal junction/papillary dermis interfaces were 3.1 μm, 6.0 μm and 5.5 μm respectively. The probabilities predicted by the classifier in the test set showed that the classifier learned an effective model of the anatomy of human skin. PMID:27088865

  6. Late Jurassic extension in the Bisbee basin: Marine and volcanic strata of the Chiricahua Mountains, Arizona

    SciTech Connect

    Lawton, T.F.; McMillan, N.J. ); Cameron, K.L. . Earth Sciences Board)

    1993-04-01

    Upper Jurassic strata in the northeastern Chiricahua Mountains provide unambiguous stratigraphic and geographic links between the Chihuahua trough of north-central Mexico and the Bisbee basin of southeastern Arizona. Approximately 1,800 m of limestone, shale, and mafic volcanic rocks overlie the Glance Conglomerate and underlie fluvial redbeds of the Lower Cretaceous Morita Formation. Basal strata are alluvial-fan and sabkha deposits. A thick (150 m), ammonite-bearing black shale interval above the sabkha deposits indicates an abrupt increase of water depths; deepening was accompanied initially by emplacement of subaerial basalt flows and subsequently by deposition of basaltic tuff and pillow lava. Ammonites are present both below and above the tuff and indicate its exclusively subaqueous origin. Arkosic deltaic deposits above the tuff were derived from Precambrian rocks of the footwall block to the northeast. At least 200 m of mafic subaerial flows, previously regarded as mid-Tertiary, overlie the deltaic deposits. The existence of a depleted mantle source beneath the Bisbee basin at 150 Ma suggests a unique tectonic setting that combined backarc and Gulf of Mexico extension.

  7. Variation in sedimentology and architecture of Eocene alluvial strata, Wind River and Washakie basins, Wyoming

    SciTech Connect

    Patterson, P.E.; Larson, E.E. )

    1991-03-01

    Eocene continental, alluvial strata of the Wind River Formation (Wind River Basin) and the Cathedral Bluffs Member of the Wasatch Formation (Washakie basin) provide two examples of Laramide intermontane basin aggradation. These alluvial sediments primarily represent overbank flood deposits marginal to channel complexes. Their sedimentology and architecture, although grossly similar, appear to vary somewhat with proximity to Laramide uplifts. In both cases, repetitive sedimentation on the floodplain produced a succession of depositional couplets, each composed of a light-gray sand overlain by a red clay-rich silt or sand. The lower sands are tabular bodies that, near their distal margins, taper discernibly. They commonly display planar and ripple-drift laminations. Upper clay-rich layers, which are laminated, are also generally tabular. Those floodplain strata depositional proximal to Laramide uplifts show little evidence of scouring prior to deposition of the next, overlying couplet. Most of these sedimentary layers, therefore, are laterally continuous (up to 2 km). This alluvial architecture results in relatively uniform porosity laterally within depositional units but variable porosity stratigraphically through the sequence. In contrast, alluvial sediments deposited farther from the Laramide uplifts have undergone sporadic incision (either during rising flood stage or subsequently) followed by aggradation. As a result, many of these floodplain couplets are discontinuous laterally and, hence, exhibit large-scale lateral variability in porosity. Both alluvial sequences have undergone similar types and extents of burial diagenesis.

  8. Numerical study on the responses of groundwater and strata to pumping and recharge in a deep confined aquifer

    NASA Astrophysics Data System (ADS)

    Zhang, Yang-Qing; Wang, Jian-Hua; Chen, Jin-Jian; Li, Ming-Guang

    2017-05-01

    Groundwater drawdown and strata settlements induced by dewatering in confined aquifers can be relieved by artificial recharge. In this study, numerical simulations of a field multi-well pumping-recharge test in a deep confined aquifer are conducted to analyze the responses of groundwater and strata to pumping and recharge. A three-dimensional numerical model is developed in a finite-difference software, which considers the fluid-mechanical interaction using the Biot consolidation theory. The predicted groundwater drawdown and ground settlements are compared to the measured data to confirm the validation of the numerical analysis of the pumping and recharge. Both numerical results and measured data indicate that the effect of recharge on controlling the groundwater drawdown and strata settlements correlates with the injection rate and well arrangements. Since the groundwater drawdown induced by pumping can be controlled by artificial recharge, soil compression can be relieved by reducing the changes of effective stress of the soils. Consequently, strata settlement induced by pumping can be relieved by artificial recharge and ground settlements can be eliminated if an appropriate injection rate and well arrangement are being determined. Moreover, the changes of the pore pressure and seepage force induced by pumping and recharge will also result in significant horizontal deformations in the strata near the recharge wells.

  9. Paleomagnetism and rock magnetism of Quaternary volcanic rocks and Late Paleozoic strata, VC-1 core hole, Valles Caldera, New Mexico, with emphasis on remagnetization of Late Paleozoic strata

    NASA Astrophysics Data System (ADS)

    Geissman, John W.

    1988-06-01

    Paleomagnetic and rock magnetic data obtained from azimuthally unoriented core samples, collected at approximately 1- to 3-m intervals, of Continental Scientific Drilling Program core hole VC-1 have prompted reinterpretations of the Quaternary volcanic stratigraphy intersected by the bore and have aided in evaluating the thermal regime within late Paleozoic strata attending fluid circulation and mineral deposition during and after development of the Toledo and Valles calderas. The results from Quaternary units (Banco Bonito Obsidian: I = +35.4°, a95 = 2.8° (inclination only determinations), n = 33; Battleship Rock Tuff: D = 359.6°, I = +42.4°, a95 = 2.8°, n = 5 site means (surface sites); VC-1 Rhyolite: I = +39.2°, a95 = 12.8°, n = 7; Upper VC-1 Tuff: I = +37.2°, a95 = 10.7°, n = 13; Middle VC-1 Tuff: I = +42.1°, a95 = 2.1°, n = 39; South Mountain Rhyolite: D = 350.9°, I = +49.9°, a95 = 3.4°, n = 10 (one surface site)) are consistent with isotopic age data, indicating that the entire moat volcanic sequence intersected is less than 650 kyr. Monitoring of natural remanent magnetization (NRM) intensity, NRM directions, directions of magnetizations isolated during progressive demagnetization, median destructive forces, and rock magnetization parameters has identified systematic variations within the thick Banco Bonito Obsidian and VC-1 Tuff units. The Permian Abo Formation, Pennsylvanian to earliest Permian Madera Limestone, and Pennsylvanian Sandia Formation typically contain a moderate positive inclination magnetization component (Abo Formation: I = +52.2°, a95 = 7.4°, n = 16; Madera Limestone: I = +58.4°, a95 = 2.8°, n = 105; Sandia Formation: I = +53.9°, a95 = 4.8°, n = 21); when residing in magnetite, it is usually unblocked in the laboratory by 350°C; when carried by hematite it is unblocked by 550°C. A moderate negative inclination (e.g., Madera and Abo strata: D = 173.1°, I = -46.6°, a95 = 5.5°; n = 47 samples; assuming a north seeking

  10. Review of Paleomagnetic Age Constraints of Mid-Continent Rift Strata, Upper Midwestern United States

    NASA Astrophysics Data System (ADS)

    Houlihan, E.; Runkel, A.; Feinberg, J. M.; Cowan, C. A.; Titus, S.

    2016-12-01

    The Keweenawan Supergroup consists of 1.1 Ga volcanic units and overlying km-thick sedimentary succession that are associated with the Midcontinent Rift (MR), one of the most prominent geologic features in the Precambrian basement rocks of the North American craton (Morey and Green, 1982; Ojakangas et al., 2001; Ojakangas and Dickas, 2002). Recent studies targeting the sedimentary sequences of the rift highlight a longstanding problem that limits the impact of their results. The studies are based on data collected from a sedimentary package of the Keweenawan Supergroup that is very poorly constrained in age. Sedimentary strata low in the succession are constrained by dated intercalated volcanics, or mineralization ages, that indicate syn-rift filling commenced at about 1087 Ma as volcanism was waning (Davis and Paces, 1990). However, km-thick younger strata within the rift are constrained in maximum age only by virtue of overlying Cambrian fossil-bearing units (Morey and Ojakangas, 1982). Thus, the bulk of the MR sedimentary succession has a range in possible age of about 500 Ma, and potentially is in places as young as Middle Cambrian. Paleomagnetic methods may hold the most promise to date the MR sedimentary succession. Widespread paleomagnetic studies have been conducted on the igneous rocks of the rift, and several previous studies have used paleomagnetic techniques to date the sedimentary units as well (Dubois, 1962; Henry et al., 1976; Elmore and Van der Voo, 1978; Roy and Robertson, 1978; Halls and Palmer, 1981; Palmer et al., 1981; Watts, 1981; McCabe and Van der Voo, 1982; Diehl and Haig, 1994; Kulakov et al., 2013 and others). These authors generally considered the paleomagnetic signatures to be consistent with a Mesoproterozoic age for both the igneous and sedimentary rocks of the rift. Recently, however, authors have suggested that the uppermost sedimentary units are much younger in age, based on a combination of zircon and paleomagnetic analysis

  11. Lower Cretaceous bentonitic strata in southwestern Montana assigned to Vaughn Member of Mowry Shale (East) and of Blackleaf Formation (West)

    USGS Publications Warehouse

    Tysdal, R.G.; Dyman, T.S.; Nichols, D.J.

    1989-01-01

    The Vaughn Member, newly assigned to the Mowry Shale in this report, comprises strata that crop out in the Greenhorn, Gravelly, Madison, and Gallatin ranges, and the Centennial and Beartooth mountains of southwestern Montana. Herein the member is correlated with the Vaughn Member of the Blackleaf Formation, which crops out to the west in the Lima Peaks area, Snowcrest Range, and Pioneer Mountains. Strata assigned to the Vaughn Member of the Blackleaf Formation in southwestern Montana exhibit the same contrasting relationships that exist in northwestern Montana. The Vaughn Member of the Mowry is late Albian in age, determined by bracketing with shallow water marine bivalves in the Muddy Sandstone below and palynomorphs in Mowry strata above. Palynomorphs from the Vaughn Member itself are typically mid-Cretaceous, but do not permit a more exact determination of age. -from Authors

  12. Metals in Devonian kerogenous marine strata at Gibellini and Bisoni properties in southern Fish Creek Range, Eureka County, Nevada

    USGS Publications Warehouse

    Desborough, George A.; Poole, F.G.; Hose, R.K.; Radtke, A.S.

    1979-01-01

    A kerogen-rich sequence of siliceous mudstone, siltstone, and chert as much as 60 m thick on ridge 7129 in the southern Fish Creek Range, referred to as Gibellini facies of the Woodruff Formation, has been evaluated on the surface and in drill holes principally for its potential resources of vanadium, zinc, selenium, molybdenum, and syncrude oil content. The strata are part of a strongly deformed allochthonous mass of eugeosynclinal Devonian marine rocks that overlie deformed allochthonous Mississippian siliceous rocks and relatively undeformed autochthonous Mississippian Antler flysch at this locality. The vanadium in fresh black rocks obtained from drill holes and fresh exposures in trenches and roadcuts occurs chiefly in organic matter. Concentrations of vanadium oxide (V2O5) in unoxidized samples range from 3,000 to 7,000 ppm. In oxidized and bleached rock that is prevalent at the surface, concentrations of vanadium oxide range from 6,000 to 8,000 ppm, suggesting a tendency toward enrichment due to surficial weathering and ground-water movement. Zinc occurs in sphalerite, and selenium occurs in organic matter; molybdenum appears to occur both in molybdenite and in organic matter. Concentrations of zinc in unoxidized rock range from 4,000 to 18,000 ppm, whereas in oxidized rock they range from 30 to 100 ppm, showing strong depletion due to weathering. Concentrations of selenium in unoxidized rock range from 30 to 200 ppm, whereas in oxidized rock they range from 200 to 400 ppm, indicating some enrichment upon weathering. Concentrations of molybdenum in unoxidized rock range from 70 to 960 ppm, whereas in oxidized rock they range from 30 to 80 ppm, indicating strong depletion upon weathering. Most fresh black rock is low-grade oil shale, and yields as much as 12 gallons/short ton of syncrude oil. Metahewettite is the principal vanadium mineral in the oxidized zone, but it also occurs sparsely as small nodules and fillings of microfractures in unweathered strata

  13. Defining relations for the orbit type strata of SU(2) -lattice gauge models

    NASA Astrophysics Data System (ADS)

    Fürstenberg, F.; Rudolph, G.; Schmidt, M.

    2017-09-01

    We consider an SU(2) -lattice gauge model in the tree gauge. Classically, this is a system with symmetries whose configuration space is a direct product of copies of SU(2) , acted upon by diagonal inner automorphisms. We derive defining relations for the orbit type strata in the reduced classical phase space. The latter is realized as a certain quotient of a direct product of copies of the complexified group SL(2 , C) (sometimes named the GIT-quotient because it provides a categorical quotient in the sense of geometric invariant theory). The relations derived can be used for the construction of the orbit type costratification of the Hilbert space of the quantum system in the sense of Huebschmann.

  14. A theorem on orbit structures (strata) of compact linear Lie groups

    NASA Astrophysics Data System (ADS)

    Sartori, G.

    1983-04-01

    We present a comprehensive constructive proof of a theorem characterizing the tangent space to a stratum (orbit structure) of the Euclidean space Rn, seat of an orthogonal representation of a compact group G. The characterization is made in terms of gradients of a complete set (integrity basis) of G-invariant polynomials. In a recent paper [M. Abud and G. Sartori, Phys. Lett. B 104, 147 (1981)], the theorem, which may be considered a generalization of a theorem by Michel [C. R. Acad. Sci. Ser. A 272, 433 (1971)], has been shown to be effective in the determination of the equations of the strata and in the determination of natural extrema of G-invariant functions.

  15. Adaptive biased urn randomization in small strata when blinding is impossible.

    PubMed

    Schouten, H J

    1995-12-01

    Adaptive biased urn randomization, applied in, e.g., a clinical trial, has certain attractive properties. If stratified randomization is desired, a good balance between group sizes can be guaranteed, even in (very) small strata. Yet treatment assignment may be kept unpredictable, which is necessary to avoid selection bias if blinding is impossible. In the present paper a more flexible urn model is described. The investigator may choose assignment probabilities that strongly depend on the degree of imbalance when the groups are still small, but with a tendency toward complete randomization when the groups become large. It is also possible to keep the difference in group size below a chosen maximum, which is useful if population characteristics may change during the course of a trial. The new urn model includes random permutations and complete randomization as special cases. An extension of the model allows the promotion of unequal group sizes. Some attention is paid to a randomized version of the minimization method.

  16. Method, system and computer program product for monitoring and optimizing fluid extraction from geologic strata

    DOEpatents

    Medizade, Masoud; Ridgely, John Robert

    2009-12-15

    An arrangement which utilizes an inexpensive flap valve/flow transducer combination and a simple local supervisory control system to monitor and/or control the operation of a positive displacement pump used to extract petroleum from geologic strata. The local supervisory control system controls the operation of an electric motor which drives a reciprocating positive displacement pump so as to maximize the volume of petroleum extracted from the well per pump stroke while minimizing electricity usage and pump-off situations. By reducing the electrical demand and pump-off (i.e., "pounding" or "fluid pound") occurrences, operating and maintenance costs should be reduced sufficiently to allow petroleum recovery from marginally productive petroleum fields. The local supervisory control system includes one or more applications to at least collect flow signal data generated during operation of the positive displacement pump. No flow, low flow and flow duration are easily evaluated using the flap valve/flow transducer arrangement.

  17. Transgressive-regressive cycles and the occurrence of coal in some Upper Cretaceous strata of Utah

    SciTech Connect

    Ryer, T.A.

    1983-04-01

    Cenomanian-Santonian strata contain about 60 per cent of the known Cretaceous coal reserves of Utah. The areal and temporal distribution of these resources can be related to the transgressive-regressive history of the western shoreline of the Interior Cretaceous seaway. Two orders of transgressive-regressive cycles, the larger of which corresponds to third order cycles of Vail et al, are deemed important in analyzing the distribution of coal in Utah. The largest coalfields are associated with extensive vertical stacking of the deposits of what are here termed fourth-order cycles at the transgressive and regressive maxima of third-order cycles. Deposits of transgressive and regressive phases of third-order cycles contain only minor amounts of coal. This genetic relationship may prove useful in predicting areas of important Cretaceous coal resources in deeper parts of structural basins in the Rocky Mountain region.

  18. Solute concentrations influence microbial methanogenesis in coal-bearing strata of the Cherokee basin, USA

    DOE PAGES

    Kirk, Matthew F.; Wilson, Brien H.; Marquart, Kyle A.; ...

    2015-11-18

    In this study, microorganisms have contributed significantly to subsurface energy resources by converting organic matter in hydrocarbon reservoirs into methane, the main component of natural gas. In this study, we consider environmental controls on microbial populations in coal-bearing strata of the Cherokee basin, an unconventional natural gas resource in southeast Kansas, USA. Pennsylvanian-age strata in the basin contain numerous thin (0.4–1.1 m) coalbeds with marginal thermal maturities (0.5–0.7% Ro) that are interbedded with shale and sandstone. We collected gas, water, and microbe samples from 16 commercial coalbed methane wells for geochemical and microbiological analysis. The water samples were Na–Cl typemore » with total dissolved solids (TDS) content ranging from 34.9 to 91.3 g L–1. Gas dryness values [C1/(C2 + C3)] averaged 2640 and carbon and hydrogen isotope ratios of methane differed from those of carbon dioxide and water, respectively, by an average of 65 and 183‰. These values are thought to be consistent with gas that formed primarily by hydrogenotrophic methanogenesis. Results from cultivation assays and taxonomic analysis of 16S rRNA genes agree with the geochemical results. Cultivable methanogens were present in every sample tested, methanogen sequences dominate the archaeal community in each sample (avg 91%), and few archaeal sequences (avg 4.2%) were classified within Methanosarcinales, an order of methanogens known to contain methylotrophic methanogens. Although hydrogenotrophs appear dominant, geochemical and microbial analyses both indicate that the proportion of methane generated by acetoclastic methanogens increases with the solute content of formation water, a trend that is contrary to existing conceptual models. Consistent with this trend, beta diversity analyses show that archaeal diversity significantly correlates with formation water solute content. In contrast, bacterial diversity more strongly correlates with location

  19. Solute Concentrations Influence Microbial Methanogenesis in Coal-bearing Strata of the Cherokee Basin, USA.

    PubMed

    Kirk, Matthew F; Wilson, Brien H; Marquart, Kyle A; Zeglin, Lydia H; Vinson, David S; Flynn, Theodore M

    2015-01-01

    Microorganisms have contributed significantly to subsurface energy resources by converting organic matter in hydrocarbon reservoirs into methane, the main component of natural gas. In this study, we consider environmental controls on microbial populations in coal-bearing strata of the Cherokee basin, an unconventional natural gas resource in southeast Kansas, USA. Pennsylvanian-age strata in the basin contain numerous thin (0.4-1.1 m) coalbeds with marginal thermal maturities (0.5-0.7% R o ) that are interbedded with shale and sandstone. We collected gas, water, and microbe samples from 16 commercial coalbed methane wells for geochemical and microbiological analysis. The water samples were Na-Cl type with total dissolved solids (TDS) content ranging from 34.9 to 91.3 g L(-1). Gas dryness values [C1/(C2 + C3)] averaged 2640 and carbon and hydrogen isotope ratios of methane differed from those of carbon dioxide and water, respectively, by an average of 65 and 183‰. These values are thought to be consistent with gas that formed primarily by hydrogenotrophic methanogenesis. Results from cultivation assays and taxonomic analysis of 16S rRNA genes agree with the geochemical results. Cultivable methanogens were present in every sample tested, methanogen sequences dominate the archaeal community in each sample (avg 91%), and few archaeal sequences (avg 4.2%) were classified within Methanosarcinales, an order of methanogens known to contain methylotrophic methanogens. Although hydrogenotrophs appear dominant, geochemical and microbial analyses both indicate that the proportion of methane generated by acetoclastic methanogens increases with the solute content of formation water, a trend that is contrary to existing conceptual models. Consistent with this trend, beta diversity analyses show that archaeal diversity significantly correlates with formation water solute content. In contrast, bacterial diversity more strongly correlates with location than solute content

  20. Hydraulic testing of low-permeability Silurian and Ordovician strata, Michigan Basin, southwestern Ontario

    NASA Astrophysics Data System (ADS)

    Beauheim, Richard L.; Roberts, Randall M.; Avis, John D.

    2014-02-01

    Straddle-packer hydraulic testing was performed in 31 Silurian intervals and 66 Ordovician intervals in six deep boreholes at the Bruce nuclear site, located near Tiverton, Ontario, as part of site-characterization activities for a proposed deep geologic repository (DGR) for low- and intermediate-level radioactive waste. The straddle-packer assembly incorporated a hydraulic piston to initiate in situ pulse tests within low hydraulic conductivity (<1E-10 m/s) test intervals. Pressure transient data collected during the hydraulic tests were analyzed using the well-test simulator nSIGHTS to estimate the hydraulic properties specified as fitting parameters for the tested intervals, quantify parameter uncertainty, and define parameter correlations. Horizontal hydraulic conductivities of the Silurian test intervals range from approximately 4E-14 to 4E-8 m/s. The average horizontal hydraulic conductivities of the Ordovician intervals range from 2E-16 to 2E-10 m/s. The Lower Member of the Cobourg Formation, the proposed host formation of the DGR between 660 and 688 meters below ground surface, was found to have a horizontal hydraulic conductivity of 4E-15 to 3E-14 m/s. The formation pressures inferred from the hydraulic testing, confirmed by long-term monitoring, show that the Upper Ordovician and Middle Ordovician Trenton Group are significantly underpressured relative to a density-compensated hydrostatic condition and relative to the overlying Silurian strata and underlying Black River Group and Cambrian strata. These underpressures could not persist if hydraulic conductivities were not as low as those measured.

  1. Westward overstepping of Lower Mississippian by Upper Mississippian strata in eastern Nevada

    SciTech Connect

    Nichols, K.M.; Silberling, N.J.; Macke, D.L. )

    1993-04-01

    The Mississippian section in western Utah includes three complete, successive stratigraphic sequence, each representing a distinct third-order transgressive-regressive (T-R) cycle. In ascending order, these sequences are informally named the Morris (MO), Sadlick (SA), and Maughan (MA) (Silberling and others, this volume). In west-central Utah, the MO is represented by strata customarily regarded as the lower part of the Joana Limestone, SA by the upper part of the Joana and the Needle Siltstone Member of the Chainman Shale, and MA by the Skunk Spring Limestone Bed and part of the overlying Chainman Shale. The systems tracts that define the stratigraphic boundaries between these three sequences can be traced westward to the southern Egan Range in Nevada. Farther west, in the White Pine Range, MA rests disconformably on MO, and SA is cut out between them. Still farther west, in the north-central Pancake Range where MO limestones are 22 m thick, terra-rossa soil and/or a sedimentary breccia of MO limestone separate MO from a few meters of micritic radiolarian limestone below a thick section of MA argillite. Through stratigraphic thicknesses of as much as a few tens of meters, discontinuous units of this micrite, along with units of encrinite, are interstratified with argillite similar to that which forms much of the overlying strata of the Dale Canyon Formation or Chainman Shale. This sequence, directly overlying the Pilot Shale, could either be MA, and thus mid or late Meramecian in age at its base, or be an older Mississippian sequence unrelated to the sequences occurring farther east in Nevada and in Utah.

  2. Comparative Sex Chromosome Genomics in Snakes: Differentiation, Evolutionary Strata, and Lack of Global Dosage Compensation

    PubMed Central

    Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

    2013-01-01

    Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes

  3. Generation and Migration of Natural Gas in Miocene Strata, Offshore Southeastern Korea

    NASA Astrophysics Data System (ADS)

    Son, Byeong-Kook

    2016-04-01

    Natural gas and condensate are produced from Miocene strata of the Tertiary marine basin, called Ulleung Basin, which is located offshore southeastern Korea. Petroleum system in the basin has not been fully understood, because effective source rocks have not been identified in the area. However, 1-D petroleum system modelling and isotope data indicate that the source rock of the natural gas and condensate might be present at deeper strata than 5,000 m in the basin. In addition, the analysis of diamondoids in the condensate shows that the gas was transformed from type II kerogen. Based on this source rock information and other geological data, 2-D petroleum system modelling was conducted on two cross sections in the southwestern margin of the basin. The 2-D models show two phase generation and migration, which are caused by the geometry of source bed and the maturity level of each pod of the bed. In addition, the accumulation of hydrocarbon is constrained greatly by the timing of development of the regional seal. The first generation and migration of oil and gas begins with a high rate of sedimentation at a deeply and early buried pod of the source bed at 15 Ma. The hydrocarbon, however, migrates upward and diffuses toward the surface. The second generation and migration occurs at around 11 Ma from the other pod of the source bed. This hydrocarbon migrates updip toward anticlines and accumulates into the traps of anticlines. On the other hand, the model shows that the generation and migration is dominated by gas, rather than oil. This model indicates that the accumulation of hydrocarbon can be completed only by the proper and sophisticated combination of the geological elements and the timing of hydrocarbon migration in time and space. This 2-D feature of generation and migration is supported by additional 1-D models of two pseudo-wells drilled on the 2-D section.

  4. Comparative sex chromosome genomics in snakes: differentiation, evolutionary strata, and lack of global dosage compensation.

    PubMed

    Vicoso, Beatriz; Emerson, J J; Zektser, Yulia; Mahajan, Shivani; Bachtrog, Doris

    2013-01-01

    Snakes exhibit genetic sex determination, with female heterogametic sex chromosomes (ZZ males, ZW females). Extensive cytogenetic work has suggested that the level of sex chromosome heteromorphism varies among species, with Boidae having entirely homomorphic sex chromosomes, Viperidae having completely heteromorphic sex chromosomes, and Colubridae showing partial differentiation. Here, we take a genomic approach to compare sex chromosome differentiation in these three snake families. We identify homomorphic sex chromosomes in boas (Boidae), but completely heteromorphic sex chromosomes in both garter snakes (Colubridae) and pygmy rattlesnake (Viperidae). Detection of W-linked gametologs enables us to establish the presence of evolutionary strata on garter and pygmy rattlesnake sex chromosomes where recombination was abolished at different time points. Sequence analysis shows that all strata are shared between pygmy rattlesnake and garter snake, i.e., recombination was abolished between the sex chromosomes before the two lineages diverged. The sex-biased transmission of the Z and its hemizygosity in females can impact patterns of molecular evolution, and we show that rates of evolution for Z-linked genes are increased relative to their pseudoautosomal homologs, both at synonymous and amino acid sites (even after controlling for mutational biases). This demonstrates that mutation rates are male-biased in snakes (male-driven evolution), but also supports faster-Z evolution due to differential selective effects on the Z. Finally, we perform a transcriptome analysis in boa and pygmy rattlesnake to establish baseline levels of sex-biased expression in homomorphic sex chromosomes, and show that heteromorphic ZW chromosomes in rattlesnakes lack chromosome-wide dosage compensation. Our study provides the first full scale overview of the evolution of snake sex chromosomes at the genomic level, thus greatly expanding our knowledge of reptilian and vertebrate sex chromosomes

  5. Ground penetrating radar imaging of cap rock, caliche and carbonate strata

    USGS Publications Warehouse

    Kruse, S.E.; Schneider, J.C.; Campagna, D.J.; Inman, J.A.; Hickey, T.D.

    2000-01-01

    Field experiments show ground penetrating radar (GPR) can be used to image shallow carbonate stratigraphy effectively in a variety of settings. In south Florida, the position and structure of cap rock cover on limestone can be an important control on surface water flow and vegetation, but larger scale outcrops (tens of meters) of cap rock are sparse. GPR mapping through south Florida prairie, cypress swamp and hardwood hammock resolves variations in thickness and structure of cap rock to ~3 m and holds the potential to test theories for cap rock-vegetation relationships. In other settings, carbonate strata are mapped to test models for the formation of local structural anomalies. A test of GPR imaging capabilities on an arid caliche (calcrete) horizon in southeastern Nevada shows depth penetration to ~2 m with resolution of the base of caliche. GPR profiling also succeeds in resolving more deeply buried (~5 m) limestone discontinuity surfaces that record subaerial exposure in south Florida. (C) 2000 Elsevier Science B.V. All rights reserved.Field experiments show ground penetrating radar (GPR) can be used to image shallow carbonate stratigraphy effectively in a variety of settings. In south Florida, the position and structure of cap rock cover on limestone can be an important control on surface water flow and vegetation, but larger scale outcrops (tens of meters) of cap rock are sparse. GPR mapping through south Florida prairie, cypress swamp and hardwood hammock resolves variations in thickness and structure of cap rock to approx. 3 m and holds the potential to test theories for cap rock-vegetation relationships. In other settings, carbonate strata are mapped to test models for the formation of local structural anomalies. A test of GPR imaging capabilities on an arid caliche (calcrete) horizon in southeastern Nevada shows depth penetration to approx. 2 m with resolution of the base of caliche. GPR profiling also succeeds in resolving more deeply buried (approx. 5

  6. Evidence for local volcanism in Mississippian continental-margin strata in southwestern Nevada, Nevada test site

    SciTech Connect

    Trexler, J.H. Jr.; Cashman, P.H. ); Herring, D.M.

    1993-04-01

    A thick section of siltstone, shale, and quartzite at NTS records continental-margin sedimentation coeval with Antler foreland-basin clastic fill to the west. These strata are Osagean and Meramecian (palynology) through upper Chesterian and Morrowan (ammonoids) in age, and appear to contain no sediment of sand or coarser size derived from the Antler allochthon. These rocks have been referred to by previous workers as part of the Eleana Fm., but the authors regard them as more properly equivalent to the Chainman Shale. Their composition has important tectonic implications. Preliminary data suggest that swelling clays in core drilled in these strata may originally have been wind-blown bentonitic ash. A continuously cored section at the north end of Syncline Ridge (hole UE17e) contains abundant swelling clays, as well as dolomite, anhydrite, and other evaporitic minerals. This mineral assemblage, combined with a paucity of fauna and bioturbation, indicates restricted circulation. Rare quartzite intervals near the top of the section are clean, current-reworked arenites with sedimentary structures indicating shallow marine, possibly intertidal conditions. This association suggests a restricted, shallowing-upward marine basin, probably anoxic at times. The clay content indicates a significant sediment input from air-fall ash. Present plate-reconstructions place southern Nevada near 2--8[degree] N latitude, with trade winds prevailing from the paleonortheast (near present north). Volcanic detritus in Late Mississippian sediments of southern Nevada is evidence that volcanism in the Antler orogenic terrane west of the foreland basin is recorded in shelf sediments east of the foreland.

  7. Solute Concentrations Influence Microbial Methanogenesis in Coal-bearing Strata of the Cherokee Basin, USA

    PubMed Central

    Kirk, Matthew F.; Wilson, Brien H.; Marquart, Kyle A.; Zeglin, Lydia H.; Vinson, David S.; Flynn, Theodore M.

    2015-01-01

    Microorganisms have contributed significantly to subsurface energy resources by converting organic matter in hydrocarbon reservoirs into methane, the main component of natural gas. In this study, we consider environmental controls on microbial populations in coal-bearing strata of the Cherokee basin, an unconventional natural gas resource in southeast Kansas, USA. Pennsylvanian-age strata in the basin contain numerous thin (0.4–1.1 m) coalbeds with marginal thermal maturities (0.5–0.7% Ro) that are interbedded with shale and sandstone. We collected gas, water, and microbe samples from 16 commercial coalbed methane wells for geochemical and microbiological analysis. The water samples were Na–Cl type with total dissolved solids (TDS) content ranging from 34.9 to 91.3 g L−1. Gas dryness values [C1/(C2 + C3)] averaged 2640 and carbon and hydrogen isotope ratios of methane differed from those of carbon dioxide and water, respectively, by an average of 65 and 183‰. These values are thought to be consistent with gas that formed primarily by hydrogenotrophic methanogenesis. Results from cultivation assays and taxonomic analysis of 16S rRNA genes agree with the geochemical results. Cultivable methanogens were present in every sample tested, methanogen sequences dominate the archaeal community in each sample (avg 91%), and few archaeal sequences (avg 4.2%) were classified within Methanosarcinales, an order of methanogens known to contain methylotrophic methanogens. Although hydrogenotrophs appear dominant, geochemical and microbial analyses both indicate that the proportion of methane generated by acetoclastic methanogens increases with the solute content of formation water, a trend that is contrary to existing conceptual models. Consistent with this trend, beta diversity analyses show that archaeal diversity significantly correlates with formation water solute content. In contrast, bacterial diversity more strongly correlates with location than solute content

  8. A Novel Geotechnical/Geostatistical Approach for Exploration and Production of Natural Gas from Multiple Geologic Strata: Quarterly report, January 1-March 31, 1997

    SciTech Connect

    1997-12-31

    This report discusses dewatering and production extension test periods, and the demonstration of newly developed technologies for multi-strata gas and water production to enhance commercial applications.

  9. Structural plays in Ellesmerian sequence and correlative strata of the National Petroleum Reserve, Alaska

    USGS Publications Warehouse

    Moore, Thomas E.; Potter, Christopher J.

    2003-01-01

    Reservoirs in deformed rocks of the Ellesmerian sequence in southern NPRA are assigned to two hydrocarbon plays, the Thrust-Belt play and the Ellesmerian Structural play. The two plays differ in that the Thrust-Belt play consists of reservoirs located in allochthonous strata in the frontal part of the Brooks Range fold-and-thrust belt, whereas those of the Ellesmerian Structural play are located in autochthonous or parautochthonous strata at deeper structural levels north of the Thrust-Belt play. Together, these structural plays are expected to contain about 3.5 TCF of gas but less than 6 million barrels of oil. These two plays are analyzed using a two-stage deformational model. The first stage of deformation occurred during the Neocomian, when distal strata of the Ellesmerian sequence were imbricated and assembled into deformational wedges emplaced northward onto regionally south-dipping authochon at 140-120 Ma. In the mid-Cretaceous following cessation of the deformation, the Colville basin, the foreland basin to the orogen, was filled with a thick clastic succession. During the second stage of deformation at about 60 Ma (early Tertiary), the combined older orogenic belt-foreland basin system was involved in another episode of north-vergent contractional deformation that deformed pre-existing stratigraphic and structurally trapped reservoir units, formed new structural traps, and caused significant amounts of uplift, although the amount of shortening was relatively small in comparison to the first episode of deformation. Hydrocarbon generation from source strata (Shublik Formation, Kingak Shale, and Otuk Formation) and migration into stratigraphic traps occurred primarily by sedimentary burial principally between 100-90 Ma, between the times of the two episodes of deformation. Subsequent burial caused deep stratigraphic traps to become overmature, cracking oil to gas, and some new generation to begin progressively higher in the section. Structural disruption of

  10. Assessment of undiscovered oil and gas resources in Jurassic and Cretaceous strata of the Gulf Coast, 2010

    USGS Publications Warehouse

    Dubiel, Russell F.; Warwick, Peter D.; Swanson, Sharon; Burke, Lauri; Biewick, Laura; Charpentier, Ronald R.; Coleman, James L.; Cook, Troy A.; Dennen, Kris; Doolan, Colin; Enomoto, Catherine; Hackley, Paul C.; Karlsen, Alexander W.; Klett, Timothy R.; Kinney, Scott A.; Lewan, Michael D.; Merrill, Matt; Pearson, Krystal; Pearson, Ofori N.; Pitman, Janet K.; Pollastro, Richard M.; Rowan, Elizabeth L.; Schenk, Christopher J.; Valentine, Brett

    2011-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 147.4 trillion cubic feet of undiscovered natural gas, 2.4 billion barrels of undiscovered oil, and 2.96 billion barrels of undiscovered natural gas liquids in Jurassic and Cretaceous strata in onshore lands and State waters of the Gulf Coast.

  11. The Effects of Socioeconomic Strata, Sex and Reading Achievement Level on the Auditory-Visual Integration Performance of Sixth Graders.

    ERIC Educational Resources Information Center

    King, Michael Duane

    This study investigates the differences between the auditory-visual integration ability of 80 sixth grade students when such variables as socioeconomic status, sex, intelligence, conservation ability, and reading achievement were controlled. Socioeconomic Strata were determined by Hollingshead's Four Factor Index of Social Position. The California…

  12. Gas migration model based on overburden strata fracture evolution law in three dimensional mine-induced stress conditions

    NASA Astrophysics Data System (ADS)

    Li, Xing; Yin, Guangzhi

    2017-04-01

    Based on the fracture features obtained from similarity simulation excavation experiment in 3D mine-induced stress condition, the gas migration model in gob area was set up, and numerical simulation using COMSOL Multiphysics software on gas migration law was studied. The research results show that: Gas pressure variety gradient and flow velocity are obviously influenced by fracture distribution shape. Gas concentration distribution presents the rounded rectangle shape in the lower strata, while in higher strata it tends to be a "O shape” morphology which is similar to the fracture form in strata above the gob. Besides, the pressure relief gas mainly accumulates in the working face fracture field, especially in the higher overlying strata. In the compaction field, gas concentration distribution form presents a “saddle” shape morphology in the vertical section, and gas concentration in boundary fracture zone is higher than in the compaction zone. It is remarkable that gas concentration in start-up fractured zone is also relatively high, and with the advance of working face, its gas enrichment degree decreases. The results of the research have an important guiding significance for coal and gas simultaneous extraction.

  13. Extensional fault-propagation folding and base-level change as controls on growth-strata geometries

    NASA Astrophysics Data System (ADS)

    Gawthorpe, Rob; Hardy, Stuart

    2002-01-01

    Outcrop and analogue modelling studies indicate that upward widening zones of distributed deformation, often monoclinal folds, form above blind normal faults and are particularly common features at the depositional surface during the early stages of rifting. With increasing displacement (strain), such folds are cut by faults as they propagate upwards into the cover. We use a kinematic model of fault-propagation folding above a blind extensional fault, together with a sedimentary model of coarse-grained clastic deposition, to investigate growth-strata geometries associated with fault-tip monoclines. In particular, we consider coarse-grained deltaic deposition where sedimentary geometries are markedly different from the simple sub-horizontal 'fill-to-the-top' sedimentation used in most growth-strata models. For a given fault dip and slip rate, growth-strata geometries are strongly influenced by the fault-propagation to slip ratio ( p/ s) and the width of the zone of distributed deformation. However, base-level changes also act as fundamental controls on sequence development. The results of a number of experiments compare favourably to well-documented examples of growth-strata. This study highlights the importance of integrating structural and stratigraphic studies in interpreting both fault/fold kinematics and the controls on stratigraphy; kinematic studies need to address the depositional geometry of stratal surfaces, whereas sequence stratigraphic interpretation of stratal patterns must deconvolve tectonic rotation and translation from depositional architecture.

  14. Migrated hydrocarbons in exposure of Maastrichtian nonmarine strata near Saddle Mountain, lower Cook Inlet, Alaska

    USGS Publications Warehouse

    LePain, D.L.; Lillis, P.G.; Helmold, K.P.; Stanley, R.G.

    2012-01-01

    Magoon and others (1980) described an 83-meter- (272-foot-) thick succession of Maastrichtian (Upper Cretaceous) conglomerate, sandstone, mudstone, and coal exposed on the south side of an unnamed drainage, approximately 3 kilometers (1.8 miles) east of Saddle Mountain in lower Cook Inlet (figs. 1 and 2). The initial significance of this exposure was that it was the first reported occurrence of nonmarine rocks of this age in outcrop in lower Cook Inlet, which helped constrain the Late Cretaceous paleogeography of the area and provided important information on the composition of latest Mesozoic sandstones in the basin. The Saddle Mountain section is thought to be an outcrop analog for Upper Cretaceous nonmarine strata penetrated in the OCS Y-0097 #1 (Raven) well, located approximately 40 kilometers (25 miles) to the south–southeast in Federal waters (fig. 1). Atlantic Richfield Company (ARCO) drilled the Raven well in 1980 and encountered oil-stained rocks and moveable liquid hydrocarbons between the depths of 1,760 and 3,700 feet. Completion reports on file with the Bureau of Ocean Energy Management (BOEM; formerly Bureau of Ocean Energy Management, Regulation and Enforcement, and prior to 2010, U.S. Minerals Management Service) either show flow rates of zero or do not mention flow rates. A fluid analysis report on file with BOEM suggests that a wireline tool sampled some oil beneath a 2,010-foot diesel cushion during the fl ow test of the 3,145–3,175 foot interval, but the recorded fl ow rate was still zero (Kirk Sherwood, written commun., January 9, 2012). Further delineation and evaluation of the apparent accumulation was never performed and the well was plugged and abandoned. As part of a 5-year comprehensive evaluation of the geology and petroleum systems of the Cook Inlet forearc basin, the Alaska Division of Geological & Geophysical Surveys obtained a research permit from the National Park Service to access the relatively poorly understood

  15. Sporomorphs from the Jackson Group (upper Eocene) and adjacent strata of Mississippi and western Alabama

    USGS Publications Warehouse

    Frederiksen, Norman O.

    1980-01-01

    This palynological study is based on 71 outcrop and core samples of the Jackson Group and adjacent strata from the type area of the group in western Mississippi and also from eastern Mississippi and western Alabama. The Jackson Group consists entirely of marine strata in the region of study. It includes the fossiliferous greensands of the Moodys Branch Formation at the base and the calcareous Yazoo Clay at the top. One hundred seventy-four sporomorph (spore and pollen) types are known from the Jackson Group and adjacent strata in the area of study; all but four of them were observed by the writer. The 174 types are assigned to 74 form genera, 37 modern genera, and 25 new species. Eleven species of pollen grains appear to have accurately determined restricted stratigraphic ranges within the sequence studied. Parsonsidites conspicuus Frederiksen and Ericipites aff. E. ericius (Potonie) Potonie have first occurrences (range bottoms) at the base of the Jackson Group. Aglaoreidia pristina Fowler has its first occurrence near the top of the Jackson. Eight species have last occurrences at or just below the top of the Jackson Group. These are Casuarinidites cf. C. granilabratus (Stanley) Srivastava, Chrysophyllum brevisulcatum (Frederiksen) n. comb., Cupanieidites orthoteichus Cookson and Pike, Symplocos gemroota n. sp., Nudopollis terminalis (Pflug and Thomson) Elsik, Sabal cf. S. granopollenites Rouse, Caprifoliipites tantulus n. sp., and Nypa echinata (Muller) n. comb. From the upper part of the Claiborne Group up through most of the Jackson, the dominant sporomorph types are Cupuliferdipollenites spp., Momipites coryloides Wodehouse, Cupuliferoidaepollenites liblarensis (Thomson) Potonie, Momipites micTofoveolatus (Stanley) Nichols, Quercoidites microhenricii (Potonie) Potonie, and Araliaceoipollenites granulatus (Potonie) n. comb. All these were probably produced by trees of the Juglandaceae and Fagaceae. Relative frequencies of each of these pollen types fluctuate

  16. Scalable Generalization of Hydraulic Conductivity in Quaternary Strata for Use in a Regional Groundwater Model

    NASA Astrophysics Data System (ADS)

    Jatnieks, J.; Popovs, K.; Klints, I.; Timuhins, A.; Kalvans, A.; Delina, A.; Saks, T.

    2012-04-01

    The cover of Quaternary sediments especially in formerly glaciated territories usually is the most complex part of the sedimentary sequences. In regional hydro-geological models it is often assumed as a single layer with uniform or calibrated properties (Valner 2003). However, the properties and structure of Quaternary sediments control the groundwater recharge: it can either direct the groundwater flow horizontally towards discharge in topographic lows or vertically, recharging groundwater in the bedrock. This work aims to present calibration results and detail our experience while integrating a scalable generalization of hydraulic conductivity for Quaternary strata in the regional groundwater modelling system for the Baltic artesian basin - MOSYS V1. We also present a method for solving boundary transitions between spatial clusters of lithologically similar structure. In this study the main unit of generalization is the spatial cluster. Clusters are obtained from distance calculations combining the Normalized Compression Distance (NCD) metric, calculated by the CompLearn parameter-free machine learning toolkit, with normalized Euclidean distance measures for coordinates of the borehole log data. A hierarchical clustering solution is used for obtaining cluster membership identifier for each borehole. Using boreholes as generator points for Voronoi tessellation and dissolving resulting polygons according to their cluster membership attribute, allows us to obtain spatial regions representing a certain degree of similarity in lithological structure. This degree of similarity and the spatial heterogeneity of the cluster polygons can be varied by different flattening of the hierarchical cluster model into variable number of clusters. This provides a scalable generalization solution which can be adapted according to model calibration performance. Using the dissimilarity matrix of the NCD metric, a borehole most similar to all the others from the lithological structure

  17. Neogene Tectonic and Climatic Records in the Marine Sedimentary Strata of the ST. Elias Mountains and the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Ridgway, K.; Enkelmann, E.; Allen, W. K.; Dunn, C. A.

    2015-12-01

    Over 5 km of Neogene marine sedimentary strata are well exposed in the St. Elias Range along the coast of Alaska. Immediately offshore in the Gulf of Alaska, the cores from the IODP Expedition 341 document correlative strata but provide a better temporally constrained record of more distal marine depositional processes. Together the onshore and offshore sedimentary records contain a transition from proximal to distal marine environments and provide insight on tectonics and surface processes interactions across a glaciated convergent margin. In this ongoing study, we document changing tectonic and climatic signals using U-Pb detrital zircon geochronology, zircon fission track thermochronology, and sedimentary lithofacies. For example, upper Miocene proximal strata consist of mudstone and sandstone that contain hummocky stratification that we interpret as being deposited in marine shelf environments. U-Pb detrital zircon ages from this unit have dominant populations from 59-63 and 85-90 Ma. In the distal submarine fan record, the upper Miocene strata consist of bioturbated mud and coarse sand that we interpret as marine sedimentary gravity flows followed by longer periods of hemipelagic deposition. The detrital zircon ages from these strata have dominant age populations from 53-54 and 60-80 Ma. The similar detrital ages from both the upper Miocene proximal and distal environments requires a common sediment link across the entire convergent margin by this time and the start of tectonic uplift of the modern mountain range. The start of Northern Hemisphere glaciation at 5.5 Ma in the proximal record is marked by submarine gravity flows interpreted to be reworked from alpine glacial deposits but to date there is no clear evidence of this climatic event in the distal record. The first clear record of glacial sediment input in the distal submarine fan environment is during the Plio-Pleistocene transition and recorded by ice-rafted muddy diamict beds.

  18. Spatial Probability Distribution of Strata's Lithofacies and its Impacts on Land Subsidence in Huairou Emergency Water Resources Region of Beijing

    NASA Astrophysics Data System (ADS)

    Li, Y.; Gong, H.; Zhu, L.; Guo, L.; Gao, M.; Zhou, C.

    2016-12-01

    Continuous over-exploitation of groundwater causes dramatic drawdown, and leads to regional land subsidence in the Huairou Emergency Water Resources region, which is located in the up-middle part of the Chaobai river basin of Beijing. Owing to the spatial heterogeneity of strata's lithofacies of the alluvial fan, ground deformation has no significant positive correlation with groundwater drawdown, and one of the challenges ahead is to quantify the spatial distribution of strata's lithofacies. The transition probability geostatistics approach provides potential for characterizing the distribution of heterogeneous lithofacies in the subsurface. Combined the thickness of clay layer extracted from the simulation, with deformation field acquired from PS-InSAR technology, the influence of strata's lithofacies on land subsidence can be analyzed quantitatively. The strata's lithofacies derived from borehole data were generalized into four categories and their probability distribution in the observe space was mined by using the transition probability geostatistics, of which clay was the predominant compressible material. Geologically plausible realizations of lithofacies distribution were produced, accounting for complex heterogeneity in alluvial plain. At a particular probability level of more than 40 percent, the volume of clay defined was 55 percent of the total volume of strata's lithofacies. This level, equaling nearly the volume of compressible clay derived from the geostatistics, was thus chosen to represent the boundary between compressible and uncompressible material. The method incorporates statistical geological information, such as distribution proportions, average lengths and juxtaposition tendencies of geological types, mainly derived from borehole data and expert knowledge, into the Markov chain model of transition probability. Some similarities of patterns were indicated between the spatial distribution of deformation field and clay layer. In the area with

  19. An integrated geophysical study on the Mesozoic strata distribution and hydrocarbon potential in the South China Sea

    NASA Astrophysics Data System (ADS)

    Hu, Weijian; Hao, Tianyao; Jiang, Weiwei; Xu, Ya; Zhao, Baimin; Jiang, Didi

    2015-11-01

    A series of drilling, dredge, and seismic investigations indicate that Mesozoic sediments exist in the South China Sea (SCS) which shows a bright prospect for oil and gas exploration. In order to study the distribution of Mesozoic strata and their residual thicknesses in the SCS, we carried out an integrated geophysical study based mainly on gravity data, gravity basement depth and distribution of residual Mesozoic thickness in the SCS were obtained using gravity inversion constrained with high-precision drilling and seismic data. In addition, the fine deep crustal structures and distribution characteristics of Mesozoic thicknesses of three typical profiles were obtained by gravity fitting inversion. Mesozoic strata in the SCS are mainly distributed in the south and north continental margins, and have been reformed by the later tectonic activities. They extend in NE-trending stripes are macro-controlled by the deep and large NE-trending faults, and cut by the NW-trending faults which were active in later times. The offset in NW direction of Mesozoic strata in Nansha area of the southern margin are more obvious as compared to the north margin. In the Pearl River Mouth Basin and Southwest Taiwan Basin of the north continental margin the Mesozoic sediments are continuously distributed with a relatively large thickness. In the Nansha area of the south margin the Mesozoic strata are discontinuous and their thicknesses vary considerably. According to the characteristics of Mesozoic thickness distribution and hydrocarbon potential analyses from drilling and other data, Dongsha Uplift-Chaoshan Depression, Southwest Taiwan Basin-Peikang Uplift and Liyue Bank have large thickness of the Mesozoic residual strata, have good hydrocarbon genesis capability and complete source-reservoir-cap combinations, show a bright prospect of Mesozoic oil/gas resources.

  20. Solute concentrations influence microbial methanogenesis in coal-bearing strata of the Cherokee basin, USA

    SciTech Connect

    Kirk, Matthew F.; Wilson, Brien H.; Marquart, Kyle A.; Zeglin, Lydia H.; Vinson, David S.; Flynn, Theodore M.

    2015-11-18

    In this study, microorganisms have contributed significantly to subsurface energy resources by converting organic matter in hydrocarbon reservoirs into methane, the main component of natural gas. In this study, we consider environmental controls on microbial populations in coal-bearing strata of the Cherokee basin, an unconventional natural gas resource in southeast Kansas, USA. Pennsylvanian-age strata in the basin contain numerous thin (0.4–1.1 m) coalbeds with marginal thermal maturities (0.5–0.7% Ro) that are interbedded with shale and sandstone. We collected gas, water, and microbe samples from 16 commercial coalbed methane wells for geochemical and microbiological analysis. The water samples were Na–Cl type with total dissolved solids (TDS) content ranging from 34.9 to 91.3 g L–1. Gas dryness values [C1/(C2 + C3)] averaged 2640 and carbon and hydrogen isotope ratios of methane differed from those of carbon dioxide and water, respectively, by an average of 65 and 183‰. These values are thought to be consistent with gas that formed primarily by hydrogenotrophic methanogenesis. Results from cultivation assays and taxonomic analysis of 16S rRNA genes agree with the geochemical results. Cultivable methanogens were present in every sample tested, methanogen sequences dominate the archaeal community in each sample (avg 91%), and few archaeal sequences (avg 4.2%) were classified within Methanosarcinales, an order of methanogens known to contain methylotrophic methanogens. Although hydrogenotrophs appear dominant, geochemical and microbial analyses both indicate that the proportion of methane generated by acetoclastic methanogens increases with the solute content of formation water, a trend that is contrary to existing conceptual models. Consistent with this trend, beta diversity analyses show that archaeal diversity significantly correlates with formation water solute content. In contrast

  1. Hierarchical sampling of multiple strata: an innovative technique in exposure characterization.

    PubMed

    Ericson, Jonathon E; Gonzalez, Elisabeth J

    2003-07-01

    Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 micro g/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P<0.05; R(2)=0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P<0.05; R(2)=0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be

  2. Epidemiological and clinical profile of paediatric malaria: a cross sectional study performed on febrile children in five epidemiological strata of malaria in Cameroon.

    PubMed

    Kwenti, Tebit Emmanuel; Kwenti, Tayong Dizzle Bita; Latz, Andreas; Njunda, Longdoh Anna; Nkuo-Akenji, Theresa

    2017-07-17

    In the wake of a decline in global malaria, it is imperative to describe the epidemiology of malaria in a country to inform control policies. The purpose of this study was to describe the epidemiological and clinical profile of paediatric malaria in five epidemiological strata of malaria in Cameroon including: the Sudano-sahelian (SS) strata, the High inland plateau (HIP) strata, the South Cameroonian Equatorial forest (SCEF) strata, the High western plateau (HWP) strata, and the Coastal (C) strata. This study involved 1609 febrile children (≤15 years) recruited using reference hospitals in the five epidemiological strata. Baseline characteristics were determined; blood glucose level was measured by a glucometer, malaria parasitaemia was assessed by Giemsa microscopy, and complete blood count was performed using an automated hematology analyser. Severe malaria was assessed and categorized based on WHO criteria. An overall prevalence of 15.0% (95% CI: 13.3-16.9) for malaria was observed in this study. Malaria prevalence was significantly higher in children between 60 and 119 months (p < 0.001) and in Limbe (C strata) (p < 0.001). The overall rate of severe malaria (SM) attack in this study was 29.3%; SM was significantly higher in children below 60 months (p < 0.046). Although not significant, the rate of SM was highest in Maroua (SS strata) and lowest in Limbe in the C strata. The main clinical phenotypes of SM were hyperparasitaemia, severe malaria anaemia and impaired consciousness. The majority (73.2%) of SM cases were in group 1 of the WHO classification of severe malaria (i.e. the most severe form). The malaria case-fatality rate was 5.8%; this was higher in Ngaoundere (HIP strata) (p = 0.034). In this study, malaria prevalence decreased steadily northward, from the C strata in the South to the SS strata in the North of Cameroon, meanwhile the mortality rate associated with malaria increased in the same direction. On the contrary, the rate of

  3. Uniparental Markers in Italy Reveal a Sex-Biased Genetic Structure and Different Historical Strata

    PubMed Central

    Sarno, Stefania; Harmant, Christine; Useli, Antonella; Sanz, Paula; Yang-Yao, Daniele; Manry, Jeremy; Ciani, Graziella; Luiselli, Donata; Quintana-Murci, Lluis; Comas, David; Pettener, Davide

    2013-01-01

    Located in the center of the Mediterranean landscape and with an extensive coastal line, the territory of what is today Italy has played an important role in the history of human settlements and movements of Southern Europe and the Mediterranean Basin. Populated since Paleolithic times, the complexity of human movements during the Neolithic, the Metal Ages and the most recent history of the two last millennia (involving the overlapping of different cultural and demic strata) has shaped the pattern of the modern Italian genetic structure. With the aim of disentangling this pattern and understanding which processes more importantly shaped the distribution of diversity, we have analyzed the uniparentally-inherited markers in ∼900 individuals from an extensive sampling across the Italian peninsula, Sardinia and Sicily. Spatial PCAs and DAPCs revealed a sex-biased pattern indicating different demographic histories for males and females. Besides the genetic outlier position of Sardinians, a North West–South East Y-chromosome structure is found in continental Italy. Such structure is in agreement with recent archeological syntheses indicating two independent and parallel processes of Neolithisation. In addition, date estimates pinpoint the importance of the cultural and demographic events during the late Neolithic and Metal Ages. On the other hand, mitochondrial diversity is distributed more homogeneously in agreement with older population events that might be related to the presence of an Italian Refugium during the last glacial period in Europe. PMID:23734255

  4. Application of deterministic deconvolution of ground-penetrating radar data in a study of carbonate strata

    USGS Publications Warehouse

    Xia, J.; Franseen, E.K.; Miller, R.D.; Weis, T.V.

    2004-01-01

    We successfully applied deterministic deconvolution to real ground-penetrating radar (GPR) data by using the source wavelet that was generated in and transmitted through air as the operator. The GPR data were collected with 400-MHz antennas on a bench adjacent to a cleanly exposed quarry face. The quarry site is characterized by horizontally bedded carbonate strata with shale partings. In order to provide groundtruth for this deconvolution approach, 23 conductive rods were drilled into the quarry face at key locations. The steel rods provided critical information for: (1) correlation between reflections on GPR data and geologic features exposed in the quarry face, (2) GPR resolution limits, (3) accuracy of velocities calculated from common midpoint data and (4) identifying any multiples. Comparing the results of deconvolved data with non-deconvolved data demonstrates the effectiveness of deterministic deconvolution in low dielectric-loss media for increased accuracy of velocity models (improved at least 10-15% in our study after deterministic deconvolution), increased vertical and horizontal resolution of specific geologic features and more accurate representation of geologic features as confirmed from detailed study of the adjacent quarry wall. ?? 2004 Elsevier B.V. All rights reserved.

  5. New occurrence of Lower Eocene (Capay Stage) strata, lower Piru Creek, Topatopa Mountains, southern California

    SciTech Connect

    Squires, R.L.; Yamashiro, D.A.

    1986-04-01

    A 900-m thick siltstone unit between Canton Canyon and Piru Creek, 16 km north of the town of Piru, California, previously was unnamed and considered as undifferentiated Eocene or middle Eocene in age. The Siltstone unconformably overlies the Whitaker Peak granodiorite basement complex. At the base of the siltstone is a veneer of gruss (weathered granodiorite). The gruss is usually overlain by about a few meters of shoreface carbonaceous sandstone that grades vertically upward into transition-zone siltstone (500 m) with storm-deposit accumulations of macrofossils. Collections made at 53 localities from these lower 500 m of strata yielded numerous shallow marine gastropods and bivalves, as well as specimens of discocyclinid foraminifers, colonial corals, calcareous worm tubes, and spataganoid echinoids. This fauna is indicative of the West Coast provincial molluscan Capay Stage (lower Eocene). Common age-diagnostic species are Turritella uvasana infera, T. Andersoni, and Ostrea haleyi. Overlying and gradational with the transition-zone siltstone is 400 m of muddy siltstone with rare storm-deposit accumulations of macrofossils. This muddy siltstone thickens westward and passes into deep-sea slope and inner-fan turbidite deposits. Collections made at three localities in the muddy siltstone yielded many shallow marine gastropods and bivalves indicative of the Domengine stage (upper lower through lower middle Eocene). Common age-diagnostic species are Turritella uvasana applinae and Pitar (Lamelliconcha) joaquinensis.

  6. Strata-1: An International Space Station Experiment into Fundamental Regolith Processes in Microgravity

    NASA Technical Reports Server (NTRS)

    Fries, M.; Abell, P.; Brisset, J.; Britt, D.; Colwell, J.; Durda, D.; Dove, A.; Graham, L.; Hartzell, C.; John, K.; Love, S.

    2016-01-01

    The Strata-1 experiment will study the evolution of asteroidal regolith through long-duration exposure of simulant materials to the microgravity environment on the International Space Station (ISS). Many asteroids feature low bulk densities, which implies high values of porosity and a mechanical structure composed of loosely bound particles, (i.e. the "rubble pile" model), a prime example of a granular medium. Even the higher-density, mechanically coherent asteroids feature a significant surface layer of loose regolith. These bodies are subjected to a variety of forces and will evolve in response to very small perturbations such as micrometeoroid impacts, planetary flybys, and the YORP effect. Our understanding of this dynamical evolution and the inter-particle forces involved would benefit from long-term observations of granular materials exposed to small vibrations in microgravity. A detailed understanding of asteroid mechanical evolution is needed in order to predict the surface characteristics of as-of-yet unvisited bodies, to understand the larger context of samples collected by missions such as OSIRIS-REx and Hayabusa 1 and 2, and to mitigate risks for both manned and unmanned missions to asteroidal bodies. Understanding regolith dynamics will inform designs of how to land and set anchors, safely sample/move material on asteroidal surfaces, process large volumes of material for in situ resource utilization (ISRU) purposes, and, in general, predict behavior of large and small particles on disturbed asteroid surfaces.

  7. Uniparental markers in Italy reveal a sex-biased genetic structure and different historical strata.

    PubMed

    Boattini, Alessio; Martinez-Cruz, Begoña; Sarno, Stefania; Harmant, Christine; Useli, Antonella; Sanz, Paula; Yang-Yao, Daniele; Manry, Jeremy; Ciani, Graziella; Luiselli, Donata; Quintana-Murci, Lluis; Comas, David; Pettener, Davide

    2013-01-01

    Located in the center of the Mediterranean landscape and with an extensive coastal line, the territory of what is today Italy has played an important role in the history of human settlements and movements of Southern Europe and the Mediterranean Basin. Populated since Paleolithic times, the complexity of human movements during the Neolithic, the Metal Ages and the most recent history of the two last millennia (involving the overlapping of different cultural and demic strata) has shaped the pattern of the modern Italian genetic structure. With the aim of disentangling this pattern and understanding which processes more importantly shaped the distribution of diversity, we have analyzed the uniparentally-inherited markers in ∼900 individuals from an extensive sampling across the Italian peninsula, Sardinia and Sicily. Spatial PCAs and DAPCs revealed a sex-biased pattern indicating different demographic histories for males and females. Besides the genetic outlier position of Sardinians, a North West-South East Y-chromosome structure is found in continental Italy. Such structure is in agreement with recent archeological syntheses indicating two independent and parallel processes of Neolithisation. In addition, date estimates pinpoint the importance of the cultural and demographic events during the late Neolithic and Metal Ages. On the other hand, mitochondrial diversity is distributed more homogeneously in agreement with older population events that might be related to the presence of an Italian Refugium during the last glacial period in Europe.

  8. Health risk assessment of ochratoxin A for all age-sex strata in a market economy

    PubMed Central

    Kuiper-Goodman, T.; Hilts, C.; Billiard, S.M.; Kiparissis, Y.; Richard, I.D.K.; Hayward, S.

    2009-01-01

    In order to manage risk of ochratoxin A (OTA) in foods, we re-evaluated the tolerable daily intake (TDI), derived the negligible cancer risk intake (NCRI), and conducted a probabilistic risk assessment. A new approach was developed to derive ‘usual’ probabilistic exposure in the presence of highly variable occurrence data, such as encountered with low levels of OTA. Canadian occurrence data were used for various raw food commodities or finished foods and were combined with US Department of Agriculture (USDA) food consumption data, which included data on infants and young children. Both variability and uncertainty in input data were considered in the resulting exposure estimates for various age/sex strata. Most people were exposed to OTA on a daily basis. Mean adjusted exposures for all age-sex groups were generally below the NCRI of 4ng OTA kg bw−1, except for 1–4-year-olds as a result of their lower body weight. For children, the major contributors of OTA were wheat-based foods followed by oats, rice, and raisins. Beer, coffee, and wine also contributed to total OTA exposure in older individuals. Predicted exposure to OTA decreased when European Commission maximum limits were applied to the occurrence data. The impact on risk for regular eaters of specific commodities was also examined. PMID:20013446

  9. Geochronology of upper Paleocene and lower Eocene strata, eastern Gulf Coastal Plain

    SciTech Connect

    Mancini, E.A.; Tew, B.H. Geological Survey of Alabama, Tuscaloosa, AL )

    1994-03-01

    Four samples of glauconitic sand from upper Paleocene and lower Eocene strata of the eastern Gulf Coastal Plain were analyzed for conventional potassium-argon (K-Ar) age determination. Results from these analyses are as follows: Coal Bluff Marl Member of the Naheola Formation of the Midway Group (58.2 [+-] 1.5 MA), Ostrea thirsae beds of the Nanafalia Formation of the Wilcox Group (56.3 [+-] 1.5 MA), upper Tuscahoma Sand of the Wilcox Group (54.5 [+-] 1.4 MA), and Bashi Marl Member of the Hatchetigbee Formation of the Wilcox Group (53.4 [+-] 1.4 MA). The Nanafalia Formation (Wilcox Group) disconformably overlies the Naheola Formation (Midway Group), and based on the data presented here, the age of this unconformity is bracketed between 59.7 and 54.8 MA. The Paleocene-Eocene Epoch boundary occurs in the Wilcox Group and coincides with the lithostratigraphic contact of the upper Paleocene Tuscahoma Sand with the lower eocene Hatchetigbee Formation. The age of this boundary, which is also an unconformity, can be placed between 55.9 and 52.0 MA. The K-Ar age dates for this boundary in the Gulf Coastal Plain compare favorably with the numerical limits placed on the Paleocene-Eocene boundary in the published literature. Generally, the Paleocene-Eocene Epoch boundary is reported as approximately 54 to 55 MA.

  10. Strata-based forest fuel classification for wild fire hazard assessment using terrestrial LiDAR

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Zhu, Xuan; Yebra, Marta; Harris, Sarah; Tapper, Nigel

    2016-10-01

    Fuel structural characteristics affect fire behavior including fire intensity, spread rate, flame structure, and duration, therefore, quantifying forest fuel structure has significance in understanding fire behavior as well as providing information for fire management activities (e.g., planned burns, suppression, fuel hazard assessment, and fuel treatment). This paper presents a method of forest fuel strata classification with an integration between terrestrial light detection and ranging (LiDAR) data and geographic information system for automatically assessing forest fuel structural characteristics (e.g., fuel horizontal continuity and vertical arrangement). The accuracy of fuel description derived from terrestrial LiDAR scanning (TLS) data was assessed by field measured surface fuel depth and fuel percentage covers at distinct vertical layers. The comparison of TLS-derived depth and percentage cover at surface fuel layer with the field measurements produced root mean square error values of 1.1 cm and 5.4%, respectively. TLS-derived percentage cover explained 92% of the variation in percentage cover at all fuel layers of the entire dataset. The outcome indicated TLS-derived fuel characteristics are strongly consistent with field measured values. TLS can be used to efficiently and consistently classify forest vertical layers to provide more precise information for forest fuel hazard assessment and surface fuel load estimation in order to assist forest fuels management and fire-related operational activities. It can also be beneficial for mapping forest habitat, wildlife conservation, and ecosystem management.

  11. Eustatic and tectonic control of sedimentation in the Pennsylvanian strata of the Central Appalachian Basin

    SciTech Connect

    Chesnut, D.R. Jr. . Kentucky Geological Survey)

    1992-01-01

    Analysis of the Breathitt Group of the Central Appalachian Basin reveals three orders of depositional cycles or trends. The Breathitt coarsening-upward trend (20 million years (my)) represents increasing intensity of the Alleghenian Orogeny. The major transgression (MT) cycle (2.5 my) was controlled by an unknown eustatic or tectonic mechanism. The major coal beds and intervening strata make up the coal-clastic cycle (CC cycle) (=Appalachian cyclothem) which has a 0.4 my periodicity. This periodicity supports eustatic control of sedimentation modulated by an orbital periodicity. Extensive coastal peats deposited at lowstand (CC cycle) were preserved as coals, whereas highstand peats were eroded during the subsequent drop in sea level. Autocyclic processes such as delta switching and avulsion occurred within CC cycles. An Early Pennsylvanian unconformity represents uplift and erosion of mid-Carboniferous foreland basin deposits. Alluvial deposits (Breathitt Group) derived from the highlands were transported to the northwest toward the forebulge. During lowstand, the only outlet available to further sediment transport (Lee sandstones) was toward the southwest (Ouachita Trough), along the Black Warrior-Appalachian foreland basins. The Middle Pennsylvanian marks a period of intermittent overfilling of the foreland basin and cresting of the forebulge. Marine transgressions entered through the foreland basins and across saddles in the forebulge. After the Ouachita Trough was destroyed during the late Middle Pennsylvanian, marine transgressions migrated only across saddles in the forebulge. In the Late Pennsylvanian, marine waters entered the basin only across the diminished forebulge north of the Jessamine Dome.

  12. Late Quaternary strata and carbon burial records in the Yellow River delta, China

    NASA Astrophysics Data System (ADS)

    Zhao, Guangming; Ye, Siyuan; Li, Guangxue; Ding, Xigui; Yuan, Hongming

    2015-06-01

    Sediment carbon sequestration plays an essential role in mitigating atmospheric CO2 increases and the subsequently global greenhouse effect. To clarify the late Quaternary strata and carbon burial records in Yellow River delta (YRD), detailed analysis of benthic foraminifera, total carbon (TC), organic carbon (Corg), sedimentary characteristics and moisture contents of sediments, was performed on core ZK3, 30.3 m in length and obtained from YRD in 2007. Eight depositional units (designated U1-U8 in ascending order) were identified. A comprehensive analysis method of historical geography and sedimentary geology was used to determine the precise depositional ages of the modern Yellow River delta (MYRD), from which pre-MYRD ages were deduced. The results indicates that the maximum burial rates of TC, inorganic carbon (IC) and Corg occurred in the delta front (U5), and the minimum in the shallow sea (U3). Remarkable high sedimentation rates in the MYRD are responsible for burial efficiency of carbon, with an average rate of Corg burial reaching 2087±251 g (m2 yr)-1, and that of IC reaching 13741±808 g (m2 yr)-1, which are much higher than those of other regions with high contents of Corg. Therefore, YRD has a significant burial efficiency for carbon sequestration.

  13. [Socioeconomic strata as a predictor factor for constant condom use among adolescents].

    PubMed

    Caballero Hoyos, R; Villaseñor Sierra, A

    2001-12-01

    Socioeconomic level plays an important role in health inequalities. In Mexico, the highest prevalence of AIDS cases is among individuals of lower socioeconomic level. The purpose of the study was to describe the socioeconomic level (adjusted for psychosocial, situational and demographic variables) as a predictor factor for the consistent condom use among adolescents of Guadalajara, Mexico. A sample of 1,410 adolescents, aged 15 to 19 years, drawn from a previous survey stratified by age, gender and socioeconomic strata was included in the study. Analysis was performed in 251 adolescents who reported sexual activity. Statistical analysis was performed using Chi-square, t-test, ANOVA, and logistic regression. The frequency of consistent condom use was 30.7% and there was a prevalence of irregular use. The highest social level was the main predictor (OR= 11.1, CI 95%=2.6-47.6). Others significant predictors were male gender, peer support and better knowledge about HIV/AIDS. Socioeconomic level is an important predictor factor for consistent condom use.

  14. Geochemistry of Lower Cretaceous strata of northern Priverkhoyansk Foreland Basin (NE SIBERIA): implications for provenance

    NASA Astrophysics Data System (ADS)

    Vasiliev, Dmitry; Ershova, Victoria; Ivensen, Galina; Prokopiev, Andrei

    2014-05-01

    The study area is located in the lower reaches of the Lena R., in between Chekurovka and Chucha Capes. The Lower Cretaceous clastic rocks of the northern part of the Priverkhoyansk foreland basin adjacent to the front of the Verkhoyansk fold-and-thrust belt have been studied. The Lower Cretaceous sections are composed of marine and fluvial terrigenous rocks. Marine deposits are represented by alternating sandstones and siltstones, while continental ones by alternating thick sandstones units (up to 400 m) and shale units with subordinate sandstones beds. The thickness of studied strata varies from 800-1900 m. The whole-rock geochemical analyses were done for 121 samples The geochemical study show: 1) uniform, persistent chemical composition close to that of acid igneous rocks; 2) low TiO2 content; 3) low MgO and FeO* values; 4) prevalence of FeO over Fe2O3 ; 5) high alkalies content with prevailing Na2O; 6) positive correlation between TiO2 and FeO* contents and negative correlation between Na2 O+K2 O and FeO* values. The data point to the same source of sediments both for marine and fluvial deposits with prevailing felsic rocks in provenance area. This research was supported by RFBR grants 14-05-31298, 13-05-00700, 13-05-00943 research grant of Saint Petersburg State University and Grant of President of Russia for Young Scientist MK-2902.2013.5.

  15. Fatty acid profile in vertical strata of elephant grass subjected to intermittent stocking.

    PubMed

    Dias, Kamila M; Schmitt, Daniel; Rodolfo, Giselle R; Deschamps, Francisco C; Camargo, Guilherme N; Pereira, Raphael S; Sbrissia, André F

    2017-01-01

    The milk and meat from animals with a pasture-based diet have higher proportions of CLA and C18:3 and lower omega-6:omega-3 ratios than products from animals with diets based on corn silage and concentrate. However, most of the published studies have evaluated fatty acid profiles in temperate climate grasses and the literature with tropical grasses is scarce. Thus, the aim of this study was to evaluate the morphological and fatty acid compositions in the vertical strata of elephant grass (Pennisetum purpureum Schum.) swards subjected to grazing heights (90 or 120 cm pre-grazing heights) and levels of defoliation (50% or 70% removal of the initial pre-grazing height). There were no interactions among pre-grazing height, the level of defoliation and grazing stratum. However, higher proportion of C18:3 (58% and 63%) was found in the 90-cm swards and in the half upper stratum. A higher proportion of C18:3 was associated with a higher leaf proportion and crude protein content. Thus, the upper stratum of sward or a grazing management scheme (e.g. first-last stocking) resulting in a higher proportion of leaves and crude protein both provide higher proportions of C18:3 to animals grazing in elephant grass swards.

  16. Health risk assessment of ochratoxin A for all age-sex strata in a market economy.

    PubMed

    Kuiper-Goodman, T; Hilts, C; Billiard, S M; Kiparissis, Y; Richard, I D K; Hayward, S

    2010-02-01

    In order to manage risk of ochratoxin A (OTA) in foods, we re-evaluated the tolerable daily intake (TDI), derived the negligible cancer risk intake (NCRI), and conducted a probabilistic risk assessment. A new approach was developed to derive 'usual' probabilistic exposure in the presence of highly variable occurrence data, such as encountered with low levels of OTA. Canadian occurrence data were used for various raw food commodities or finished foods and were combined with US Department of Agriculture (USDA) food consumption data, which included data on infants and young children. Both variability and uncertainty in input data were considered in the resulting exposure estimates for various age/sex strata. Most people were exposed to OTA on a daily basis. Mean adjusted exposures for all age-sex groups were generally below the NCRI of 4 ng OTA kg bw(-1), except for 1-4-year-olds as a result of their lower body weight. For children, the major contributors of OTA were wheat-based foods followed by oats, rice, and raisins. Beer, coffee, and wine also contributed to total OTA exposure in older individuals. Predicted exposure to OTA decreased when European Commission maximum limits were applied to the occurrence data. The impact on risk for regular eaters of specific commodities was also examined.

  17. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: Depth- and strata-dependent spatial variability from rock-core sampling.

    PubMed

    Goode, Daniel J; Imbrigiotta, Thomas E; Lacombe, Pierre J

    2014-12-15

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  18. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: Depth- and strata-dependent spatial variability from rock-core sampling

    NASA Astrophysics Data System (ADS)

    Goode, Daniel J.; Imbrigiotta, Thomas E.; Lacombe, Pierre J.

    2014-12-01

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55 years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  19. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: depth- and strata-dependent spatial variability from rock-core sampling

    USGS Publications Warehouse

    Goode, Daniel J.; Imbrigiotta, Thomas E.; Lacombe, Pierre J.

    2014-01-01

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55 years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  20. Inversion of Bedding and Parasequence Types Preserved in Shelfal Mudstone Strata to Significant Marine Processes

    NASA Astrophysics Data System (ADS)

    Bohacs, K.; Lazar, R.; Demko, T.

    2012-12-01

    Mudstone strata contain an almost bewildering variety of physical, chemical, and biogenic attributes at the lamina to bed scale (mm - dm). Our observations of more than 7 km of Paleozoic to Pliocene mudstone revealed patterns in this variety of such macroscopic attributes as lithofacies, bedding, sedimentary structures, and stratal stacking patterns at the bedset to parasequence scale (cm - m). We quantified characteristics of each association and linked them to sets of depositional processes. Most shelfal mudstone strata appear to have accumulated in one of three end-member facies association successions (FASs) that can be related to physiographic settings and depositional regimes through characteristic modes of sediment transport and accumulation, as well as variations in benthic-energy and oxygen levels. FAS-1 comprises 1- to 10-meter-thick coarsening/thickening-upward stratal units, defined by lithologic indices: percent sandstone/siltstone/grainstone (Ss/Zs/Gs), maximum grain size, thickness of individual Ss/Zs/Gs bedsets. These FASs also have increasing total-organic-carbon content (TOC) and planktonic material in basal bedsets, overlain by an interval with an upward decrease in TOC and planktonic microfossil abundance along with an upward increase in skeletal phosphate, palynomorph content, and bioturbation. FAS-2 comprise 1- to 14-meter-thick coarsening/thickening-upward stratal units, defined by similar lithologic indices and changes as FAS-1; FAS-2 also has an upward decrease in content of TOC and planktonic microfossils, skeletal phosphate, and ichnofossil abundance and diversity. Very basal bedsets tend to have relatively low concentrations of planktonic material. Also distinctive are the common occurrence of palynodebris throughout (in post-Silurian rocks), with thin lags of macrofossils and skeletal phosphate in basal portions, Bouma B-C bedsets, and soft-sediment deformation with minimal, horizontal burrows in its middle portions, and scours, graded

  1. Natural hydraulic fractures and the mechanical stratigraphy of shale-dominated strata

    NASA Astrophysics Data System (ADS)

    Imber, Jonathan; Armstrong, Howard; Atar, Elizabeth; Clancy, Sarah; Daniels, Susan; Grattage, Joshua; Herringshaw, Liam; Trabucho-Alexandre, João; Warren, Cassandra; Wille, Jascha; Yahaya, Liyana

    2016-04-01

    The aim of this study is to investigate stratigraphic variations in the spatial distribution and density of natural hydraulic and other fractures within oil mature, shale-dominated strata from the Cleveland Basin, northeast England. The studied interval includes the Pliensbachian Cleveland Ironstone and Toarcian Whitby Mudstone Formations. The Cleveland Ironstone Formation (ca. 25m thick) consists of silt- and mudstone units with discrete ironstone layers (seams). Ironstones account for 20% of the thickness of the formation. The Whitby Mudstone Formation is up to ca. 100 m thick; up to 2% of its total thickness consists of discrete calcium carbonate horizons, such as the Top Jet Dogger. Natural hydraulic fractures, characterised by plumose marks and concentric arrest lines on fracture surfaces are ubiquitous throughout both formations; shear fractures with mm- to cm-scale displacements occur locally, particularly within silt- and mudstones. Natural hydraulic fractures locally contain thin, sometimes fibrous, calcite fills and are commonly observed to terminate at bedding plane interfaces between silt- or mudstone and carbonate beds. We have recorded fracture locations and apertures along 139 transects in both shale (i.e. silt- and mudstone intervals) and carbonate strata. Natural hydraulic and shear fractures, measured along transects up to 50m long within all lithologies in both formations, typically display uniform distributions. There is no correlation between spacing distribution and bulk extension in any lithology. Median fracture densities recorded within the Cleveland Ironstone Formation are higher in intervening ironstone beds (<2.1 fractures per m in ironstone layers) compared with dominant shales (<0.9 fractures per m in silt- and mudstones). A qualitatively similar pattern occurs within the Whitby Mudstone Formation. However, the absolute values of median fracture density within different members of the Whitby Mudstone Formation range from 2

  2. Ion drag as a mechanism of plasma dust structure rotation in a strata in a magnetic field

    NASA Astrophysics Data System (ADS)

    Dzlieva, E. S.; Karasev, V. Yu.; Mashek, I. Ch.; Pavlov, S. I.

    2016-06-01

    In experiments on complex plasmas, afixed strata region in which the levitation of dust structures is observed is investigated using the method of probing by calibrated dust particles of different sizes in an applied magnetic field under elevated pressures. The measured azimuthal velocity of the probing particles corresponds to the action of the ion drag force for 4 μm-size particles and to the entrainment by the rotating gas owing to the electron vortex flow inside the strata for 1 μm-size particles. Extrapolation to pressures and magnetic fields in which the rotation inversion of dust structures is observed in experiments shows that the ion drag is the dominating force causing rotation with a negative projection of the angular velocity onto the magnetic induction.

  3. Assessment of pore pressures and specific storage within sedimentary strata overlying underground mines

    NASA Astrophysics Data System (ADS)

    Timms, W.; David, K.; Barbour, L. S.

    2016-12-01

    Realistic values of specific storage (Ss) for groundwater systems are important to determine the spatial extent and timing of c pore pressure changes when the groundwater system is stressed. However, numerical groundwater models of underground excavations typically assume constant literature values of Ss. One part of our research program utilised high frequency pore pressure data to evaluate variability and changes in Ss within sedimentary strata overlying a longwall coal mine. Pore pressure data from a vertical series of 6 vibrating wire piezometers (50 to 278 m depth) recording at hourly intervals were compared with barometric pressure data over a period of several years, including data before and during mining. The site was located near the centre of a longwall panel that extracted 3 m of coal at a depth of 330 m. The data was processed to calculate loading efficiency and Ss values by multi-method analyses of barometric and earth tide responses. In situ Ss results varied over one to two orders of magnitude and indicated that Ss changed before and after excavation of underlying coal seams. The vertical leakage of groundwater within the constrained zone ( 10 to 150 m depth) was found to be limited, although some degree of vertical hydraulic connectivity was observed. Depressurization was evident in the fractured zone directly overlying the coal seam, and Ss changes at 250 m depth indicated this confined aquifer may have become unconfined. Our results demonstrate that high frequency pore pressure data can provide realistic Ss values. In situ Ss values were an order of magnitude lower than Ss measured by geomechnical tests of cores, and were significantly different to textbook values set in most local groundwater models. The timing and extent of groundwater level drawdown predicted by models may therefore be underestimated. We have shown, for the first time, that variability of Ss can be significant, and that these changes can provide important insights into how

  4. Basal keratinocytes contribute to all strata of the adult zebrafish epidermis.

    PubMed

    Lee, Raymond T H; Asharani, P V; Carney, Thomas J

    2014-01-01

    The epidermis of terrestrial vertebrates is a stratified epithelium and forms an essential protective barrier. It is continually renewed, with dead corneocytes shed from the surface and replaced from a basal keratinocyte stem cell population. Whilst mouse is the prime model system used for epidermal studies, there is increasing employment of the zebrafish to analyse epidermis development and homeostasis, however the architecture and ontogeny of the epidermis in this system are incompletely described. In particular, it is unclear if adult zebrafish epidermis is derived entirely from the basal epidermal stem cell layer, as in the mouse, or if the most superficial keratinocyte layer is a remnant of the embryonic periderm. Furthermore, a relative paucity of cellular markers and genetic reagents to label and manipulate the basal epidermal stem cell compartment has hampered research. Here we show that the type I keratin, krtt1c19e, is a suitable marker of the basal epidermal layer and identify a krtt1c19e promoter fragment able to drive strong and specific expression in this cell type. Use of this promoter to express an inducible Cre recombinase allowed permanent labelling of basal cells during embryogenesis, and demonstrated that these cells do indeed generate keratinocytes of all strata in the adult epidermis. Further deployment of the Cre-Lox system highlighted the transient nature of the embryonic periderm. We thus show that the epidermis of adult zebrafish, as in the mouse, derives from basal stem cells, further expanding the similarities of epidermal ontogeny across vertebrates. Future use of this promoter will assist genetic analysis of basal keratinocyte biology in zebrafish.

  5. Basal Keratinocytes Contribute to All Strata of the Adult Zebrafish Epidermis

    PubMed Central

    Carney, Thomas J.

    2014-01-01

    The epidermis of terrestrial vertebrates is a stratified epithelium and forms an essential protective barrier. It is continually renewed, with dead corneocytes shed from the surface and replaced from a basal keratinocyte stem cell population. Whilst mouse is the prime model system used for epidermal studies, there is increasing employment of the zebrafish to analyse epidermis development and homeostasis, however the architecture and ontogeny of the epidermis in this system are incompletely described. In particular, it is unclear if adult zebrafish epidermis is derived entirely from the basal epidermal stem cell layer, as in the mouse, or if the most superficial keratinocyte layer is a remnant of the embryonic periderm. Furthermore, a relative paucity of cellular markers and genetic reagents to label and manipulate the basal epidermal stem cell compartment has hampered research. Here we show that the type I keratin, krtt1c19e, is a suitable marker of the basal epidermal layer and identify a krtt1c19e promoter fragment able to drive strong and specific expression in this cell type. Use of this promoter to express an inducible Cre recombinase allowed permanent labelling of basal cells during embryogenesis, and demonstrated that these cells do indeed generate keratinocytes of all strata in the adult epidermis. Further deployment of the Cre-Lox system highlighted the transient nature of the embryonic periderm. We thus show that the epidermis of adult zebrafish, as in the mouse, derives from basal stem cells, further expanding the similarities of epidermal ontogeny across vertebrates. Future use of this promoter will assist genetic analysis of basal keratinocyte biology in zebrafish. PMID:24400120

  6. Selenium speciation in Lower Cambrian Se-enriched strata in South China and its geological implications

    NASA Astrophysics Data System (ADS)

    Fan, Haifeng; Wen, Hanjie; Hu, Ruizhong; Zhao, Hui

    2011-12-01

    To understand the impact of Selenium (Se) into the biogeochemical cycle and implications for palaeo-redox environment, a sequential extraction method was utilized for samples including black shales, cherts, a Ni-Mo-Se sulfide layer, K-bentonite and phosphorite from Lower Cambrian Se-enriched strata in southern China. Seven species (water-soluble, phosphate exchangeable, base-soluble, acetic acid-soluble, sulfide/selenide associated, residual Se) and different oxidation states (selenate Se(VI), selenite Se(IV), organic Se, Se (0) and mineral Se(-II)) were determinated in this study. We found that the Ni-Mo-Se sulfide layer contained a significantly greater amount of Se(-II) associated with sulfides/selenides than those in host black shales and cherts. Furthermore, a positive correlation between the degree of sulfidation of iron (DOS) and the percentage of the sulfide/selenide-associated Se(-II) was observed for samples, which suggests the proportion of sulfide/selenide-associated Se(-II) could serve as a proxy for palaeo-redox conditions. In addition, the higher percentage of Se(IV) in K-bentonite and phosphorite was found and possibly attributed to the adsorption of Se by clay minerals, iron hydroxide surfaces and organic particles. Based on the negative correlations between the percentage of Se(IV) and that of Se(-II) in samples, we propose that the K-bentonite has been altered under the acid oxic conditions, and the most of black shale (and cherts) and the Ni-Mo-Se sulfide layer formed under the anoxic and euxinic environments, respectively. Concerning Se accumulation in the Ni-Mo-Se sulfide layer, the major mechanism can be described by (1) biotic and abiotic adsorption and further dissimilatory reduction from oxidized Se(VI) and Se(IV) to Se(-II), through elemental Se, (2) contribution of hydrothermal fluid with mineral Se(-II).

  7. Time Scale Optimization and the Hunt for Astronomical Cycles in Deep Time Strata

    NASA Astrophysics Data System (ADS)

    Meyers, Stephen R.

    2016-04-01

    A valuable attribute of astrochronology is the direct link between chronometer and climate change, providing a remarkable opportunity to constrain the evolution of the surficial Earth System. Consequently, the hunt for astronomical cycles in strata has spurred the development of a rich conceptual framework for climatic/oceanographic change, and has allowed exploration of the geologic record with unprecedented temporal resolution. Accompanying these successes, however, has been a persistent skepticism about appropriate astrochronologic testing and circular reasoning: how does one reliably test for astronomical cycles in stratigraphic data, especially when time is poorly constrained? From this perspective, it would seem that the merits and promise of astrochronology (e.g., a geologic time scale measured in ≤400 kyr increments) also serves as its Achilles heel, if the confirmation of such short rhythms defies rigorous statistical testing. To address these statistical challenges in astrochronologic testing, a new approach has been developed that (1) explicitly evaluates time scale uncertainty, (2) is resilient to common problems associated with spectrum confidence level assessment and 'multiple testing', and (3) achieves high statistical power under a wide range of conditions (it can identify astronomical cycles when present in data). Designated TimeOpt (for "time scale optimization"; Meyers 2015), the method employs a probabilistic linear regression model framework to investigate amplitude modulation and frequency ratios (bundling) in stratigraphic data, while simultaneously determining the optimal time scale. This presentation will review the TimeOpt method, and demonstrate how the flexible statistical framework can be further extended to evaluate (and optimize upon) complex sedimentation rate models, enhancing the statistical power of the approach, and addressing the challenge of unsteady sedimentation. Meyers, S. R. (2015), The evaluation of eccentricity

  8. Paleogene strata of the Eastern Los Angeles basin, California: Paleogeography and constraints on neogene structural evolution

    USGS Publications Warehouse

    McCulloh, T.H.; Beyer, L.A.; Enrico, R.J.

    2000-01-01

    Post-Paleogene dextral slip of 8-9 km is demonstrated for the southeastern part of the Whittier fault zone in the eastern Los Angeles basin area of southern California. A linear axis of greatest thickness for the combined upper Paleocene and lower to lower-middle Eocene clastic formations intersects the fault zone and is offset by it to give the new measure. Fragmentary evidence hints that the Whittier structural zone may have exerted control on bathymetric-topographic relief and sedimentation even in latest Paleocene (ca. 54 Ma). A clear topographic influence was exerted by 20-17 Ma. Strike-slip and present deformational style is younger than ca. 8 Ma. Our Paleogene isopach map extends as far west as long 117??58'W and is a foundation for companion zonal maps of predominant lithology and depositional environments. Integration of new palynological data with published biostratigraphic results and both new and published lithologic and sedimentological interpretations support the zonal maps. Reconstruction of marine-nonmarine facies and fragmented basin margins yields a model for the northeastern corner of a Paleogene coastal basin. Palinspastic adjustment for the Neogene-Quaternary Whittier fault offset and a reasoned westerly extension of the northern edge of the basin model yield a reconstruction of Paleogene paleogeography-paleoceanography. Our reconstruction is based partly on the absence of both Paleocene and Eocene deposits beneath the unconformable base of the middle Miocene Topanga Group in a region nowhere less than 15 km wide between the Raymond-Sierra Madre-Cucamonga fault zone and the northern edge of the Paleocene basin. Thus, Paleogene strata of the Santa Monica Mountains could not have been offset from the northern extension of the Santa Ana Mountains by sinistral slip on those boundary faults. Structural rearrangements needed to accommodate the clockwise rotation of the western Transverse Ranges from the early Miocene starting position are thereby

  9. Detrital zircon geochronology of Neoproterozoic to Middle Cambrian miogeoclinal and platformal strata: Northwest Sonora, Mexico

    USGS Publications Warehouse

    Gross, E.L.; Stewart, John H.; Gehreis, G.E.

    2000-01-01

    Eighty-five detrital zircon grains from Mesoproterozoic and/or Neoproterozoic to Middle Cambrian sedimentary strata in northwest Sonora, Mexico, have been analyzed to determine source terranes and provide limiting depositional ages of the units. The zircon suites from the Mesoproterozoic and/or Neoproterozoic El Alamo Formation and El Aguila unit yield ages between 1.06 Ga and 2.67 Ga, with predominant ages of 1.1 to 1.2 Ga. Zircons from the Lower? and Middle Cambrian Bolsa Quartzite show age groups from 525 Ma to 1.63 Ga, with a dominant population of 1.1 to 1.2 Ga grains. Grains older than 1.2 Ga in the samples were most likely derived from basement terranes and ???1.4 Ga granitic bodies of the southwest U.S. and northwest Mexico. It is also possible that the sediments were transported from the south, although source rocks of the appropriate age are not presently exposed south of the study area in northern Mexico. Three possibilities for the dominant 1.1 to 1.2 Ga grains include derivation from: (I) exposures of the Grenville belt in southern North America, (2) local 1.1-1.2 Ga granite bodies, or (3) a southern source, such as the Oaxaca terrane, that was subsequently rifted away. Sampling of additional units in the western U.S. and northern Mexico may help resolve the ambiguity surrounding the source of the 1.1 to 1.2 Ga grains.

  10. Mesoporous Hybrid Polypyrrole-Silica Nanocomposite Films with a Strata-Like Structure.

    PubMed

    Farghaly, Ahmed A; Collinson, Maryanne M

    2016-06-14

    Using a single-potential-step coelectrodeposition route, Ppy-SiO2 nanocomposite films characterized by a multimodal porous structure were cathodically deposited from ethanolic solutions on oxidizable and nonoxidizable substrates for the first time. The materials produced have an interesting and unique strata-like pore structure along their depth. With the exception of a silica-rich inner region, the nanocomposite films are homogeneous in composition. Because the region closest to the electrode surface is silica-rich, the fabrication of Ppy-SiO2 and Ppy free-standing films become possible using a multistep etching strategy. Such films can be captured on a variety of different supports depending on the application, and they maintain their conductivity when interfaced with an electrode surface. These mesoporous composite films form through a unique mechanism that involves the production of two catalysts, OH(-) and NO(+). Through the process of understanding the reaction mechanism, we highlighted the effect of two simultaneous competing redox reactions occurring at the electrode interface on the morphology of the electrodeposited Ppy nanocomposite films and how solvent can influence the Ppy electropolymerization reaction mechanism and hence control the morphology of the final material. In an ethanolic solvent system, the pyrrole monomers undergo a step-growth polymerization, and particulate-like nanostructured films were obtained even upon changing the monomer or acid concentration. In an aqueous-based system, nanowire-like structures were produced, which is consistent with a chain-growth mechanism. Such materials are promising candidates for a wide range of applications including electrochemical sensing, energy storage, and catalysis.

  11. Trace fossils in diatomaceous strata of Miocene Monterey Formation: their character and implications

    SciTech Connect

    Savdra, C.E.; Bottjer, D.J.

    1986-04-01

    Younger parts of the Miocene Monterey Formation are commonly characterized by relatively unaltered diatomaceous strata. A common characteristic of these deposits is the preservation of varvelike lamination, indicative of deposition under anoxic or nearly anoxic conditions. Although laminated rock types are volumetrically dominant, bioturbated intervals are by no means rare, but little attention has been paid to the trace fossils themselves. Our study of trace fossils in the Monterey Formation demonstrated the significance of these biogenic structures in paleoenvironmental and paleoecologic analyses. In particular, trace fossils provide a means for detailed reconstruction of paleo-oxygenation conditions during Monterey deposition. Trace fossils in several Monterey sections exposed in central and southern California were examined in detail. At all localities, three major ichnofossil assemblages or ichnofacies were recognized: (1) Chondrites, (2) Planolites, and (3) Thalassinoides. The size and diversity of the three major ichnofacies and their lithologic associations suggest that the distribution of these facies is controlled primarily by the level of paleo-bottom water oxygenation. The Chondrites ichnofacies represents very low paleo-oxygen levels just above the anoxic threshold. The Planolites ichnofacies, with greater variety of larger burrow types, is indicative of slightly higher levels of oxygenation. Moderately to well-oxygenated conditions are suggested by the Thalassinoides ichnofacies. More detailed information on paleoenvironmental conditions can be gleaned by applying a refined trace-fossil tiering model. When used in detailed (centimeter-scale) vertical sequence analyses, this tiering model permits the translation of data on the composition, size parameters, and cross-cutting relationships of trace-fossil assemblages into relative paleo-oxygenation curves.

  12. Hydrogeophysical investigation of aquifer properties and lithological strata in Abraka, Nigeria

    NASA Astrophysics Data System (ADS)

    Anomohanran, Ochuko

    2015-02-01

    The purpose of this study is to investigate the aquifer properties and lithological strata of Abraka, Nigeria. This was carried out by employing the geoelectric, geophysical well logging and pumping test methods. Ten vertical electrical soundings using the Schlumberger configuration were occupied to investigate the geoelectric properties of the subsurface, while two wells were drilled to evaluate the lithology and aquifer parameters of the study area. The result of the lithological study showed that the subsurface formations consist of lateritic sand, fine and medium grain sand mixed with clay, coarse sand, medium coarse sand and very coarse sand. The interpretation of the geoelectric data using a combination of curve matching and Win Resist computer iteration showed close correlation with the well record. The geoelectric result revealed that the fifth layer with a resistivity range of between 509 and 1033 Ω m and a depth range of between 31.5 and 45.9 m is the preferred layer to source for good quality water in the area. The result of well logs also showed that the electrical conductivity and the total dissolve solid which were obtained as 0.0105 mS/m and 67.43 mg/m3 respectively falls within the World Health Organisation benchmark for potable water. The result of pumping test further revealed that the transmissivity, storativity and specific capacity of the aquifer are 0.0713 m2/min, 1.3 × 10-5 and 0.39 m2/min respectively. It is inferred from this survey that the aquifer is confined and capable of yielding adequate and good quality water for the people.

  13. Geometric and kinematic modeling of detachment folds with growth strata based on Bézier curves

    NASA Astrophysics Data System (ADS)

    Liu, Chun; Zhang, Yikun; Shi, Bin

    2009-03-01

    In our geometric modeling, the inner layer of competent rock units in a detachment fold is approximated by several quadratic Bézier curves, which are joined together according to some geometrical rules, whereas the outer layers are calculated from the inner layer by parallel folding mechanism. In this model, an ideal fold is determined by three parameters: w, half of the distance between the locations of the fold's two limbs where their dips are measured, θ1 and θ2, the dip angles of its two limbs. Two more parameters, respectively the axial lift-up ratio ( u) and the limb elongation ( E) may be used to change the ideal fold shape, if necessary. In kinematic modeling, downward deflection in the two synclines flanking an anticline is assumed to maintain constant area during folding. Both mathematical derivation and numerical simulation show that the reduction of the balanced area ( Ar) is directly proportional to the downward deflection angle ( φ), and there is an approximate linear relationship between the detachment depth and the downward deflection angle. Based on this relationship, an iterative method is used to find the approximate value of φ. Furthermore, syn-folding growth strata can be modeled through calculating the velocity field above a detachment fold during folding. The method is applied to three seismic interpretation cross-sections of detachment folds respectively in Tarim Basin (western China), Zagros fold-belt (Iran) and Niger delta (western Africa). Variations of φ with the development of the detachment folds indicate the transfer of rock materials between the synclinal and anticlinal areas of the folds.

  14. Injury-Related Unsafe Behavior Among Households from Different Socioeconomic Strata in Pune City

    PubMed Central

    Mirkazemi, Roksana; Kar, Anita

    2009-01-01

    Introduction: Behavior pattern influences the risk of unintentional injuries. This study was conducted to identify the pattern of household unsafe behavior in different socioeconomic strata, in Pune city, India. Materials and Method: Population-based, cross-sectional study. Behaviors influencing the risk of burn, poisoning, drowning, and road traffic injuries were questioned from 200 randomly selected households. Results: Nearly 28% of the households did not have a separate kitchen, 37.5% cooked at the ground level, 33.5% used a kerosene pressure stove, 12% used unprotected open fire as a source of warmth in winter, and 34.5% stored inflammable substances at home. Ninety one percent of the households reported storing poisonous chemicals in places that could not be locked. In 68.3% of the households with children below five years, these chemicals were kept in places accessible to children. Nearly 21% of the individuals, who could swim, did so in unsafe places and 25.2% of them were not trained in swimming. In 35.5% of the households, children used streets as playgrounds. Among all two-wheeled vehicle riders, 35.6% reported not having a helmet and 57.7% of those who had a helmet did not use it regularly. Socioeconomic status was strongly associated with the unsafe behaviors related to burns, drowning, and road traffic injuries. Conclusion: The study identifies the sociocultural and behavioral factors leading to unsafe behaviors, placing individuals at risk of unintentional injuries, which can be used as a first step toward prevention. PMID:20165622

  15. Age constraints on pre and synextensional Tertiary strata and normal faulting in the Windermere Hills, northeast Nevada

    SciTech Connect

    Mueller, K.J. . Dept. of Geology); Cerveny, P.F. ); Snee, L.W. ); Brown, F.H. . Dept. of Geology)

    1993-04-01

    Tertiary strata exposed in the eastern Windermere Hills and northern Pequop Mountains define the development of a widespread late eocene volcanic landscape and multiple generations of Oligocene-Miocene extensional half-grabens. 28 new [sup 40]Ar/[sup 39]Ar and fission-track age determinations and tephrachronology analyses on ash-flow and air fall tuffs suggest a complex history of extensional strain. The oldest Tertiary rocks exposed in the region consist of a diverse suite of calc alkaline volcanic rocks and volcaniclastic sediments. [sup 40]Ar/[sup 39]Ar age determinations of volcanic strata in this sequence indicate that it ranges from 39.18 [+-] .12 to 40.38 [+-] 0.6 Ma in age; strata exposed in the Deadman Creek area include 260 meters of rhyolitic ash-flow tuff, andesitic flow breccia, a rhyodacite lava flow and volcaniclastic conglomerate and sandstone. Subsequent extension is defined by the development of west-tilted, extensional half-grabens between 34.79 [+-] .18 to 39.18 [+-] .12 Ma ([sup 40]Ar/[sup 39]Ar). These basins evolved during the development of the Black Mountain fault (BMF), an east-rooted low-angle normal fault overlain by an array of synthetic tilt-blocks. Subsequent extension is defined by a poorly constrained, north-dipping normal fault of Oligocene or Miocene age. Both the BMF and the north-dipping normal fault are overprinted by two east-dipping listric normal faults which bound 1--3 km deep half-grabens filled with 11.9 [+-] 0.3 to about 15 Ma strata (zircon fission track, tephrachronology analyses and mammalian fossils). An important aspect of the thermal history of the Windermere Hills includes a middle Miocene (ca. 11--16 Ma) thermal event (200 [+-] 50 C > T > 280 C), which annealed, or partially annealed fission tracks in zircon grains in several of the extensional basins discussed above.

  16. Evidence for an allocyclic origin of marine strata bounding the Upper Carboniferous Mary Lee coal zone, Warrior Basin, Alabama

    SciTech Connect

    Gastaldo, R.A. . Dept. of Geology); Demko, T.M. . Dept. of Geosciences)

    1992-01-01

    The Black Warrior Basin, a triangular foreland basin of Carboniferous age, is located at the southern end of the Appalachian orogen. A southwestward wedge of Mississippian and Lower Pennsylvanian sedimentary rocks occurs in the basin. The generally accepted model for basin-fill involves the progradation of a single delta, or multiple deltas (the Pottsville Formation), over an offshore carbonate bank (the Bangor Limestone). The Pottsville Formation is typical of Euramerican Carboniferous strata and is composed of the cyclical alternation of marine and terrestrial facies. The deposition of marine facies overlying terrestrial facies has been interpreted to have been the result of delta lobe switching and the compaction of underlying sediments, hence, autocyclic processes. Sedimentological features associated with the marine strata bounding the Mary Lee coal zone, the informal Jagger bedrock sandstone below and the Morris Shale above, are not indicative of circumstances generated by autocyclic processes. Rather, the marine strata highlight features resulting from allocyclic processes. The Jagger bedrock sandstone is a thick (> 15 m) sublitharenite interpreted as representing subtidal, shore-parallel bars. It is a sandstone body that was stranded on the shoreline during regional regression. The terrestrial coal-bearing strata are truncated by an erosional surface, marking the base of the Morris Shale. This ravinement surface is overlain by a ravinement bed representing a substrate developed by regional transgressive erosion that was subsequently colonized by open-marine macroinvertebrates. The ravinement bed is interpreted as a condensed section that accumulated under maximum water depth. Both of these features are indicative of development in response to extrinsic causes rather than intrinsic ones.

  17. Tight gas reservoir simulation: Modeling discrete irregular strata-bound fracture network flow, including dynamic recharge from the matrix

    SciTech Connect

    McKoy, M.L., Sams, W.N.

    1997-10-01

    The US Department of Energy, Federal Energy Technology Center, has sponsored a project to simulate the behavior of tight, fractured, strata-bound gas reservoirs that arise from irregular discontinuous, or clustered networks of fractures. New FORTRAN codes have been developed to generate fracture networks, or simulate reservoir drainage/recharge, and to plot the fracture networks and reservoirs pressures. Ancillary codes assist with raw data analysis.

  18. Factors Influencing the Temporal and Spatial Variability of the Textural Characteristics of Event-Scale Strata on the Eel Shelf

    DTIC Science & Technology

    2001-09-30

    shelf (see Leithold , 1989). The final push to complete our STRATAFORM studies resulted in eight poster presentations, 4 at the Fall 2000 AGU and 4 at...the strata on the modern shelf, except that we did not find any equivalents to the thick (10 - 40 cm) Fleener Sands ( Leithold , 1989) in the modern...turbulence on floc size in the Eel River flood plume. (Abs.) AGU Fall Meeting, EOS, 79, page F455. Leithold , E., 1989, Depositional processes on an

  19. The effect of a sedimentary wedge on earthquake ground motions: The influence of eastern U.S. Atlantic Coastal Plain strata

    NASA Astrophysics Data System (ADS)

    Pratt, Thomas; Magnani, Beatrice

    2017-04-01

    Coastal regions of the eastern U.S. are underlain by a wedge of partially consolidated Atlantic Coastal Plain (ACP) marine sedimentary strata overlying a bedrock of crystalline or indurated sedimentary rocks. The ACP strata extend more than 200 km inland, tapering landward from as much as 1 km near the coast. Unconsolidated, shallow sedimentary strata strongly influence earthquake ground motions due to low seismic impedance and strong reflections from the bedrock contact. Site response estimates primarily determine high-frequency amplifications from shear-wave velocities in the upper 30 m (Vs30), but thicker sedimentary sequences can increase longer-period ground motions important to large structures. Here we use data from continental-scale seismic experiments that span the ACP (e.g. Eastern North America Margin [ENAM], Earthscope Transportable Array) to examine the influence of ACP strata on earthquake ground motions. We use teleseismic and regional earthquake recordings to compute spectral ratios relative to bedrock sites. Thin ACP strata produce fundamental resonance peaks at high frequencies (>5 Hz), but the fundamental peaks decrease to about 0.45 Hz as the sediments thicken to about 500 m. Amplitudes of the fundamental resonance peaks decrease as the strata thicken, but even coastal sites show amplification factors as great as 5. In addition, we use the frequency of the resonance peaks to invert for an average velocity function within the ACP strata. A smaller array within the city of Washington, DC, which is underlain by a wedge 0- to 270-m-thick ACP strata, shows large amplifications at frequencies of 0.7 to 5 Hz. These amplifications likely contributed to the widespread damage to the city during the relatively modest, M5.8 Virginia earthquake in 2011. This work confirms amplification of short-period ground motions by thin ACP strata, and documents longer-period amplifications caused by thick sedimentary sequences beneath coastal regions of the eastern U.S.

  20. Beetle assemblages from an Australian tropical rainforest show that the canopy and the ground strata contribute equally to biodiversity

    PubMed Central

    Stork, Nigel E; Grimbacher, Peter S

    2006-01-01

    There remains great uncertainty about how much tropical forest canopies contribute to global species richness estimates and the relative specialization of insect species to vertical zones. To investigate these issues, we conducted a four-year sampling program in lowland tropical rainforest in North Queensland, Australia. Beetles were sampled using a trap that combines Malaise and flight interception trap (FIT) functions. Pairs of this trap, one on the ground and a second suspended 15–20 m above in the canopy were located at five sites, spaced 50 m or more apart. These traps produced 29 986 beetles of 1473 species and 77 families. There were similar numbers of individuals (canopy 14 473; ground 15 513) and species (canopy 1158; ground 895) in each stratum, but significantly more rare species in the canopy (canopy 509; ground 283). Seventy two percent of the species (excluding rare species) were found in both strata. Using IndVal, we found 24 and 27% of the abundant species (n≥20 individuals) to be specialized to the canopy and the ground strata, respectively, and equivalent analyses at the family level showed figures of 30 and 22%, respectively. These results show that the canopy and the ground strata both provide important contributions to rainforest biodiversity. PMID:16822759

  1. Yellow-tailed woolly monkey (Lagothrix flavicauda) proximal spacing and forest strata use in La Esperanza, Peru.

    PubMed

    Shanee, Sam

    2014-10-01

    Inter-individual spacing of primates and their use of forest strata depend on temporal and spatial changes in the environment and on predator avoidance, group demography, and social conditions. Greater proximity also increases the chances of agonistic and affinitive contact between individuals. I collected behavioral data for three groups of yellow-tailed woolly monkeys (Lagothrix flavicauda) by instantaneous sampling of focal animals for 15 months in La Esperanza, northeastern Peru. By use of combined data for all groups I examined the effects of season, activity, and age/sex class on nearest-neighbor distances and forest strata use. Small differences were observed for nearest-neighbor distances, forest strata use by different age/sex classes, and activity. Adult males had the lowest contact index scores. Contact index scores were low for juvenile females, for which nearest-neighbor distances were largest. Very little aggressive behavior was observed. Focal animals preferred upper levels of the forest with little difference in height for different activities. Lagothrix flavicauda have very cohesive groups with little seasonal or activity-dependent difference between nearest-neighbor distances or proximity. These results suggest that this species has less variable social organization and greater group cohesion than other Atelini. However, more studies are needed on other populations of L. flavicauda to better determine the species' social organization. Studies are also required to determine the extent to which dispersal times and kinship affect proximity, nearest-neighbor distances, and aggression.

  2. Stratigraphic correlation by integrating photostratigraphy and remote sensing multispectral data: An example from Jurassic-Eocene strata, Northern Somalia

    SciTech Connect

    Sgavetti, M.; Ferrari, M.C.; Chiari, R.

    1995-11-01

    Integrated analyses of aerial photographs and multispectral remote sensing images were used for stratigraphic correlation in mainly carbonate and evaporitic rocks. These rocks crop out in an area of northern Somalia characterized by an arid climate. By the aerial photo analysis, we recognized photostratigraphic logs and stratal patterns and established correlations based on the tracing of physical surfaces with chronostratigraphic significance, such as photohorizons and photostratigraphic discontinuities. A limited number of field sections provided the lithological interpretation of the packages of strata delineated in aerial photos. By satellite multispectral (Landsat Thematic Mapper{trademark}) data analysis we identified image facies that represent packages of strata with different lithological characteristics. To interpret the image facies, we compared the responses in the thematic mapper (TM) bands with the laboratory spectroscopic properties of rock samples from the study area, and interpreted the absorption features by petrographic analysis. The Mesozoic and Tertiary strata analyzed herein are part of several formations deposited on a passive margin preceding the Oligocene-Miocene Gulf of Aden rifting and initial drifting. Following this approach, a number of stratigraphic units were recognized and mapped on aerial photos, and a framework of photostratigraphic correlation surfaces was delineated over significantly wide areas. These surfaces approximate time surfaces and are traced both within and across the lithostratigraphic units, improving existing maps. This method represents a mapping tool preliminary to more detailed field work, and is particularly useful in areas of difficult access.

  3. New aspects of deformed cross-strata in fluvial sandstones: Examples from Neoproterozoic formations in northern Norway

    NASA Astrophysics Data System (ADS)

    Røe, Signe-Line; Hermansen, Marita

    2006-05-01

    Extensive (20-200 m long) exposures of tabular cross-sets in Neoproterozoic fluvial sandstone in Northern Norway demonstrate that deformed cross-strata, in the form of recumbently folded cross-strata with associated massive sand, are localized features passing in both up- and down-current direction into undeformed, concave-upward or sigmoidal cross-strata. The deformation occurs in down-current inclined, tangential wedge-shaped zones beneath reactivation surfaces, and less commonly as flat-topped lenticular zones. The localized nature of the sediment deformation is attributed to local liquefaction below the top of the bed in the case of the flat-topped lenses and at the dune front in the case of the more common tangential wedges. The position of the flat-topped lenses suggests deformation by the shear stress of high-velocity, suspension-laden currents. Although liquefaction of the dune front implies the action of gravity forces, it is argued that the fluvial currents were the main driving force at the instant of bed liquefaction. Post-folding gravitational shearing probably enhanced the deformation within the upper part of the wedges, with their long, flat-lying toeset resulting from redeposition of downslope-moving liquefied sand. The down-current alternation of deformed tangential wedges and undeformed cross-strata suggests that the mechanism that triggered the liquefaction of the dune lee side was related to the fluvial system itself and hence was of autokinetic origin. The tabular cross-sets have previously been interpreted as a product of the dune upper-stage plane-bed flow regime. In this flow context, it can be speculated that the liquefaction and deformation occurred when the flow conditions approached the plane-bed phase, probably inducing a highly differential turbulent pattern and pressure fluctuations sufficient to liquefy the fine/medium sand. The small flat-topped deformation lenses also suggest liquefaction by cyclic loading, whereas the solitary

  4. Testing restoration-based fracture prediction methods using field studies of fracturing in syn-tectonic strata

    NASA Astrophysics Data System (ADS)

    Shackleton, J. R.; Cooke, M. L.; Johnson, G.; Cilona, A.

    2012-12-01

    We use three-dimensional restorations of Sant Corneli anticline in the Spanish Pyrenees to test the fracture prediction capability of several structural restoration algorithms in fold and thrust belts. Sant Corneli anticline is a plunging thrust-related anticline, cored by fractured carbonates and overlain by a sequence of syn-tectonic sediments. Reconstruction of the three-dimensional architecture of the syn-tectonic strata provides a template for incrementally unfolding the anticline using different geometrical and geomechanical restoration techniques. We use several commercially available techniques to unfold the anticline, including a simple shear algorithm, a flexural slip algorithm, and a geomechanical algorithm. To evaluate the strain predictions produced by the restoration, we utilize the strain history recorded by faults and joints at Sant Corneli anticline. Structural restoration provides a link between fold evolution and fracturing because unfolding and forward modeling of unfolded strata can be used to predict the orientation of faults and fractures. The goal of the restoration is to predict the generalized strain patterns associated with fault-related folding within Sant Corneli anticline at different stages of deformation. Cross cutting relationships of joints suggest the following sequence of fractures associated with folding: ● Fracturing associated with early development of the anticline was characterized by approximately radial joints and faults (J1/J3), possibly including faulting events related to fold growth. These events probably continued throughout the early and middle stages of folding. ● A N-NW striking jointing event (J2) that may be associated with lateral propagation and gravity faulting that only affects several of the upper growth strata sequences (Montesquiu and Orcau-Vell sequences). ● Pervasive and through-going joint sets that are closer to bed strike than previous joint sets (J4/J5) are interpreted to have formed during the

  5. Paleogeography and Depositional Systems of Cretaceous-Oligocene Strata: Eastern Precordillera, Argentina

    NASA Astrophysics Data System (ADS)

    Reat, Ellen J.; Fosdick, Julie C.

    2016-04-01

    New data from the Argentine Precordillera in the southern Central Andes document changes in depositional environment and sediment accumulation rates during Upper Cretaceous through Oligocene basin evolution, prior to the onset Miocene foredeep sedimentation. This work presents new sedimentology, detrital geochronology, and geologic mapping from a series of continental strata within this interval to resolve the timing of sedimentation, nature of depositional environments, and basin paleogeography at the nascent phase of Andean orogenic events, prior to the uplift and deformation of the Precordillera to the west. Five stratigraphic sections were measured across both limbs of the Huaco Anticline, detailing sedimentology of the terrestrial siliciclastic upper Patquía, Ciénaga del Río Huaco (CRH), Puesto la Flecha, Vallecito, and lower Cerro Morado formations. Paleocurrent data indicate a flow direction change from predominantly NE-SW in the upper Patquía and the lower CRH to SW-NE directed flow in the upper CRH, consistent with a large meandering river system and a potential rise in topography towards the west. This interpretation is further supported by pebble lag intervals and 1-3 meter scale trough cross-bedding in the CRH. The thinly laminated gypsum deposits and siltstones of the younger Puesto la Flecha Formation indicate an upsection transition into overbank and lacustrine sedimentation during semi-arid climatic conditions, before the onset of aeolian dune formation. New maximum depositional age results from detrital zircon U-Pb analysis indicate that the Puesto la Flecha Formation spans ~57 Myr (~92 to ~35 Ma) across a ~48 m thick interval without evidence for major erosion, indicating very low sedimentation rates. This time interval may represent distal foredeep or forebulge migration resultant from western lithospheric loading due to the onset of Andean deformation at this latitude. Detrital zircon U-Pb age spectra also indicate shifts in sediment routing

  6. Late Cretaceous climate changes recorded in Eastern Asian lacustrine deposits and North American Epieric sea strata

    NASA Astrophysics Data System (ADS)

    Wang, Chengshan; Scott, Robert W.; Wan, Xiaoqiao; Graham, Stephan A.; Huang, Yongjian; Wang, Pujun; Wu, Huaichun; Dean, Walter E.; Zhang, Laiming

    2013-11-01

    Cretaceous climate data of the long-lived Cretaceous Songliao Basin (SB) in eastern Asia is correlated and compared with the Western Interior Seaway (WIS) on the northern American plate, in order to understand better the dynamics of the Earth's past 'greenhouse' climates. Nearly continuous Late Cretaceous terrestrial deposition in the Songliao Basin is represented by two cores totaling 2431 m in length. The Turonian-Maastrichtian age of the section is based on integrated stratigraphy, and is comparable in age with Upper Cretaceous strata in the WIS. Being consistent with global trends, the dynamic Late Cretaceous climates of both the SB and WIS gradually cooled from the warmest Albian-Cenomanian time to the end of the Maastrichtian with several intervening warm periods as did the global climate. However regional differences existed, the Songliao Basin climate was humid to semi-humid, warm temperate-subtropical and the Western Interior Seaway was in the humid, warm temperate zone and experienced only moderate climatic changes. The shifts of oxygen isotope data in the Songliao Basin were frequent and abrupt, whereas WIS records more gradual change affected mainly by fresh-water runoff mixing with southern Tethyan and northern Arctic waters. Sedimentary cycles of eccentricity, obliquity and precession bands are recorded in both the SB and WIS basins. The sedimentary cycles in the WIS and SB are interpreted to be related to variations of the wet/dry runoff cycles, which indicate that orbital forcing played an important role in global climate change in Late Cretaceous. The most favorable condition for organic carbon burial in both the SB and WIS basin was bottom water anoxia regardless of the cause of the anoxia. But the organic carbon burial rate was usually much higher in the Songliao Lake than in the WI epeiric sea suggesting that giant lakes may serve as important sinks of atmospheric CO2. In both basins organic-rich deposits formed during a rise in water level and

  7. Sequence and seismic stratigraphy of the Jurassic strata in northeastern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Obid, Jamal A.

    The Upper Jurassic section in the northeastern Gulf of Mexico includes the Norphlet and Smackover Formations (Oxfordian), considered as one of the most prolific oil and gas producers in the area, the Haynesville Formation (Kimmeridgian), and the Cotton Valley Group (Tithonian to Berriasian/Lower Valanginian). The study area, located in the onshore-offshore southwest Alabama, consists of mixed siliciclastic and carbonate deposits representing continental, marginal marine, and marine environments. Well log, core and two-dimensional reflection seismic data were used to provide a sequence stratigraphic framework for the Jurassic section through identification of transgressive-regressive sequences and their associated key stratigraphic surfaces. Three transgressive-regressive (T-R) sequences were identified in the Upper Jurassic-Lower Cretaceous strata onshore Alabama, using well log and limited core data. In the offshore area, four transgressive-regressive sequences were recognized on well logs. Stratigraphic analysis of the reflection seismic data yielded three T-R sequences. Sequence boundaries and marine flooding events were identified on seismic sections through interpretation of reflection termination patterns of seismic reflectors. The reflection seismic data were eventually integrated with well log data using check-shot surveys and synthetic seismogram. The recognized transgressive-regressive sequences have utility for regional stratigraphic correlation of the Jurassic sediments across the northern Gulf of Mexico. The Oxfordian (Smackover), the Late Kimmeridgian (Haynesville), and the Berriasian (Cotton Valley) marine flooding events have potential for global correlation. Sequence boundaries and marine flooding surfaces were identified as major events in the geohistory of the northern Gulf of Mexico. Several approaches to sequence stratigraphy have been established. The three most popular approaches are the depositional sequence, the genetic stratigraphic

  8. Sequence stratigraphic analysis of Eocene Rock Strata, Offshore Indus, southwest Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, Natasha; Rehman, Khaista; Ahmad, Sajjad; Khokher, Jamil; Hajana, M. Iqbal; Hanif, M.

    2016-09-01

    In this study, seismic data from two wells (Pak G2-1 and Indus Marine-1C) and age diagnostic larger benthic foraminifera (LBF) within drill cuttings has been used for the first time to identify depositional sequences within the carbonates in the Offshore Indus Basin, Pakistan. The Offshore Indus is tectonically categorized as a passive continental margin where carbonates occur as shelf carbonates in the near offshore and on volcanic seamounts in deeper waters. Seismic data analysis has indicated the presence of minor faults and carbonate buildups above the igneous basement in the south. Patterns of the seismic reflections enabled definition of three seismic facies units identified as: Unit 1 basement, represented by chaotic, moderate amplitude reflection configuration; while parallel bedding and the drape of overlying strata is typical character of Unit 2, carbonate mound facies. The younger Miocene channels represent Unit 3. The diagnosis of Alveolina vredenburgi/cucumiformis biozone confirmed the Ilerdian (55-52 Ma) stage constituting a second order cycle of deposition for the Eocene carbonates (identified as Unit 2). The carbonate succession has been mainly attributed to an early highstand system tract (HST). The environmental conditions remained favorable leading to the development of keep-up carbonates similar to pinnacle buildups as a result of aggradation during late transgressive system tract and an early HST. The carbonate sequence in the south (Pak G2-1) is thicker and fossiliferous representing inner to middle shelf depths based on fauna compared to the Indus Marine-1C in the north, which is devoid of fossils. Three biozones (SBZ 5, SBZ 6 and SBZ 8) were identified based on the occurrence of LBF. The base of the SBZ 5 zone marks the larger foraminifera turnover and the Paleocene-Eocene (P-E) boundary. The LBF encountered in this study coincides with earlier findings for the P-E boundary. Our findings indicate that the entire Ilerdian stage ranges from 55

  9. Paternal X inactivation does not correlate with X chromosome evolutionary strata in marsupials.

    PubMed

    Rodríguez-Delgado, Claudia L; Waters, Shafagh A; Waters, Paul D

    2014-12-24

    X chromosome inactivation is the transcriptional silencing of one X chromosome in the somatic cells of female mammals. In eutherian mammals (e.g. humans) one of the two X chromosomes is randomly chosen for silencing, with about 15% (usually in younger evolutionary strata of the X chromosome) of genes escaping this silencing. In contrast, in the distantly related marsupial mammals the paternally derived X is silenced, although not as completely as the eutherian X. A chromosome wide examination of X inactivation, using RNA-seq, was recently undertaken in grey short-tailed opossum (Monodelphis domestica) brain and extraembryonic tissues. However, no such study has been conduced in Australian marsupials, which diverged from their American cousins ~80 million years ago, leaving a large gap in our understanding of marsupial X inactivation. We used RNA-seq data from blood or liver of a family (mother, father and daughter) of tammar wallabies (Macropus eugenii), which in conjunction with available genome sequence from the mother and father, permitted genotyping of 42 expressed heterozygous SNPs on the daughter's X. These 42 SNPs represented 34 X loci, of which 68% (23 of the 34) were confirmed as inactivated on the paternally derived X in the daughter's liver; the remaining 11 X loci escaped inactivation. Seven of the wallaby loci sampled were part of the old X evolutionary stratum, of which three escaped inactivation. Three loci were classified as part of the newer X stratum, of which two escaped inactivation. A meta-analysis of previously published opossum X inactivation data revealed that 5 of 52 genes in the old X stratum escaped inactivation. We demonstrate that chromosome wide inactivation of the paternal X is common to an Australian marsupial representative, but that there is more escape from inactivation than reported for opossum (32% v 14%). We also provide evidence that, unlike the human X chromosome, the location of loci within the oldest evolutionary stratum on

  10. Understanding the early Mesozoic world: New geochronological data from terrestrial and marine strata

    NASA Astrophysics Data System (ADS)

    Mundil, Roland; Irmis, Randall B.; Ickert, Ryan B.

    2013-04-01

    The first ~50 Ma of the Mesozoic (the Triassic Period) are marked by two major mass extinctions at the end-Permian and end-Triassic, extensive flood volcanic events (the Siberian Traps and the Central Atlantic Magmatic Province), perturbations of the ocean chemistry, paleoenvironmental changes in a greenhouse world and the origin of modern terrestrial ecosystems. Marine records of events leading to the end-Permian extinction as well as subsequent recovery during the Early and Middle Triassic are now well understood in terms of their relative and absolute timing, mainly due to significant advances in both the quantity and quality of geochronological data. This includes a detailed understanding of the Middle and end-Permian extinction events and their potential causes, their aftermath, and also the timing of large scale perturbations of the global carbon cycle in the Early Triassic. For the remaining ~30 Ma of the Triassic, however, there was until recently virtually no chronostratigraphic framework, and hence there is a major lag in our understanding of major events such as the origin and early diversification of dinosaurs, major reef building episodes in marine ecosystems, paleoenvironmental changes (e.g., the Carnian Pluvial Event), and a large extraterrestrial bolide impact (the Manicouagan impact). In absence of high-resolution radioisotopic ages, assumptions about causal inference and the role of these events, remain poorly constrained. We have therefore started to build a chronostratigraphic framework by applying U-Pb CA-TIMS analyses to zircon from primary and redeposited volcanic strata within both marine and terrestrial sequences of Late Triassic age. In particular, the potential of geochronological techniques applied to redeposited volcanic layers has long been ignored because the time lag between zircon crystallization and deposition is unknown; however, our initial results calibrating terrestrial sequences in North and South America are very promising

  11. Tephrochronology of rare Plio-Pleistocene fossiferous strata in south-central Afar, Ethiopia

    NASA Astrophysics Data System (ADS)

    DiMaggio, E.; Arrowsmith, R.; Campisano, C. J.; Deino, A. L.

    2013-12-01

    Sedimentary basins in the south and central Afar Depression archive the complex structural, climatic, volcanic, and biologic development of the region during the Pliocene and Pleistocene. The lower Awash Valley in central Afar has long served as a focus for these investigations, including the extensive work conducted to place fossil assemblages (including hominins) into stratigraphic and temporal context. Here we present a detailed analysis of tephra chemistry, correlations, and ages of the newly mapped and fossiliferous area of eastern Ledi-Geraru (ELG) in the lower Awash Valley (~3-2.5 Ma). Our results allow us to construct a tephrostratigraphic framework that provides important constraints for regional studies previously lacking a calibrated sedimentary record spanning 3 to 2.7 Ma. Based on glass chemistry and morphology, 40Ar/39Ar dating of feldspars, and stratigraphic mapping, we identified 23 distinct tephras (8 of which were dated) in >100 m of newly mapped fluvial and lacustrine sediments at ELG. The oldest tuff at ELG (Kuhulta Tuff; 2.994 Ma) is exposed in lake sediments (diatomite) that lie 3-5 m above basalt flows dated to ca. 3 Ma. The youngest ELG tephra (ca. 2.44 Ma) outcrops as a lenticular channel tuff in sediments faulted against older strata (~2.7 Ma). Between these two tephras lies the Gurumaha Tuff (ca. 2.82 Ma) and the Daáma and Bulinan Tuffs (both ca. 2.85 Ma), which provide excellent stratigraphic ties across a distance of 7.5 km, allowing us to document a lateral facies change from lacustrine in northern ELG to more nearshore in the south. These tuffs also confirm the presence of a fossiferous sedimentary record spanning the late Pliocene sedimentary gap in lower Awash Valley stratigraphy (ca. 2.94 - 2.7 Ma). While the youngest and oldest tephras at ELG temporally overlap with dated tephras from the well-described Hadar (3.8 - 2.94 Ma) and Busidima (2.7 - 0.016 Ma) Formations, we have yet to confirm geochemical correlates to any tephra

  12. Approaches to detect genetic effects that differ between two strata in genome-wide meta-analyses: Recommendations based on a systematic evaluation

    PubMed Central

    Justice, Anne E.; Cupples, L. Adrienne; Kronenberg, Florian

    2017-01-01

    Genome-wide association meta-analyses (GWAMAs) conducted separately by two strata have identified differences in genetic effects between strata, such as sex-differences for body fat distribution. However, there are several approaches to identify such differences and an uncertainty which approach to use. Assuming the availability of stratified GWAMA results, we compare various approaches to identify between-strata differences in genetic effects. We evaluate type I error and power via simulations and analytical comparisons for different scenarios of strata designs and for different types of between-strata differences. For strata of equal size, we find that the genome-wide test for difference without any filtering is the best approach to detect stratum-specific genetic effects with opposite directions, while filtering for overall association followed by the difference test is best to identify effects that are predominant in one stratum. When there is no a priori hypothesis on the type of difference, a combination of both approaches can be recommended. Some approaches violate type I error control when conducted in the same data set. For strata of unequal size, the best approach depends on whether the genetic effect is predominant in the larger or in the smaller stratum. Based on real data from GIANT (>175 000 individuals), we exemplify the impact of the approaches on the detection of sex-differences for body fat distribution (identifying up to 10 loci). Our recommendations provide tangible guidelines for future GWAMAs that aim at identifying between-strata differences. A better understanding of such effects will help pinpoint the underlying mechanisms. PMID:28749953

  13. Differences in the epidemiology of theileriosis on smallholder dairy farms in contrasting agro-ecological and grazing strata of highland Kenya.

    PubMed Central

    Gitau, G. K.; McDermott, J. J.; Katende, J. M.; O'Callaghan, C. J.; Brown, R. N.; Perry, B. D.

    2000-01-01

    A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total, 225 calves from 188 smallholder farms were examined from birth to 6 months of age and visited within the first 2 weeks of life and thereafter at bi-weekly intervals for up to 14 visits. The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity and mortality) and potential control of ECF between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA assay by the percent positivity (PP) of serum samples relative to a strong positive reference serum. Sero-conversion risks of T. parva were highest in the open-grazing strata. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in open-grazing strata. While different, all five AEZ-grazing strata were considered to be endemically unstable for ECF. East Coast fever challenge was low in all zero-grazing strata and this challenge is likely to remain low due to continuing intensification of smallholder farming in the central highlands. In the open-grazing strata, there was higher challenge and a greater impact of ECF. PMID:10813159

  14. Differences in the epidemiology of theileriosis on smallholder dairy farms in contrasting agro-ecological and grazing strata of highland Kenya.

    PubMed

    Gitau, G K; McDermott, J J; Katende, J M; O'Callaghan, C J; Brown, R N; Perry, B D

    2000-04-01

    A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total, 225 calves from 188 smallholder farms were examined from birth to 6 months of age and visited within the first 2 weeks of life and thereafter at bi-weekly intervals for up to 14 visits. The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity and mortality) and potential control of ECF between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA assay by the percent positivity (PP) of serum samples relative to a strong positive reference serum. Sero-conversion risks of T. parva were highest in the open-grazing strata. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in open-grazing strata. While different, all five AEZ-grazing strata were considered to be endemically unstable for ECF. East Coast fever challenge was low in all zero-grazing strata and this challenge is likely to remain low due to continuing intensification of smallholder farming in the central highlands. In the open-grazing strata, there was higher challenge and a greater impact of ECF.

  15. Supercritical strata in Lower Paleozoic fluvial rocks: a super critical link to upper flow regime processes and preservation in nature

    NASA Astrophysics Data System (ADS)

    Lowe, David; Arnott, Bill

    2015-04-01

    Recent experimental work has much improved our understanding of the lithological attributes of open-channel supercritical flow deposits, namely those formed by antidunes, chutes-and-pools and cyclic steps. However their limited documentation in the ancient sedimentary record brings into question details about their geological preservation. Antidune, chute-and-pool and cyclic step deposits are well developed in sandy ephemeral fluvial deposits of the Upper Cambrian - Lower Ordovician Potsdam Group in the Ottawa Embayment of eastern North America. These high energy fluvial strata form dm- to a few m-thick units intercalated within thick, areally expansive successions of sheet sandstones consisting mostly of wind ripple and adhesion stratification with common deflation lags. Collectively these strata record deposition in a semi-arid environment in which rare, episodic high-energy fluvial events accounted for most of the influx of sediment from upland sources. Following deposition, however, extensive aeolian processes reworked the sediment pile, and hence modified profoundly the preserved stratigraphic record. Antidune deposits occur as 0.2 - 1.6 m thick cosets made up of 2 - 15 cm thick lenticular sets of low angle (≤ 20o) cross-stratified, medium- to coarse-grained sandstone bounded by low-angle (5 - 15o) concave-upward scours and, in many cases, capped by low angle (10 - 15o) convex-upwards symmetrical formsets. Chute-and-pool deposits form single sets, 5 - 55 cm thick and 0.6 - 6 m wide, with scoured bases and low to high angle (5 - 25o) sigmoidal cross-strata consisting of medium- to coarse-grained sandstone. Cyclic step deposits consist of trough cross-stratified sets, 20 cm - 1.6 m thick, 2.5 - 12 m long and 7 - 35 m wide, typically forming trains that laterally are erosively juxtaposed at regularly-spaced intervals. They are composed of medium- to coarse-grained sandstone with concave-up, moderate to high angle (15 - 35o) cross-strata with tangential bases

  16. Petrophysical, Lithological and Mineralogical Characteristics of the Shale Strata of the Volga- Ural Region

    NASA Astrophysics Data System (ADS)

    Morozov, Vladimir P.; Plotnikova, Irina N.; Pronin, Nikita V.; Nosova, Fidania F.; Pronina, Nailya R.

    2014-05-01

    The objects of the study are Upper Devonian carbonate rocks in the territory of South-Tatar arch and Melekess basin in the Volga- Urals region. We studied core material of Domanicoid facies from the sediments of Mendymski and Domanik horizons of middle substage of Frasnian stage of the Upper Devonian. Basic analytical research methods included the following: study of the composition, structural and textural features of the rocks, the structure of their voids, filter and reservoir properties and composition of the fluid. The complex research consisted of macroscopic description of the core material, optical microscopy analysis, radiographical analysis, thermal analysis, x-ray tomography, electron microscopy, gas-liquid chromatography, chromate-mass spectrometry, light hydrocarbons analysis using paraphase assay, adsorbed gases analysis, and thermal vacuum degassing method. In addition, we performed isotopic studies of hydrocarbons saturating shale rocks. Shale strata are mainly represented by carbonate-chert rocks. They consist mainly of calcite and quartz. The ratio of these rock-forming minerals varies widely - from 25 to 75 percent. Pyrite, muscovite, albite, and microcline are the most common inclusions. Calcareous and ferruginous dolomite (ankerite), as well as magnesian calcite are tracked down as secondary minerals. While performing the tests we found out that the walls of open fractures filled with oil are stacked by secondary dolomite, which should be considered as an indication moveable oil presence in the open-cut. Electron microscopy data indicate that all the studied samples have porosity - both carbonates and carbonate-siliceous rocks. Idiomorphism of the rock-forming grains and pores that are visible under a microscope bring us to that conclusion. The analysis of the images indicates that the type of reservoir is either porous or granular. The pores are distributed evenly in the volume of rock. Their size is very unstable and varies from 0.5 microns

  17. Longshore-drift dispersed, storm-generated cross-stratified sandstone from some Cretaceous shallow marine strata, Rocky Mountain region

    SciTech Connect

    Gustason, E.R. )

    1990-05-01

    Most Cretaceous shallow marine strata of the Rocky Mountain region are characterized by asymmetrical upward-coarsening and upward-thickening sequences. The strata typically contain similar lithofacies (i.e., normally graded planar parallel laminated claystone, siltstone, and sandstone; hummocky cross-stratified sandstone; symmetrical and asymmetrical ripple cross-lamination; and trough and planar tublar cross-stratified sandstone) and display an upward increase in the thickness and frequency of sharp-based sandstone beds that grade into amalgamated cross-stratified sandstone. Most workers agree that sharp-based sandstone beds and hummocky cross-stratified sandstone are storm generated. However, the origin of trough and planar tabular cross-stratified sandstone is controversial. Most workers interpret these sedimentary structures as deposited from either storm-generated traction currents or combined flow currents on the shelf, tide-generated traction currents, or tidally dispersed, storm-generated suspension clouds. Detailed analysis of three-dimensional outcrops has revealed several significant features of these sedimentary structures that indicate they may have been deposited by longshore drift dispersed, storm-generated suspension clouds. Sets of trough and planar cross-stratified sandstone form medium-scale discontinuous, irregularly shaped sand bodies, bound by erosional surfaces and composed of unidirectional dip-oriented cross strata. Individual cross stratum commonly have a sigmoidal shape, are bound by either reactivation surfaces or mudstone drapes, and contain normally graded concordant laminae. Top-set laminae, are truncated by the upper set boundary, whereas bottom-set laminae, become asymptotic to the lower set boundary and commonly are reworked and overlain by wave generated, ripple cross-lamination or mudstone drapes.

  18. [Concept of living conditions or social strata?--which approach is more suitable for describing unhealthy living circumstances of mothers?].

    PubMed

    Sperlich, S; Geyer, S

    2010-11-01

    The aim of this study was to identify living conditions associated with elevated health risks for mothers. Following up the debate on appropriate characterisation of social structure in modern societies, two different approaches, namely the 'social strata concept' and the 'concept of living conditions', were considered. Of particular interest was the question if the concept of living conditions, which is based on a broader definition of social status, allowed a more precise description of health-related living circumstances. The study was based on clinical data from 6,094 inpatients in Mother-Child rehabilitation centres in Germany. Taking socioeconomic status, household characteristics and psychosocial stressors into account seven typical living conditions of mothers could be identified by cluster analysis. Social status was measured by the Winkler Index. A moderate health-related gradient of increasing health risks with decreasing social position could be found for psychological and bodily disabilities. The approach of living conditions revealed that two living circumstances of mothers could be identified as being related to extremely poor health. These are i) dissatisfied single mothers with high degrees of psychosocial distress and lack of social support, and ii) married mothers with conflicts within the family and self-perceived lack of appreciation. Different from these findings, a pronounced social gradient could be found for overweight and smoking. Here the concept of social strata revealed in part excessive risks compared to the concept of living conditions. Overall, the integration of further social determinants allowed a more detailed insight into health-related living conditions, which are not solely determined by socioeconomic position. A global answer about the adequacy of the 'social strata concept' versus 'concept of living conditions' for identifying unhealthy living conditions could not be given because the relevance of both conceptual frameworks

  19. Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah

    SciTech Connect

    LORENZ, JOHN C.; COOPER, SCOTT P.

    2001-12-01

    Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, and sandstones of the Frontier Formation along the western edge of the Green River basin in southwestern Wyoming), show that although each fracture domain may contain consistently oriented fractures, the orientations and patterns of the fractures vary considerably from domain to domain. Most of the fracture patterns in the brittle sandstones are related to local stresses created by subtle, irregular flexures resulting from mobility of the associated, interbedded ductile strata (halite or shale). Sequential episodes of evaporite dissolution and/or mobility in different directions can result in multiple, superimposed fracture sets in the associated sandstones. Multiple sets of superimposed fractures create reservoir-quality fracture interconnectivity within restricted localities of a formation. However, it is difficult to predict the orientations and characteristics of this type of fracturing in the subsurface. This is primarily because the orientations and characteristics of these fractures typically have little relationship to the regional tectonic stresses that might be used to predict fracture characteristics prior to drilling. Nevertheless, the high probability of numerous, intersecting fractures in such settings attests to the importance of determining fracture orientations in these types of fractured reservoirs.

  20. 76 FR 71082 - Strata Energy, Inc., Ross Uranium Recovery Project; New Source Material License Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ...) and chemical compounds (sodium ] bicarbonate) through a series of injection wells. The uranium-rich solution is transferred from production wells to either the central processing plant or satellite facility... staff met with, and gathered information from, Federal, State, and local agencies as well as with public...

  1. Structure-Based Prediction of Drug Distribution Across the Headgroup and Core Strata of a Phospholipid Bilayer Using Surrogate Phases

    PubMed Central

    2015-01-01

    Solvation of drugs in the core (C) and headgroup (H) strata of phospholipid bilayers affects their physiological transport rates and accumulation. These characteristics, especially a complete drug distribution profile across the bilayer strata, are tedious to obtain experimentally, to the point that even simplified preferred locations are only available for a few dozen compounds. Recently, we showed that the partition coefficient (P) values in the system of hydrated diacetyl phosphatidylcholine (DAcPC) and n-hexadecane (C16), as surrogates of the H- and C-strata of the bilayer composed of the most abundant mammalian phospholipid, PC, agree well with the preferred bilayer location of compounds. High P values are typical for lipophiles accumulating in the core, and low P values are characteristic of cephalophiles preferring the headgroups. This simple pattern does not hold for most compounds, which usually have more even distribution and may also accumulate at the H/C interface. To model complete distribution, the correlates of solvation energies are needed for each drug state in the bilayer: (1) for the H-stratum it is the DAcPC/W P value, calculated as the ratio of the C16/W and C16/DAcPC (W for water) P values; (2) for the C-stratum, the C16/W P value; (3) for the H/C interface, the P values for all plausible molecular poses are characterized using the fragment DAcPC/W and C16/W solvation parameters for the parts of the molecule embedded in the H- and C-strata, respectively. The correlates, each scaled by two Collander coefficients, were used in a nonlinear, mass-balance based model of intrabilayer distribution, which was applied to the easily measurable overall P values of compounds in the DMPC (M = myristoyl) bilayers and monolayers as the dependent variables. The calibrated model for 107 neutral compounds explains 94% of experimental variance, achieves similar cross-validation levels, and agrees well with the nontrivial, experimentally determined bilayer

  2. Detrital zircon U-Pb geochronology of Cambrian to Triassic miogeoclinal and eugeoclinal strata of Sonora, Mexico

    USGS Publications Warehouse

    Gehrels, G.E.; Stewart, John H.

    1998-01-01

    One hundred and eighty two individual detrital zircon grains from Cambrian through Permian miogeoclinal strata, Ordovician eugeoclinal rocks, and Triassic post-orogenic sediments in northwestern Sonora have been analyzed. During Cambrian, Devonian, Permian, and Triassic time, most zircons accumulating along this part of the Cordilleran margin were shed from 1.40-1.45 and 1.62-1.78 Ga igneous rocks that are widespread in the southwestern United States and northwestern Mexico. Zircons with ages of approximately 1.11 Ga are common in Cambrian strata and were apparently shed from granite bodies near the sample site. The sources of 225-280 Ma zircons in our Triassic sample are more problematic, as few igneous rocks of these ages are recognized in northwestern Mexico. Such sources may be present but unrecognized, or the grains could have been derived from igneous rocks of the appropriate ages to the northwest in the Mojave Desert region, to the east in Chihuahua and Coahuila, or to the south in accreted(?) arc-type terranes. Because the zircon grains in our Cambrian and Devonian to Triassic samples could have accumulated in proximity to basement rocks near their present position or in the Death Valley region of southern California, our data do not support or refute the existence of the Mojave-Sonora megashear. Ordovician strata of both miogeoclinal and eugeoclinal affinity are dominated by >1.77 Ga detrital zircons, which are considerably older than most basement rocks in the region. Zircon grains in the miogeoclinal sample were apparently derived from the Peace River arch area of northwestern Canada and transported southward by longshore currents. The eugeoclinal grains may also have come from the Peace River arch region, with southward transport by either sedimentary or tectonic processes, or they may have been shed from off-shelf slivers of continents (perhaps Antarctica?) removed from the Cordilleran margin during Neoproterozoic rifting. It is also possible that the

  3. Structure-based prediction of drug distribution across the headgroup and core strata of a phospholipid bilayer using surrogate phases.

    PubMed

    Natesan, Senthil; Lukacova, Viera; Peng, Ming; Subramaniam, Rajesh; Lynch, Sandra; Wang, Zhanbin; Tandlich, Roman; Balaz, Stefan

    2014-10-06

    Solvation of drugs in the core (C) and headgroup (H) strata of phospholipid bilayers affects their physiological transport rates and accumulation. These characteristics, especially a complete drug distribution profile across the bilayer strata, are tedious to obtain experimentally, to the point that even simplified preferred locations are only available for a few dozen compounds. Recently, we showed that the partition coefficient (P) values in the system of hydrated diacetyl phosphatidylcholine (DAcPC) and n-hexadecane (C16), as surrogates of the H- and C-strata of the bilayer composed of the most abundant mammalian phospholipid, PC, agree well with the preferred bilayer location of compounds. High P values are typical for lipophiles accumulating in the core, and low P values are characteristic of cephalophiles preferring the headgroups. This simple pattern does not hold for most compounds, which usually have more even distribution and may also accumulate at the H/C interface. To model complete distribution, the correlates of solvation energies are needed for each drug state in the bilayer: (1) for the H-stratum it is the DAcPC/W P value, calculated as the ratio of the C16/W and C16/DAcPC (W for water) P values; (2) for the C-stratum, the C16/W P value; (3) for the H/C interface, the P values for all plausible molecular poses are characterized using the fragment DAcPC/W and C16/W solvation parameters for the parts of the molecule embedded in the H- and C-strata, respectively. The correlates, each scaled by two Collander coefficients, were used in a nonlinear, mass-balance based model of intrabilayer distribution, which was applied to the easily measurable overall P values of compounds in the DMPC (M = myristoyl) bilayers and monolayers as the dependent variables. The calibrated model for 107 neutral compounds explains 94% of experimental variance, achieves similar cross-validation levels, and agrees well with the nontrivial, experimentally determined bilayer

  4. ‘Teach a Man to Fish’: The Doctrine of Sustainability and Its Effects on Three Strata of Malawian Society

    PubMed Central

    Swidler, Ann; Watkins, Susan Cotts

    2009-01-01

    This paper analyzes the social impacts of the commitment to “sustainability” in donor-funded AIDS programs. Using survey, interview, and ethnographic data from rural Malawi, we examine how efforts to mobilize and empower local communities affect three strata of Malawian society: the villagers these programs are meant to help, the insecure local elites whose efforts directly link programs to their intended beneficiaries, and, more briefly, national elites who implement AIDS policies and programs. We describe indirect effects of sustainability on the experiences, identities, and aspirations of Malawians—effects that are much broader and deeper than the direct impacts of funding. PMID:20161458

  5. Paleoclimate cycles and tectonic controls on fluvial, lacustrine, and eolian strata in upper Triassic Chinle Formation, San Juan basin

    SciTech Connect

    Dubiel, R.F. )

    1989-09-01

    Sedimentologic study of the Upper Triassic Chinle Formation in the San Juan basin (SJB) indicates that Late Triassic paleoclimate and tectonic movements influenced the distribution of continental lithofacies. The Shinarump, Monitor Butte, and Petrified Forest Members in the lower part of the Chinle consist of complexly interfingered fluvial, floodplain, marsh, and lacustrine rocks; the Owl Rock and Rock Point Members in the upper part consists of lacustrine-basin and eolian sandsheet strata. Facies analysis, vertebrate and invertebrate paleontology, and paleoclimate models demonstrate that the Late Triassic was dominated by tropical monsoonal circulation, which provided abundant precipitation interspersed with seasonally dry periods. Owl Rock lacustrine strata comprise laminated limestones that reflect seasonal monsoonal precipitation and larger scale, interbedded carbonates and fine-grained clastics that represent longer term, alternating wet and dry climatic cycles. Overlying Rock Point eolian sand-sheet and dune deposits indicate persistent alternating but drier climatic cyclicity. Within the Chinle, upward succession of lacustrine, alternating lacustrine/eolian sand-sheet, and eolian sand-sheet/dune deposits reflects an overall decrease in precipitation due to the northward migration of Pangaea out of low latitudes dominated by monsoonal circulation.

  6. Geoacoustic models of Coastal Bottom Strata at Jeongdongjin in the Korean continental margin of the East Sea

    NASA Astrophysics Data System (ADS)

    Ryang, Woo Hun; Han, Jooyoung

    2017-04-01

    Geoacoustic models provide submarine environmental data to predict sound transmission through submarine bottom layers of sedimentary strata and acoustic basement. This study reconstructed four geoacoustic models for sediments of 50 m thick at the Jeongdongjin area in the western continental margin of the East Sea. Bottom models were based on about 1100 line-km data of the high-resolution air-gun seismic and subbottom profiles (SBP) with sediment cores. The 4 piston cores were analyzed for reconstruction of the bottom and geoacoustic models in the study area, together with 2 long cores in the adjacent area. P-wave speed in the core sediment was measured by the pulse transmission technique, and the resonance frequency of piezoelectric transducers was maintained at 1 MHz. Measurements of 42 P-wave speeds and 41 attenuations were fulfilled in three core sediments. For actual modeling, the P-wave speeds of the models were compensated to in situ depth below the sea floor using the Hamilton method. These geoacoustic models of coastal bottom strata will be used for geoacoustic and underwater acoustic experiments reflecting vertical and lateral variability of geoacoustic properties in the Jeongdongjin area of the East Sea. Keywords: geoacosutic model, bottom model, P-wave speed, Jeongdongjin, East Sea Acknowledgements: This research was supported by the research grants from the Agency of Defense Development (UD140003DD and UE140033DD).

  7. Does the Great Valley Group contain Jurassic strata? Reevaluation of the age and early evolution of a classic forearc basin

    USGS Publications Warehouse

    Surpless, K.D.; Graham, S.A.; Covault, J.A.; Wooden, J.L.

    2006-01-01

    The presence of Cretaceous detrital zircon in Upper Jurassic strata of the Great Valley Group may require revision of the lower Great Valley Group chronostratigraphy, with significant implications for the Late Jurassic-Cretaceous evolution of the continental margin. Samples (n = 7) collected from 100 km along strike in the purported Tithonian strata of the Great Valley Group contain 20 Cretaceous detrital zircon grains, based on sensitive high-resolution ion microprobe age determinations. These results suggest that Great Valley Group deposition was largely Cretaceous, creating a discrepancy between biostratigraphy based on Buchia zones and chronostratigraphy based on radiometric age dates. These results extend the duration of the Great Valley Group basal unconformity, providing temporal separation between Great Valley forearc deposition and creation of the Coast Range Ophiolite. If Great Valley forearc deposition began in Cretaceous time, then sediment by passed the developing forearc in the Late Jurassic, or the Franciscan subduction system did not fully develop until Cretaceous time. In addition to these constraints on the timing of deposition, pre-Mesozoic detrital zircon age signatures indicate that the Great Valley Group was linked to North America from its inception. ?? 2006 Geological Society of America.

  8. Fault-related fold kinematics recorded by terrestrial growth strata, Sant Llorenç de Morunys, Pyrenees Mountains, NE Spain

    NASA Astrophysics Data System (ADS)

    Carrigan, James H.; Anastasio, David J.; Kodama, Kenneth P.; Parés, Josep M.

    2016-10-01

    Foreland basin growth strata are ideal recorders of deformation rates and kinematics in tectonically active regions. This study develops a high-resolution chronostratigraphic age model to determine folding rates in the Eocene-Oligocene terrestrial growth strata of the Berga Conglomerate Group, NE Spain. The Berga Conglomerate Group was sampled for rock magnetic, magnetostratigraphic, and magnetic susceptibility (χ) cyclostratigraphy analyses. Analysis of rock magnetic measurements indicate a mixed mineral assemblage with both paramagnetic and ferromagnetic minerals. A new magnetic reversal stratigraphy constrains the time frame of folding and is in agreement with previous interpretations. Time series analysis of χ variations show statistically significant power at expected orbital frequencies and provides precession-scale (20 kyr) temporal resolution. Strain measurements including anisotropy of magnetic susceptibility (AMS) fabrics and bedding plane strain worm burrow distortion are consistent with fixed hinge, flexural folding kinematics. Fault-related folding was modeled using χ cyclostratigraphy timing and strain measurement kinematic constraints. The onset of folding was at 33.85 Ma and the end of deformation is less constrained but is younger than 31.06 Ma. Deformation and sediment accumulation rates are unsteady at 20 kyr time scales but appear artificially steady at polarity chron time scales.

  9. SHRIMP U-Pb geochronology of volcanic rocks, Belt Supergroup, western Montana: Evidence for rapid deposition of sedimentary strata

    USGS Publications Warehouse

    Evans, K.V.; Aleinikoff, J.N.; Obradovich, J.D.; Fanning, C.M.

    2000-01-01

    New sensitive high resolution ion microprobe (SHRIMP) U-Pb zircon analyses from two tuffs and a felsic flow in the middle and upper Belt Supergroup of northwestern Montana significantly refine the age of sedimentation for this very thick (15-20 km) Middle Proterozoic stratigraphic sequence. In ascending stratigraphic order, the results are (1) 1454 ?? 9 Ma for a tuff in the upper part of the Helena Formation at Logan Pass, Glacier National Park; (2) 1443 ?? 7 Ma for a regionally restricted porphyritic rhyolite to quartz latite flow of the Purcell Lava in the Yaak River region; and (3) 1401 ?? 6 Ma for a tuff in the very thin transition zone between the Bonner Quartzite and Libby Formation, west of the town of Libby. Combining these ages with those previously published by other workers for ca. 1470-Ma sills in the lower Belt in Montana and Canada indicates that all but the uppermost Belt strata (about 1700 m) were deposited over a period of about 70 million years, considerably reducing the time span from longstanding estimates ranging from 250 to 600 million years. Calculated sediment accumulation rates between dated samples indicates rapid, but not unreasonable, values for early Belt strata, with decreasing rates through time. These ages also suggest the inadequacy of previously published paleomagnetic data to resolve Belt Supergroup chronology at an appropriate level of accuracy.

  10. Fault-related fold kinematics recorded by terrestrial growth strata, Sant Llorenc de Morunys, Pyrenees Mountains, NE Spain

    NASA Astrophysics Data System (ADS)

    Carrigan, James

    This study develops a high-resolution chronostratigraphy age model based on magnetic susceptibility (chi) variations to determine folding rates recorded by Eocene- Oligocene synorogenic terrestrial growth strata of the Berga Conglomerate Formation near Sant Llorenc de Morunys, NE Spain. This region was selected for its excellent preservation and exposure of synorogenic growth strata which allows for examination of deformation at high-resolution (20 kyr) time scales. The Berga Conglomerate was sampled for rock magnetic, paleomagnetic, and chi cyclostratigraphy analyses. Analysis of rock magnetic measurements indicate paramagnetic phyllosilicates are the dominant minerals that control chi cyclostratigraphy in a mixed mineral assemblage. Anisotropy of magnetic susceptibility (AMS) fabrics are most consistent with a fixed hinge flexural folding and transecting cleavage developed in the foreland synclinal hinge. Paleomagnetic reversal stratigraphy provided absolute time frame on folding at the million year timescale. Time series analysis of chi variations shows statistically significant power in expected orbital ratios (long eccentricity, obliquity, and precession). A calibrated age model was constructed using chi variations tuned to obliquity (41 kyr) cycles, which focuses power into precession index bands and long eccentricity. The age model predicts the onset of deformation at 33.85 Ma and shows that deformation and sediment accumulation rates were unsteady at 20 kyr time scales. Deformation rates range from quiescent to 100°/Myr and are not related to changes in sediment accumulation rate. Modeled fault slip predicts variable displacement rates ranging from 115 - 265 m/ Myr.

  11. Testing the Mojave-Sonora megashear hypothesis: Evidence from Paleoproterozoic igneous rocks and deformed Mesozoic strata in Sonora, Mexico

    USGS Publications Warehouse

    Amato, J.M.; Lawton, T.F.; Mauel, D.J.; Leggett, W.J.; Gonzalez-Leon, C. M.; Farmer, G.L.; Wooden, J.L.

    2009-01-01

    U-Pb ages and Nd isotope values of Proterozoic rocks in Sonora, Mexico, indicate the presence of Caborca-type basement, predicted to lie only south of the Mojave-Sonora mega-shear, 40 km north of the postulated megashear. Granitoids have U-Pb zircon ages of 1763-1737 Ma and 1076 Ma, with ??Nd(t) values from +1.4 to -4.3, typical of the Caborca block. Lower Jurassic strata near the Proterozoic rocks contain large granitic clasts with U-Pb ages and ??Nd(t) values indistinguishable from those of Caborcan basement. Caborca-type basement was thus present at this location north of the megashear by 190 Ma, the depositional age of the Jurassic strata. The Proterozoic rocks are interpreted as parautochthonous, exhumed and juxtaposed against the Mesozoic section by a reverse fault that formed a footwall shortcut across a Jurassic normal fault. Geochronology, isotope geochemistry, and structural geology are therefore inconsistent with Late Jurassic megashear displacement and require either that no major transcurrent structure is present in Sonora or that strike-slip displacement occurred prior to Early Jurassic time. ?? 2009 The Geological Society of America.

  12. New assemly model of Jiangnan Orogen: insight from detrital zircon geochronology of pre-Cretaceous strata, South China

    NASA Astrophysics Data System (ADS)

    Su, J.; Dong, S.

    2013-12-01

    The Jiangnan Orogen separates the Yangtze and Cathaysian Blocks in South China and provokes a longstanding debate on the amalgamation history between the two Blocks. The assembly of the two Blocks is termed Sibao orogeny marked by undeformed Late Neoproterozoic strata (Banxi Group) overlying on the deformed Early Neoproterozoic strata (Lengjiaxi Group) in China. Detrital zircons can provide critical links in recognizing the source history of a deposit, sedimentary dispersal systems and tectonic reconstructions. Therefore, fifteen sandstone samples taken from pre-Cretaceous strata of Yangtze Block are analyzed to constrain the evolution of the South China Block (SCB), especially the assembly between Yangtze and Cathaysia Blocks. The results show that the detrital zircons from the Neoproterozoic Lengjiaxi Group (ca. 830 Ma) near the boundary of large detachment fault of Hengshan have similar age populations with that in the other sites of the Jiangnan Orogen, different from that of the Kunyang and Dahongshan Groups (>960 Ma) in the southwestern margin of the Yangtze Block. The detrital zircons from Paleozoic samples have similar age populations with that in the Cathaysia Block. We infer that they originate from the Cathaysia Block, together with paleogeography, paleocurrent and former research. The detrital zircons of middle-late Jurassic sandstones in southwestern and central Yangtze yield dominant populations at 2.0-1.7 Ga and subordinate Groups of 2.6-2.4Ga, 0.7-0.8Ga and 0.6-0.4Ga. The provenance of late Triassic strata may be derived from southern Yangtze and North China Block due to the collisions among the Indosina, South China and North China Blocks, whereas the Jurassic sediments may be partly derived from uplift erosion of Jiangnan Orogen due to intra-continental orogeny induced by pacific subduction towards Eurasia Plate. The tectothermal event occurred at ca. 1.1-0.8 Ga has long been attributed to the assembly or breakup of Yangtze and Cathaysia Blocks

  13. Outcrops, Fossils, Geophysical Logs, and Tectonic Interpretations of the Upper Cretaceous Frontier Formation and Contiguous Strata in the Bighorn Basin, Wyoming and Montana

    USGS Publications Warehouse

    Merewether, E.A.; Cobban, W.A.; Tillman, R.W.

    2010-01-01

    In the Bighorn Basin of north-central Wyoming and south-central Montana, the Frontier Formation of early Late Cretaceous age consists of siliciclastic, bentonitic, and carbonaceous beds that were deposited in marine, brackish-water, and continental environments. Most lithologic units are laterally discontinuous. The Frontier Formation conformably overlies the Mowry Shale and is conformably overlain by the Cody Shale. Molluscan fossils collected from outcrops of these formations and listed in this report are mainly of marine origin and of Cenomanian, Turonian, and Coniacian ages. The lower and thicker part of the Frontier in the Bighorn Basin is of Cenomanian age and laterally equivalent to the Belle Fourche Member of the Frontier in central Wyoming. Near the west edge of the basin, these basal strata are disconformably overlain by middle Turonian beds that are the age equivalent of the Emigrant Gap Member of the Frontier in central Wyoming. The middle Turonian beds are disconformably overlain by lower Coniacian strata. Cenomanian strata along the south and east margins of the basin are disconformably overlain by upper Turonian beds in the upper part of the Frontier, as well as in the lower part of the Cody; these are, in turn, conformably overlain by lower Coniacian strata. Thicknesses and ages of Cenomanian strata in the Bighorn Basin and adjoining regions are evidence of regional differential erosion and the presence of an uplift during the early Turonian centered in northwestern Wyoming, west of the basin, probably associated with a eustatic event. The truncated Cenomanian strata were buried by lower middle Turonian beds during a marine transgression and possibly during regional subsidence and a eustatic rise. An uplift in the late middle Turonian, centered in north-central Wyoming and possibly associated with a eustatic fall, caused the erosion of lower middle Turonian beds in southern and eastern areas of the basin as well as in an adjoining region of north

  14. Upper Permian (Late Changhsingian) marine strata in Nan Province, northern Thailand

    NASA Astrophysics Data System (ADS)

    Fontaine, Henri; Hoang, Thi Than; Kavinate, Sathaporn; Suteethorn, Varavudh; Vachard, Daniel

    2013-10-01

    In the Upper Permian of northeastern Thailand (Loei Province), continental plants have been found and to the north in Laos near Luang Prabang, continental vertebrates (Dicynodon species) have been discovered. The Middle Permian is in sharp contrast to this as it is represented only by marine sediments. West of these areas in the province of Nan in Thailand, the Upper Permian is represented by marine sediments which extend to a high level in the Upper Permian and continental beds appear to be entirely absent, at least at Pha Dang Khwai, a locality where limestone extends from the end of the Lower Permian to the Triassic.

  15. Stratigraphy, depositional history and environments of deposition of Cretaceous through Tertiary strata in the Lamu Basin, southeast Kenya and implications for reservoirs for hydrocarbon exploration

    NASA Astrophysics Data System (ADS)

    Nyagah, Kivuti

    1995-04-01

    The Lamu Basin, which is characterized by an extensional tectonic style, is the failed arm of a tri-radial rift system and possesses tectonic and stratigraphic elements in the post-rift series that are analogous to those of the west coast of Africa. Development of the southern part of the basin as a passive margin, is closely related to considerations of the pre-drift position of Madagascar and formation of the Indian Ocean basin during Mesozoic time. Cretaceous and Tertiary strata in the basin comprise an eastward-thickening gross succession of sediments on which eustatic sea-level fluctuations and a sequence of unconformities related to pulses of transgressive and regressive depositional trends, are superimposed. Recognition of these trends has provided the basis for classification of the strata into megasequences representing distinct provinces with regard to time stratigraphy, sedimentation, tectonics, depositional environments and hydrocarbon potential. Megasequence I (Karoo Group and Jurassic) includes strata of the Permian through Jurassic, the discussion of which is beyond the scope of this paper. Megasequence II (Sabaki Group) includes strata of the Cretaceous and Early Paleocene, deposited in tide-influenced shelf and marine settings. These are, in ascending order: the Ewaso Sands, the Walu Shale, the Hagarso Limestone, the Freretown Limestone and the Kofia Sands. Megasequence III (Tana Group) includes strata of the Eocene through Oligocene, which were deposited in fluvial, deltaic, and restricted-shelf settings. These are, in ascending order: the Kipini Formation, the Pate Limestone, the Linderina Limestone, the Dodori Limestone and the Barren Beds Formation. Megasequence IV (Coastal Group) includes strata of the Miocene through Pliocene, which were deposited in restricted-shelf, middle- to outer-shelf, deep-marine and fluvial settings. These are, in ascending order: the Baratumu Formation, the Lamu Reefs, the Simba Shales and the Marafa Formation

  16. Use of Landsat Thematic Mapper images in regional correlation of syntectonic strata, Colorado river extensional corridor, California and Arizona

    NASA Technical Reports Server (NTRS)

    Beratan, K. K.; Blom, R. G.; Crippen, R. E.; Nielson, J. E.

    1990-01-01

    Enhanced Landsat TM images were used in conjunction with field work to investigate the regional correlation of Miocene rocks in the Colorado River extensional corridor of California and Arizona. Based on field investigations, four sequences of sedimentary and volcanic strata could be recognized in the Mohave Mountains (Arizona) and the eastern Whipple Mountains (California), which display significantly different relative volumes and organization of lithologies. The four sequences were also found to have distinctive appearances on the TM image. The recognition criteria derived from field mapping and image interpretation in the Mohave Mountains and Whipple Mountains were applied to an adjacent area in which stratigraphic affinities were less well known. The results of subsequent field work confirmed the stratigraphic and structural relations suggested by the Tm image analysis.

  17. Investigation of suspected gulls in the Jurassic limestone strata of the Cotswold Hills, Gloucestershire, England using electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Barron, A. J. M.; Uhlemann, S.; Pook, G. G.; Oxby, L.

    2016-09-01

    An electrical resistivity tomography survey has clearly indicated the presence of substantial vertical zones of contrasting material beneath a set of conspicuous linear surface hollows that cut across a spur forming part of the Cotswold Hills escarpment in Gloucestershire. These zones are compared with nearby quarry exposures and are inferred to be gulls - graben-like structures at least 80 m deep filled with collapsed blocks of bedrock with intervening air-filled spaces, lying within areas of relatively undisrupted gently dipping strata, and which under some circumstances would present a significant geohazard. Our results confirm the great potential of this non-invasive and rapid survey technique for investigating such phenomena, and provide an exemplar for comparison with surveys elsewhere, to assist identification of similar features.

  18. A new biostratigraphic correlation for Late Cretaceous-Paleocene strata of the Gulf of Guinea: Evidence from dinoflagellate cysts

    NASA Astrophysics Data System (ADS)

    Sánchez-Pellicer, Raquel; Masure, Edwige; Villier, Loïc

    2017-01-01

    A new biostratigraphic correlation for Late Cretaceous and Palaeocene strata of the Côte d'Ivoire-Ghana continental margin has been developed from the identification of significant dinoflagellate cyst events in ODP Hole 959D. The Late Cretaceous stage boundaries are mostly consistent with previous studies. However, the Maastrichtian/Danian boundary is placed much lower than previously recognized on the basis of the first occurrences of Carpatella cornuta and Damassadinium californicum. The base of the Selandian is recognized from the last occurrence of Cerodinium diebelii and the first occurrence of Adnatosphaeridium multispinosum. The base of the Thanetian is recognized from the first occurrence of Areoligera gippingensis. The rarity of the age-marker taxa is the main reason for different age determinations among studies of the same section.

  19. An R package for spatial coverage sampling and random sampling from compact geographical strata by k-means

    NASA Astrophysics Data System (ADS)

    Walvoort, D. J. J.; Brus, D. J.; de Gruijter, J. J.

    2010-10-01

    Both for mapping and for estimating spatial means of an environmental variable, the accuracy of the result will usually be increased by dispersing the sample locations so that they cover the study area as uniformly as possible. We developed a new R package for designing spatial coverage samples for mapping, and for random sampling from compact geographical strata for estimating spatial means. The mean squared shortest distance (MSSD) was chosen as objective function, which can be minimized by k-means clustering. Two k-means algorithms are described, one for unequal area and one for equal area partitioning. The R package is illustrated with three examples: (1) subsampling of square and circular sampling plots commonly used in surveys of soil, vegetation, forest, etc.; (2) sampling of agricultural fields for soil testing; and (3) infill sampling of climate stations for mainland Australia and Tasmania. The algorithms give satisfactory results within reasonable computing time.

  20. Revised lithostratigraphy and biostratigraphy of the Middle-Upper Devonian strata of central Missouri, southern part of Iowa basin

    SciTech Connect

    Day, J. . Dept. of Geography-Geology)

    1993-03-01

    Middle-Upper Devonian strata of central Missouri are now included in the Cedar Valley Formation and Snyder Creek Shale. The Cedar Valley is divided into the Cooper, Mineola, and Callaway members. The Snyder Creek Shale is now defined to include: the New Bloomfield, Craghead Branch, Cow Creek, and Warren Branch members. The Cooper and Mineola members make up a carbonate-dominated late Givetian age depositional sequence. Cooper and Mineola strata contain brachiopods that correlate with the Rhyssochonetes bellarugosa-Neatrypa waterlooensis zones of the Little Cedar Formation of Iowa. Deposition of the Little Cedar of Iowa and Cedar Valley of Missouri corresponds to the lower part of Euramerican Devonian T-R Cycle IIa of Johnson et al. (1985). Carbonates of the Callaway Member and mixed shales and carbonates of the overlying Snyder Creek Shale make up a latest Givetian-early Frasnian depositional sequence. The Callaway brachiopod fauna is correlated with the Allanella allani Zone, and the Snyder Creek brachiopod fauna is correlated with the Strophodonta callawayensis Zone of the Lithograph City Formation of Iowa. Conodont faunas recovered from the Callaway correlate with the interval of the P. insita Fauna (latest Givetian-early Frasnian). Conodont faunas from the Snyder Creek contain species of Ancyrodella and Mesotaxis that provide the basis for direct correlation with Zone 3 of the Frasnian Montagne Noire conodont zonation of Klapper (1989) as discussed in Johnson and Klapper (1992). Deposition of the Callaway-Snyder Creek of Missouri and Lithograph City of Iowa corresponds to Euramerican Devonian T-R Cycle IIb of Johnson et al. (1985).

  1. Tectonic evolution of the North Patagonian Andes (41°-44° S) through recognition of syntectonic strata

    NASA Astrophysics Data System (ADS)

    Echaurren, A.; Folguera, A.; Gianni, G.; Orts, D.; Tassara, A.; Encinas, A.; Giménez, M.; Valencia, V.

    2016-05-01

    The North Patagonian fold-thrust belt (41°-44° S) is characterized by a low topography, reduced crustal thickness and a broad lateral development determined by a broken foreland system in the retroarc zone. This particular structural system has not been fully addressed in terms of the age and mechanisms that built this orogenic segment. Here, new field and seismic evidence of syntectonic strata constrain the timing of the main deformational stages, evaluating the prevailing crustal regime for the different mountain domains through time. Growth strata and progressive unconformities, controlled by extensional or compressive structures, were recognized in volcanic and sedimentary rocks from the cordilleran to the extra-Andean domain. These data were used to construct a balanced cross section, whose deep structure was investigated through a thermomechanical model that characterizes the upper plate rheology. Our results indicate two main compressive stages, interrupted by an extensional relaxation period. The first contractional stage in the mid-Cretaceous inverted Jurassic-Lower Cretaceous half graben systems, reactivating the western Cañadón Asfalto rift border ~ 500 km away from the trench, at a time of arc foreland expansion. For this stage, available thermochronological data reveal forearc cooling episodes, and global tectonic reconstructions indicate mid-ocean ridge collisions against the western edge of an upper plate with rapid trenchward displacement. Widespread synextensional volcanism is recognized throughout the Paleogene during plate reorganization; retroarc Paleocene--Eocene flare up activity is interpreted as product of a slab rollback, and fore-to-retroarc Oligocene slab/asthenospheric derived products as an expression of enhanced extension. The second stage of mountain growth occurred in Miocene time associated with Nazca Plate subduction, reaching nearly the same amplitude than the first compressive stage. Extensional weakening of the upper plate

  2. Lithostratigraphic, conodont, and other faunal links between lower Paleozoic strata in northern and central Alaska and northeastern Russia

    USGS Publications Warehouse

    Dumoulin, Julie A.; Harris, Anita G.; Gagiev, Mussa; Bradley, Dwight C.; Repetski, John E.

    2002-01-01

    Lower Paleozoic platform carbonate strata in northern Alaska (parts of the Arctic Alaska, York, and Seward terranes; herein called the North Alaska carbonate platform) and central Alaska (Farewell terrane) share distinctive lithologic and faunal features, and may have formed on a single continental fragment situated between Siberia and Laurentia. Sedimentary successions in northern and central Alaska overlie Late Proterozoic metamorphosed basement; contain Late Proterozoic ooid-rich dolostones, Middle Cambrian outer shelf deposits, and Ordovician, Silurian, and Devonian shallow-water platform facies, and include fossils of both Siberian and Laurentian biotic provinces. The presence in the Alaskan terranes of Siberian forms not seen in wellstudied cratonal margin sequences of western Laurentia implies that the Alaskan rocks were not attached to Laurentia during the early Paleozoic.The Siberian cratonal succession includes Archean basement, Ordovician shallow-water siliciclastic rocks, and Upper Silurian–Devonian evaporites, none of which have counterparts in the Alaskan successions, and contains only a few of the Laurentian conodonts that occur in Alaska. Thus we conclude that the lower Paleozoic platform successions of northern and central Alaska were not part of the Siberian craton during their deposition, but may have formed on a crustal fragment rifted away from Siberia during the Late Proterozoic. The Alaskan strata have more similarities to coeval rocks in some peri-Siberian terranes of northeastern Russia (Kotelny, Chukotka, and Omulevka). Lithologic ties between northern Alaska, the Farewell terrane, and the peri-Siberian terranes diminish after the Middle Devonian, but Siberian afµnities in northern and central Alaskan biotas persist into the late Paleozoic.

  3. Rare earth element geochemistry of shallow carbonate outcropping strata in Saudi Arabia: Application for depositional environments prediction

    NASA Astrophysics Data System (ADS)

    Eltom, Hassan A.; Abdullatif, Osman M.; Makkawi, Mohammed H.; Eltoum, Isam-Eldin A.

    2017-03-01

    The interpretation of depositional environments provides important information to understand facies distribution and geometry. The classical approach to interpret depositional environments principally relies on the analysis of lithofacies, biofacies and stratigraphic data, among others. An alternative method, based on geochemical data (chemical element data), is advantageous because it can simply, reproducibly and efficiently interpret and refine the interpretation of the depositional environment of carbonate strata. Here we geochemically analyze and statistically model carbonate samples (n = 156) from seven sections of the Arab-D reservoir outcrop analog of central Saudi Arabia, to determine whether the elemental signatures (major, trace and rare earth elements [REEs]) can be effectively used to predict depositional environments. We find that lithofacies associations of the studied outcrop (peritidal to open marine depositional environments) possess altered REE signatures, and that this trend increases stratigraphically from bottom-to-top, which corresponds to an upward shallowing of depositional environments. The relationship between REEs and major, minor and trace elements indicates that contamination by detrital materials is the principal source of REEs, whereas redox condition, marine and diagenetic processes have minimal impact on the relative distribution of REEs in the lithofacies. In a statistical model (factor analysis and logistic regression), REEs, major and trace elements cluster together and serve as markers to differentiate between peritidal and open marine facies and to differentiate between intertidal and subtidal lithofacies within the peritidal facies. The results indicate that statistical modelling of the elemental composition of carbonate strata can be used as a quantitative method to predict depositional environments and regional paleogeography. The significance of this study lies in offering new assessments of the relationships between

  4. USE OF EXPERT RATINGS AS SAMPLING STRATA FOR A MORE COST-EFFECTIVE PROBABILITY SAMPLE OF A RARE POPULATION

    PubMed Central

    McCaffrey, Daniel; Perlman, Judith; Marshall, Grant N.; Hambarsoomians, Katrin

    2010-01-01

    We consider situations in which externally observable characteristics allow experts to quickly categorize individual households as likely or unlikely to contain a member of a rare target population. This classification can form the basis of disproportionate stratified sampling such that households classified as “unlikely” are sampled at a lower rate than those classified as “likely,” thereby reducing screening costs. Design weights account for this approach and allow unbiased estimates for the target population. We demonstrate that with sensitivity and specificity of expert classification at least 70%, and ideally at least 80%, our approach can economically increase effective sample size for a rare population. We develop heuristics for implementing this approach and demonstrate that sensitivity drives design effects and screening costs whereas specificity only drives the latter. We demonstrate that the potential gains from this approach increase as the target population becomes rarer. We further show that for most applications, unlikely strata should be sampled at 1/6 to ½ the rate of likely strata. This approach was applied to a survey of Cambodian immigrants in which the 82% of households rated “unlikely” were sampled at ¼ the rate as “likely” households, reducing screening from 9.4 to 4.0 approaches per complete. Sensitivity and specificity were 86% and 91% respectively. Weighted estimation had a design effect of 1.26 so screening costs per effective sample size were reduced 47%. We also note that in this instance, expert classification appeared to be uncorrelated with survey outcomes of interest among eligibles. PMID:20936050

  5. Vitamin D status of apparently healthy schoolgirls from two different socioeconomic strata in Delhi: relation to nutrition and lifestyle.

    PubMed

    Puri, Seema; Marwaha, Raman K; Agarwal, Neha; Tandon, Nikhil; Agarwal, Rashmi; Grewal, Khushi; Reddy, D H K; Singh, Satveer

    2008-04-01

    Forty to fifty per cent of skeletal mass, accumulated during childhood and adolescence, is influenced by sunlight exposure, physical activity, lifestyle, endocrine status, nutrition and gender. In view of scarce data on association of nutrition and lifestyle with hypovitaminosis D in Indian children and adolescents, an in-depth study on 3,127 apparently healthy Delhi schoolgirls (6-18 years) from the lower (LSES, n 1,477) and upper socioeconomic strata (USES, n 1650) was carried out. These girls were subjected to anthropometry and clinical examination for hypovitaminosis D. Girls randomly selected from the two strata (LSES, n 193; USES, n 211) underwent detailed lifestyle, dietary, biochemical and hormonal assessment. Clinical vitamin D deficiency was noted in 11.5 % girls (12.4 % LSES, 10.7 % USES). USES girls had significantly higher BMI than LSES counterparts. Prevalence of biochemical hypovitaminosis D (serum 25-hydroxyvitamin D < 50 nmol/l) was seen in 90.8 % of girls (89.6 % LSES, 91.9 % USES, NS). Mean intake of energy, protein, fat, Ca, vitamin D and milk/milk products was significantly higher in USES than LSES girls. Conversely, carbohydrate, fibre, phytate and cereal intakes were higher in LSES than USES girls. Physical activity and time spent outdoors was significantly higher in LSES girls (92.8 v. 64 %, P = 0.000). Significant correlation between serum 25-hydroxyvitamin D and estimated sun exposure (r 0.185, P = 0.001) and percentage body surface area exposed (r 0.146, P = 0.004) suggests that these lifestyle-related factors may contribute significantly to the vitamin D status of the apparently healthy schoolgirls. Hence, in the absence of vitamin D fortification of foods, diet alone appears to have an insignificant role.

  6. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    1997-06-01

    This document contains the Quarterly Report of a Novel Geotechnical/Geostatistical Approach for Exploration and Production of Natural Gas from Multiple Geologic Strata for October 1 - December 31, 1996. This report is presented to the US DOE, Office of Fossil Energy by the College of West Virginia. A brief summary update of the following ongoing projects is presented: production of natural gas from multiple geologic strata (including coal deposits), dewatering of producing wells, and descriptions of cold weather production problems. A brief update of the project in Poland where brine wastewater is converted into potable water is also mentioned.

  7. Floristic and ecological significance of coal balls from late Middle Pennsylvanian strata of western Pennsylvania, USA

    SciTech Connect

    Feng, B.C.

    1987-01-01

    342 coal balls or pieces of coal balls, representing a single concretionary mass occupying the full thickness of the original peat mass of a thin Allegheny Formation coal seam, were collected at the Derringer Corners locality, Lawrence County, western Pennsylvania, late Middle Pennsylvanian age. In the study of systematics of pteridosperms, two stem species (Schopfiastrum decussatum and Sutcliffia insignis), two leaf species (Alethopteris lesquereuxii and Alethopteris sullivantii), and one seed species (Pachytesta noei) are described and illustrated; the concentric leaf traces of Sutcliffia has been proved; one new stem species (Heterangium crossii) is designated. Morphological and anatomical variance of medullosan roots are also discussed. The technique transferring the entire epidermal tissue and cuticle of alethopterid pinnules from coal ball specimens, macerated by using EDTA solution, has been illustrated. Such preparations provide three-dimensional structure. The coal ball flora was composed of four major plant groups comprising about 30 genera common in the Pennsylvania Euramerican coal swamps. The abundance of lycopods found in the coal balls is generally recognized as an indicator of a wet environment or habitat. However, the low shoot/root ratio determined infers relatively dry conditions in the coal-forming peat swamps at the Derringer Corners. The discrepancy of these two environmental indicators is discussed, and it is suggested that the regional climate was relatively dry, compared to that of some earlier coal-forming environment, but edaphic and perhaps geomorphic conditions resulted in local areas of wet habitat.

  8. Characterization of oil source strata organic matter of Jurassic age and its contribution to the formation of oil and gas deposits

    NASA Astrophysics Data System (ADS)

    Pronin, Nikita; Nosova, Fidania; Plotnikova, Irina

    2013-04-01

    Within the frames of this work we carried out comprehensive geochemical study of high-carbon rocks samples taken from the three segments of the Jurassic system - from the lower (Kotuhtinskaya suite), from the medium (Tyumenskaya suite) and from the upper (Vasyuganskaya, Georgievskaya and the Bazhenovskaya suites), all within the north-eastern part of the Surgut oil and gas region. Altogether we investigated 27 samples. The complex study of the organic matter (OM) of these strata included the following: chloroform extraction of bitumen, the determination of the group and element composition, gas chromatography (GC) and gas chromatomass-spectrometry (GC/MS). These methods allow giving high quality assessments of the potential oil and gas source strata and thus identifying the possible oil and gas generating strata among them, ie, those strata that could be involved in the formation of oil and gas within the area. As a result of this work we identified various biomarkers that allow characterizing each oil and gas source strata under the study in the open-cast of the Jurassic system: 1. Kotuhtinskaya Suite. The build-up of this suite took place in the coastal marine weakly reducing conditions. In their composition these deposits contain some highly transformed humus organic matter (gradation of catagenesis MK3). 2. Tyumenskaya Suite. Accumulation of OM in these deposits occured mainly in the coastal marine environment with the influx of a large number of terrestrial vegetation in the basin of deposition. As for the type of agents - it is a humus or sapropel-humus OM with a rich content of continental organics. Source type of this OM is mixed - bacterial and algal. OM of the rocks of Tyumenskaya suite is situated in the area of high maturity (stage of catagenesis at MK3 level). 3. Vasyuganskaya Suite. In this case the accumulation of OM occurred mainly in the laguna (lake-delta) weak-reduction close to oxidative conditions with the influx of bacterial matter and the

  9. Pentatomidae (Hemiptera: Heteroptera) in Herbaceous and Shrub Strata of Atlantic Forest Remnants in Northeastern Brazil.

    PubMed

    Firmino, João V L; Mendonça, Milton D S; Lima, Iracilda M M; Grazia, Jocelia

    2017-06-01

    Most pentatomids are phytophagous, many of which are economically important crop pests. The family may also be a potentially important group to monitor the health of neotropical forests. However, there is a lack of biological inventories of Pentatomidae, especially in forest remnants of the Brazilian Atlantic forest. This is the first systematic survey of pentatomids reported in three Atlantic forest fragments in northeastern Brazil. In total, 997 individuals belonging to 38 species were recorded, some of which are considered economically important pests. Singletons and doubletons represented 45.9% of all species collected. The most abundant genera were Mormidea Amyot & Serville, 1843; Stictochilus Bergroth, 1918; Xynocoris Garbelotto & Campos 2014; and Edessa F., 1803. Species richness differed among fragments, with a richness gradient correlated with decreased urbanization and increased fragment size. The species abundance distribution fitted the logseries function but not the lognormal, in accordance with what is found for other assemblages in southern Brazil. Species composition also changed, in association with changes in temperature (revealed by the canonical correspondence analysis [CCA]), among fragments. Murici is one of the last remaining dense forests with high plant diversity in the region, having higher pentatomid species richness and a distinctive fauna. This first diversity study for Pentatomidae in fragments of tropical Atlantic Forest in northeastern Brazil reveals richness comparable with those from subtropical southern Brazil, with some species in common as well. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Plant diversity increases spatio-temporal niche complementarity in plant-pollinator interactions.

    PubMed

    Venjakob, Christine; Klein, Alexandra-Maria; Ebeling, Anne; Tscharntke, Teja; Scherber, Christoph

    2016-04-01

    Ongoing biodiversity decline impairs ecosystem processes, including pollination. Flower visitation, an important indicator of pollination services, is influenced by plant species richness. However, the spatio-temporal responses of different pollinator groups to plant species richness have not yet been analyzed experimentally. Here, we used an experimental plant species richness gradient to analyze plant-pollinator interactions with an unprecedented spatio-temporal resolution. We observed four pollinator functional groups (honeybees, bumblebees, solitary bees, and hoverflies) in experimental plots at three different vegetation strata between sunrise and sunset. Visits were modified by plant species richness interacting with time and space. Furthermore, the complementarity of pollinator functional groups in space and time was stronger in species-rich mixtures. We conclude that high plant diversity should ensure stable pollination services, mediated via spatio-temporal niche complementarity in flower visitation.

  11. The study on the movement law of overlying strata in fully mechanized caving face under alluvium with huge thickness in deep mine

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Gong, Feng-gang; Zhao, Ming

    2017-03-01

    Xin ju-long Mine has characteristics of deep buried depth and large alluvium’s thickness, and the ground pressure is obvious. In order to realize the effective control of the overlying strata in the fully mechanized caving face under alluvium with huge thickness in deep mine, the movement law of overlying strata is studied. The relationship between the key stratum’s fracture and the movement of overlying strata is analyzed based on ‘the key stratum’ theory, and the movement law is obtained by numerical simulation. The results show that: 1)after the bedrock is completely broken, the strength of the overlying alluvium becomes low, and its supporting capacity is gradually lost and it will gradually sink with the breaking of the bedrock; 2)with the increase of the alluvium’s thickness, the roof subsidence is gradually increasing, and with the continuous advancement of the working face, the influence range of the support pressure and the amount of roof subsidence also show a trend of increasing; 3)the study on the movement law of overlying strata under this condition provides a reliable and theoretical guide for the selection of the support and the control of ground pressure.

  12. An Analysis of Strata Differences in Higher Education Opportunities (1982-2010)--Based on an Empirical Survey of 16 Chinese Universities

    ERIC Educational Resources Information Center

    Weiyi, Wang

    2015-01-01

    Empirical study results show that in the past 30 years, after slightly expanding in the early 1990s, the differences in overall higher education opportunities among the children of all strata of China have continually shrunk. Regarding different types of higher education opportunities, the differences in access to key universities first expanded,…

  13. Raster Images of Geologic Maps of Middle Proterozoic Belt strata in parts of Benewah, Bonner, Kootenai and Shoshone Counties, Idaho and Lincoln, Mineral and Sanders Counties, Montana

    USGS Publications Warehouse

    Boleneus, David E.; Appelgate, Larry M.; Joseph, Nancy L.; Brandt, Theodore R.

    2001-01-01

    Geologic maps of the western part of the Belt Basin of western Montana and northern Idaho were converted into digital raster (TIFF image) format to facilitate their manipulation in geographic information systems. The 85-mile x 100-mile map area mostly contains rocks belonging to the lower and middle Belt Supergroup. The area is of interest as these Middle Proterozoic strata contain vein-type lead-zinc-silver deposits in the Coeur d?Alene Mining District in the St. Regis and Revett formations and strata-bound copper-silver deposits, such as the Troy mine, within the Revett Formation. The Prichard Formation is also prospective for strata-bound lead-zinc deposits because equivalent Belt strata in southern British Columbia, Canada host the Sullivan lead-zinc deposit. Map data converted to digital images include 13 geological maps at scales ranging from 1:48,000 to 1:12,000. Geologic map images produced from these maps by color scanning were registered to grid tick coverages in a Universal Transverse Mercator (North American Datum of 1927, zone 11) projection using ArcView Image Analysis. Geo-registering errors vary from 10 ft to 114 ft.

  14. Regional surface melt constrained from exposed strata on the Greenland ice sheet using structural geology, satellite imagery and IcePod data.

    NASA Astrophysics Data System (ADS)

    Tinto, K. J.; Bell, R. E.; Porter, D. F.; Das, I.; Frearson, N.; Bertinato, C.; Boghosian, A.; Chu, W.; Creyts, T. T.; Dhakal, T.; Dong, L.; Starke, S. E.

    2014-12-01

    Surface melt in the ablation zone of Greenland varies considerably, with increasing rates over the satellite observational period. Prior to airborne and satellite altimetry studies, the record is primarily based on point measurements. Here, we develop an independent method of estimating supraglacial melt from satellite images to produce a broad spatial record of mass balance in west Greenland through three decades. The ablation zone along the margin of the ice sheet in central west Greenland shows a band of dark grey ice approximately 25 km wide traceable over 150 km from 66° 40' N to 68° 20' N, inland from Kangerlussuaq, and visible again to the north of Jakobshavn Isbrae. This grey ice is characterized by large, km-scale zigzags of alternating dark and light ice bands. Ice penetrating radar data show that the outcropping ice throughout this band is strongly stratified, with strata dipping inland towards the centre of the ice sheet. The large zigzags across the ice surface are seen on the surface where these dipping strata undulate, or when the ice surface is incised by meltwater channels. The amplitude of the zigzags is determined by the relative dip of the strata and the surface topography. We focus on data from the Russell Glacier, where surface velocity is on the order of 100 m/yr, and surface melt erodes the bare ice on the order of 1 m/yr. While ice flow moves the exposed strata upwards and towards the margin, surface melt displaces the exposed trace of the stratigraphy down dip, i.e. towards the interior of the ice sheet. By cross-correlating satellite images from a 30 year period we can distinguish the seaward movement of ice surface features, such as crevasses and melt channels that move with ice flow, from the landward apparent displacement of the exposed strata. We combine this with high resolution DEMs, photographs and shallow ice radar from Operation IceBridge and the IcePod instrument suite to constrain the geometry of the ice surface and exposed

  15. A Jurassic Shock-Aftershock Earthquake Sequence Recorded by Small Clastic Pipes and Dikes within Dune Cross-Strata, Zion National Park, Utah

    NASA Astrophysics Data System (ADS)

    Loope, D. B.; Zlotnik, V. A.; Kettler, R. M.; Pederson, D. T.

    2012-12-01

    Eolian sandstones of south-central and southeast Utah contain large volumes of contorted cross-strata that have long been recognized as products of liquefaction caused by seismic shaking. Unlike most sites where Navajo Sandstone is exposed, in Zion National Park (southwestern Utah), the Navajo contains very, very few contorted strata. We have, however, mapped the distribution of more than 1,000 small-scale, vertical pipes and dikes in uncontorted cross-strata of the Navajo at two small study sites in Zion. Pipes are 2-5 cm in diameter and up to 3 m long; dikes are ~6 cm wide. Clusters of the water-escape structures lie directly above and below numerous, near-horizontal bounding surfaces. Dikes are restricted to the wind-ripple strata that lie above the bounding surfaces. Pipes are common both above and below the bounding surfaces. In map view, most pipes are arranged in lines. Near the bounding surfaces, pipes merge upward with shallow dikes trending parallel to the lines of pipes. Pipes formed in grainflows—homogeneous, well-sorted sand lacking cohesion. Dikes formed above the bounding surface, in more-cohesive, poorly sorted, wind-ripple strata. As liquefaction began, expansion of subsurface sand caused spreading within the unliquified (capping) beds near the land surface. Dikes intruded cracks in the wind-ripple strata, and pipes rose from the better-sorted sand to interdune surfaces, following trends of cracks. Because the wind-ripple strata had low cohesive strength, a depression formed around each rupture, and ejected sand built upward to a flat-topped surface rather than forming the cone of a classic sand volcano. In one 3 m2 portion of the map area, a cluster of about 20 pipes and dikes, many with truncated tops, record eight stratigraphically distinct seismic events. The large dunes that deposited the Navajo cross-strata likely moved ~1m/yr. When, in response to seismic shaking, a few liters of fluidized sand erupted onto the lowermost portion of the

  16. An evaluation of the carbon sequestration potential of the Cambro-Ordovician Strata of the Illinois and Michigan basins

    SciTech Connect

    Leetaru, Hannes

    2014-12-01

    The studies summarized herein were conducted during 2009–2014 to investigate the utility of the Knox Group and St. Peter Sandstone deeply buried geologic strata for underground storage of carbon dioxide (CO2), a practice called CO2 sequestration (CCS). In the subsurface of the midwestern United States, the Knox and associated strata extend continuously over an area approaching 500,000 sq. km, about three times as large as the State of Illinois. Although parts of this region are underlain by the deeper Mt. Simon Sandstone, which has been proven by other Department of Energy-funded research as a resource for CCS, the Knox strata may be an additional CCS resource for some parts of the Midwest and may be the sole geologic storage (GS) resource for other parts. One group of studies assembles, analyzes, and presents regional-scale and point-scale geologic information that bears on the suitability of the geologic formations of the Knox for a CCS project. New geologic and geo-engineering information was developed through a small-scale test of CO2 injection into a part of the Knox, conducted in western Kentucky. These studies and tests establish the expectation that, at least in some locations, geologic formations within the Knox will (a) accept a commercial-scale flow rate of CO2 injected through a drilled well; (b) hold a commercial-scale mass of CO2 (at least 30 million tons) that is injected over decades; and (c) seal the injected CO2 within the injection formations for hundreds to thousands of years. In CCS literature, these three key CCS-related attributes are called injectivity, capacity, and containment. The regional-scale studies show that reservoir and seal properties adequate for commercial-scale CCS in a Knox reservoir are likely to extend generally throughout the Illinois and Michigan Basins. Information distinguishing less prospective subregions from more prospective fairways is included in

  17. Composition and depositional environment of concretionary strata of early Cenomanian (early Late Cretaceous) age, Johnson County, Wyoming

    USGS Publications Warehouse

    Merewether, E.A.; Gautier, Donald L.

    2000-01-01

    Unusual, concretion-bearing mudrocks of early Late Cretaceous age, which were deposited in an early Cenomanian epeiric sea, have been recognized at outcrops in eastern Wyoming and in adjoining areas of Montana, South Dakota, Nebraska, and Colorado. In Johnson County, Wyo., on the western flank of the Powder River Basin, these strata are in the lower part of the Belle Fourche Member of the Frontier Formation. At a core hole in south-central Johnson County, they are informally named Unit 2. These strata are about 34 m (110 ft) thick and consist mainly of medium- to dark-gray, noncalcareous, silty shale and clayey or sandy siltstone; and light-gray to grayish-red bentonite. The shale and siltstone are either bioturbated or interlaminated; the laminae are discontinuous, parallel, and even or wavy. Several ichnogenera of deposit feeders are common in the unit but filter feeders are sparse. The unit also contains marine and continental palynomorphs and, near the top, a few arenaceous foraminifers. No invertebrate macrofossils have been found in these rocks. Unit 2 conformably overlies lower Cenomanian shale in the lowermost Belle Fourche Member, informally named Unit 3, and is conformably overlain by lower and middle Cenomanian shale, siltstone, and sandstone within the member, which are informally named Unit 1. The mineral and chemical composition of the three Cenomanian units is comparable and similar to that of shale and siltstone in the Upper Cretaceous Pierre Shale, except that these units contain more SiO2 and less CaO, carbonate carbon, and manganese. Silica is generally more abundant and CaO is generally less abundant in river water than in seawater. The composition of Unit 2 contrasts significantly with that of the underlying and overlying units. Unit 2 contains no pyrite and dolomite and much less sulfur than Units 1 and 3. Sulfate is generally less abundant in river water than in seawater. Unit 2 also includes sideritic and calcitic concretions, whereas Units

  18. Constraining the Age of Synorogenic Continental Paleogene Strata in the Eastern Cordillera of Colombia, South America: A Combined Palynological and Paleomagnetic Approach

    NASA Astrophysics Data System (ADS)

    Jaramillo, C.; Bayona, G.; Pardo, A.; Mejia, M.; Opdike, N.; Sanchez, J.

    2002-12-01

    Several decades of palynological studies in marginal to continental Paleogene strata in the Eastern Cordillera of Colombia (EC) have yielded few constraints in the age of deposition of these rocks. Recent research in Upper Cretaceous-Paleogene strata of the EC and bordering thrust belts have suggested (1) a Late Cretaceous to Paleogene deformation in the EC previous to Neogene uplift; and (2) stratigraphic record of Paleogene strata is thicker and with fewer unconformities in the axial zone of the EC than in bordering thrust belts. Because of the importance of constraining the age of Paleogene strata for better documentation of events of deformation and fluid migration, we began a detailed palynological and paleomagnetic study of one section ca 500m thick in the axial zone of the EC. The Cosgua section (Boyaca, Colombia) is in an overturned footwall syncline of the Soapaga thrust fault. Previous works have proposed fault activity of the Soapaga and the Boyaca faults in middle Paleogene time. Details of palynological and paleomagnetic sampling strategies and expected results are as follow. Sampling for palynology was carried out at each 2-5 m, and for paleomagnetism at an interval of 8 m. Because this is a first attempt of using paleomagnetism in this region, we collected cores in lower to middle Paleogene units at different limbs of footwall folds, as well as in Jurassic and Devonian strata in the hanging wall. The results of the paleomagnetic work will determine (1) if it is possible to uncover the primary magnetization component in lower to middle Paleogene rocks, and if positive, a preliminary magnetostratigraphic column will be produced; (2) the possible uses of secondary magnetization for structural analysis; and (3) some constrain on events of fluid migration.

  19. Burden of micronutrient deficiencies by socio-economic strata in children aged 6 months to 5 years in the Philippines.

    PubMed

    Wieser, Simon; Plessow, Rafael; Eichler, Klaus; Malek, Olivia; Capanzana, Mario V; Agdeppa, Imelda; Bruegger, Urs

    2013-12-11

    Micronutrient deficiencies (MNDs) are a chronic lack of vitamins and minerals and constitute a huge public health problem. MNDs have severe health consequences and are particularly harmful during early childhood due to their impact on the physical and cognitive development. We estimate the costs of illness due to iron deficiency (IDA), vitamin A deficiency (VAD) and zinc deficiency (ZnD) in 2 age groups (6-23 and 24-59 months) of Filipino children by socio-economic strata in 2008. We build a health economic model simulating the consequences of MNDs in childhood over the entire lifetime. The model is based on a health survey and a nutrition survey carried out in 2008. The sample populations are first structured into 10 socio-economic strata (SES) and 2 age groups. Health consequences of MNDs are modelled based on information extracted from literature. Direct medical costs, production losses and intangible costs are computed and long term costs are discounted to present value. Total lifetime costs of IDA, VAD and ZnD amounted to direct medical costs of 30 million dollars, production losses of 618 million dollars and intangible costs of 122,138 disability adjusted life years (DALYs). These costs can be interpreted as the lifetime costs of a 1-year cohort affected by MNDs between the age of 6-59 months. Direct medical costs are dominated by costs due to ZnD (89% of total), production losses by losses in future lifetime (90% of total) and intangible costs by premature death (47% of total DALY losses) and losses in future lifetime (43%). Costs of MNDs differ considerably between SES as costs in the poorest third of the households are 5 times higher than in the wealthiest third. MNDs lead to substantial costs in 6-59-month-old children in the Philippines. Costs are highly concentrated in the lower SES and in children 6-23 months old. These results may have important implications for the design, evaluation and choice of the most effective and cost-effective policies aimed

  20. Lake-level Fluctuation and Climate Cyclicity Observed in Lake Strata in the Northwestern Qaidam Basin, China

    NASA Astrophysics Data System (ADS)

    Riegel, H. B.; Heermance, R. V., III; Nie, J.; Su, Q.; Garzione, C. N.

    2015-12-01

    The Pliocene and Quaternary are times of rapid, extreme climate variability, but 3-D geologic exposures of lacustrine strata from this time are rare, impeding observations of the impact of climate-change on lake sedimentation. The Qaidam Basin (QB) in western China provides a unique geologic setting, where internally drained lakes have existed for the past few million years, and recent deformation of the basin floor has uplifted and exposed lacustrine strata. This stratigraphy records a detailed history of lake level fluctuation, evaporite deposition, and climate change. We provide new paleomagnetic, δ18O and δ13C data combined with detailed sedimentology from the lower 475 m of a 900 m thick stratigraphic section (38.28N, 91.54E) in the northwestern QB to reveal a high-resolution record of sedimentation and climate change during the Plio-Quaternary. 12 magnetozones indicate an age for the lower half of the section between 6.0-3.0 Ma. The section consists of 9 lithofacies (1 mudstone, 4 sandstone, 1 conglomerate, 2 gypsum, 1 halite) that can be divided into 3 stratigraphic units based on evaporite concentration. Alternating mud, gypsum, and halite beds imply multiple lake-level fluctuations and occasional complete drying of the lake. This is consistent with >12.5‰ variation in the δ18O values of lacustrine carbonates (δ18Oc), indicating large-scale lake level fluctuation below 410 m, consistent with the boundary of Unit 1 and 2. Between 410 and 475 m, the δ18Oc values are ~-5 ‰. Above 475 m, an increase in gypsum concentration causes a thick salt-crust to develop on the outcrop, making sampling impossible. This stratigraphic level corresponds to an age of ~3.0 Ma, when the QB became hyper-arid. The presence of gypsum and halite throughout the section implies that the QB was arid and internally drained by at least 6 Ma, although the basin may have been divided into multiple lakes based on the bimodal δ18O values from different parts of the QB during that

  1. A Case Study on the Strata Movement Mechanism and Surface Deformation Regulation in Chengchao Underground Iron Mine

    NASA Astrophysics Data System (ADS)

    Cheng, Guanwen; Chen, Congxin; Ma, Tianhui; Liu, Hongyuan; Tang, Chunan

    2017-04-01

    The regular pattern of surface deformation and the mechanism of underground strata movement, especially in iron mines constructed with the block caving method, have a great influence on infrastructure on the surface, so they are an important topic for research. Based on the engineering geology conditions and the surface deformation and fracture features in Chengchao Iron Mine, the mechanism of strata movement and the regular pattern of surface deformation in the footwall were studied by the geomechanical method, and the following conclusions can be drawn: I. The surface deformation process is divided into two stages over time, i.e., the chimney caving development stage and the post-chimney deformation stage. Currently, the surface deformation in Chengchao Iron Mine is at the post-chimney deformation stage. II. At the post-chimney deformation stage, the surface deformation and geological hazards in Chengchao Iron Mine are primarily controlled by the NWW-trending joints, with the phenomenon of toppling deformation and failure on the surface. Based on the surface deformation characteristics in Chengchao Iron Mine, the surface deformation area can be divided into the following four zones: the fracture extension zone, the fracture closure zone, the fracture formation zone and the deformation accumulation zone. The zones on the surface can be determined by the surface deformation characteristics. III. The cantilever beams near the chimney caving area, caused by the NWW-trending joints, have been subjected to toppling failure. This causes the different deformation and failure mechanisms in different locations of the deep rock mass. The deep rock can be divided into four zones, i.e., the fracture zone, fracture transition zone, deformation zone and undisturbed zone, according to the different deformation and failure mechanisms. The zones in the deep rock are the reason for the zones on the surface, so they can be determined by the zones on the surface. Through these

  2. Paleomagnetic and palynologic analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia

    USGS Publications Warehouse

    Hicks, J.F.; Brinkman, D.L.; Nichols, D.J.; Watabe, M.

    1999-01-01

    strata are no older than middle to late Albian. The rocks at Bayn Shireh (the Bayn Shireh Formation) have been assigned a 'Baynshirenian' biostratigraphic age that may range from Cenomanian to early Campanian. The magnetostratigraphy results presented here indicate that the strata at both the Bayn Shireh and Burkhant localities do not cross the Santonian/Campanian Stage boundary, however, as this is believed to lie at, or very near, the C34n/C33r reversal boundary. Thus, the Bayn Shireh Formation was most likely deposited near the end of the Cretaceous Long Normal Interval, no later than the latest Santonian.

  3. Geophysical methods as mapping tools in a strata-bound gold deposit: Haile mine, South Carolina slate belt.

    USGS Publications Warehouse

    Wynn, J.C.; Luce, R.W.

    1984-01-01

    The Haile mine is the largest gold producer in the eastern USA. It is postulated to be a strata-bound gold deposit formed by a fumarolic or hot-spring system in felsic tuffs of Cambrian(?) age. Two mineralized zones occur, each composed of a sericitic part overlain by a siliceous part. Au is concentrated in especially silicified horizons and in pyrite horizons in the siliceous part of each mineralized zone. The tuffs are metamorphosed to greenschist facies and intruded by diabase and other mafic dykes. Weathering is deep and the mineralized tuffs are partly covered by coastal-plain sediments. It is suggested that certain geophysical methods may be useful in mapping and exploring Haile-type deposits in the Carolina slate belt. Very low frequency electromagnetic resistivity surveys help define alteration and silicified zones. A magnetic survey found sharp highs that correlate with unexposed mafic and ultramafic dykes. Induced polarization proved useful in giving a two-dimensional view of the structure.-G.J.N.

  4. Trace element signature of Late Jurassic siliciclastic-carbonate sedimentary strata from western Montana, southeastern British Columbia and southern Alberta

    SciTech Connect

    Sablock, J. . Dept. of Geosciences)

    1992-01-01

    A trace element signature, a characteristic pattern of enrichment and depletion of trace elements, was determined for a group of siliciclastic-carbonate Oxfordian and Kimmeridgian sedimentary strata, collected from outcrops in western Montana, southeastern British Columbia and southern Alberta. The average values, by petrofacies, of 10 major and 18 trace elements were measured for 40 samples. These data were normalized to Upper Continental Crust (UCC), and plotted against averaged published values of graywackes from the same facies. The rare earth elements (REEs), as well as Ti, Zr, Nb and Y are considered immobile even through diagenesis, and at least low level metamorphism. So these elements should form a reliable part of the geochemical signature. Compared to UCC and average graywacke, Jurassic samples are very depleted in Zr, Nb and Y. Oxfordian samples have slightly higher rare earth element values, i.e. La, Ce and Nd, than either other Jurassic samples or average graywacke. The most likely source of REE values are garnets and tourmaline which occur as inclusions in monocrystalline quartz grains. This pattern, and petrological study, point to a sedimentary source area, deficient in feldspar, heavy minerals and rock fragments. The consistency of the signature throughout this time may indicate slow uplift of a widespread sedimentary source area, or could be an effect of greater mixing and shorter residence time of dissolved materials in an epeiric sea.

  5. The record of time in cratonic interior strata: Does exceptionally slow subsidence necessarily result in exceptionally poor stratigraphic completeness?

    USGS Publications Warehouse

    Runkel, Anthony C.; Miller, J.F.; McKay, R.M.; Palmer, A.R.; Taylor, John F.

    2008-01-01

    A newly constructed a high-resolution chronostratigraphic and lithostratigraphic framework for the Upper Cambrian and Lower Ordovician Sauk Sequence in the cratonic interior of North America provides insight into the long-standing question of how time is recorded in sedimentary packages deposited in shallow epeiric seas across regions with exceptionally slow subsidence. It reveals that time is recorded in these strata in a manner fundamentally similar to the way it is in a number of nearshore marine-dominated sedimentary packages that were deposited under conditions of markedly higher subsidence rates. The principal consequence of slow subsidence in the cratonic interior appears largely to be a pronounced shingling of chronostratigraphic units perpendicular to depositional strike. An evaluation of relative stratigraphic completeness of the Upper Cambrian and Lower Ordovician of this region suggests that a number of routine interpretations and assumptions must be re-evaluated. Our results are inconsistent with the common interpretation that: (1) cratonic interior sedimentary packages are exceptionally stratigraphically incomplete; and (2) that conditions of very slow subsidence and a bathymetrically shallow shelf by themselves preclude deposition of a relatively complete record of time. In refuting these conventional assumptions, our conclusions have implications for a variety of approaches that require a fundamental understanding of the stratigraphic record of time, such as efforts to construct eustatic sea level curves and evaluations of the fossil record of evolution.

  6. Sensitivity Analysis of Mechanical Parameters of Different Rock Layers to the Stability of Coal Roadway in Soft Rock Strata

    PubMed Central

    Zhao, Zeng-hui; Wang, Wei-ming; Gao, Xin; Yan, Ji-xing

    2013-01-01

    According to the geological characteristics of Xinjiang Ili mine in western area of China, a physical model of interstratified strata composed of soft rock and hard coal seam was established. Selecting the tunnel position, deformation modulus, and strength parameters of each layer as influencing factors, the sensitivity coefficient of roadway deformation to each parameter was firstly analyzed based on a Mohr-Columb strain softening model and nonlinear elastic-plastic finite element analysis. Then the effect laws of influencing factors which showed high sensitivity were further discussed. Finally, a regression model for the relationship between roadway displacements and multifactors was obtained by equivalent linear regression under multiple factors. The results show that the roadway deformation is highly sensitive to the depth of coal seam under the floor which should be considered in the layout of coal roadway; deformation modulus and strength of coal seam and floor have a great influence on the global stability of tunnel; on the contrary, roadway deformation is not sensitive to the mechanical parameters of soft roof; roadway deformation under random combinations of multi-factors can be deduced by the regression model. These conclusions provide theoretical significance to the arrangement and stability maintenance of coal roadway. PMID:24459447

  7. Leaiid conchostracans from the uppermost Permian strata of the Paraná Basin, Brazil: Chronostratigraphic and paleobiogeographic implications

    NASA Astrophysics Data System (ADS)

    Ferreira-Oliveira, Luis Gustavo; Rohn, Rosemarie

    2010-03-01

    Conchostracan fossils are abundant and relatively diversified in the Rio do Rasto Formation (Passa Dois Group, Paraná Basin, southern Brazil), but leaiids (' Leaia pruvosti' [Reed, F.R.C., 1929. Novos Phyllopodos Fósseis do Brasil. Boletim do Serviço Geológico e Mineralógico do Brasil 34, 2-16]) were previously found at only one locality of the formation in the northern Santa Catarina State. New specimens of the Family Leaiidae, collected from two outcrops in central Paraná State near the top of the formation, stimulated a revision of related taxa. Both the new and the previously known leaiids are herein assigned to Hemicycloleaia mitchelli [Etheridge Jr., R., 1892. On Leaia mitchelli Etheridge. Proceedings of the Linnean Society of New South Wales 7, 307-310] based on the presence of three carinae and subovate shape. This species was originally recorded in the upper Tatarian (Wuchiapingian, Late Permian) of Sydney Basin, eastern Australia and therefore corroborates the interpretation that the leaiid bearing strata of the Rio do Rasto Formation cannot be younger than Permian. H. mitchelli possibly was one of the most widespread, eurytopic and conservative Late Paleozoic conchostracans of Gondwana (although records from Africa, India and Antarctica must still be confirmed) and it was also found in the Tatarian of Russia. The sudden disappearance of leaiids after their apparent success is consistent with the hypothesis about the biotic crisis around the Permo-Triassic boundary.

  8. Neoproterozoic Glacial Strata of the Centralian Superbasin: New Insight From Subsurface Data in the Southern Georgina Basin, Australia

    NASA Astrophysics Data System (ADS)

    Verdel, C.; Willink, R. J.; Gurney, J.

    2014-12-01

    The Georgina Basin portion of the Centralian Suberbasin locally preserves extensive successions of Neoproterozoic sediments, including some of the thickest Cryogenian glacial deposits in the world. Surficial exposure of these units is poor, however, necessitating description and sampling of subsurface stratigraphic records. We have examined drillcore from boreholes in the southern part of the Georgina Basin that penetrate particularly thick accumulations of glaciogenic strata. One of these cores includes, in stratigraphic succession, ~500 meters of laminated diamictite, an overlying 150 meters of coarse-grained sandstone and conglomerate, and an upper 30 meter interval of carbonate that includes conspicuous pink dolostone. C isotope values of the carbonate interval are approximately -1‰ at its base, rise to values around 0‰ within the pink dolostone, then decline to -1 to -2% at the top of the cored interval. While it is currently unclear whether the carbonate is a Neoproterozoic cap or an unconformably overlying Cambrian unit, correlations based on regional seismic and well data suggest that the thick accumulation of diamictite is a well-preserved record of Neoproterozoic glaciation. We have obtained high-resolution visible and shortwave-infrared reflectance spectroscopy data from these cores with a HyLogger instrument. These data permit detailed mineralogical description of the glacial interval at a scale of ~1 cm and comprise a fully digital stratigraphic record.

  9. [Plants associated to Abies guatemalensis (Pinaceae) forests in Western Guatemala].

    PubMed

    Arévalo, José Vicente Martínez

    2013-03-01

    The fragments of Abies guatemalensis forests in Western Guatemala are the reservoirs of plant species that have been poorly documented, missing the opportunity to expand the knowledge of the local flora and its use in conservation planning. To assess this, a floristic study was done in areas between 2 950-3 360masl in Western Guatemala between 2010-2011. Ten locations were sampled: in each a 500m2 plot was surveyed, and plants were classified in four strata by plant height (0.05-30m). A total of 119 species, 92 genera and 50 families in four divisions were found. The families with more species were Asteraceae, Poaceae, Rosaceae, Lamiaceae, Apiaceae and Solanaceae, and the most abundant genera were Salvia, Alchemilla and Bidens. The number of species found by strata was: 33 (low herbaceous), 49 (high herbaceous), 30 (shrubs) and seven in the tree strata. Regarding geographical distribution, the biggest species group detected was from central Mexico to Central America with 67%, which compared to the forests of A. guatemalensis in central and Southern Mexico, showed high floristic affinity, especially at the family and genus level. However, even having families and genera in common in the general structure of the fir forests, their floristic particularities should be taken into account when making management and conservation plans, because these are influenced by soil, latitude and microclimate conditions.

  10. Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas

    USGS Publications Warehouse

    Befus, K.S.; Hanson, R.E.; Miggins, D.P.; Breyer, J.A.; Busbey, A.B.

    2009-01-01

    Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive complexes with 40Ar/39Ar dates of ~ 47-46??Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial deposits that, at the onset of intrusive activity, would have been > 400-500??m above the present level of exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions. Eocene conglomerate slumped downward from higher levels during vent excavation. Coherent to pillowed basaltic intrusions emplaced at the close of explosive activity formed peperite within the conglomerate, within disrupted Cretaceous strata in the conduit walls, and within inferred remnants of the phreatomagmatic slurry that filled the vents during explosive volcanism. A younger series of intrusions with 40Ar/39Ar dates of ~ 42??Ma underwent nonexplosive interaction with Upper Cretaceous to Paleocene mud and sand. Dikes and sills show fluidal, billowed, quenched margins against the host strata, recording development of surface instabilities between magma and groundwater-rich sediment. Accentuation of billowed margins resulted in propagation of intrusive pillows into the adjacent sediment. More intense disruption and mingling of quenched magma with sediment locally produced fluidal and blocky peperite, but sufficient volumes of pore fluid were not heated rapidly enough to generate phreatomagmatic explosions. This work suggests that

  11. Magnetostratigraphy of Upper Permian to Lower Triassic (?) Beaufort Group Strata, Karoo Basin, South Africa: Can We "See Through" the Karoo Large Igneous Province event?

    NASA Astrophysics Data System (ADS)

    Geissman, J. W.; Gastaldo, R. A.; Neveling, J.

    2016-12-01

    A multifaceted effort to understand the timing of inferred environmental changes in the Karoo Basin, from Late Permian to possibly Early Triassic (?) time, as recorded in Beaufort Group strata, includes work to establish robust magnetic polarity records for sections previously interpreted to encompass end-Permian extinction events. Demonstrating preservation of early-acquired RM in Karoo strata is challenging, due to thermochemical effects related to the Early Jurassic (ca. 183 Ma) Karoo Large Igneous Province (LIP), the fact that Early Jurassic field directions are similar to those of Late Permian age (and the PDF!), and the NE to SW increase in burial diagenesis attending Cape Fold Belt tectonism. The response of Beaufort strata to such thermal effects bears on extracting meaningful polarity records. We obtain 7-10+ independent samples per individual horizon to assess ChRM uniformity. Eastern Cape Province sections yield a NNW seeking, moderate to steep negative inclination ChRM (normal polarity); NRM intensities are 1 to 5 mA/m. This ChRM persists in progressive thermal demagnetization to about 580o C, the magnetite maximum laboratory unblocking temperature (Tlub). Some beds show unblocking of a normal ChRM by 450oC and then the isolation of a SSE, moderate to steep positive (reverse) ChRM, which is inferred to indicate that any ChRM persisting above Tlub of 425oC is pre-Karoo LIP in origin, and likely primary. If the RM unblocked below about 425oC is thermoviscous, then, based on theoretical relaxation time/magnetization blocking relations, the rocks were heated to 150-300o C for ca. 1 Ma (+/-) (T estimates vary by relaxation time/RM blocking relations). The Bethulie section, Free State Province, is cut by many <2 m wide Karoo LIP dikes. Strata well-removed from dikes yield both normal and reverse polarity ChRM. BT15 (image) is dominated by a well-defined reverse RM with a normal overprint RM unblocked below 400oC, implying elevated temperatures (i.e., 100 to

  12. K-Ar ages confirm Pliocene age for oldest Neogene marine strata near Loreto, Baja California Sur, Mexico

    SciTech Connect

    McLean, H.

    1987-05-01

    Beds of pumiceous tuff interbedded with mollusk-rich sedimentary rocks provide new age constraints on the timing of the late Neogene subsidence and marine transgression a few kilometers north of Loreto, Baja California Sur, Mexico. The lower part of the Neogene section consists of approximately 1500 m of early to middle Miocene nonmarine volcanic-derived sandstone, breccia, and porphyritic andesite and dacite lavas, called the Comondu Formation or Comondu Group by previous workers. The Miocene rocks are unconformably overlain by nearly 1000 m of predominantly marine sandstone, siltstone, conglomerate, coquina, and tuff of Pliocene age. This 1000-m section grades upward from unfossiliferous fanglomerate, sandstone, and pelitic red beds that are interpreted to be nonmarine into mollusk-rich marine strata; this sequence indicates that marine transgression occurred within the Pliocene section. Plagioclase and hornblende from three pumiceous tuff beds stratigraphically located near the base, middle, and top of the marine section yield K-Ar ages of 3.2, 1.9, and 1.8 Ma, respectively; these ages are similar to Pliocene ages indicated by reconnaissance studies of ostracods, diatoms, and foraminifers. The diatoms indicate open-ocean waters and the foraminifers indicate outer shelf depth. Ostracods, oysters, pectens, and other fossil bivalves seem to indicate a shallow-water embayment. Lateral distribution of nonmarine and marine facies suggests a paleoenvironment in which alluvial fans fed coarse debris into a series of coastal fan deltas. The Pliocene basin may have been a largely landlocked embayment similar to the modern Bahia Concepcion, located 70 km north of Loreto. Marine and volcanic rocks are assumed to be associated with the opening of the Gulf of California. If this assumption is correct, the beds near Loreto suggest that the opening occurred during the Pliocene.

  13. Origin and chemical evolution of formation waters from Silurian-Devonian strata in the Illinois basin, USA

    SciTech Connect

    Stueber, A.M. ); Walter, L.M. )

    1991-01-01

    A suite of formation-water samples from Silurian-Devonian reservoirs in the Illinois basin has been analyzed for major, minor, and trace element concentrations and for H, O, and Sr isotopic compositions in order to interpret origin of salinity and geochemical evolution of brine compositions in this evaporite- and shale-poor cratonic basin. Although chloride concentrations range from 2,000 to 137,000 mg/L, Cl/Br ratios (291 {plus minus} 18) are consistent with those of seawater or seawater evaporated short of halite saturation (Cl/Br = 292). Thus, during Silurian-Devonian time, subaerially evaporated, penesaline brine entered the subsurface where it was chemically modified through brine-rock interactions. Cation/Br ratios and mineralogy of associated strata indicate that Na and K were depleted through interaction with clay minerals, Ca was enriched and Mg depleted by dolomitization, and Sr was enriched as a result of CaCO{sub 3} recrystallization and dolomitization. Brine {sup 87}Sr/{sup 86}Sr ratios range from 0.7092 to 0.7108; when these ratios are plotted versus 1/Sr, a two-component mixing trend is suggested, although Sr concentrations have experienced local diagenetic modification. A {sup 87}Sr-enriched fluid may have accompanied petroleum migration from New Albany shales into adjacent Silurian-Devonian carbonates where it mixed with remnant evaporated seawater. This event probably preceded the influx of meteoric water, as {delta}D and {delta}{sup 18}O are not correlated with Sr isotopic compositions of formation waters.

  14. Karst development in the Tobosa basin (Ordovician-Devonian) strata in the El Paso border region of west Texas

    SciTech Connect

    Lemone, D.V. . Dept. of Geological Sciences)

    1993-02-01

    Karst development within the Tobosa basin strata in the El Paso border region is best displayed during two time intervals: Middle Ordovician (27 Ma) developed on the Lower Ordovician El Paso Group and Middle Silurian to Middle Devonian (40 Ma) karst developed on the Lower-Middle Fusselman Formation. These major exposure intervals are recognized in regional outcrops as well as in the subsurface of the Permian Basin where they form major reservoirs. Minor local karsting is noted also within and upon the Upper Ordovician (Montoya Group) and within the shoaling upward members of overlying the Fusselman Formation. Middle Ordovician karsting with major cavern development extends down into McKellingon Canyon Formation approximately 1,000 feet below the top of the Lower Ordovician El Paso Group. The McKellingon is overlain by the cavern roof-forming early diagenetic dolomites, lower Scenic Drive Formation which in turn is overlain by the locally karsted upper Scenic Drive and Florida Mountains formations. Collapse of the overlying Montoya Group into El Paso Group rocks is observed. The Fusselman Formation rests disconformably on the Montoya Group. It is a massive, vuggy, fine- to coarsely-crystalline, whitish dolomite. Extensive karsting has developed on the top of the Fusselman. The middle Devonian Canutillo Formation with a basal flooding deposit overlies this karst surface. Minor karsting following fracture systems extends from the major karst of the El Paso Group up into the major karst in the Fusselman. The karst seems to be following and developing along the same linear fracture systems. If so, it is not unreasonable to interpret these fracture systems as being inherited from the earlier Precambrian structures underlying them.

  15. Cancer related knowledge and behavior among women across various socio-economic strata: A study from Delhi, India.

    PubMed

    Sharma, Rahul; Bhasin, Sanjiv K; Agrawal, Sandeep; Tewari, Reeti

    2013-04-01

    Cancer is predicted to be an increasingly important cause of morbidity and mortality in the next few decades worldwide. One important step in reducing the burden of morbidity and mortality from cancers is awareness among the population about the causes and prevention of cancers. To study the knowledge and preventive behavior regarding common cancers among the women from an area of Delhi, India. Cross-sectional study. Four purposively selected residential areas representing various socio-economic strata, in North-East Delhi. One thousand two hundred and six women in the age group 18-60 years. Proportions, Chi-square test. Majority of the women (43.9%) were graduates while 10.4% were illiterate. The awareness about breast cancer was maximum with 73.8% of the respondents being aware about it. The proportions of women aware about the other cancers were low. Only 52 (4.3%) had ever been for a preventive check-up for cancer. The most common cancer checkup for which the respondents reported visiting a hospital was, breast cancer. Among the respondents, 46 (3.8%) reported having a female member in their family who ever had cancer. Five hundred and seventy seven (47.8%) had not seen any message regarding cancers common in females in any mass media. Women with a higher education level, having a female family member with cancer, and those who could recall mass media message regarding cancers, were significantly more likely to have had a preventive cancer checkup for self. The knowledge and actual preventive behavior about cancers was found to be low among the women. Increased mass media exposure and targeted strategies can possibly increase the awareness and the cancer-related health behavior among the women.

  16. Development of a Persistent Reactive Treatment Zone for Containment of Sources Located in Lower-Permeability Strata

    NASA Astrophysics Data System (ADS)

    Marble, J.; Carroll, K. C.; Brusseau, M. L.; Plaschke, M.; Brinker, F.

    2013-12-01

    Source zones located in relatively deep, low-permeability formations provide special challenges for remediation. Application of permeable reactive barriers, in-situ thermal, or electrokinetic methods would be expensive and generally impractical. In addition, the use of enhanced mass-removal approaches based on reagent injection (e.g., ISCO, enhanced-solubility reagents) is likely to be ineffective. One possible approach for such conditions is to create a persistent treatment zone for purposes of containment. This study examines the efficacy of this approach for containment and treatment of contaminants in a lower permeability zone using potassium permanganate (KMnO4) as the reactant. A localized 1,1-dichloroethene (DCE) source zone is present in a section of the Tucson International Airport Area (TIAA) Superfund Site. Characterization studies identified the source of DCE to be located in lower-permeability strata adjacent to the water table. Bench-scale studies were conducted using core material collected from boreholes drilled at the site to measure DCE concentrations and determine natural oxidant demand. The reactive zone was created by injecting ~1.7% KMnO4 solution into multiple wells screened within the lower-permeability unit. The site has been monitored for ~8 years to characterize the spatial distribution of DCE and permanganate. KMnO4 continues to persist at the site, demonstrating successful creation of a long-term reactive zone. Additionally, the footprint of the DCE contaminant plume in groundwater has decreased continuously with time. This project illustrates the application of ISCO as a reactive-treatment system for lower-permeability source zones, which appears to effectively mitigate persistent mass flux into groundwater.

  17. Forest strata drive spatial structure of bacterial and archaeal communities and microbial methane cycling in neotropical bromeliad wetlands

    NASA Astrophysics Data System (ADS)

    Martinson, Guntars; Brandt, Franziska; Conrad, Ralf

    2016-04-01

    Several thousands of tank bromeliads per hectare of neotropical forest create a unique wetland ecosystem that harbors diverse communities of archaea and bacteria and emit substantial amounts of methane. We studied spatial distribution of archaeal and bacterial communities, microbial methane cycling and their environmental drivers in tank bromeliad wetlands. We selected tank bromeliads of different species and functional types (terrestrial and canopy bromeliads) in a neotropical montane forest of Southern Ecuador and sampled the organic tank slurry. Archaeal and bacterial communities were characterized using terminal-restriction fragment length polymorphism (T-RFLP) and Illumina MiSeq sequencing, respectively, and linked with physico-chemical tank-slurry properties. Additionally, we performed tank-slurry incubations to measure methane production potential, stable carbon isotope fractionation and pathway of methane formation. Archaeal and bacterial community composition in bromeliad wetlands was dominated by methanogens and by Alphaproteobacteria, respectively, and did not differ between species but between functional types. Hydrogenotrophic Methanomicrobiales were the dominant methanogens among all bromeliads but the relative abundance of aceticlastic Methanosaetaceae increased in terrestrial bromeliads. Complementary, hydrogenotrophic methanogenesis was the dominant pathway of methane formation but the relative contribution of aceticlastic methanogenesis increased in terrestrial bromeliads and led to a concomitant increase in total methane production. Rhodospirillales were characteristic for canopy bromeliads, Planctomycetales and Actinomycetalis for terrestrial bromeliads. While nitrogen concentration and pH explained 32% of the archaeal community variability, 29% of the bacterial community variability was explained by nitrogen, acetate and propionate concentrations. Our study demonstrates that bromeliad functional types, associated with different forest strata

  18. Difference in social determinants of health between men in the poor and the wealthy social strata in a Caribbean nation

    PubMed Central

    Bourne, Paul A.; Eldemire-Shearer, Denise

    2010-01-01

    Background: Studies that have examined social determinants of health have made their investigations on the population, but none have reviewed them from the perspective of particular social hierarchies. Aim: The study examined the factors determining the self-reported health of men of different socioeconomic status, by using models derived through econometric analyses. Materials & Methods: The study used a sample of 6,474 respondents: 2,704 from the two poor quintiles and 3,770 from the two wealthy quintiles. The survey used a random stratified probability sampling technique and involved the use of self-administered questionnaires. Multiple logistic regression technique was used to identify variables which are associated with health conditions of men in the two social hierarchies. Results: The findings revealed that the self-reported health of men in the two wealthiest quintiles were substantially influenced by private health insurance coverage (Odds Ratio (OR) = 32.9, 95%CI: 20.64, 52.45) and age of respondents (OR = 1.03, 95%CI: 1.02, 1.04) This was similar for men in the two poorest income quintiles; private health insurance coverage (OR = 16.97, 95%CI: 10.18, 28.27) and age (OR=1.05, 95%CI: 1.03, 1.06). Negative affective psychological conditions, consumption and medical expenditure affected the self-reported health of those in the two wealthiest quintiles, while positive affective, secondary levels of education and living alone influenced those in the two poorest quintiles. Conclusion: This research serves as a foundation for further work relating to the determinants of self-reported health conditions, inequity across socio-economic strata for men, and how patient care should be addressed. PMID:22574302

  19. Large Carbonate Associated Sulfate isotopic variability between brachiopods, micrite, and other sedimentary components in Late Ordovician strata

    NASA Astrophysics Data System (ADS)

    Present, Theodore M.; Paris, Guillaume; Burke, Andrea; Fischer, Woodward W.; Adkins, Jess F.

    2015-12-01

    Carbonate Associated Sulfate (CAS) is trace sulfate incorporated into carbonate minerals during their precipitation. Its sulfur isotopic composition is often assumed to track that of seawater sulfate and inform global carbon and oxygen budgets through Earth's history. However, many CAS sulfur isotope records based on bulk-rock samples are noisy. To determine the source of bulk-rock CAS variability, we extracted CAS from different internal sedimentary components micro-drilled from well-preserved Late Ordovician and early Silurian-age limestones from Anticosti Island, Quebec, Canada. Mixtures of these components, whose sulfur isotopic compositions vary by nearly 25‰, can explain the bulk-rock CAS range. Large isotopic variability of sedimentary micrite CAS (34S-depleted from seawater by up to 15‰) is consistent with pore fluid sulfide oxidation during early diagenesis. Specimens recrystallized during burial diagenesis have CAS 34S-enriched by up to 9‰ from Hirnantian seawater, consistent with microbial sulfate reduction in a confined aquifer. In contrast to the other variable components, brachiopods with well-preserved secondary-layer fibrous calcite-a phase independently known to be the best-preserved sedimentary component in these strata-have a more homogeneous isotopic composition. These specimens indicate that seawater sulfate remained close to about 25‰ (V-CDT) through Hirnantian (end-Ordovician) events, including glaciation, mass extinction, carbon isotope excursion, and pyrite-sulfur isotope excursion. The textural relationships between our samples and their CAS isotope ratios highlight the role of diagenetic biogeochemical processes in setting the isotopic composition of CAS.

  20. Correlation of Upper Cretaceous strata from Lima Peaks area to Madison Range, southwestern Montana and southeastern Idaho, USA

    USGS Publications Warehouse

    Dyman, T.S.; Tysdal, R.G.; Perry, W.J.; Obradovich, J.D.; Haley, J.C.; Nichols, D.J.

    1997-01-01

    An 40Ar/39Ar age of 85.81 Ma ?? 0.22 my was obtained on sanidine from a volcanic procellanite bed near the top of the 2135 + m-thick Upper Cretaceous Frontier Formation in the Lima Peaks area of southwestern Montana. This early Santonian age, combined with previously determined age data including a palynological age of Cenomanian for the lower Frontier at Lima Peaks, and a U-Pb isotopic date of about 95 Ma for the base of the Frontier Formation in the eastern Pioneer Mountains north of the Lima Peaks area, provides an age range for this nonmarine formation. In the Madison Range, farther east in southwestern Montana, this age range corresponds to marine strata of not only the Frontier Formation, but also the overlying Cody Shale and Telegraph Creek Formation, a sequence that totals less than 760 m thick. The Upper Cretaceous marine formations of the Madison Range are closely zoned by molluscan faunas that are well constrained with radiometric dates. The 40Ar/39Ar age of 85.81 Ma ?? 0.22 my at Lima Peaks is bracketed by radiometric dates for the Scaphites depressus - Protexanites bourgeoisianus biozone and the overlying Clioscaphites saxitonianus - Inoceramus undulatoplicatus biozone of the Western Interior. Fossils of both of these biozones are present in the Cody Shale and the Telegraph Creek Formation in the Madison Range. The Telegraph Creek contains two units of volcanic ash that are approximate time equivalents of the volcanic procellanite of the Lima Peaks area. Clasts in the conglomerate of the upper part of the Frontier in the Lima Peaks area were shed during the initial stages of uplift of the Blacktail-Snowcrest highlands which rose to the north. The dated porcellanite lies above the conglomerates and indicates that the uplift was initiated by middle or late Coniacian, 87-88 Ma. ?? 1997 Academic Press Limited.

  1. Cancer related knowledge and behavior among women across various socio-economic strata: A study from Delhi, India

    PubMed Central

    Sharma, Rahul; Bhasin, Sanjiv K.; Agrawal, Sandeep; Tewari, Reeti

    2013-01-01

    Background: Cancer is predicted to be an increasingly important cause of morbidity and mortality in the next few decades worldwide. One important step in reducing the burden of morbidity and mortality from cancers is awareness among the population about the causes and prevention of cancers. Objective: To study the knowledge and preventive behavior regarding common cancers among the women from an area of Delhi, India. Study Design: Cross-sectional study. Setting: Four purposively selected residential areas representing various socio-economic strata, in North-East Delhi. Participants: One thousand two hundred and six women in the age group 18-60 years. Statistical Analysis: Proportions, Chi-square test. Results: Majority of the women (43.9%) were graduates while 10.4% were illiterate. The awareness about breast cancer was maximum with 73.8% of the respondents being aware about it. The proportions of women aware about the other cancers were low. Only 52 (4.3%) had ever been for a preventive check-up for cancer. The most common cancer checkup for which the respondents reported visiting a hospital was, breast cancer. Among the respondents, 46 (3.8%) reported having a female member in their family who ever had cancer. Five hundred and seventy seven (47.8%) had not seen any message regarding cancers common in females in any mass media. Women with a higher education level, having a female family member with cancer, and those who could recall mass media message regarding cancers, were significantly more likely to have had a preventive cancer checkup for self. Conclusion: The knowledge and actual preventive behavior about cancers was found to be low among the women. Increased mass media exposure and targeted strategies can possibly increase the awareness and the cancer-related health behavior among the women. PMID:24455555

  2. Task 50 - deposition of lignites in the Fort Union Group and related strata of the northern Great Plains

    SciTech Connect

    Hartman, J.H.; Roth, B.; Kihm, A.J.

    1997-08-11

    Late Cretaceous, Paleocene, and early Eocene geologic and paleontologic studies were undertaken in western North Dakota, eastern and south-central Montana, and northwestern and northeastern Wyoming. These study areas comprise the Williston, Bighorn, and Powder River Basins, all of which contain significant lignite resources. Research was undertaken in these basins because they have the best geologic sections and fossil record for the development of a chronostratigraphic (time-rock) framework for the correlation of lignite beds and other economic resources. A thorough understanding of the precise geologic age of the deposition of sediments permits a powerful means of interpreting the record of geologic events across the northern Great Plains. Such an understanding allows for rigorous interpretation of paleoenviromnents and estimates of resource potential and quality in this area of economically significant deposits. This work is part of ongoing research to document change in the composition of molluscan fossil faunas to provide a paleoenvironmentally sensitive independent means of interpreting time intervals of brief duration during the Late Cretaceous, Paleocene, and Eocene. This study focuses on the record of mollusks and, to a lesser extent, mammals in the (1) Hell Creek-Tullock Formations, which include the Cretaceous-Paleocene boundary, in the western portion of the Williston Basin, Montana; (2) uppermost Cretaceous, Paleocene, and lowermost Eocene strata in western North Dakota, which -includes the last interior seaway in North Dakota; (3) upper Paleocene and lowermost Eocene of the northern portion of the Bighorn Basin of south-central Montana and northwestern Wyoming; and (4) Powder River Basin of northeastern Wyoming and southeastern Montana. The geologic record provides different physical and paleontological information to aid in interpreting the geologic record through the study interval.

  3. Detrital zircon microtextures and U-PB geochronology of Upper Jurassic to Paleocene strata in the distal North American Cordillera foreland basin

    NASA Astrophysics Data System (ADS)

    Finzel, E. S.

    2017-07-01

    Detrital zircon surface microtextures, geochronologic U-Pb data, and tectonic subsidence analysis from Upper Jurassic to Paleocene strata in the Black Hills of South Dakota reveal provenance variations in the distal portion of the Cordillera foreland basin in response to tectonic events along the outboard margin of western North America. During Late Jurassic to Early Cretaceous time, nonmarine strata record initially low rates of tectonic subsidence that facilitated widespread recycling of older foreland basin strata in eolian and fluvial systems that dispersed sediment to the northeast, with minimal sediment derived from the thrust belt. By middle Cretaceous time, marine inundation reflects increased subsidence rates coincident with a change to eastern sediment sources. Lowstand Albian fluvial systems in the Black Hills may have been linked to fluvial systems upstream in the midcontinent and downstream in the Bighorn Basin in Wyoming. During latest Cretaceous time, tectonic uplift in the study area reflects dynamic processes related to Laramide low-angle subduction that, relative to other basins to the west, was more influential due to the greater distance from the thrust load. Provenance data from Maastrichtian and lower Paleocene strata indicate a change back to western sources that included the Idaho-Montana batholith and exhumed Belt Supergroup. This study provides a significant contribution to the growing database that is refining the tectonics and continental-scale sediment dispersal patterns in North America during Late Jurassic-early Paleocene time. In addition, it demonstrates the merit of using detrital zircon grain shape and surface microtextures to aid in provenance interpretations.

  4. High-resolution sequence-stratigraphic correlation between shallow-marine and terrestrial strata: Examples from the Sunnyside Member of the Cretaceous Blackhawk Formation Book Cliffs eastern Utah

    SciTech Connect

    Davies, R.; Howell, J.; Boyd, R.; Flint, S.; Diessel, C.

    2006-07-15

    The Sunnyside Member of the Upper Cretaceous Blackhawk Formation in the Book Cliffs of eastern Utah provides an ideal opportunity to investigate high-resolution sequence-stratigraphic correlation between shallow-marine and terrestrial strata in an area of outstanding outcrop exposure. The thick, laterally extensive coal seam that caps the Sunnyside Member is critical for correlating between its shallow-marine and terrestrial components. Petrographic analysis of 281 samples obtained from 7 vertical sections spanning more than 30 km (18 mi) of depositional dip enabled us to recognize a series of transgressive-regressive coal facies trends in the seam. On this basis, we were able to identify a high-resolution record of accommodation change throughout the deposition of the coal, as well as a series of key sequence-stratigraphic surfaces. The stratigraphic relationships between the coal and the siliciclastic components of the Sunnyside Member enable us to correlate this record with that identified in the time-equivalent shallow-marine strata and to demonstrate that the coal spans the formation of two marine parasequences and two high-frequency, fourth-order sequence boundaries. This study has important implications for improving the understanding of sequence-stratigraphic expression in terrestrial strata and for correlating between marine and terrestrial records of base-level change. It may also have implications for improving the predictability of vertical and lateral variations in coal composition for mining and coalbed methane projects.

  5. Glacial-eustatic sea-level fluctuation curve for Carboniferous-Permian boundary strata based on outcrops in the North American Midcontinent and North-Central Texas

    SciTech Connect

    Boardman, D.R. . School of Geology)

    1993-02-01

    Based on lithologic and faunal analysis of uppermost Carboniferous through Lower Permian strata (Wabaunsee through lower Chase groups) exposed from southeastern Nebraska through north-central Oklahoma, a preliminary glacial-eustatic sea-level fluctuation curve is presented herein. In addition to the sea-level curve presented for the Midcontinent region, one for coeval outcropping strata (middle and upper Cisco Group) of the Eastern Shelf of the Midland Basin is also presented based on similar criteria. This sea-level curve is derived from new field studies as well as a refinement of earlier curves presented by Harrison (1973), and Boardman and Malinky (1985). The conclusion on the nature of the Carboniferous-Permian boundary strata cyclothems in the Midcontinent is mirrored by the results of that from North-Central Texas. Each of the primary biostratigraphically-based picks for the Carboniferous-Permian boundary coincide with either intermediate of major cycles in both study areas. Utilization of a glacial-eustatic maximum transgressive event for the Carboniferous-Permian boundary should result in a more correlatable level for intercontinental correlation.

  6. Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation

    NASA Astrophysics Data System (ADS)

    Karacan, C. Özgen; Olea, Ricardo A.

    2014-06-01

    Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile. For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Hölder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs. Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal-Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths. Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas

  7. Links between sedimentary basin development and Pacific basin plate kinematics recorded in Jurassic to Miocene strata on the western Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Finzel, E.; Ridgway, K.

    2016-12-01

    Late Jurassic to Miocene strata exposed on the western Alaska Peninsula record major changes in plate dynamics and sedimentary basin development along the northern Pacific region. These changes include Late Jurassic to Late Cretaceous accretion of the Wrangellia composite terrane (WCT), establishment of a Late Cretaceous continental volcanic arc, and middle Eocene Pacific plate reorganization and subduction initiation marked by the Alaska Peninsula-Aleutian volcanic arc. Stratigraphic descriptions and detrital zircon geochronology allow reconstruction of sediment dispersal and basinal response to these plate scale events. Upper Jurassic strata contain a dominant population of Late Triassic-Late Jurassic detrital zircons that reflect sediment input from the adjacent oceanic Talkeetna arc located to the north into a marine forearc basin on the outboard side of the WCT. The dominant population of 180 to 140 Ma detrital zircons is related to a large magmatic flux event that extended throughout the northwestern Cordillera. By Late Cretaceous time, after final suturing of the WCT, detrital zircon ages indicate the presence of a new continental volcanic arc system with minor sediment input from older inboard terranes. With final subduction of the Resurrection plate during early Eocene time, the southern margin of the northwestern Cordillera was again reconfigured. Along the western Alaska Peninsula, the Aleutian and Meshik volcanic arcs initiated in response to a shift toward more orthogonal subduction. These arcs are part of a middle-late Eocene time and extend over 3,000 km on the northern rim of the Pacific basin. The basinal response to this event is a shift from nonmarine to marine depositional systems and to a southerly provenance. Middle Eocene through Miocene strata have detrital zircon ages that indicate recycling of the older Mesozoic forearc strata into a developing backarc basin. Dynamic subsidence associated with the change in subduction parameters and

  8. Caledonian terrane amalgamation in Svalbard: Detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen

    NASA Astrophysics Data System (ADS)

    Gasser, D.; Andresen, A.

    2012-04-01

    The role and place of the different pre-Devonian terranes of Svalbard during the Caledonian collision and subsequent disintegration have been a matter of debate since the pioneering work of Harland (1971, 1985). Harland (1971, 1985) suggested that Svalbard consists of a series of far-travelled terranes, which were assembled by long-distance movements along large-scale sinistral strike-slip faults during the Devonian. The recognition of remarkable similarities between north-eastern Svalbard (Nordaustlandet), north-western Svalbard (Albert I Land) and Eastern Greenland subsequently led to models deriving these parts of Svalbard mainly from the Laurentian margin slightly (e.g. Gee and Tebenkov, 2004) or considerably (e.g. Andresen 2001, Petterson et al. 2010) to the south of their current positions. In contrast, the origin of western and south-western Svalbard is less well known: An enigmatic Ordovician blueschist unit has been linked to similar rocks occurring on Pearya in Arctic Canada (e.g. Harland, 1985), whereas the recognition of ca. 650 Ma metamorphism and a related unconformity led others to link south-western Svalbard with the Timanide orogen of northern Baltica (e.g. Mazur et al. 2009). In order to better characterize the Proterozoic to Carboniferous strata under- and overlying the enigmatic blueschist unit in western Svalbard we analysed detrital zircons from six samples covering the entire stratigraphic section of this area. The oldest three samples (maximum depositional ages of 1016±13 Ma, 948±65 Ma, 713±7 Ma) are dominated by latest Paleo- to Mesoproterozoic detritus similar to other sedimentary successions of these ages in the North Atlantic region. These samples probably formed part of the vast latest Meso- to Neoproterozoic sediments deposited on top of/close to the Grenvillian orogen within or at the border of Rodinia (e.g. Cawood et al., 2010). The Ordovician sample directly overlying the blueschists is characterized by very similar latest Paleo

  9. Effect of interleukin-6 polymorphism on risk of preterm birth within population strata: a meta-analysis

    PubMed Central

    2013-01-01

    Background Because of the role of inflammation in preterm birth (PTB), polymorphisms in and near the interleukin-6 gene (IL6) have been association study targets. Several previous studies have assessed the association between PTB and a single nucleotide polymorphism (SNP), rs1800795, located in the IL6 gene promoter region. Their results have been inconsistent and SNP frequencies have varied strikingly among different populations. We therefore conducted a meta-analysis with subgroup analysis by population strata to: (1) reduce the confounding effect of population structure, (2) increase sample size and statistical power, and (3) elucidate the association between rs1800975 and PTB. Results We reviewed all published papers for PTB phenotype and SNP rs1800795 genotype. Maternal genotype and fetal genotype were analyzed separately and the analyses were stratified by population. The PTB phenotype was defined as gestational age (GA) < 37 weeks, but results from earlier GA were selected when available. All studies were compared by genotype (CC versus CG+GG), based on functional studies. For the maternal genotype analysis, 1,165 PTBs and 3,830 term controls were evaluated. Populations were stratified into women of European descent (for whom the most data were available) and women of heterogeneous origin or admixed populations. All ancestry was self-reported. Women of European descent had a summary odds ratio (OR) of 0.68, (95% confidence interval (CI) 0.51 – 0.91), indicating that the CC genotype is protective against PTB. The result for non-European women was not statistically significant (OR 1.01, 95% CI 0.59 - 1.75). For the fetal genotype analysis, four studies were included; there was no significant association with PTB (OR 0.98, 95% CI 0.72 - 1.33). Sensitivity analysis showed that preterm premature rupture of membrane (PPROM) may be a confounding factor contributing to phenotype heterogeneity. Conclusions IL6 SNP rs1800795 genotype CC is protective against PTB in

  10. Age and stratigraphic context of Pliopithecus and associated fauna from Miocene sedimentary strata at Damiao, Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Kaakinen, Anu; Abdul Aziz, Hayfaa; Passey, Benjamin H.; Zhang, Zhaoqun; Liu, Liping; Salminen, Johanna; Wang, Lihua; Krijgsman, Wout; Fortelius, Mikael

    2015-03-01

    Since the discovery of mammalian fossils in Central Inner Mongolia in the beginning of the 20th century, this area has produced a rich and diverse record of Miocene faunas. Nevertheless, the stratigraphy has remained poorly constrained owing to scattered faunal horizons and lack of continuous vertical exposures. Consequently, most age estimates of these Miocene sites are based on paleontological evidence alone, with very few sites having been dated independently. Our field investigations in Damiao, in Siziwang Qi, Inner Mongolia have yielded more than 30 new fossiliferous localities from three horizons, including a pliopithecid fauna. This study presents the litho-, bio- and magnetostratigraphy of the Damiao area and provides age estimates for the three fossil-bearing horizons. The sedimentary sequence is interpreted as the remains of a fluvial system comprising channels, subaerially exposed floodplains and floodbasin environments. The two local stratigraphic sections measured and sampled for paleomagnetic analysis coincide with species-rich vertebrate fossil localities. The paleomagnetic results and faunal evidence suggest a correlation of lowermost fossil horizon (DM16) producing relatively rich small mammal assemblage to the early Miocene chron C6Ar or C6An.1r, roughly in 20-21 Ma age range. The pliopithecid locality level (DM01) represents latest middle Miocene and has an age estimate of about 12.1 Ma while the youngest localities (DM02) with cervoids and abundant and diverse small mammal fauna represents the earliest late Miocene with an age estimate of about 11.6 Ma. Our magnetostratigraphic results confirm that the Damiao strata constitute one of the best sequences in Inner Mongolia with early, middle and late Miocene mammalian faunas in stratigraphic superposition. The results also provide constraints on the paleoenvironmental evolution and bioevents of the area. The occurrence of pliopithecid primates in the middle Miocene of Inner Mongolia suggests humid

  11. Eustatic and tectonic control of deposition of the lower and middle Pennsylvanian strata of the Central Appalachian Basin

    USGS Publications Warehouse

    Chesnut, D.R.

    1997-01-01

    Stratigraphic analysis of Lower and Middle Pennsylvanian rocks of part of the Central Appalachian Basin reveals two orders of cycles and one overall trend in the vertical sequence of coal-bearing rocks. The smallest order cycle, the coal-clastic cycle, begins at the top of a major-resource coal bed and is composed of a vertical sequence of shale, siltstone, sandstone, seat rock, and overlying coal, which, in turn, is overlain by the next coal-clastic sequence. The average duration of the coal-clastic cycle has been calculated to be about 0.4 m.y. The major marine-transgression cycle is composed of five to seven coal-clastic cycles and is distinguished by the occurrence of widespread, relatively thick (generally thicker than 5 m) marine strata at its base. The duration of this cycle has been calculated to be about 2.5 m.y. The Breathitt coarsening-upward trend describes the general upward coarsening of the Middle Pennsylvanian part of the Breathitt Group. The Breathitt Group includes eight major marine-transgression cycles, and was deposited during a period of approximately 20 m.y. The average duration of coal-clastic cycles is of the same order of magnitude (105 year) as the Milankovitch orbital-eccentricity cycles, and matches the 0.4 m.y. second-order eccentricity cycle (Long Earth-Eccentricity cycle). These orbital periodicities are thought to modulate glacial stages and glacio-eustatic levels. The calculated periodicities of the coal-clastic cycles can be used as evidence for glacio-eustatic control of the coal-bearing rocks of the Appalachian Basin. The 2.5-m.y. periodicity of the major marine-transgression cycle does not match any known orbital or tectonic cycle; the cause of this cycle is unknown, but it might represent episodic thrusting in the orogen, propagation of intraplate stresses, or an unidentified orbital cycle. The Breathitt coarsening-upward trend is interpreted to represent the increasing intensity and proximity of the Alleghenian Orogeny

  12. The role of bitumen in strata-bound copper deposit formation in the Copiapo area, Northern Chile

    NASA Astrophysics Data System (ADS)

    Cisternas, M. Eugenia; Hermosilla, Juan

    2006-07-01

    In northern Chile, between 27 and 33°S, there are numerous deposits where residual petroleum is associated with Cu-(Ag) mineralisation (the most famous being El Soldado). All of these deposits are hosted by Lower Cretaceous volcanic or volcanoclastic facies along the axis of a former backarc basin. This close relationship suggests that the generation, migration and emplacement of hydrocarbons in the Cretaceous volcanic units is a regional process, associated with the evolution of the Cretaceous backarc basin and points to the importance of pyrobitumen as an exploration tool for similar Cu-(Ag) deposits. The present work analyses four small strata-bound copper deposits located along a north-south belt approximately 10 km east of Copiapó in northern Chile. These deposits are typically hosted by pyrobitumen-rich andesitic volcanic to volcanoclastic rocks intercalated with the marine carbonate Pabellón Formation, the youngest formation within the Chañarcillo Group. The strong genetic and spatial relationships between the pyrobitumen-rich lavas and the mineral deposits allow us to define this volcanic belt as the Ocoita-Pabellón Metallotect. Two hydrothermal events can be distinguished based on the mineralogical, textural, fluid inclusion and isotope data of ore and gangue and on the optical properties of residual petroleum. During the early event, petroleum was mobilised from the source rocks into the primary and secondary porosity of the lavas by Fe-rich hydrothermal fluids, which precipitated pyrite as an early sulphide phase. The second event is characterised by Cu-rich hydrothermal fluids, which induced three successive sub-stages of Cu-sulphide precipitation. The hydrothermal fluids chemically and thermally altered the first-stage bitumen, transforming it into pyrobitumen. The present work documents similarities between the Ocoita-Pabellón Metallotect and the El Soldado ore deposit and emphasises important differences. In the El Soldado host rocks, a

  13. Orientation Patterns of Chalcedony Veins and Clastic Dikes in Tertiary strata of NW Nebraska and SW South Dakota

    NASA Astrophysics Data System (ADS)

    Harmon, H. D.

    2008-12-01

    Stratiform bound arrays of subvertical chalcedony veins occur in distinct patches of varying size in White River Group strata in the study area. At Toadstool Geologic Park in Nebraska they are associated with normal faults, and within a patch display orthogonal patterns with one direction dominant. Junctures and tip interactions indicate the orthogonal veins formed together. Two different patches at Toadstool show different orientations. At three separate study sites in Badlands National Park patches of chalcedony vein patches are not associated with faults, but are associated with clastic dike systems. Field relations indicate clastic dike formation preceded vein formation, but common orientation patterns, composite dike-vein features and a spatial association suggest similar timing and a genetic linkage. While vein strikes for two sites appear polygonal and are statistically random, within each site subareas are organized, and do not display a simple polygonal triple junction geometry. Whether strike distributions are random or organized is partly scale dependent. The third site shows a strong preferred direction. At all localities chalcedony veins exhibit vertical shortening, explained most simply by compaction. The vein arrays are similar to polygonal faults, and are interpreted to be the result of stratigraphically controlled diagenetic driven deformation. Clastic dikes can traverse most of the Tertiary section, but are concentrated in the Sharps Formation, and taper downwards into the Chadron Formation, where some merge with veins. Clastic dike orientations have been studied at three localities, two of which show different preferred directions, and one of which appears random. A provisional model includes basal high fluid pressures in silt/mudstones rich in volcanic ash that aids overlying clastic dike formation, producing fracture drainage paths that trigger diagenetically driven deformation, and associated compaction, forming chalcedony veins. An initial

  14. Seismic analysis of clinoform depositional sequences and shelf-margin trajectories in Lower Cretaceous (Albian) strata, Alaska North Slope

    USGS Publications Warehouse

    Houseknecht, D.W.; Bird, K.J.; Schenk, C.J.

    2009-01-01

    Lower Cretaceous strata beneath the Alaska North Slope include clinoform depositional sequences that filled the western Colville foreland basin and overstepped the Beaufort rift shoulder. Analysis of Albian clinoform sequences with two-dimensional (2D) seismic data resulted in the recognition of seismic facies inferred to represent lowstand, transgressive and highstand systems tracts. These are stacked to produce shelf-margin trajectories that appear in low-resolution seismic data to alternate between aggradational and progradational. Higher-resolution seismic data reveal shelf-margin trajectories that are more complex, particularly in net-aggradational areas, where three patterns commonly are observed: (1) a negative (downward) step across the sequence boundary followed by mostly aggradation in the lowstand systems tract (LST), (2) a positive (upward) step across the sequence boundary followed by mostly progradation in the LST and (3) an upward backstep across a mass-failure d??collement. These different shelf-margin trajectories are interpreted as (1) fall of relative sea level below the shelf edge, (2) fall of relative sea level to above the shelf edge and (3) mass-failure removal of shelf-margin sediment. Lowstand shelf margins mapped using these criteria are oriented north-south in the foreland basin, indicating longitudinal filling from west to east. The shelf margins turn westward in the north, where the clinoform depositional system overstepped the rift shoulder, and turn eastward in the south, suggesting progradation of depositional systems from the ancestral Brooks Range into the foredeep. Lowstand shelf-margin orientations are consistently perpendicular to clinoform-foreset-dip directions. Although the Albian clinoform sequences of the Alaska North Slope are generally similar in stratal geometry to clinoform sequences elsewhere, they are significantly thicker. Clinoform-sequence thickness ranges from 600-1000 m in the north to 1700-2000 m in the south

  15. Upper Cretaceous and Lower Jurassic strata in shallow cores on the Chukchi Shelf, Arctic Alaska: Chapter C in Studies by the U.S. Geological Survey in Alaska, vol. 15

    USGS Publications Warehouse

    Houseknecht, David W.; Craddock, William H.; Lease, Richard O.

    2016-02-12

    Shallow cores collected in the 1980s on the Chukchi Shelf of western Arctic Alaska sampled pre-Cenozoic strata whose presence, age, and character are poorly known across the region. Five cores from the Herald Arch foreland contain Cenomanian to Coniacian strata, as documented by biostratigraphy, geochronology, and thermochronology. Shallow seismic reflection data collected during the 1970s and 1980s show that these Upper Cretaceous strata are truncated near the seafloor by subtle angular unconformities, including the Paleogene mid-Brookian unconformity in one core and the Pliocene-Pleistocene unconformity in four cores. Sedimentary structures and lithofacies suggest that Upper Cretaceous strata were deposited in a low accommodation setting that ranged from low-lying coastal plain (nonmarine) to muddy, shallow-marine environments near shore. These observations, together with sparse evidence from the adjacent western North Slope, suggest that Upper Cretaceous strata likely were deposited across all of Arctic Alaska.A sixth core from the Herald Arch contains lower Toarcian marine strata, indicated by biostratigraphy, truncated by a Neogene or younger unconformity. These Lower Jurassic strata evidently were deposited south of the arch, buried structurally to high levels of thermal maturity during the Early Cretaceous, and uplifted on the Herald thrust-fault system during the mid to Late Cretaceous. These interpretations are based on regional stratigraphy and apatite fission-track data reported in a complementary report and are corroborated by the presence of recycled palynomorphs of Early Jurassic age and high thermal maturity found in Upper Cretaceous strata in two of the foreland cores. This dataset provides evidence that uplift and exhumation of the Herald thrust belt provided sediment to the foreland during the Late Cretaceous.

  16. Sedimentology, conodonts and ostracods of the Devonian - Carboniferous strata of the Anseremme railway bridge section, Dinant Basin, Belgium

    USGS Publications Warehouse

    Casier, J.-G.; Mamet, B.; Preat, A.; Sandberg, C.A.

    2004-01-01

    Seven major carbonate microfacies are defined in the Devonian - Carboniferous (D/C) strata (50 m) of the Anseremme railway bridge section, south of Dinant. They permit recognition of several levels encompassing the Etroeungt and Hastie??re formations. "Bathymetric" sequences range from open marine, below the storm wave base, to semi-restricted lagoon. This sequence records a shallowing-upward trend of the relative sea level, from environments below the storm wave base to strongly eroded supraticial pre-evaporitic environments. Faunal components (echinoderms, brachiopods...) indicate open-marine domain for the first six microfacies located within the dysphoticeuphotic zone in relatively shallow waters. The textures of the rocks (mudstones to rudstones) associated with lamination characteristics indicate the position of the storm (SWB) and the fair-weather (FWWB) wave bases. Microfacies seven suggests a semi-restricted platform with salinity fluctuations from hypersaline brines to brackish waters. Thus, the boundary of the Etroeungt/Hastie??re formations is marked by an abrupt drop in sea level. Carbonate micro-conglomerates recording an important erosive phase and a sedimentary hiatus. The environment is again open marine in the upper part of the Hastie??re Formation. Our conclusion is that the Anseremme section is not a reliable continuous succession for the study of the D/C boundary. This confirms the VAN STEENWINKEL (1988, 1993 hypothesis based on other arguments. Conodont faunas demonstrate that the Devonian sequence spans the five youngest conodont zones, but that two of these zones are not represented. The Epinette Formation is dated as the youngest part of the Middle expansa Zone. Thus, the boundary with the Late praesulcata Zone probably coincides with the sharp sedimentological change at the base of the Etroeungt Formation, which is interpreted to belong entirely to this zone. The disconformably overlying basal bed 159 of the Hastie??re Formation is dated

  17. Ephemeral deposition, seabed mixing and fine-scale strata formation in the York River estuary, Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Dellapenna, Timothy M.; Kuehl, Steven A.; Schaffner, Linda C.

    2003-11-01

    A process-oriented sedimentary facies model is developed for the York River estuary, a sub-estuary of the lower Chesapeake Bay. This facies model was based on 210Pb and grain-size profiles, as well as X-radiographs taken from kasten cores and box cores collected in a series of across-river transects. Throughout most of the energetic microtidal York River, the seabed is characterized by physical mixing to depths of 25-200 cm. A strong cross-estuary gradient in processes is observed with one side, including channel, flank and shoal, dominated by frequent deep erosion and redeposition (physical mixing), while physical mixing is reduced on the other side, resulting in a greater preservation of biological mixing signatures. Within the physically dominated side of the river, the mixed layer is characterized by 'stair-stepped' 210Pb profiles with one or more segments (˜25-200 cm thick) of nearly uniform excess activity. X-radiographs reveal that, although a record of limited biogenic sediment modification is preserved, sedimentary structures within the mixed layer are dominated by centimeter to decimeter scale units of finely to coarsely laminated strata bounded by hiatal surfaces. This demonstrates that mixing results primarily from erosion, resuspension and deposition. Reduced salinity limits the number of benthic species in the York River. Physical disturbance leads to an impoverishment of this community, which is composed primarily of small, opportunistic species with a paucity of larger macrofauna. As a result, mixing in the biologically dominated side of the river is generally on the order of a few centimeters, but may be as deep as 40 cm, and 210Pb geochronology yields low biodiffusion rates (0.43-3.35 cm 2 yr -1). X-radiographs reveal the presence of some laminations which suggest that although the mixing is controlled by biological processes the mixing intensity is relatively low. Based on 210Pb geochronologies, residence time estimates for particles within the

  18. Evidence for Mojave-Sonora megashear-Systematic left-lateral offset of Neoproterozoic to Lower Jurassic strata and facies, western United States and northwestern Mexico

    USGS Publications Warehouse

    Stewart, John H.

    2005-01-01

    Major successions as well as individual units of Neoproterozoic to Lower Jurassic strata and facies appear to be systematically offset left laterally from eastern California and western Nevada in the western United States to Sonora, Mexico. This pattern is most evident in units such as the "Johnnie oolite," a 1- to 2-m-thick oolite of the Neoproterozoic Rainstorm Member of the Johnnie Formation in the western United States and of the Clemente Formation in Sonora. The pattern is also evident in the Lower Cambrian Zabriskie Quartzite of the western United States and the correlative Proveedora Quartzite in Sonora. Matching of isopach lines of the Zabriskie Quartzite and Proveedora Quartzite suggests ???700-800 km of left-lateral offset. The offset pattern is also apparent in the distribution of distinctive lithologic types, unconformities, and fossil assemblages in other rocks ranging in age from Neoproterozoic to Early Jurassic. In the western United States, the distribution of facies in Neoproterozoic and Paleozoic strata indicates that the Cordilleran miogeocline trends north-south. A north-south trend is also suggested in Sonora, and if so is compatible with offset of the miogeocline but not with the ideas that the miogeocline wrapped around the continental margin and trends east-west in Sonora. An imperfect stratigraphic match of supposed offset segments along the megashear is apparent. Some units, such as the "Johnnie oolite" and Zabriskie-Proveedora, show almost perfect correspondence, but other units are significantly different. The differences seem to indicate that the indigenous succession of the western United States and offset segments in Mexico were not precisely side by side before offset but were separated by an area-now buried, eroded, or destroyed-that contained strata of intermediate facies. ?? 2005 Geological Society of America.

  19. Characterization of Shiga toxin-producing Escherichia coli isolated from ground beef collected in different socioeconomic strata markets in Buenos Aires, Argentina.

    PubMed

    Llorente, Patricia; Barnech, Laura; Irino, Kinue; Rumi, María Valeria; Bentancor, Adriana

    2014-01-01

    Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1%) samples were stx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC were stx1, 5.3% (3/57); stx2, 86.0% (49/57); stx1/stx2, 8.8% (5/57); ehxA, 61.4% (35/57); eae, 26.3% (15/57); saa, 24.6% (14/57). Shiga toxin subtypes were stx2, 31.5% (17/54); stx2c-vhb, 24.1% (13/54); stx2c-vha, 20.4% (11/54); stx2/stx2c-vha, 14.8% (8/54); stx2/stx2c-vhb, 5.6% (3/54); stx2c-vha/vhb, 3.7% (2/54). Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1%) were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population.

  20. Characterization of Shiga Toxin-Producing Escherichia coli Isolated from Ground Beef Collected in Different Socioeconomic Strata Markets in Buenos Aires, Argentina

    PubMed Central

    Llorente, Patricia; Barnech, Laura; Irino, Kinue; Rumi, María Valeria

    2014-01-01

    Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1%) samples were stx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC were stx1, 5.3% (3/57); stx2, 86.0% (49/57); stx1/stx2, 8.8% (5/57); ehxA, 61.4% (35/57); eae, 26.3% (15/57); saa, 24.6% (14/57). Shiga toxin subtypes were stx2, 31.5% (17/54); stx2c-vhb, 24.1% (13/54); stx2c-vha, 20.4% (11/54); stx2/stx2c-vha, 14.8% (8/54); stx2/stx2c-vhb, 5.6% (3/54); stx2c-vha/vhb, 3.7% (2/54). Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1%) were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population. PMID:25006586

  1. Provenance of Oligo-Miocene Strata from the Adriatic Foredeep of the Alps-Apennines System Determined through Detrital-Zircon U-Pb Geochronology

    NASA Astrophysics Data System (ADS)

    Dafov, L. N.; Anfinson, O. A.; Malusa', M. G.; Stockli, D. F.

    2014-12-01

    U-Pb geochronology of detrital zircon is an effective method for evaluating exhumation history, provenance, and depositional age constraints of sedimentary deposits. Over 1400 grains evaluated from thirteen samples collected from distal and proximal Oligo-Miocene strata of Adriatic turbidites are consistent with modern characterization of the proposed source region. Studies indicate that the principal source area of Oligo-Miocene strata from Adriatic deposits is the Lepontine Dome of the Central Alps. Our data reveals a significant shift in detrital zircon U-Pb age populations during the Oligocene-Miocene boundary which, when compared with data from modern sands, closely correlates to the westward shift of the erosional foci within the Lepontine Dome, from the Ticino to the Toce subdome, due to progressive indentation of Adria. This is coeval with progressive unroofing of Periadriatic magmatic rocks of Tertiary age along the Insubric Fault. The lowermost Upper Oligocene proximal samples collected from the Como and Villa Olmo Conglomerates are dominated by Caledonian and Cadomian detrital zircon U-Pb age populations. The uppermost Oligocene and lower Miocene proximal samples collected from the Como Conglomerate are dominated instead by Periadriatic detrital zircon. Distal samples collected from the Lower Oligocene Aveto Formation have a dominant Periadriatic age peak with lesser amounts of late Cretaceous, Variscan, Caledonian and Cadomian detrital zircon. The lowermost Upper Oligocene distal samples collected from the Macigno Formation contain populations of Periadriatic, Variscan, Caledonian, and Cadomian detrital zircon, with major shifts in relative abundance from the lower to upper strata. The most dramatic shift in provenance in the distal units is between two samples located relatively proximally to one another in the Modino unit: Upper Oligocene marls contains primarily Variscan and Caledonian zircon grains with no individuals yielding Periadriatic ages

  2. The Geology and Geochemistry of Strata at the Base of Aeolis Mons as Characterized by the Curiosity Rover, Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Sumner, D. Y.

    2015-12-01

    The Mars Science Laboratory team is using the Curiosity rover to investigate fluvial, lacustrine, and eolian strata that form the base of Aeolis Mons (Mt. Sharp). Basal outcrops that form the lowest stratigraphic unit of Aeolis Mons, the Murray formation, are dominated by lacustrine mudstones with interbedded fluvial sandstones and conglomerates. They are unconformably overlain by younger, likely eolian sandstones, which onlap the slopes of Aeolis Mons. Interpretation of the stratal relationships requires combined regional-scale orbital mapping and in situ observations of bedding geometry and sedimentary structures due to the laterally discontinuous nature of fluvial interbeds in the Murray formation and the similarity in appearance of the fluvial and eolian sandstones in orbital data. Team efforts demonstrate at least 10's of meters of relief on the unconformity separating the Murray formation from younger sandstones. The mudstone facies of the Murray formation show substantial variations in elemental composition. SiO2 ranges from <50 to >80 wt %, and Fe (calculated as FeO) varies from <3 to >15 wt %. Magnetite, hematite, ilmenite, and jarosite are present in significantly varying ratios. Cristobalite is also present in some, but not all of the mudstone. Textures in the mudstones include sub millimeter-scale lamination as well as diagenetic textures such as small crystal laths, 3d dendritic concretions, subspherical concretions, and at least two generations of mineral precipitation in fractures. Overall, the stratigraphic relationships, textural characteristics, elemental composition and mineralogy indicate deposition in a lake followed by multiple diagenetic events related to lithification, burial, subsurface fluid flow, and weathering. Cross cutting relationships constrain the relative timing of some of these events, but the complexity of the geological history of the basal strata of Aeolis Mons suggests a rich geological history for the basal strata of Aeolis

  3. Preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for samples from Upper and Lower Cretaceous strata, Maverick Basin, south Texas

    USGS Publications Warehouse

    Hackley, Paul C.; Dennen, Kristin O.; Gesserman, Rachel M.; Ridgley, Jennie L.

    2009-01-01

    The Lower Cretaceous Pearsall Formation, a regionally occurring limestone and shale interval of 500-600-ft maximum thickness (Rose, 1986), is being evaluated as part of an ongoing U.S. Geological Survey (USGS) assessment of undiscovered hydrocarbon resources in onshore Lower Cretaceous strata of the northern Gulf of Mexico. The purpose of this report is to release preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for Pearsall Formation, Glen Rose Formation, Hosston Formation, Austin Group, and Eagle Ford Group samples from the Maverick Basin in south Texas in order to aid in the characterization of these strata in this area. The preliminary nature of this report and the data contained herein reflect that the assessment and characterization of these samples is a work currently in progress. Pearsall Formation subdivisions are, in ascending stratigraphic order, the Pine Island Shale, James Limestone, and Bexar Shale Members (Loucks, 2002). The Lower Cretaceous Glen Rose Formation is also part of the USGS Lower Cretaceous assessment and produces oil in the Maverick Basin (Loucks and Kerans, 2003). The Hosston Formation was assessed by the USGS for undiscovered oil and gas resources in 2006 (Dyman and Condon, 2006), but not in south Texas. The Upper Cretaceous Austin Group is being assessed as part of the USGS assessment of undiscovered hydrocarbon resources in the Upper Cretaceous strata of the northern Gulf of Mexico and, along with the Upper Cretaceous Eagle Ford Group, is considered to be an important source rock in the Smackover-Austin-Eagleford Total Petroleum System (Condon and Dyman, 2006). Both the Austin Group and the Eagle Ford Group are present in the Maverick Basin in south Texas (Rose, 1986).

  4. Sedimentary record and climatic implications of recurrent deformation in the Tian Shan: Evidence from Mesozoic strata of the north Tarim, south Junggar, and Turpan basins, northwest China

    SciTech Connect

    Hendrix, M.S.; Graham, S.A.; Sobel, E.R.

    1992-01-01

    Detailed stratigraphic, sedimentologic, paleocurrent, and subsidence analyses were conducted on Mesozoic nonmarine sedimentary sections of the south Junggar, north Tarim, and Turpan basins, Xinjang Uygur Autonomous Region, northwest China. These three basins have been foreland basins throughout the Mesozoic and Cenozoic eras, as demonstrated by asymmetrically distributed basinwide sediment accumulations, foreland-style subsidence profiles, and a variety of outcrop and subsurface facies data. Mesozoic paleocurrent indicators measured in the south Junggar and north Tarim basins, as well as Mesozoic sandstone compositions from both basins, indicate that the intervening Tian Shan has existed as a positive physiographic feature partitioning the two basins throughout Mesozoic and Cenozoic time. Paleocurrent, facies, and subsurface isopach data suggest that the Turpan basin was established as a discrete feature by the Early Jurassic period. The timing and style of depositional systems within the north Tarim Mesozoic depocenter, the south Junggar Mesozoic depocenter, and the central Turpan basin are remarkably similar. Upper Triassic strata of each basin consist of alluvial conglomerate and associated braided-fluvial sandstone and siltstone which fine upward into lower through Middle Jurassic, locally organic-rich, meandering-fluvial, and lacustrine strata. Upper Jurassic braided-fluvial red beds in each basin are overlain by a distinct pulse of uppermost Jurassic alluvial conglomerate. Lower Cretaceous exposures consist of fine-grained red beds in north Tarim and Turpan and interbedded red and gray shale with local silty carbonates in south Junggar. Upper Cretaceous strata of the north Tarim and south Junggar basins are composed of alluvial conglomerate with associated braided-fluvial sandstone and siltstone. 94 refs., 17 figs.

  5. Hazardous geology zoning and influence factorsin the near-shore shallow strata and seabed surfaceof the modern Yellow River Delta, China

    NASA Astrophysics Data System (ADS)

    Li, P.

    2016-12-01

    In this study, on the basis of 3,200 km shallow stratigraphic section and sidescan sonar data of the coastal area of the Yellow River Delta, we delineated and interpreted a total of seven types of typical hazardous geologies, including the hazardous geology in the shallow strata (buried ancient channel and strata disturbance) and hazardous geology in the seabed surface strata (pit, erosive residual body, sand patch, sand wave and scour channel). We selected eight parameters representing the development scale of the hazardous geology as the zoning indexes, including the number of hazardous geology types, pit depth, height of erosive residual body, length of scour channel, area of sand patch, length of sand wave, width of the buried ancient channel and depth of strata disturbance, and implemented the grid processing of the research area to calculate the arithmetic sum of the zoning indexes of each unit grid one by one. We then adopted the clustering analysis method to divide the near-shore waters of the Yellow River Delta into five hazardous geology areas, namely the serious erosion disaster area controlled by Diaokou lobe waves, hazardous geology area of multi-disasters under the combined action of the Shenxiangou lobe river wave flow, accumulation type hazardous geology area controlled by the current estuary river, hazardous geology area of single disaster in the deep water area and potential hazardous geology area of the Chengdao Oilfield. All four of the main factors affecting the development of hazardous geology, namely the diffusion and movement of sediment flux of the Yellow River water entering the sea, seabed stability, bottom sediment type and distribution, as well as the marine hydrodynamic characteristics, show significant regional differentiation characteristics and laws. These characteristics and laws are consistent with the above-mentioned zoning results, in which the distribution, scale and genetic mechanism of hazardous geology are considered

  6. The geospatial relationship of geologic strata, geological fractures, and land use attained by a time-series aridity index in a semiarid region.

    PubMed

    Rodríguez-Moreno, Victor M; Kretzschmar, Thomas G; Padilla-Ramírez, J Saúl

    2015-07-01

    In a vast semiarid region of the Baja California Peninsula, remote sensing and GIS techniques were applied to moderate resolution images of Landsat 5 TM to explore the geospatial correlation among the grid aridity index (AI), shapefiles of geologic strata, land use, and geological fractures. A dataset of randomized sample points in a time-series of one hydrologic year along with vector file GIS delineated geologic fractures-including the area between their left/right parallel buffer lines-was used as mask analysis. MANOVA results were significant (p < 0.05) for geologic strata, land use, and basin. Overall results reveal the effects of soil texture on water retention on deeper soil horizons and the rate of vertical motion of rainwater. Despite the fact that geologic fractures underlie a large number of biotic communities, in both latitude and longitude gradients of the peninsula, no statistical significance was observed among the fractures themselves or the areas between their parallel buffer lines. One pulse rainfall event was documented by the AI grid maps enabling a robust vegetative response in early summer to an abnormal amount of rain provided by tropical storm Julio. AI grids appear to be useful for characterizing an ecosystem's dynamism. New options are suggested for this research strategy by expanding the number of datasets and incorporating geographic exclusion areas.

  7. A giant submarine slope failure on the insular slope north of Puerto Rico: A response of Arecibo basin strata to tectonic stress

    SciTech Connect

    Schwab, W.C.; Danforth, W.W.; Scanlon, K.M. )

    1990-06-01

    An amphitheater-shaped scarp, approximately 55 km across in water depths from about 3,000 m to 6,700 m was imaged on the northern insular slope of Puerto Rico (southern slope of the Puerto Rico Trench) using the GLORIA side-scan sonar system. This scarp represents the removal of more than 1,500 m{sup 3} of Tertiary Arecibo basin strata. The head of the scarp coincides with the location of a fault zone observed on nearby seismic-reflection profiles. Interpretation of the GLORIA imagery, and a review of available bathymetric, geophysical, and stratigraphic data and tectonic-framework models suggest that the scarp formed as a consequence of slope failure induced by tectonic oversteepening of the insular slope. The oversteepening may be a result of the most recent episode of convergence of the Caribbean and North American plates, which began approximately 4 million years ago. The Arecibo basin strata have been tilted approximately 4{degree} to the north and are apparently gravitationally unstable under the present seismic regime. The volume of material involved in this slope failure is comparable to the material displaced in tsunamogenic submarine landslides along the Peru Trench and Hawaiian Ridge. Therefore, if the slope failure north of Puerto Rico was catastrophic, it was large enough to have generated a tsunami that would have flooded the low ground of northern Puerto Rico.

  8. Paleozoic strata of the Dyckman Mountain area, northeastern Medfra quadrangle, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

    USGS Publications Warehouse

    Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.

    2000-01-01

    Paleozoic rocks in the Dyckman Mountain area (northeastern Medfra quadrangle; Farewell terrane) include both shallowand deep-water lithologies deposited on and adjacent to a carbonate platform. Shallow-water strata, which were recognized by earlier workers but not previously studied in detail, consist of algal-laminated micrite and skeletal-peloidal wackestone, packstone, and lesser grainstone. These rocks are, at least in part, of Early and (or) Middle Devonian age but locally could be as old as Silurian; they accumulated in shallow subtidal to intertidal settings with periodically restricted water circulation. Deepwater facies, reported here for the first time, are thin, locally graded beds of micrite and calcisiltite and subordinate thick to massive beds of lime grainstone and conglomerate. Conodonts indicate an age of Silurian to Middle Devonian; the most tightly dated intervals are early Late Silurian (early to middle Ludlow). These strata formed as hemipelagic deposits, turbidites, and debris flows derived from shallow-water lithologies of the Nixon Fork subterrane. Rocks in the Dyckman Mountain area are part of a broader facies belt that is transitional between the Nixon Fork carbonate platform to the west and deeper water, basinal lithologies (Minchumina “terrane”) to the east. Transitional facies patterns are complex because of Paleozoic shifts in the position of the platform margin, Mesozoic shortening, and Late Cretaceous-Tertiary disruption by strike-slip faulting.

  9. A review of Arbuckle Group strata in Kansas from a sedimentologic perspective: Insights for future research from past and recent studies

    USGS Publications Warehouse

    Franseen, E.K.

    2000-01-01

    Arbuckle Group and equivalent-age rocks (Cambrian and Lower Ordovician) represent an important record of sediment deposition in the history of the North American continent and they contain important accumulations of hydrocarbons (oil and gas) and base metal deposits. This is true for Kansas as well where Arbuckle strata account for approximately 40% of the volume of produced petroleum and known reserves. However, in comparison to their counterparts in other areas, such as the Ellenburger and Knox, Arbuckle rocks in Kansas remain relatively understudied, especially with respect to sedimentology and diagenesis. The Arbuckle is present in the subsurface in most of Kansas and is absent only in areas of northeastern and northwestern Kansas, and over ancient uplifts and buried Precambrian highs. Arbuckle rocks thicken from north to south and are up to 1,390 feet in the southeastern corner of Kansas. Arbuckle Group and equivalent-age rocks from Kansas and surrounding areas are similar, consisting of platform deposits dominated by ramp-type subtidal to peritidal carbonates (mostly dolomitized) which can be subdivided into cycles, less than 0.5 m to 40 m thick, based on facies type and depositional patterns. Recent studies from central Kansas show that major depositional facies consist of coarse-grained packstones/ grainstones, fine-grained packstones/wackestones/mudstones, stromatolites-thrombolites, intraclastic conglomerate and breccia, and shale. In addition, secondary features include dolomitization, breccia, fracture, and conglomerate related to early subaerial exposure and later karst, burial or structural processes, silicification, and local mineralization. Arbuckle and equivalent strata in the Midcontinent were affected by prolonged subaerial exposure that began immediately after Arbuckle deposition, forming the sub-Tippecanoe to sub-Absaroka unconformity. Favorable reservoir qualities generally are thought to be related directly to basement structural elements and

  10. Water balance report for the Oak Ridge Y-12 Plant

    SciTech Connect

    1994-07-01

    The Y-12 Plant, which occupies approximately 800 acres, was built by the Army Corps of Engineers in 1943 as part of the Manhattan Project in Oak Ridge, Tennessee. Recently, Martin Marietta Energy Systems, who manages the Y-12 Plant, has been concerned with the effects of water consumption and losses at the plant facility, and the ability of ground water beneath the site to act as a source of water seepage into East Fork Poplar Creek or as a source of water infiltration into subsurface strata. This has prompted the need to perform a water balance study on the facility. Data regarding all uses of municipal water and sources of discharge from the plant were recorded and then water balance calculations were performed using a computer model developed in a multi-dimensional electronic spreadsheet. This report describes the results of this research and includes the flow data collected during the study.

  11. Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa.

    PubMed

    Berna, Francesco; Goldberg, Paul; Horwitz, Liora Kolska; Brink, James; Holt, Sharon; Bamford, Marion; Chazan, Michael

    2012-05-15

    The ability to control fire was a crucial turning point in human evolution, but the question when hominins first developed this ability still remains. Here we show that micromorphological and Fourier transform infrared microspectroscopy (mFTIR) analyses of intact sediments at the site of Wonderwerk Cave, Northern Cape province, South Africa, provide unambiguous evidence--in the form of burned bone and ashed plant remains--that burning took place in the cave during the early Acheulean occupation, approximately 1.0 Ma. To the best of our knowledge, this is the earliest secure evidence for burning in an archaeological context.

  12. Considering Plants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1991-01-01

    Examples from research that incorporate plants to illustrate biological principles are presented. Topics include dried pea shape, homeotic genes, gene transcription in plants that are touched or wounded, production of grasslands, seaweed defenses, migrating plants, camouflage, and family rivalry. (KR)

  13. Considering Plants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1991-01-01

    Examples from research that incorporate plants to illustrate biological principles are presented. Topics include dried pea shape, homeotic genes, gene transcription in plants that are touched or wounded, production of grasslands, seaweed defenses, migrating plants, camouflage, and family rivalry. (KR)

  14. Correlation of aptian-albian carbon isotope excursions in continental strata of the cretaceous Foreland Basin, Eastern Utah, U.S.A.

    USGS Publications Warehouse

    Ludvigson, Greg A.; Joeckel, R.M.; Gonzalez, Luis A.; Gulbranson, E.L.; Rasbury, E.T.; Hunt, G.J.; Kirkland, J.I.; Madsen, S.

    2010-01-01

    Nodular carbonates ("calcretes") in continental foreland-basin strata of the Early Cretaceous Cedar Mountain Formation (CMF) in eastern Utah yield ??13C and ??O records of changes in the exogenic carbon cycle related to oceanic anoxic events (OAEs), and terrestrial paleoclimate. Chemostratigraphic profiles of both forebulge and foredeep sections show two prominent positive ??13C excursions, each with a peak value of -3% VPDB, and having background ??13C values of about -6% VPDB. These excursions correlate with the global early Aptian (Ap7) and late Aptian-early Albian (Apl2-All) carbon isotope excursions. Aptian-Albian positive ??13C excursions in the CMF also correspond to 3-4 per mil increases in carbonate ??18O. These phenomena record local aridification events. The chemostratigraphic profile on the thinner forebulge section of the CMF is calibrated, for the first time, by a radiogenic U-Pb date of 119.4 ?? 2.6 Ma on a carbonate bed, and by detrital zircon U-Pb dates on two bounding sandstone units (maximum depositional ages of 146 Ma and 112 Ma). P??trographie observations and diagenetic analyses of micritic to microsparitic carbonates from nodules indicate palustrine origins and demonstrate that they crystallized in shallow early meteoric phreatic environments. Meteoric calcite lines derived from CMF carbonates have ??18O values ranging between -8.1 to -7.5%o VPDB, supporting an estimate of zonal mean groundwater ??18O of -6% VSMOW for an Aptian-Albian paleolatitude of 34?? N. Furthermore, our two chemostratigraphic profiles exhibit a generally proportionate thinning of correlative strata from the foredeep on to the forebulge, suggesting that there were consistently lower rates of accumulation on the forebulge during the Aptian-Albian. Identification of the global Aptian-Albian ??13C excursions in purely continental strata, as demonstrated in this paper, opens a new avenue of research by identifying specific stratigraphie intervals that record the terrestrial

  15. [Poisonous plants].

    PubMed

    Hoppu, Kalle; Mustonen, Harriet; Pohjalainen, Tiina

    2011-01-01

    Approximately ten species of dangerously poisonous plants are found in Finland. Severe plant poisonings are very rare. Edible plants eaten raw or wrongly processed may cause severe symptoms. As first aid, activated charcoal should be given to the person who has eaten a plant causing a risk of significant poisoning. In case of exposure to topically irritating plant fluids, the exposed person's eyes must be irrigated and mouth or skin washed with copious amounts of water. In combination with solar UV radiation, light-sensitizing plants cause local burns. The diagnosis of plant poisoning is usually based on incidental information; the plant should be identified in order to make the correct treatment decisions.

  16. Geologic Map of Upper Cretaceous and Tertiary Strata and Coal Stratigraphy of the Paleocene Fort Union Formation, Rawlins-Little Snake River Area, South-Central Wyoming

    USGS Publications Warehouse

    Hettinger, R.D.; Honey, J.G.; Ellis, M.S.; Barclay, C.S.V.; East, J.A.

    2008-01-01

    This report provides a map and detailed descriptions of geologic formations for a 1,250 square mile region in the Rawlins-Little Snake River coal field in the eastern part of the Washakie and Great Divide Basins of south-central Wyoming. Mapping of geologic formations and coal beds was conducted at a scale of 1:24,000 and compiled at a scale of 1:100,000. Emphasis was placed on coal-bearing strata of the China Butte and Overland Members of the Paleocene Fort Union Formation. Surface stratigraphic sections were measured and described and well logs were examined to determine the lateral continuity of individual coal beds; the coal-bed stratigraphy is shown on correlation diagrams. A structure contour and overburden map constructed on the uppermost coal bed in the China Butte Member is also provided.

  17. Pre-, syn-, and postcollisional stratigraphic framework and provenance of upper triassic-upper cretaceous strata in the northwestern talkeetna mountains, alaska

    USGS Publications Warehouse

    Hampton, B.A.; Ridgway, K.D.; O'Neill, J. M.; Gehrels, G.E.; Schmidt, J.; Blodgett, R.B.

    2007-01-01

    Mesozoic strata of the northwestern Talkeetna Mountains are located in a regional suture zone between the allochthonous Wrangellia composite terrane and the former Mesozoic continental margin of North America (i.e., the Yukon-Tanana terrane). New geologic mapping, measured stratigraphic sections, and provenance data define a distinct three-part stratigraphy for these strata. The lowermost unit is greater than 290 m thick and consists of Upper Triassic-Lower Jurassic mafic lavas, fossiliferous limestone, and a volcaniclastic unit that collectively we informally refer to as the Honolulu Pass formation. The uppermost 75 m of the Honolulu Pass formation represent a condensed stratigraphic interval that records limited sedimentation over a period of up to ca. 25 m.y. during Early Jurassic time. The contact between the Honolulu Pass formation and the overlying Upper Jurassic-Lower Cretaceous clastic marine strata of the Kahiltna assemblage represents a ca. 20 m.y. depositional hiatus that spans the Middle Jurassic and part of Late Jurassic time. The Kahiltna assemblage may to be up to 3000 m thick and contains detrital zircons that have a robust U-Pb peak probability age of 119.2 Ma (i.e., minimum crystallization age/maximum depositional age). These data suggest that the upper age of the Kahiltna assemblage may be a minimum of 10-15 m.y. younger than the previously reported upper age of Valanginian. Sandstone composition (Q-43% F-30% L-27%-Lv-71% Lm-18% Ls-11%) and U-Pb detrital zircon ages suggest that the Kahiltna assemblage received igneous detritus mainly from the active Chisana arc, remnant Chitina and Talkeetna arcs, and Permian-Triassic plutons (Alexander terrane) of the Wrangellia composite terrane. Other sources of detritus for the Kahiltna assemblage were Upper Triassic-Lower Jurassic plutons of the Taylor Mountains batholith and Devonian-Mississippian plutons; both of these source areas are part of the Yukon-Tanana terrane. The Kahiltna assemblage is overlain

  18. Late Oligocene-Early Miocene larger benthic foraminifera from the mixed siliciclastic-carbonate and reefal strata of Kharabeh Sanji stratigraphic section, NW Iran

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, R.

    2012-04-01

    The marine Oligo-Miocene sediments of the Qom Formation at Kharabeh Sanji section west Uromieh consisting of mixed siliciclastic-carbonates changing to reefal strata were studied in detail to establish a high resolution biostratigraphic zonal scheme. Contineous distribution of larger benthic foraminifera (mainly miogypsinids) allowed us to correlate the identified taxa with the shallow benthic zonation (SBZ) already introduced for European sequences and to ascribe detailed age to the study section based on the determined biozones. The identified fauna include the genera Miogypsinodes, Miogypsina, Neorotalia, Nephrolepidina, Eulepidina and Spiroclypeus. The foraminifereal assemblage resemble to the fauna described from European basins characterizing the SBZ 23 to SBZ 25 zones representing a time interval from the Late Chattian to Burdigalian.

  19. Tectonic controls on deposition of Middle Jurassic strata in a retroarc foreland basin, Utah-Idaho trough, western interior, United States

    NASA Astrophysics Data System (ADS)

    Bjerrum, Christian J.; Dorsey, Rebecca J.

    1995-08-01

    An electronic supplement of this material may be obtained on a diskette or Anonymous FTP from KOSMOS.AGU.ORG. (LOGIN to AGU's FTP account using ANONYMOUS as the username and GUEST as the password. Go to the right directory by typing CD APEND. Type LS to see what files are available. Type GET and the name of the file to get it. Finally, type EXIT to leave the system.) (Paper 95TC01448, Tectonic controls on deposition of Middle Jurassic strata in a retroarc foreland basin, Utah-Idaho trough, western interior, United States, Christian J. Bjerrum and Rebecca J. Dorsey). Diskette may be ordered from American Geophysical Union, 2000 Florida Avenue, N. W., Washington, DC 20009; $15.00. Payment must accompany order. A thick succession of Jurassic nonmarine and marine sedimentary rocks is exposed in a large area from northern Arizona to eastern Idaho and western Wyoming. These sediments accumulated in the Utah-Idaho trough, a deep elongate cratonal basin whose origin has recently been debated. Detailed stratigraphic analysis, subsidence analysis, and first-order flexural modeling of these deposits (this study) provide new insights into the timing and mechanisms of subsidence in the Utah-Idaho trough. Lower and Middle Jurassic strata are divided into six unconformity-bounded sequences. In contrast to the overall uniform thickness of Lower Jurassic sequences (1 and 2), Middle Jurassic strata (sequences 3 through 6) consist of distinctly westward thickening sedimentary packages in which basal shallow marine deposits onlap eastward onto bounding unconformities. Basal strata of sequences 3 through 6 pass upward into widespread progradational continental deposits that are truncated progressively toward the east (cratonward) by the next unconformity. Decompacted total subsidence curves show that the rate of subsidence in most sections increased sharply at the end of sequence 2 time (J-2 unconformity; ˜170 Ma). This is interpreted to record the onset of Middle Jurassic deposition

  20. Strata-bound, silver-bearing iron, lead, and zinc sulfide deposits in Silurian and Ordovician rocks of allochthonous terranes, Nevada and northern Mexico

    USGS Publications Warehouse

    Ketner, Keith Brindley

    1983-01-01

    Allochthonous terranes in northern Nevada contain strata-bound sulfide deposits at two horizons in Silurian and Ordovician siliceous sedimentary rocks. The most intensively mineralized horizon and most extensive deposit is at the base of the Silurian. Another less extensive deposit is in the lower Middle Ordovician. Spectrographic analyses of gossan from the basal Silurian horizon indicate anomalously high values of lead and zinc; and in about 40 percent of the samples, silver values are anomalously high. Suhsurface samples contain the primary minerals pyrite, galena, and sphalerite. The basal Silurian deposits are in thick-bedded chert that is overlain by micaceous siltstone. They are underlain by a thick-bedded black chert unit of Late Ordovician age. The basal Silurian gossan has been identified also in southwestern Nevada and in northern Mexico in stratigraphic sequences very similar to that of northern Nevada.

  1. Plant traits determine forest flammability

    NASA Astrophysics Data System (ADS)

    Zylstra, Philip; Bradstock, Ross

    2016-04-01

    Carbon and nutrient cycles in forest ecosystems are influenced by their inherent flammability - a property determined by the traits of the component plant species that form the fuel and influence the micro climate of a fire. In the absence of a model capable of explaining the complexity of such a system however, flammability is frequently represented by simple metrics such as surface fuel load. The implications of modelling fire - flammability feedbacks using surface fuel load were examined and compared to a biophysical, mechanistic model (Forest Flammability Model) that incorporates the influence of structural plant traits (e.g. crown shape and spacing) and leaf traits (e.g. thickness, dimensions and moisture). Fuels burn with values of combustibility modelled from leaf traits, transferring convective heat along vectors defined by flame angle and with plume temperatures that decrease with distance from the flame. Flames are re-calculated in one-second time-steps, with new leaves within the plant, neighbouring plants or higher strata ignited when the modelled time to ignition is reached, and other leaves extinguishing when their modelled flame duration is exceeded. The relative influence of surface fuels, vegetation structure and plant leaf traits were examined by comparing flame heights modelled using three treatments that successively added these components within the FFM. Validation was performed across a diverse range of eucalypt forests burnt under widely varying conditions during a forest fire in the Brindabella Ranges west of Canberra (ACT) in 2003. Flame heights ranged from 10 cm to more than 20 m, with an average of 4 m. When modelled from surface fuels alone, flame heights were on average 1.5m smaller than observed values, and were predicted within the error range 28% of the time. The addition of plant structure produced predicted flame heights that were on average 1.5m larger than observed, but were correct 53% of the time. The over-prediction in this

  2. Quaternary activity of the range front thrust system in the Longmen Shan piedmont, China, revealed by seismic imaging and growth strata

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Liu-Zeng, Jing; Jia, Dong; Sun, Chuang; Wang, Wei; Yuan, Zhaode; Liu, Baojin

    2016-12-01

    Reliable estimates of Quaternary or Cenozoic upper crustal shortening in the Longmen Shan fold-and-thrust belt are rare. In this paper, we report on our use of high-resolution 2-D and 3-D seismic reflection profiles at various scales, together with borehole data, to investigate the structural geometry of the Longmen Shan piedmont. The results reveal a thrust system beneath the Longmen Shan, termed the range front thrust system, which consists of the range front blind thrust and its upward splay faults. Moreover, on these faults we identified growth strata that provide an excellent opportunity for assessing the activity of this thrust system. Analyses of the growth strata reveal early to late Pleistocene activity on the range front blind thrust, with minimum dip slip and horizontal shortening rates of 1.1 ± 0.2 mm/yr and 1 mm/yr. Accordingly, the maximum accumulated slip on the range front blind thrust is calculated to be 7.5 ± 0.3 km in the Longmen Shan. Using the new horizontal shortening rate and other published data, we also estimated that the long-term shortening rate across the Longmen Shan fold-and-thrust belt is 1-3 mm/yr, which is comparable to the short-term GPS rate. The similarity of these rates suggests that the Longmen Shan attained a steady state condition over the past 2 Myr. An additional highlight of our results is that we show Quaternary activity around the Tibetan Plateau to have been nearly synchronous in different regions, including in the Longmen Shan, the Himalayas, the western Kunlun Shan, and the northern Qilian Shan.

  3. Remagnetization of Cretaceous forearc strata on Santa Margarita and Magdalena Islands, Baja California Sur: Implications for northward transport along the California margin

    NASA Astrophysics Data System (ADS)

    Hagstrum, Jonathan T.; Sedlock, Richard L.

    1998-12-01

    Paleomagnetic data for two sections of Cretaceous forearc strata with different structural attitudes on Santa Margarita and Magdalena Islands in Baja California Sur, Mexico, indicate that these rocks have been remagnetized, probably during the late Cenozoic. The in situ paleomagnetic directions, however, are similar to data from other Cretaceous rocks on peninsular California with unexpectedly shallow inclinations and easterly declinations. These data have been interpreted as indicating either northward tectonic transport (10°-15° of latitude) and clockwise rotation (>20°) or compaction shallowing of magnetic inclinations in sedimentary rocks combined with southwestward tilting of plutonic rocks. The available paleomagnetic data for Cretaceous forearc strata in southern and Baja California can be divided into three groups: (1) sections with normal-polarity magnetizations that fail fold tests and are remagnetized, (2) sections with normal-polarity magnetizations with no or inconclusive fold tests that may or may not be remagnetized, and (3) sections with both normal-and reversed-polarity intervals where pervasive remagnetization has not occurred. Other rocks of the Mesozoic Great Valley Group, Coast Range ophiolite, and Franciscan Complex in California also have secondary magnetizations with directions similar to younger geomagnetic field directions. Although these widespread remagnetizations could have variable local causes, we propose regional burial and uplift, related to changes in subduction parameters, as a possible explanation. Two episodes of remagnetization are apparent: one in the Late Cretaceous and a second in the late Cenozoic. On the other hand, the unremagnetized and apparently reliable data from sedimentary and plutonic rocks on the Baja Peninsula consistently indicate northward translation (14° ± 3°) and clockwise rotation (29° ± 8°) with respect to North America since the Late Cretaceous.

  4. Agglutinated foraminifera from the Sydney Coalfield, Nova Scotia: Their use as indicators of sea-level changes in Carboniferous coal-bearing strata

    SciTech Connect

    Wightman, W.G.; Scott, D.B.; Medioli, F.M.; Gibling, M.R. . Centre for Marine Geology)

    1992-01-01

    Agglutinated foraminifera and arcellaceans (the camoebians) were examined from Carboniferous (Late Westphalian-Stephanian) cyclothems in the Sydney Basin of Nova Scotia. Their presence confirms that the laterally extensive coal seams, limestones, mudstones and carbonaceous shales were deposited in a paralic setting. Four distinctive assemblages are documented from the coal-bearing strata, and these may be used as accurate paleo sea-level indicators on the basis of the modern distribution of similar assemblages. Mixed assemblages dominated by Ammobaculites characterize siltstones overlying the coal seams, an association typical of mineralic substrates within modern estuarine environments. Assemblages dominated by small, finely agglutinated specimens of Ammotium and Ammobaculites occur in organic rich strata between coal seam splits. Similar assemblages are found in modern salt marshes and upper estuarine settings. Trochammina dominated assemblages occur in mudstones underlying the coal seams. Such assemblages are typical of higher elevations in modern brackish and saline marshes. Monotypic assemblages of the arcellacean Difflugia are also found in the seat earths below coal seams. Similar associations occur today in mineralic substrates below modern freshwater floating marshes. The presence of a Trochammina assemblage has aided recognition of a maximum flooding (transgression) surface below the base of an incised paleovalley, interpreted as a type 1 sequence boundary, in the Bonar cyclothem of the Sydney Basin. The valley incision is attributed to glacioeustatic sea-level lowering. The upper 10m of the 25m thick valley fill contains assemblages of Difflugia, which are succeeded by Trochammina assemblages within the seat earth beneath the coal at the top of the cyclothem.

  5. The influence of paleogeography in epicontinental seas: A case study based on Middle Devonian strata from the MacKenzie Basin, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Corlett, Hilary; Jones, Brian

    2011-08-01

    The history of Middle Devonian sea level changes are recorded in the Chinchaga Formation, Lonely Bay Formation, Horn Plateau Formation, and the Horn River Formations that originated in the MacKenzie Basin, which is located in the southern Northwest Territories, Canada. These strata record an almost consistent sea-level rise throughout the Middle Devonian with punctuated deepenings. Deposition began in the MacKenzie Basin in the Eifelian with restricted shallow water evaporites and dolomites of the Chinchaga Formation. Overlying the Chinchaga Formation are the open-marine carbonates belonging to the Lonely Bay Formation, which were overlain by the Horn Plateau Formation buildups. Pelagic shales of the Horn River Formation in the Late Givetian/Early Frasnian later covered these buildups. During the Early and Middle Devonian many continental basins in North America had limited interactions with open ocean waters. These restricted shallow-water basins were vulnerable to the effects of clastic shedding and evaporitic drawdown that commonly caused local lowstands. Several of these shallow basins, including the MacKenzie Basin, have been used to construct Devonian sea-level curves. Comparison of the Middle Devonian strata that formed in the MacKenzie Basin with well-established sea level curves shows that the Late-Givetian regression interpreted from some of those successions is not evident in the succession found in the MacKenzie Basin. This probably reflects the fact that the Mackenzie Basin was directly linked to the open ocean and was not influenced by the changes in sea level that affected many of the enclosed basins.

  6. Within-plant distribution of Aulacorthum solani (Hemiptera: Aphididae), on various greenhouse plants with implications for control.

    PubMed

    Jandricic, S E; Mattson, N S; Wraight, S P; Sanderson, J P

    2014-04-01

    Foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), has recently undergone a status change from an occasional pest to a serious pest in greenhouses of North America and the United Kingdom. Little nonanecdotal information exists on the ecology of this insect in greenhouse crops. To help improve integrated pest management decisions for A. solani, the within-plant distribution of this pest was explored on a variety of common greenhouse plants in both the vegetative and flowering stage. This aphid generally was found on lower leaves of vegetative plants, but was found higher in the canopy on reproductive plants (on flowers, flower buds, or upper leaves). Aphid numbers were not consistently positively correlated with total leaf surface areas within plant strata across plant species. Thus, the observed differences in preferred feeding sites on vegetative versus flowering plants are possibly a response to differences in nutritional quality of the various host-plant tissues. Despite being anecdotally described as a "stem-feeding aphid," A. solani was rarely found feeding on stems at the population densities established in our tests, with the exception of racemes of scarlet sage (Salvia splendans). Although some previous reports suggested that A. solani prefers to feed on new growth of plants, our results indicate that mature leaves are preferred over growing tips and young leaves. The implications of the within-plant feeding preferences of A. solani populations with respect to both biological and chemical control are discussed.

  7. Palynology of latest Neogene (Middle Miocene to late Pliocene) strata in the Delmarva Peninsula of Maryland and Virginia

    USGS Publications Warehouse

    Sirkin, L.; Owens, J.P.

    1998-01-01

    Palynology of Miocene and Pliocene formations in the Delmarva Peninsula of Maryland and Virginia reveals a significant representation of exotic pollen interspersed in pollen assemblages that are otherwise comparable to those from the modern vegetation of the Mid-Alantic coastal plain region. The late Tertiary arboreal pollen (AP) assemblages are dominated by oak, hickory, pine, birch and alder with minor amounts of mid- and southern coastal tree taxa, as well as minor spruce and hemlock and a trace of fir. Nonarboreal pollen (NAP) include grass, sedge, composite and aquatic taxa. Exotic pollen in these assemblages represent plants now foreign to this region. They may be placed in three categories. First, there are extinct forms, such as Labrapollis, Plicatopollis, and Multiporopollenites, that can be traced from the Cretaceous or Early Tertiary into the Late Tertiary. The second group includes forms, such as Podocarpus, Engelhardtia, Pterocarya, Ephedra, Eucommia, Ulmus-Zelkova, Glyptostrobus, Palmae, and Cyathea, that are not found in this region today and not found in early Pleistocene sediments in the eastern United States. Many of these taxa are subtropical or greatly restricted in geographic range. A third group of exotics, mainly Cyrilla, Planera, Gordonia, Jussiaea, and Sapotacaea, including Minusops, are generally found south of the study area or have their northern limit here at this time. The lack of the extinct or distant exotics in early to mid-Pleistocene sediments in the mid-Atlantic coastal plain and the last appearance of Pterocarya, as the last exotic taxon in the early Pleistocene of western Europe, support the stratigraphic assignment of the Pliocene units. The number of exotic taxa diminish markedly between the Miocene pollen assemblages and those of the Late Pliocene. Climatic fluctuations characterize the Late Tertiary environments. The Miocene, for example, incorporates a warming trend between the upper, middle Miocene and the Manokin beds

  8. School Achievement of Pupils from the Lower Strata in Public, Private Government-Dependent and Private Government-Independent Schools: A Cross-National Test of the Coleman-Hoffer Thesis

    ERIC Educational Resources Information Center

    Corten, Rense; Dronkers, Jaap

    2006-01-01

    We consider the question whether pupils from the lower social strata perform better in private government-dependent schools than in public or private-independent schools, using the PISA 2000 data on European high schools. In the eighty's, Coleman and Hoffer (1987) found in the USA that the performance of these pupils was better at religious…

  9. Poisonous Plants

    MedlinePlus

    ... Publications and Products Programs Contact NIOSH NIOSH POISONOUS PLANTS Recommend on Facebook Tweet Share Compartir Photo courtesy ... U.S. Department of Agriculture Many native and exotic plants are poisonous to humans when ingested or if ...

  10. The Mexican Ridges Fold Belt, Gulf of Mexico: Deformation, Dynamics of Deposition of Growth Strata, and the Delay of Sedimentary Response to Tectonic Forcing

    NASA Astrophysics Data System (ADS)

    Yarbuh Lugo, U. I.; Contreras, J.

    2014-12-01

    Deformation of the Mexican Ridges fold belt (MRFB), western Gulf of Mexico, initiated in the Late Neogene in response to normal faulting along the Quetzalcoatl Extensional System offshore Veracruz. Previous authors analyzed stacking patterns of growth strata concluding deformation occurred in two stages: the western section of the fold belt developed during the Upper Miocene whereas the eastern part became active during the Lower Pliocene. Here we analyze a regional seismic line to determine whether deformation migrated progressively eastward. In contrast to previous studies we do not use stacking patterns but excess area. This parameter provides direct information of both linear shortening, and superficial mass transport. We construct excess-area plots for each of the folds comprising the MRFB; from them we estimate the shortening and the degradation path of the seafloor deformed by folding. Moreover, by assuming denudation is in steady state, we are able to differentiate sediments derived locally from sediments transported from distant sources. Results show tectonic transport in the MRFB is 11.8 km; shortening of individual folds ranges 3-16%, with an average strain for the entire MRFB of ~10%; structures grew at a mean uplift rate of 0.2 mm/yr. We estimate the constant of mass diffusivity, which controls the rate of degradation, has a mean value of 0.27 m2/yr. This value is characteristic of rapid, episodic mass movements. Finally, the sedimentation rate is ~0.2 mm/yr. Those parameters, however, are not constant; they decrease toward the deepwater portion of the fold belt. The structures proximal to the continental shelf are rising rapidly and are being degraded more intensely than those in the distal part of the fold belt. Our results reveal that deformation started synchronously throughout the MRFB during the Late Miocene and not in two episodes as previously reported. The reason for the seeming discrepancy is due to the copious sedimentation in the eastern

  11. Effect of a policy to reduce user fees on the rate of skilled birth attendance across socioeconomic strata in Burkina Faso.

    PubMed

    Langlois, Étienne V; Karp, Igor; Serme, Jean De Dieu; Bicaba, Abel

    2016-05-01

    In Sub-Saharan Africa, maternal and neonatal morbidity and mortality rates are associated with underutilization of skilled birth attendance (SBA). In 2007, Burkina Faso introduced a subsidy scheme for SBA fees. The objective of this study was to evaluate the effect of Burkina Faso's subsidy policy on SBA rate across socioeconomic status (SES) strata. We used a quasi-experimental design. The data sources were two representative surveys (n = 1408 and n = 1403) of women from Houndé and Ziniaré health districts of Burkina Faso, and a survey of health centres assessing structural quality of care. Multilevel Poisson regression models were used with robust variance estimators. We estimated adjusted rate ratios (RR) and rate differences (RD) as a function of time and SES. For lowest-SES women, immediately upon the introduction of the subsidy policy, the rate of SBA was 45% higher (RR = 1.45, 95% confidence interval (CI): 1.19-1.77) than expected in the absence of subsidy introduction. The results indicated a sustained effect after introduction of the subsidy policy, based on RR estimate (95% CI) of 1.48 (1.21-1.81) at 2 years. For middle-SES women, the RR estimates were 1.28 (1.09-1.49) immediately after introduction of the subsidy policy and 1.30 (1.11-1.51) at 2 years, respectively. For highest-SES women, the RR estimates were 1.19 (1.02-1.38) immediately after subsidy introduction and 1.21 (1.06-1.38) at 2 years, respectively. The RD (95% CI) was 14% (3-24%) for lowest-SES women immediately after introduction of the policy, and the effect was sustained at 14% (4-25%) at 2 years. Our study suggests that the introduction of a user-fee subsidy in Burkina Faso resulted in increased rates of SBA across all SES strata. The increase was sustained over time and strongest among the poorest women. These findings have important implications for evidence-informed policy making in Burkina Faso and other countries in Sub-Saharan Africa. © The Author 2015. Published by

  12. Provenance Ages of Protoliths From the Chiapas Massif Complex and Adjacent Strata of the Southern Maya Block - Implications on the Paleozoic Reconstruction of Middle America.

    NASA Astrophysics Data System (ADS)

    Weber, B.; Schaaf, P.; Valencia, V. A.; Lopez-Martinez, M.; Ortega-Gutierrez, F.

    2007-05-01

    The basement of the Maya block is exposed in the Maya Mountains of Belize, the Chuacús Complex of Guatemala, and in the Chiapas Massif Complex (CMC) of SE Mexico. In the CMC medium- to high-grade metasedimentary rocks occur as isolated domains in mostly metaigneous crystalline rocks. The most important tectonothermal event in the entire CMC is of late Permian age, culminating in partial anatexis and the intrusion of the Chiapas batholith. In this work we present U-Pb data obtained by LA-MC-ICPMS from detrital zircon cores of metasediments from the CMC and from detrital zircons of Paleozoic strata exposed in SE Chiapas. The Pennsylvanian-Permian Santa Rosa Formation (SRF) contains mostly Pan-African (500-650 Ma) zircons, minor populations of Silurian-Early Devonian (400-420 Ma) and Grenville (1.0-1.25 Ga) zircons, and few Paleoproterozoic and Archean grains. The maximum sedimentation age is documented by ~320 Ma old zircons. Metagreywacke and metasandstones of the central CMC have inherited detrital zircon cores with age distributions indistinguishable from those of the SRF. High-grade metapelites and para-amphibolites from the CMC, instead, have inherited zircon cores with one single population of 1.0 Ga or with populations at 1.0, 1.2, and 1.5 Ga. In the southern part of the CMC leucocratic granites intrude sedimentary rocks whose detrital zircons yielded mostly 1.53 Ga ages with some grains in the range of 1.6-1.7 Ga, but no younger zircons. White mica grown in contact with the leucogranite has a 40Ar- 39Ar age of 406 ± 4 Ma, defining a minimum age for both deposition of the sediments and intrusion of the leucogranite. Our data indicate that the CMC has a composite pre-metamorphic basement, containing sedimentary protoliths from the Pennsylvanian-Permian SRF and from early Paleozoic strata intruded by Silurian-Early Devonian granites. This favors a similar pre-Permian geologic history for the CMC as for the Maya Mountains of Belize. The early Paleozoic

  13. Effect of a policy to reduce user fees on the rate of skilled birth attendance across socioeconomic strata in Burkina Faso

    PubMed Central

    Langlois, Étienne V; Karp, Igor; Serme, Jean De Dieu; Bicaba, Abel

    2016-01-01

    Background. In Sub-Saharan Africa, maternal and neonatal morbidity and mortality rates are associated with underutilization of skilled birth attendance (SBA). In 2007, Burkina Faso introduced a subsidy scheme for SBA fees. The objective of this study was to evaluate the effect of Burkina Faso’s subsidy policy on SBA rate across socioeconomic status (SES) strata. Methods. We used a quasi-experimental design. The data sources were two representative surveys (n = 1408 and n = 1403) of women from Houndé and Ziniaré health districts of Burkina Faso, and a survey of health centres assessing structural quality of care. Multilevel Poisson regression models were used with robust variance estimators. We estimated adjusted rate ratios (RR) and rate differences (RD) as a function of time and SES. Results. For lowest-SES women, immediately upon the introduction of the subsidy policy, the rate of SBA was 45% higher (RR = 1.45, 95% confidence interval (CI): 1.19–1.77) than expected in the absence of subsidy introduction. The results indicated a sustained effect after introduction of the subsidy policy, based on RR estimate (95% CI) of 1.48 (1.21–1.81) at 2 years. For middle-SES women, the RR estimates were 1.28 (1.09–1.49) immediately after introduction of the subsidy policy and 1.30 (1.11–1.51) at 2 years, respectively. For highest-SES women, the RR estimates were 1.19 (1.02–1.38) immediately after subsidy introduction and 1.21 (1.06–1.38) at 2 years, respectively. The RD (95% CI) was 14% (3–24%) for lowest-SES women immediately after introduction of the policy, and the effect was sustained at 14% (4–25%) at 2 years. Conclusion. Our study suggests that the introduction of a user-fee subsidy in Burkina Faso resulted in increased rates of SBA across all SES strata. The increase was sustained over time and strongest among the poorest women. These findings have important implications for evidence-informed policymaking in Burkina Faso and other

  14. Burden of micronutrient deficiencies by socio-economic strata in children aged 6 months to 5 years in the Philippines

    PubMed Central

    2013-01-01

    Background Micronutrient deficiencies (MNDs) are a chronic lack of vitamins and minerals and constitute a huge public health problem. MNDs have severe health consequences and are particularly harmful during early childhood due to their impact on the physical and cognitive development. We estimate the costs of illness due to iron deficiency (IDA), vitamin A deficiency (VAD) and zinc deficiency (ZnD) in 2 age groups (6–23 and 24–59 months) of Filipino children by socio-economic strata in 2008. Methods We build a health economic model simulating the consequences of MNDs in childhood over the entire lifetime. The model is based on a health survey and a nutrition survey carried out in 2008. The sample populations are first structured into 10 socio-economic strata (SES) and 2 age groups. Health consequences of MNDs are modelled based on information extracted from literature. Direct medical costs, production losses and intangible costs are computed and long term costs are discounted to present value. Results Total lifetime costs of IDA, VAD and ZnD amounted to direct medical costs of 30 million dollars, production losses of 618 million dollars and intangible costs of 122,138 disability adjusted life years (DALYs). These costs can be interpreted as the lifetime costs of a 1-year cohort affected by MNDs between the age of 6–59 months. Direct medical costs are dominated by costs due to ZnD (89% of total), production losses by losses in future lifetime (90% of total) and intangible costs by premature death (47% of total DALY losses) and losses in future lifetime (43%). Costs of MNDs differ considerably between SES as costs in the poorest third of the households are 5 times higher than in the wealthiest third. Conclusions MNDs lead to substantial costs in 6-59-month-old children in the Philippines. Costs are highly concentrated in the lower SES and in children 6–23 months old. These results may have important implications for the design, evaluation and choice of the

  15. Morphological and biochemical re-evaluation of the process of cavitation in the rat knee joint: cellular and cell strata alterations in the interzone

    PubMed Central

    ITO, MASAAKI M.; KIDA, MASAHIKO Y.

    2000-01-01

    To assess the contribution of apoptosis to the mechanism of synovial joint cavitation, and to clarify morphological cellular changes during cavitation, we investigated the development of the rat knee joint by light and electron microscopy, TUNEL methods, and electrophoresis of DNA fragments. Although cavitation occurred within the interzone, which consists of 2 outer and a middle layer termed the intermediate zone, no morphological or biochemical signs of cell death, in particular apoptosis, were seen in the interzone at any embryonic stage. Microscopic and ultrastructural alterations affecting cell differentiation were clearly observed in the interzone, i.e. mesenchymal cells gradually showed elongation, cytoplasmic vacuolation and pyknosis in the intermediate zone where the elongated cells were arranged in parallel in some strata. Some of these cells were further flattened into spindle cells and the number of strata decreased to 2. The rest of the cells were incorporated secondarily into the outer layers, becoming chondroblasts. Collagen fibrils were arranged in a network structure in the outer layers, which obviously differed from the directional pattern parallel to the long axis of elongated cells in the intermediate zone. In addition, the density of collagen fibrils was higher in the outer layers than in the intermediate zone. During cavitation, the initial separation was detected between the elongated cells in the intermediate zone in paraffin sections at E16.5 and the spindle cells in epoxy sections at E18.5. The spindle cells lining the cavity, namely, the surfaces of the epiphysis and meniscus, finally became chondrocytes. The diminution of proteoglycans and collagen fibrils and the synthesis of hyaluronan in the extracellular matrix are now generally believed to be parts of the mechanism for cavitation based on the concept of ‘loss of cohesion’. The microscopic and ultrastructural alterations in the interzone seemed to reflect differences in the

  16. Prediction of Cardiovascular Disease by the Framingham-REGICOR Equation in the High-Risk PREDIMED Cohort: Impact of the Mediterranean Diet Across Different Risk Strata.

    PubMed

    Amor, Antonio J; Serra-Mir, Mercè; Martínez-González, Miguel A; Corella, Dolores; Salas-Salvadó, Jordi; Fitó, Montserrat; Estruch, Ramón; Serra-Majem, Lluis; Arós, Fernando; Babio, Nancy; Ros, Emilio; Ortega, Emilio

    2017-03-13

    The usefulness of cardiovascular disease (CVD) predictive equations in different populations is debatable. We assessed the efficacy of the Framingham-REGICOR scale, validated for the Spanish population, to identify future CVD in participants, who were predefined as being at high-risk in the PREvención con DIeta MEDiterránea (PREDIMED) study-a nutrition-intervention primary prevention trial-and the impact of adherence to the Mediterranean diet on CVD across risk categories. In a post hoc analysis, we assessed the CVD predictive value of baseline estimated risk in 5966 PREDIMED participants (aged 55-74 years, 57% women; 48% with type 2 diabetes mellitus). Major CVD events, the primary PREDIMED end point, were an aggregate of myocardial infarction, stroke, and cardiovascular death. Multivariate-adjusted Cox regression was used to calculate hazard ratios for major CVD events and effect modification from the Mediterranean diet intervention across risk strata (low, moderate, high, very high). The Framingham-REGICOR classification of PREDIMED participants was 25.1% low risk, 44.5% moderate risk, and 30.4% high or very high risk. During 6-year follow-up, 188 major CVD events occurred. Hazard ratios for major CVD events increased in parallel with estimated risk (2.68, 4.24, and 6.60 for moderate, high, and very high risk), particularly in men (7.60, 13.16, and 15.85, respectively, versus 2.16, 2.28, and 3.51, respectively, in women). Yet among those with low or moderate risk, 32.2% and 74.3% of major CVD events occurred in men and women, respectively. Mediterranean diet adherence was associated with CVD risk reduction regardless of risk strata (P>0.4 for interaction). Incident CVD increased in parallel with estimated risk in the PREDIMED cohort, but most events occurred in non-high-risk categories, particularly in women. Until predictive tools are improved, promotion of the Mediterranean diet might be useful to reduce CVD independent of baseline risk. URL: http

  17. Nature plants.

    PubMed

    2014-06-01

    We welcome our new sister journal Nature Plants and the increased commitment to the plant science community that it represents. This is an opportunity for Nature Genetics to emphasize the use of genetic and genomic tools and resources in discovering new plant biology and solving major agricultural challenges.

  18. Medicinal Plants.

    ERIC Educational Resources Information Center

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  19. Hardwood planting

    Treesearch

    Richard M. Godman

    1992-01-01

    Hardwood planting used to be most common on private land. Now more and more hardwoods are being planted on public land. Not much hardwood planting research is going on but recent summaries of earlier trials allow us to give you the following guidelines.

  20. Medicinal Plants.

    ERIC Educational Resources Information Center

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  1. Autoluminescent Plants

    PubMed Central

    Krichevsky, Alexander; Meyers, Benjamin; Vainstein, Alexander; Maliga, Pal; Citovsky, Vitaly

    2010-01-01

    Prospects of obtaining plants glowing in the dark have captivated the imagination of scientists and layman alike. While light emission has been developed into a useful marker of gene expression, bioluminescence in plants remained dependent on externally supplied substrate. Evolutionary conservation of the prokaryotic gene expression machinery enabled expression of the six genes of the lux operon in chloroplasts yielding plants that are capable of autonomous light emission. This work demonstrates that complex metabolic pathways of prokaryotes can be reconstructed and function in plant chloroplasts and that transplastomic plants can emit light that is visible by naked eye. PMID:21103397

  2. Plant nanotoxicology.

    PubMed

    Dietz, Karl-Josef; Herth, Simone

    2011-11-01

    The anthropogenic release of nanoparticles (NPs) to the environment poses a potential hazard to human health and life. The interplay between NPs and biological processes is receiving increasing attention. Plants expose huge interfaces to the air and soil environment. Thus, NPs are adsorbed to the plant surfaces, taken up through nano- or micrometer-scale openings of plants and are translocated within the plant body. Persistent NPs associated with plants enter the human food chain. In this Opinion, we document the occurrence and character of NPs in the environment and evaluate the need for future research on toxicological effects. Plant nanotoxicology is introduced as a discipline that explores the effects and toxicity mechanisms of NPs in plants, including transport, surface interactions and material-specific responses. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Structural and tectonic implications of pre-Mt. Simon strata -- or a lack of such -- in the western part of the Illinois basin

    SciTech Connect

    Sargent, M.L. )

    1993-03-01

    The discovery of a pre-Mt. Simon lithic arenite (arkose) in southwestern Ohio has lead to reevaluation of many basement tests in the region. Several boreholes in adjacent states have been reexamined by others and are now believed to bottom in the Middle Run Formation. Seismic-reflection sections in western Ohio and Indiana have indicated pre-Mt. Simon basins filled with layered rocks that are interpreted to be Middle Run, however, the pre-Mt. Simon basins and east of Illinois. Samples from Illinois basement tests were reexamined to determine whether they had encountered similar strata. All reported crystalline-basement tests in Illinois show diagnostic igneous textures and mineralogical associations. Coarsely crystalline samples in cores show intergrown subhedral grains of quartz, microcline, and sodic plagioclase. Medium-crystalline rocks in cuttings samples show numerous examples of micrographic intergrowths of quartz and K-feldspar. This texture cannot be authigenically grown in a sediment and probably could not have survived a single cycle of erosion and deposition. Aphanitic rocks show porphyritic and spherulitic textures that are distinctly igneous and would be destroyed by weathering. Substantial relief on the Precambrian crystalline surface in Illinois is postulated for major structural features like the LaSalle Anticlinorium, the Sparta Shelf, the Ste. Genevieve Fault zone, etc. Paleotopographic relief up to 300 m (1,000 feet) is documented from drilling on the western flank of the basin.

  4. Basin analysis of Upper Cretaceous strata of the Washakie and Red Desert basins, southwestern Wyoming, employing computer-generated maps and cross sections

    SciTech Connect

    Kohles, K.M.; Potts, J. ); Reid, F.S.

    1991-03-01

    The Washakie and Red Desert basins comprise the eastern portion of the Greater Green River basins of southwestern Wyoming. Stratigraphically the basins are dominated by a thick package of Cretaceous clastic sediments, as much as 16,000 ft thick, which resulted from several major transgressive-regressive cycles. Upper Cretaceous strata deposited during the latest cycle contain extensive deposits of commercial hydrocarbons, particularly gas. Much of the present structural configuration of the area is the result of the Laramide Orogeny in Late Cretaceous time. To facilitate a comprehensive geological analysis of the area a computerized subsurface data base was constructed from available well logs for approximately 3,000 wells in the Washakie and Red Desert basins. This data base contains correlated tops for most of the major Upper Cretaceous stratigraphic units, including selected subdivisions and net sand thickness values. Consistent correlations were achieved through the use of a tight, loop-tied cross section and key well network containing over 400 correlated well-logs. A complete suite of structure contour maps on all correlated horizons was generated from the data base with commercially available software. These maps, along with selected computer-generated structural cross sections, reveal a detailed subsurface picture of the Washakie and Red Desert basins. Isopachous maps of selected intervals were also produced to illustrate the Late Cretaceous depositional history of the area.

  5. Graphic correlation of early Pennsylvania-Middle Permian strata of the southwestern United States using a modified version of Shaw's method

    SciTech Connect

    Benoist, S.L.; Nestell, M.K. . Dept. of Geology)

    1993-02-01

    A composite standard reference section (CSRS) to act as an objective standard of reference for Early Pennsylvanian-Middle Permian strata (Morrowan to Leonardian) of the southwestern US is made using a modified version of Shaw's graphic correlation method. The first and last occurrences of fusulinaceans from 45 measured sections are used as a data base. A section located on Ferguson Mt., northeastern Nevada, was selected as a standard reference section (SRS) because it contains a long and well documented Early Pennsylvanian to Middle Permian fusulinacean-bearing sequence. Graphic compositing of the data, using a manual placement of the line of correlation (LOC), proceeded in a west-to-east pattern employing sections in northeastern and southern Nevada, southeastern Arizona, southern New Mexico, and western Texas. Graphcor, a commercial software package, was used to ease data manipulation. Several rounds of compositing were necessary to stabilize the range data in the CSRS in which the ranges of fusulinacean genera closely mirror published range data. Factors hindering the evaluation of the CSRS range data are: (1) the inability to place confidence intervals due to the semi-quantitative nature of the correlation method, (2) the difficulty in accurately placing the LOC between sections due to a paucity of shared data points, reflecting the facies-controlled and endemic nature of fusulinacean distributions; and (3) the uncertainty of published species assignments. Therefore, though a refined, objective zonation can be generated using composite standard ranges of fusulinacean species, the correlative utility of the zonal boundaries is limited.

  6. Investigation on the Influence of Abutment Pressure on the Stability of Rock Bolt Reinforced Roof Strata Through Physical and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Kang, Hongpu; Li, Jianzhong; Yang, Jinghe; Gao, Fuqiang

    2017-02-01

    In underground coal mining, high abutment loads caused by the extraction of coal can be a major contributor to many rock mechanic issues. In this paper, a large-scale physical modeling of a 2.6 × 2.0 × 1.0 m entry roof has been conducted to investigate the fundamentals of the fracture mechanics of entry roof strata subjected to high abutment loads. Two different types of roof, massive roof and laminated roof, are considered. Rock bolt system has been taken into consideration. A distinct element analyses based on the physical modeling conditions have been performed, and the results are compared with the physical results. The physical and numerical models suggest that under the condition of high abutment loads, the massive roof and the laminated roof fail in a similar pattern which is characterized as vertical tensile fracturing in the middle of the roof and inclined shear fracturing initiated at the roof and rib intersections and propagated deeper into the roof. Both the massive roof and the laminated roof collapse in a shear sliding mode shortly after shear fractures are observed from the roof surface. It is found that shear sliding is a combination of tensile cracking of intact rock and sliding on bedding planes and cross joints. Shear sliding occurs when the abutment load is much less than the compressive strength of roof.

  7. 40Ar/(39)Ar dating of Chemeron Formation strata encompassing the site of hominid KNM-BC 1, Tugen Hills, Kenya.

    PubMed

    Deino, Alan L; Hill, Andrew

    2002-01-01

    A fossil hominid temporal bone (KNM-BC 1) from surface exposures at Baringo Paleontological Research Project site BPRP#2 in the Chemeron Formation outcropping in a tributary drainage of the Kapthurin River west of Lake Baringo, Kenya has been attributed to Homo sp. indet. K-feldspar phenocrysts from lapilli tuffs bracketing the inferred fossiliferous horizon yield single-crystal(40)Ar/(39)Ar ages of 2.456+/-0.006 and 2.393+/-0.013 Ma. These age determinations are supported by stratigraphically consistent ages on higher tuff horizons and from nearby sections. In addition, new(40)Ar/(39)Ar ages on tuffaceous units near the base and top of the formation along the Kapthurin River yield 3.19+/-0.03 and 1.60+/-0.05 Ma respectively. The base of the formation along the Kapthurin River is thus approximately 0.5 Ma younger than the uppermost Chemeron Formation strata exposed at Tabarin, 23 km to the north-northwest. The upper half of the formation along the Kapthurin River was deposited at an average rate of approximately 11 cm/ka, compared to 21-23 cm/ka at Tabarin.

  8. Progressive evolution of a fault-related fold pair from growth strata geometries, Sant Llorenç de Morunys, SE Pyrenees

    NASA Astrophysics Data System (ADS)

    Ford, Mary; Williams, Edward A.; Artoni, Andrea; Vergés, Jaume; Hardy, Stuart

    1997-03-01

    New structural-stratigraphical mapping constrains the three-dimensional kinematics and mechanisms of Eocene-Oligocene growth folding at Sant Llorenç de Morunys (NE Ebro basin, Spain). A 1 km wide sub-vertical panel of syntectonic alluvial gravels passes southwards via a highly asymmetrical growth fold-pair to shallowlydipping strata. The axial surface of the anticline comprises either continuous or en échelon segments while that of the syncline is concave and usually continuous. While converging upwards, the axial surfaces do not define growth triangles. Principal and subsidiary growth unconformities and thickness changes occur across both axial surfaces and the common limb. Dips within the common limb decrease up-stratigraphy and up-dip. Mesostructures indicate that internal deformation was ongoing during folding at all stratigraphical levels, and concentration of cleavage in the syncline indicates that this hinge was essentially fixed. Sequential restoration of three profiles shows that folds amplified principally by limb rotation but incorporated minor passive hinge migration. Particle movement vectors, generated by section restoration, are arcuate about a hinterland pinpoint. A new trishear model of fault propagation folding involving non-rigid limb rotation reproduces the rounded hinge forms, thickening geometries and limb dip variations observed. Simple kink band migration models (fixed axis and constant thickness theories) do not replicate these features.

  9. Patterns beyond Faraday waves: observation of parametric crossover from Faraday instabilities to the formation of vortex lattices in open dual fluid strata

    NASA Astrophysics Data System (ADS)

    Ohlin, Kjell; Berggren, Karl Fredrik

    2016-07-01

    Faraday first characterised the behaviour of a fluid in a container subjected to vertical periodic oscillations. His study pertaining to hydrodynamic instability, the ‘Faraday instability’, has catalysed a myriad of experimental, theoretical, and numerical studies shedding light on the mechanisms responsible for the transition of a system at rest to a new state of well-ordered vibrational patterns at fixed frequencies. Here we study dual strata in a shallow vessel containing distilled water and high-viscosity lubrication oil on top of it. At elevated driving power, beyond the Faraday instability, the top stratum is found to ‘freeze’ into a rigid pattern with maxima and minima. At the same time there is a dynamic crossover into a new state in the form of a lattice of recirculating vortices in the lower layer containing the water. Instrumentation and the physics behind are analysed in a phenomenological way together with a basic heuristic modelling of the wave field. The study, which is based on relatively low-budget equipment, stems from related art projects that have evolved over the years. The study is of value within basic research as well as in education, especially as more advanced collective project work in e.g. engineering physics, where it invites further studies of pattern formation, the emergence of vortex lattices and complexity.

  10. (40)Ar/(39)Ar dating, paleomagnetism, and tephrochemistry of Pliocene strata of the hominid-bearing Woranso-Mille area, west-central Afar Rift, Ethiopia.

    PubMed

    Deino, Alan L; Scott, Gary R; Saylor, Beverly; Alene, Mulugeta; Angelini, Joshua D; Haile-Selassie, Yohannes

    2010-02-01

    (40)Ar/(39)Ar dating of tuffs and mafic lavas, tephra geochemistry, and paleomagnetic reversal stratigraphy have been used to establish the chronostratigraphy of the Pliocene hominid-bearing fossiliferous succession at Woranso-Mille, a paleontological study area in the western part of the central Afar region of Ethiopia. The succession in the northwestern part of the study area ranges in (40)Ar/(39)Ar age from 3.82-3.570 Ma, encompassed by paleomagnetic subchron C2Ar (4.187-3.596 Ma). One of the major tuff units, locally named the Kilaytoli tuff, is correlative on the basis of age and geochemistry to the Lokochot Tuff of the Turkana Basin. A hominid partial skeleton (KSD-VP-1) was found in strata whose precise stratigraphic position and age is still under investigation, but is believed to correspond to the later part of this interval. Woranso-Mille fills a significant gap in the fossil record of northeastern Africa at the time of the lower to middle Pliocene transition, when many extant species lineages of African fauna were established.

  11. Health Surveys Using Mobile Phones in Developing Countries: Automated Active Strata Monitoring and Other Statistical Considerations for Improving Precision and Reducing Biases

    PubMed Central

    Blynn, Emily; Ahmed, Saifuddin; Gibson, Dustin; Pariyo, George; Hyder, Adnan A

    2017-01-01

    In low- and middle-income countries (LMICs), historically, household surveys have been carried out by face-to-face interviews to collect survey data related to risk factors for noncommunicable diseases. The proliferation of mobile phone ownership and the access it provides in these countries offers a new opportunity to remotely conduct surveys with increased efficiency and reduced cost. However, the near-ubiquitous ownership of phones, high population mobility, and low cost require a re-examination of statistical recommendations for mobile phone surveys (MPS), especially when surveys are automated. As with landline surveys, random digit dialing remains the most appropriate approach to develop an ideal survey-sampling frame. Once the survey is complete, poststratification weights are generally applied to reduce estimate bias and to adjust for selectivity due to mobile ownership. Since weights increase design effects and reduce sampling efficiency, we introduce the concept of automated active strata monitoring to improve representativeness of the sample distribution to that of the source population. Although some statistical challenges remain, MPS represent a promising emerging means for population-level data collection in LMICs. PMID:28476726

  12. Detached strata in a Tertiary low-angle normal fault terrane, southeastern California: a sedimentary record of unroofing, breaching, and continued slip

    SciTech Connect

    Miller, J.M.G.; John, B.E.

    1988-07-01

    Miocene sedimentary strata exposed in the eastern Chemehuevi Mountains, southeastern California, record development of an evolving low-angle normal fault system. The sequence includes more than 1 km of conglomerate and sandstone with rare interbedded monolithologic breccia and volcanic flows. Clasts of Peach Springs Tuff in basal units indicate that this succession is younger than 18 Ma. These rocks have been displaced by a regionally extensive low-angle normal fault, the Chemehuevi detachment, and are folded and faulted. Structural reconstructions and the character of associated fault rocks indicate that the Chemeheuvi fault was initiated at a low angle and that the footwall was progressively unloaded through thinning and displacement of its cover during extensional deformation. The syntectonic sedimentary rocks described here provide evidence that movement continued on the gently dipping (< 15/sup 0/) fault even after part of the fault was breached and the footwall eroded. The Conglomerates and sandstones were deposited by stream flow and debris flow on alluvial fans. Synsedimentary faulting is suggested by angular discordance below one monolithologic breccia bed and by local coarsening-upward sequences. Clast types reveal progressive unroofing of hanging-wall rocks to exposer the Chemehuevi fault zone, from which chloritic, brecciated granite clasts were derived. Clasts were then derived from both the hanging wall and the footwall, footwall debris being dominant high in the section. Distinctive clasts show that late displacement on this evolving fault system was on the order of 1 to 5 km.

  13. Diagenesis associated with subaerial exposure of Miocene strata, southeastern Spain: Implications for sea-level change and preservation of low-temperature fluid inclusions in calcite cement

    USGS Publications Warehouse

    Goldstein, R.H.; Franseen, E.K.; Mills, M.S.

    1990-01-01

    Many ancient carbonate rocks contain calcite cements that precipitated from shallow, fresh groundwater that entered strata during events of subaerial exposure. Such low-temperature cementation may be difficult to interpret from fluid inclusion studies because some of the inclusions may reequilibrate during later thermal events. Miocene rocks of southeast Spain provide an example of the utility of fluid inclusion studies in rocks that have not been subjected to significant heating. In the Mesa Roldan area, one type of calcite cement occurs exclusively below a regional stratigraphic surface of enigmatic origin. The cement has petrographic characteristics indicative of cementation in the vadose zone (generally thought to be a zone of oxidation) but has cathodoluminescent bands containing reduced manganese and iron. Primary fluid inclusions contain mostly fresh water, have variable ratios of vapor to liquid, and are at one atmosphere of pressure. Our observations indicate that calcite precipitated from a freshwater vadose zone, which was subjected to local or repetitive saturation, and minor brackish water. The fluid inclusion data indicate that low-temperature fluid inclusions can be preserved in ancient sequences despite a later history of different pore fluids. This indication of subaerial diagenesis of distal slope deposits suggests a relative sea-level drop of at least 50-55 m during the Late Miocene. Similar petrographic and fluid inclusion observations can be used to interpret sea-level changes in other areas. ?? 1990.

  14. The application of well logging and seismic modeling to assess the degree of gas saturation in Miocene strata (Carpathian Foredeep, Poland)

    NASA Astrophysics Data System (ADS)

    Marzec, Paweł; Niepsuj, Magdalena; Bała, Maria; Pietsch, Kaja

    2014-02-01

    The presence of natural gas in the pore space of reservoir rocks results in a significant decrease in P-wave velocity. Even low gas saturation can generate seismic anomalies (DHI) and false image of gas accumulation of economic importance. This article presents an attempt to evaluate gas saturation from 2D seismic section in the Miocene sandstone strata in the south-eastern part of the Carpathian Foredeep. The ESTYMACJA program and the Biot-Gassmann model were used to study the dependence between elastic parameters and saturating fluids (water and gas) recorded in wells. Series of calculations was carried out using a method of fluid substitution for various gas saturation. The applicability of seismic data for evaluating gas saturation of reservoir beds was assessed with the use of 1D modelling (synthetic seismograms) and 2D modelling (theoretical seismic section) calculated for different gas saturation. The proposed methodology can be used to identify low and high gas-saturated zones and contour the reservoir.

  15. [Plant hormones, plant growth regulators].

    PubMed

    Végvári, György; Vidéki, Edina

    2014-06-29

    Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

  16. Detrital zircon U-Pb and (U-Th)/He double-dating of Upper Cretaceous-Cenozoic Zagros foreland basin strata in the Kurdistan Region of northern Iraq

    NASA Astrophysics Data System (ADS)

    Barber, D. E.; Stockli, D. F.; Koshnaw, R. I.; Horton, B. K.; Tamar-Agha, M. Y.; Kendall, J. J.

    2014-12-01

    The NW Zagros orogen is the result of the multistage collisional history associated with Late Cretaceous-Cenozoic convergence of the Arabian and Eurasian continents and final closure of Neotethys. Siliciclastic strata preserved within a ~400 km segment of the NW Zagros fold-thrust belt and foreland basin in the Iraqi Kurdistan Region (IKR) provide a widespread record of exhumation and sedimentation. As a means of assessing NW Zagros foreland basin evolution and chronostratigraphy, we present coupled detrital zircon (DZ) U-Pb and (U-Th)/He geo-thermochronometric data of Upper Cretaceous to Pliocene siliciclastic strata from the Duhok, Erbil, and Suleimaniyah provinces of IKR. LA-ICP-MS U-Pb age analyses reveal that the foreland basin fill in IKR in general was dominantly derived from Pan-African/Arabian-Nubian, Peri-Gondwandan, Eurasian, and Cretaceous volcanic arc terrenes. However, the provenance of these strata varies systematically along strike and through time, with an overall increase in complexity upsection. DZ age distribution of Paleocene-Eocene strata is dominated by a ~95 Ma grain age population, likely sourced from the Late Cretaceous Hassanbag-Bitlis volcanic arc complex along the northern margin of Arabia. In contrast, DZ U-Pb age distributions of Neogene strata show a major contribution derived from various Eurasian (e.g., Iranian, Tauride, Pontide; ~45, 150, 300 Ma) and Pan-African (~550, 950 Ma) sources. The introduction of Eurasian DZ ages at the Paleogene-Neogene transition likely records the onset of Arabian-Eurasian collision. Along strike to the southeast, the DZ U-Pb spectra of Neogene strata show a decreased percentage of Pan-African, Peri-Gondwandan, Tauride, and Ordovician ages, coupled with a dramatic increase in 40-50 Ma DZ ages that correspond to Urumieh-Dokhtar magmatic rocks in Iran. Combined with paleocurrent data, this suggests that Neogene sediments were transported longitudinally southeastward through an unbroken foreland basin

  17. Electronic plants

    PubMed Central

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  18. Patterns of Gondwana plant colonisation anddiversification

    NASA Astrophysics Data System (ADS)

    Anderson, J. M.; Anderson, H. M.; Archangelsky, S.; Bamford, M.; Chandra, S.; Dettmann, M.; Hill, R.; McLoughlin, S.; Rösler, O.

    Charting the broad patterns of vascular plant evolution for Gondwana againstthe major global environmental shifts and events is attempted here for the first time. This is based on the analysis of the major vascular plant-bearing formations of the southern continents (plus India) correlated against the standard geological time-scale. Australia, followed closely by South America, are shown to yield by far the most complete sequences of productive strata. Ten seminal turnover pulses in the unfolding evolutionary picture are identified and seen to be linked to continental drift, climate change and mass global extinctions. The rise of vascular plants along the tropical belt, for instance, followed closely after the end-Ordovician warming and extinction. Equally remarkable is that the Late Devonian extinction may have caused both the terrestrialisation of the vertebrates and the origin of the true gymnosperms. The end-Permian extinction, closure of Iapetus, together with warming, appears to have set in motion an unparalleled, explosive, gymnosperm radiation; whilst the Late Triassic extinction dramatically curtailed it. It is suggested that the latitudinal diversity gradient clearly recognised today, where species richness increases towards the tropics, may have been partly reversed during phases of Hot House climate. Evidence hints at this being particularly so at the heyday of the gymnosperms in the Late Triassic super-Hot House world. As for the origin of terrestrial, vascular, plant life, the angiosperms seem closely linked to a phase of marked shift from Ice House to Hot House. Insect and tetrapod evolutionary patterns are discussed in the context of the plants providing the base of the ever-changing ecosystems. Intimate co-evolution is often evident. This isn't always the case, for example the non-linkage between the dominant, giant, long-necked, herbivorous sauropod dinosaurs and the dramatic radiation of the flowering plants in the Mid Cretaceous.

  19. Plant Factory

    NASA Astrophysics Data System (ADS)

    Ikeda, Hideo

    Recently, much attention is paid on the plant factory, as it enable to grow plants stably under extraordinary climate condition such as high and/or low air temperature and less rain. Lots of questions such as decreasing investing cost, realizing stable plant production and developing new growing technique should be solved for making popular this growing system. However, I think that we can introduce a highly developed Japanese industrial now-how to plant factory system and can produce a business chance to the world market.

  20. Plant Minders

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Indoor plants are automatically watered by the Aqua Trends watering system. System draws water from building outlets or from pump/reservoir module and distributes it to the plants via a network of tubes and adjustable nozzles. Key element of system is electronic controller programmed to dispense water according to the needs of various plants in an installation. Adjustable nozzle meters out exactly right amount of water at proper time to the plant it's serving. More than 100 Aqua/Trends systems are in service in the USA, from a simple residential system to a large Mirage III system integrated to water all greenery in a large office or apartment building.

  1. CHARACTERIZING MARINE GAS-HYDRATE RESERVOIRS AND DETERMINING MECHANICAL PROPERTIES OF MARINE GAS-HYDRATE STRATA WITH 4-COMPONENT OCEAN-BOTTOM-CABLE SEISMIC DATA

    SciTech Connect

    B.A. Hardage; M.M. Backus; M.V. DeAngelo; R.J. Graebner; P. Murray; L.J. Wood assisted by K. Rogers

    2002-01-01

    The technical approach taken in this gas-hydrate research is unique because it is based on applying large-scale, 3-D, multi-component seismic surveys to improve the understanding of marine gas-hydrate systems. Other gas-hydrate research uses only single-component seismic technology. In those rare instances when multi-component seismic data have been acquired for gas-hydrate research, the data acquisition has involved only a few receiver stations and a few source stations, sometimes only three or four of each. In contrast, the four-component, 3-D, ocean-bottom-cable (4C3D OBC) data used in this study were acquired at thousands of receiver stations spaced 50 m apart over an area of approximately 1,000 km{sup 2} using wavefields generated at thousands of source stations spaced 75 m apart over this same survey area. The reason for focusing research attention on marine multi-component seismic data is that 4C3D OBC will provide a converted-SV image of gas-hydrate systems in addition to an improved P-wave image. Because P and SV reflectivities differ at some stratal surfaces, P and SV data provide two independent, and different, images of subsurface geology. The existence of these two independent seismic images and the availability of facies-sensitive SV seismic attributes, which can be combined with conventional facies-sensitive, P-wave seismic attributes, means that marine gas-hydrate systems should be better evaluated using multi-component seismic data than using conventional single-component seismic data. Conventional seismic attributes, such as instantaneous reflection amplitude and reflection coherency, have been extracted from the P and SV data volumes created from the 4C3D OBC data used in this research. Comparisons of these attributes and comparisons of P and SV time slices and vertical slices show that SV data provide a more reliable image of stratigraphy and structure associated with gas-invaded strata than do P-wave data. This finding confirms that multi

  2. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    SciTech Connect

    Erdlac, Richard J., Jr.

    2006-10-12

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities

  3. Facies analysis and sequence stratigraphic framework of upper Campanian strata (Neslen and Mount Garfield formations, Bluecastle Tongue of the Castlegate sandstone, and Mancos shale), Eastern Book cliffs, Colorado and Utah

    USGS Publications Warehouse

    Kirschbaum, Mark A.; Hettinger, Robert D.

    2004-01-01

    Facies and sequence-stratigraphic analysis identifies six high-resolution sequences within upper Campanian strata across about 120 miles of the Book Cliffs in western Colorado and eastern Utah. The six sequences are named after prominent sandstone units and include, in ascending order, upper Sego sequence, Neslen sequence, Corcoran sequence, Buck Canyon/lower Cozzette sequence, upper Cozzette sequence, and Cozzette/Rollins sequence. A seventh sequence, the Bluecastle sequence, is present in the extreme western part of the study area. Facies analysis documents deepening- and shallowing- upward successions, parasequence stacking patterns, downlap in subsurface cross sections, facies dislocations, basinward shifts in facies, and truncation of strata.All six sequences display major incision into shoreface deposits of the Sego Sandstone and sandstones of the Corcoran and Cozzette Members of the Mount Garfield Formation. The incised surfaces represent sequence-boundary unconformities that allowed bypass of sediment to lowstand shorelines that are either attached to the older highstand shorelines or are detached from the older highstand shorelines and located southeast of the main study area. The sequence boundary unconformities represent valley incisions that were cut during successive lowstands of relative sea level. The overlying valley-fill deposits generally consist of tidally influenced strata deposited during an overall base level rise. Transgressive surfaces can be traced or projected over, or locally into, estuarine deposits above and landward of their associated shoreface deposits. Maximum flooding surfaces can be traced or projected landward from offshore strata into, or above, coastal-plain deposits. With the exception of the Cozzette/Rollins sequence, the majority of coal-bearing coastal-plain strata was deposited before maximum flooding and is therefore within the transgressive systems tracts. Maximum flooding was followed by strong progradation of

  4. Provenance of bentonite layers in the Palaeocene strata of the Central Basin, Svalbard: implications for magmatism and rifting events around the onset of the North Atlantic Igneous Province

    NASA Astrophysics Data System (ADS)

    Jones, Morgan T.; Eliassen, Gauti T.; Shephard, Grace E.; Svensen, Henrik H.; Jochmann, Malte; Friis, Bjarki; Augland, Lars E.; Jerram, Dougal A.; Planke, Sverre

    2016-11-01

    A fold-and-thrust belt developed between Greenland and Svalbard during the Palaeogene, with an associated foreland basin forming in what is now Spitsbergen. This Central Basin is comprised of the Van Mijenfjorden Group, a 2.3 km thick sandstone-shale dominated succession that contains prominent and laterally continuous bentonite layers in the lower formations. These altered tephra layers can be used as stratigraphic markers that connect the basin development with regional explosive volcanism and changes to relative plate motions. We sampled and analysed bentonites from nine borehole cores across the Central Basin. Each layer shows evidence of alteration, with mobile elements such as alkali and alkali earth metals particularly disrupted. However, immobile elements including rare earth elements (REE) and preserved igneous minerals retain a magmatic signature, allowing for comparisons with potential volcanic sources to be made. The majority of bentonites are both evolved and strongly alkaline, with chemical signatures that are much closer to the continental rift events around Ellesmere Island and North Greenland than to the early activity of the North Atlantic Igneous Province (NAIP). There is a clear difference between tephra layers in the mid Palaeocene versus late Palaeocene strata. The early bentonites have a REE signature comparable to the volcanics of the Kap Washington Group exposed in North Greenland. The later bentonites have likely come from volcanic centres in the Nares Strait that are also the source of abundant volcaniclastic sediments in the Judge Daly Promontory, Ellesmere Island. These findings suggest that a mid to late Palaeocene change in locus of volcanic provenance may reflect changes in relative plate motions related to the formation of the West Spitsbergen fold-and-thrust belt and the emplacement of the NAIP. However, the lack of bentonites matching NAIP sources suggests that explosive volcanism was of insufficient magnitude to lead to

  5. Detrital mica K/Ar ages for Devonian-Pennsylvanian strata of the north central Appalachian Basin: Dominance of the Acadian Orogen as provenance

    SciTech Connect

    Aronson, J.L. . Dept. of Geological Sciences); Lewis, T.L. . Dept. of Geological Sciences)

    1992-01-01

    Detrital micas were separated from: the Upper Devonian Walton Sandstone and Ohio Shale; Lower Mississippian Berea Sandstone; Upper Mississippian Mauch Chunk Formation; and the Lower-Middle Pennsylvanian Pottsville and Allegheny Sandstones. A total of 12 separates were conventionally dated, the only biotite being from the Allegheny Formation sandstone, from which a muscovite was also dated. The total range in dates for the study was encompassed by the Allegheny sample of 414 m.y. (muscovite) to 361 m.y. (biotite), each date having an uncertainty of about [+-] 9 m.y. Excluding this sample, a narrower range of Early to Middle Devonian dates from 406--371 m.y. is obtained. For the Walton Sandstone of the proximal Catskill Wedge and for the northeast OH samples of the distal Catskill Wedge, all deposited within Late Devonian-Early Mississippian time, a very narrow span of 20 m.y. is obtained entirely within Early Devonian time and only approximately 30 m.y. older than deposition. All of these provenance ages have been previously found as primary ages of crystallization or cooling therefrom of regional metamorphism and plutonism in the Acadian Orogen of New England. The mean provenance ages are so close to the age of deposition of the distal Devonian/mississippian Catskill strata as to preclude almost any Precambrian contribution from either the Canadian Shield or the uplifted cores of the Orogen. These results support the paleocurrent and paleoenvironmental analysis of the northeast OH section by Lewis (1988) and argue against the classic Bedford Delta interpretation sourced from the north. Furthermore, the Acadian Orogen persisted as the major provenance for the clastic pulses that prograded into the central Appalachian Basin after the post-Catskill transgression, at least up until Middle Pennsylvanian time.

  6. Evidence for multi-cycle sedimentation and provenance constraints from detrital zircon U-Pb ages: Triassic strata of the Lusitanian basin (western Iberia)

    NASA Astrophysics Data System (ADS)

    Pereira, M. F.; Gama, C.; Chichorro, M.; Silva, J. B.; Gutiérrez-Alonso, G.; Hofmann, M.; Linnemann, U.; Gärtner, A.

    2016-06-01

    Laser ablation ICP-MS U-Pb analyses were conducted on detrital zircons of Triassic sandstone and conglomerate from the Lusitanian basin in order to: i) document the age spectra of detrital zircon; ii) compare U-Pb detrital zircon ages with previous published data obtained from Upper Carboniferous, Ordovician, Cambrian and Ediacaran sedimentary rocks of the pre-Mesozoic basement of western Iberia; iii) discuss potential sources; and iv) test the hypothesis of sedimentary recycling. U-Pb dating of zircons established a maximum depositional age for this deposit as Permian (ca. 296 Ma), which is about sixty million years older compared to the fossil content recognized in previous studies (Upper Triassic). The distribution of detrital zircon ages obtained points to common source areas: the Ossa-Morena and Central Iberian zones that outcrop in and close to the Porto-Tomar fault zone. The high degree of immaturity and evidence of little transport of the Triassic sediment suggests that granite may constitute primary crystalline sources. The Carboniferous age of ca. 330 Ma for the best estimate of crystallization for a granite pebble in a Triassic conglomerate and the Permian-Carboniferous ages (< ca. 315 Ma) found in detrital zircons provide evidence of the denudation of Variscan and Cimmerian granites during the infilling of continental rift basins in western Iberia. The zircon age spectra found in Triassic strata are also the result of recycling from the Upper Carboniferous Buçaco basin, which probably acted as an intermediate sediment repository. U-Pb data in this study suggest that the detritus from the Triassic sandstone and conglomerate of the Lusitanian basin is derived from local source areas with features typical of Gondwana, with no sediment from external sources from Laurussia or southwestern Iberia.

  7. Diffusion of Photochemically Produced Hydrogen Peroxide in the Martian Regolith and Estimates of the Depth of Oxidized Strata on the Surface of Mars

    NASA Astrophysics Data System (ADS)

    Quinn, R. C.; Zent, A. P.

    1997-07-01

    The initial biological examination of Mars by Viking failed to detect life; instead the Viking experiments revealed that the Martian soil appeared to contain chemical oxidants (e.g., Klein, 1979). Any reducing materials that are relict of pre-biotic chemical evolution are susceptible to chemical attack by such oxidants, and their recovery is contingent upon penetrating oxidized strata. Zent and McKay (1993) concluded that the most consistent explanation for the Viking results calls on photochemically produced oxidants (odd-hydrogen and odd-oxygen species), which originate in the atmosphere and diffuse into the regolith. One study of the diffusion of hydrogen peroxide into the regolith (Bullock, et al., 1993) has suggested that the depth of the oxidized layer may be no more than several meters, although that modeling study was limited by the lack of data on the lifetime of hydrogen peroxide against reaction in the regolith, and it's adsorptive behavior. We report on the experimental determination of diffusion rates of hydrogen peroxide vapor through Mars soil analogs. Peroxide penetration rates, depths, and adsorptive coverage are examined as a function of regolith surface area and temperature. Further constraints on the depth of oxidation based on mixing by impact cratering will be reported (Zent and Quinn, 1997). References: Bullock, M., C. R. Stoker, C. P. McKay, A. P. Zent, (1993). Icarus, 107, 142-154. Klein, H. P., (1979). Rev. Geophys. and Space Phys., 17, 1655-1662. Zent, A. P., C. P. McKay, (1994). Icarus, 108. 146-157. Zent, A. P., R. C. Quinn, (1997). Planet. Space Sci., submitted.

  8. Palynological correlation of Atokan and lower desmoinesian (Pennsylvanian) strata between the Illinois basin and the Forest City basin in Eastern Kansas

    USGS Publications Warehouse

    Peppers, R.A.; Brady, L.L.

    2007-01-01

    Palynological correlation is made between Atokan and lower Desmoinesian strata in the Illinois basin an the Forest City basin in eastern Kansas. Spore data from previous studies of coals in the Illinois basin and other coal basins are compared with data from spore assemblages in coal and carbonaceous shale bands in a core drilled in Leavenworth County, Kansas. Correlations are based on first and/or last occurrences of 31 species common to the Illinois basin and eastern Kansas and on significant increases or decreases in abundance of several of those taxa. The oldest coal, which is 26 ft (8 m) above the top of the Mississippian, is early Atokan (early Westphalian B) in age and is approximately equivalent to the Bell coal bed in the Illinois basin. The Riverton coal bed at the top of the studied interval in Kansas is early Desmoinesian (early Westphalian D) and correlates with about the Lewisport coal bed in the Illinois basin. Three coal beds near the base of the Pennsylvanian in three cores drilled in Cherokee County, Kansas, which were also studied, range in age from late Atokan to early Desmoinesian. As in other coal basins, Lycospora, borne by lycopod trees, greatly dominates the lower and middle Atokan spore assemblages in coals and shale, but spores from ferns, especially tree ferns, significantly increase in abundance in the upper Atokan and lower Desmoinesian. The pattern of change of dominance among Lycosporapellucida, L. granulata, and L, micropapillata in middle Atokan (Westphalian B-C transition) that has been demonstrated earlier in the Illinois basin and eastern Kentucky and Tennessee, also occurs in eastern Kansas. At least 10 species of spores, which appeared in the middle Atokan in other parts of the equatorial coal belt, also appeared at this time in eastern Kansas. Most of these species have their affinities with the ferns, which were adapted to drier habitats than lycopods. Thus, the climate may have become a little drier in the equatorial coal

  9. Information and communication technology demands at work: the association with job strain, effort-reward imbalance and self-rated health in different socio-economic strata.

    PubMed

    Stadin, Magdalena; Nordin, Maria; Broström, Anders; Magnusson Hanson, Linda L; Westerlund, Hugo; Fransson, Eleonor I

    2016-10-01

    The use of information and communication technology (ICT) is common in modern working life. ICT demands may give rise to experience of work-related stress. Knowledge about ICT demands in relation to other types of work-related stress and to self-rated health is limited. Consequently, the aim of this study was to examine the association between ICT demands and two types of work-related stress [job strain and effort-reward imbalance (ERI)] and to evaluate the association between these work-related stress measures and self-rated health, in general and in different SES strata. This study is based on cross-sectional data from the Swedish Longitudinal Occupational Survey of Health collected in 2014, from 14,873 gainfully employed people. ICT demands, job strain, ERI and self-rated health were analysed as the main measures. Sex, age, SES, lifestyle factors and BMI were used as covariates. ICT demands correlated significantly with the dimensions of the job strain and ERI models, especially with the demands (r = 0.42; p < 0.01) and effort (r = 0.51; p < 0.01) dimensions. ICT demands were associated with suboptimal self-rated health, also after adjustment for age, sex, SES, lifestyle and BMI (OR 1.49 [95 % CI 1.36-1.63]), but job strain (OR 1.93 [95 % CI 1.74-2.14) and ERI (OR 2.15 [95 % CI 1.95-2.35]) showed somewhat stronger associations with suboptimal self-rated health. ICT demands are common among people with intermediate and high SES and associated with job strain, ERI and suboptimal self-rated health. ICT demands should thus be acknowledged as a potential stressor of work-related stress in modern working life.

  10. A portrait of single and multiple HPV type infections in Brazilian women of different age strata with squamous or glandular cervical lesions

    PubMed Central

    2014-01-01

    Background Cervical cancer ranks third in prevalence and fourth as cause of death in women worldwide. In Brazil, 17,540 women were diagnosed in 2012 with the disease. Persistent infection with high-risk HPV types is a necessary condition for the development of pre-invasive and invasive cervical neoplasia. Currently, over 100 HPV types have been identified, but HPV16 and 18 are recognized as the mayor culprits in cervical carcinogenesis. Our objective was to assess the relationships between single- (ST) and multiple-type (MT) HPV infections with patients’ age and lesion pathological status. Methods 328 patients with either squamous or glandular intraepithelial or invasive cervical lesion were selected. All subjects were tested for HPV genotypes with reverse hybridization for 21 high- (hr-HPV) and 16 low-risk (lr-HPV) probes. Prevalence of ST and MT HPV infections was compared across histological types and age strata. Results 287 (87%) women had at least one HPV type detected and 149 (52%) had MT infections. The most prevalent HPV type was HPV16, present in 142 cases (49% of all HPV-positive cases), followed by HPV58, 52, 31, 35 and 33. HPV18, in single or multiple infections, occurred in 23 cases (8% of hr-HPV cases). Almost all glandular lesions were associated with HPV16 and 18 alone. Multiple infections were significantly more prevalent in squamous than in glandular lesion for HPV16 and 18 (P = 0.04 and 0.03 respectively). The prevalence of MT infections followed a bimodal distribution; peaking in women younger 29 years and in those aged 50 to 59. Conclusions Our data indicate that prevention strategies for pre-invasive and invasive squamous lesions should be focused on HPV16 and a few alpha-9 HPV types. It is clear to us that in young women, prophylaxis must cover a large amalgam of HPV types beyond classic HPV16 and 18. PMID:24751127

  11. A portrait of single and multiple HPV type infections in Brazilian women of different age strata with squamous or glandular cervical lesions.

    PubMed

    Resende, Leandro Santos de Araújo; Rabelo-Santos, Sílvia Helena; Sarian, Luís Otávio; Figueiredo Alves, Rosane Ribeiro; Ribeiro, Andréa Alves; Zeferino, Luiz Carlos; Derchain, Sophie

    2014-04-22

    Cervical cancer ranks third in prevalence and fourth as cause of death in women worldwide. In Brazil, 17,540 women were diagnosed in 2012 with the disease. Persistent infection with high-risk HPV types is a necessary condition for the development of pre-invasive and invasive cervical neoplasia. Currently, over 100 HPV types have been identified, but HPV16 and 18 are recognized as the mayor culprits in cervical carcinogenesis. Our objective was to assess the relationships between single- (ST) and multiple-type (MT) HPV infections with patients' age and lesion pathological status. 328 patients with either squamous or glandular intraepithelial or invasive cervical lesion were selected. All subjects were tested for HPV genotypes with reverse hybridization for 21 high- (hr-HPV) and 16 low-risk (lr-HPV) probes. Prevalence of ST and MT HPV infections was compared across histological types and age strata. 287 (87%) women had at least one HPV type detected and 149 (52%) had MT infections. The most prevalent HPV type was HPV16, present in 142 cases (49% of all HPV-positive cases), followed by HPV58, 52, 31, 35 and 33. HPV18, in single or multiple infections, occurred in 23 cases (8% of hr-HPV cases). Almost all glandular lesions were associated with HPV16 and 18 alone. Multiple infections were significantly more prevalent in squamous than in glandular lesion for HPV16 and 18 (P = 0.04 and 0.03 respectively). The prevalence of MT infections followed a bimodal distribution; peaking in women younger 29 years and in those aged 50 to 59. Our data indicate that prevention strategies for pre-invasive and invasive squamous lesions should be focused on HPV16 and a few alpha-9 HPV types. It is clear to us that in young women, prophylaxis must cover a large amalgam of HPV types beyond classic HPV16 and 18.

  12. Deciphering shallow paleomagnetic inclinations: 2. Implications from Late Cretaceous strata overlapping the Insular/Intermontane Superterrane boundary in the southern Canadian Cordillera

    NASA Astrophysics Data System (ADS)

    Enkin, R. J.; Mahoney, J. B.; Baker, J.; Riesterer, J.; Haskin, M. L.

    2003-04-01

    Significant discrepancies exist between paleomagnetic and geologic estimates of the timing and magnitude of terrane displacement in the southern Canadian Cordillera. Lithostratigraphic, palynological, geochronologic, geochemical, and structural data, to which we add paleomagnetic data, demonstrate that Upper Cretaceous strata in Churn Creek are laterally equivalent facies of the Silverquick/Powell Creek (SPC) succession. These rocks therefore comprise a single overlap sequence linking the Insular and Intermontane Superterranes by Late Albian-Cenomanian time (˜95 Ma), contradicting previous assertions based solely on paleomagnetic interpretation that major (˜2000 km) latitudinal displacement separated the two regions. The Churn Creek succession retains primary magnetic remanence, as demonstrated by positive fold, conglomerate and contact tests. The sediments do not hold the anisotropy signature of compaction-shallowed inclinations. The mean inclination of all SPC sites, from both Mount Tatlow and Churn Creek, is 55.6° ± 2.3° (N = 36 sites), corresponding to a paleolatitude of 36.1° ± 2.4°. This reflects northward translation of the composite Insular/Intermontane Superterrane of 3050 ± 450 km between 85 and 50 Ma. The Silverquick/Powell Creek succession at Churn Creek unconformably overlies the northern end of the Spences Bridge Group, a late Early Cretaceous volcanic arc assemblage on the Intermontane Superterrane. Paleomagnetic data in the companion paper place it 1050 ± 450 km south of its current position between 100 and 105 Ma. Integration of these new data sets require that the Insular and Intermontane Superterranes formed a single, enormous crustal block that underwent complex, episodic south-north translation between circa 105 and 50 Ma. The timing, rate, and vectors of translation are problematic in terms of geologic constraints along the continental margin.

  13. Differences between forest type and vertical strata in the diversity and composition of hymenopteran families and mymarid genera in northeastern temperate forests.

    PubMed

    Vance, C C; Smith, S M; Malcolm, J R; Huber, J; Bellocq, M I

    2007-10-01

    Most insects' assemblages differ with forest type and show vertical stratification. We tested for differences in richness, abundance and composition of hymenopteran families and mymarid genera between sugar maple (Acer saccharum) and white pine (Pinus strobus) stands and between canopy and understory in northeastern temperate forests in Canada. We used flight interception traps (modified malaise traps) suspended in the canopy and the understory in a split-split block design, with forest type as the main factor, forest stratum as the first split factor, and collection bottle location as the second split factor. Hymenopteran families and mymarid genera differed in their diversity depending on forest type and stratum. Both family and genera richness were higher in maple than in pine forests, whereas family richness was higher in the canopy and top bottles and generic richness was higher in the understory and bottom bottles. Multivariate analysis separated samples by forest type, vegetation stratum, and bottle location. Family composition showed 77% similarity between forest types and 73% between the canopy and understory. At the lower taxa level, mymarid genera showed only 47% similarity between forest types and 40% between forest strata, indicating vertical stratification and relatively high beta-diversity. Our study suggests that hymenopteran diversity and composition is strongly dependent on forest type and structure, making flying members of this order particularly vulnerable to forest management practices. It also shows that insect assemblage composition (especially at low-taxon levels), rather than relative abundance and richness, is the community attribute most sensitive to forest type and vertical stratification.

  14. The impact of evolving current rheology on multi-scale heterogeneity in submarine lobe strata: an example from the Upper Cretaceous Point Loma Formation, San Diego, California

    NASA Astrophysics Data System (ADS)

    McGlown, A.; Mohrig, D. C.; Perillo, M. M.

    2014-12-01

    Increasing recognition of transitional flow deposits in submarine fans has shown that the evolution of flow rheology in sediment-gravity currents can have a significant impact on the heterogeneity of deepwater sediment accumulations. Sea-cliff exposure of the Cretaceous Point Loma Formation in San Diego, California, provides a unique opportunity to document the internal variability and spatial distribution of thin, fine-grained event beds. Upper portions of beds which commonly appear as featureless mud in exposures of typical quality are revealed as thin, clast-rich debrites in areas where sea cliffs are polished by waves. The ubiquity of these deposits in distal lobe strata suggests complex rheological evolution for nearly all currents that were able to run out to lobe margins. Here we supplement qualitative outcrop characterization with statistical analysis to quantify relationships between deposit thickness, grain size, and the spatial distribution of sedimentary facies. Intervals dominated by transitional flow deposits are shown to occur vertically near the base of coarsening-upward successions and laterally toward lobe margins, reflecting a combination of dynamic processes during individual events and the spatial distribution of consecutive deposits. We show that the ability to distinguish patterns of bed-scale variability reflecting flow evolution from patterns associated with larger-scale processes, such as distributary channel avulsion and compensational stacking, is critical if one is to accurately model heterogeneity within submarine fan systems. Furthermore, the observation that thin, fine-grained debrites can be nearly impossible to distinguish from featureless mud intervals unless exceptionally well-exposed may cast doubt on existing interpretations where outcrop quality is less than remarkable.

  15. Provenance and paleogeography of the Mesozoic strata in the Muang Xai Basin, northern Laos: petrology, whole-rock geochemistry, and U-Pb geochronology constraints

    NASA Astrophysics Data System (ADS)

    Wang, Yanlu; Wang, Licheng; Wei, Yushuai; Shen, Lijian; Chen, Ke; Yu, Xiaocan; Liu, Chenglin

    2017-06-01

    The Muang Xai Basin, located in northern Laos, is associated with the Simao, Vientiane, and Khorat Basins. The paleogeographic link of these basins has not been investigated in great detail; thus, the investigation presented in this study is a comprehensive analysis of petrology, whole-rock geochemistry, and detrital zircon U-Pb chronology used to characterize the provenance of the Muang Xai Basin. Results suggest that the sedimentary source includes felsic rocks from an active continental margin or continental arc with minor amounts of recycled passive continental margin sediments. Sandstones of the Muang Xai Basin contain detrital zircons with varying U-Pb peak ages. The youngest age peak of all the zircons is 103 Ma, which limits the age of the Mesozoic strata to the Late Cretaceous. Detrital zircon U-Pb and trace element data, combined with geochemical result, reveal that the pre-Ordovician zircons were derived from recycled sediments of the Yangtze Block, which are originally sourced from the Qinling Orogenic belt. This provenance is shared with coeval sediments in the Simao and Khorat Basins, while magmatic rocks of the Ailaoshan, Truong Son Belt, and Lincang terrane are responsible for zircons of 416-466 and 219-308 Ma in age. Zircons of 101-110 and 149-175 Ma in age were sourced from magmatic rocks of the southwestern South China Block and northern Vietnam. These provenance results suggest that sediments flow into the Khorat red beds was likely from the Great Simao Basin and northern Vietnam, and not directly from the Yangtze Block.

  16. A Major Unconformity Between Permian and Triassic Strata at Cape Kekurnoi, Alaska Peninsula: Old and New Observations on Stratigraphy and Hydrocarbon Potential

    USGS Publications Warehouse

    Blodgett, Robert B.; Sralla, Bryan

    2008-01-01

    A major angular unconformity separates carbonates and shales of the Upper Triassic Kamishak Formation from an underlying unnamed sequence of Permian agglomerate, volcaniclastic rocks (sandstone), and limestone near Puale Bay on the Alaska Peninsula. For the first time, we photographically document the angular unconformity in outcrop, as clearly exposed in a seacliff ~1.3 mi (2.1 km) west of Cape Kekurnoi in the Karluk C?4 and C?5 1:63,360-scale quadrangles. This unconformity is also documented by examination of core chips, ditch cuttings, and (or) open-hole electrical logs in two deep oil-and-gas-exploration wells (Humble Oil & Refining Co.?s Bear Creek No. 1 and Standard Oil Co. of California?s Grammer No. 1) drilled along the Alaska Peninsula southwest of Puale Bay. A third well (Richfield Oil Corp.?s Wide Bay Unit No. 1), south of and structurally on trend with the other two wells, probed deeply into the Paleozoic basement, but Triassic strata are absent, owing to either a major unconformity or a large fault. Here we briefly review current and newly acquired data on Permian and Triassic rocks of the Puale Bay-Becharof Lake-Wide Bay area on the basis of an examination of surface and subsurface materials. The resulting reinterpretation of the Permian and Triassic stratigraphy has important economic ramifications for oil and gas exploration on the Alaska Peninsula and in the Cook Inlet basin. We also present a history of petroleum exploration targeting Upper Triassic reservoirs in the region.

  17. Root profile in Multi-layered Dehesas: an approach to plant-to-plant Interaction

    NASA Astrophysics Data System (ADS)

    Rolo, V.; Moreno, G.

    2009-04-01

    Assessing plant-to-plant relationship is a key issue in agroforestry systems. Due to the sessile feature of plants most of these interactions take place within a restricted space, so characterizing the zone where the plant alters its environment is important to find overlapping areas where the facilitation or competition could occur. Main part of plan-to-plant interactions in the dehesa are located at belowground level, thus the main limited resources in Mediterranean ecosystems are soil nutrient and water. Hence a better knowledge of rooting plant profile can be useful to understand the functioning of the dehesa. The Iberian dehesa has always been considered as a silvopastoral system where, at least, two strata of vegetation coexist: native grasses and trees. However the dehesa is also a diverse system where cropland and encroached territories have been systematically combined, more or less periodically, with native pasture in order to obtain agricultural, pastoral and forestry outputs. These multipurpose mosaic-type systems generate several scenarios where the plant influence zone may be overlapped and the interaction, competition or facilitation, between plants can play an important role in the ecosystem functioning in terms of productivity and stability. In the present study our aim was to characterize the rooting profile of multi-layered dehesas in order to understand the competitive, and/or facilitative, relationships within the different plant strata. The root profile of Quercus ilex subsp. ballota, Cistus ladanifer, Retama spaherocarpa and natural grasses was studied. So 48 trenches, up to 2 meters deep, were excavated in 4 different environments: (i) grass; (ii) tree-grass; (iii) tree-shrub and (iv) tree-shrub-grass (12 trenches in each environment). The study was carried out in 4 dehesas, 2 encroached with C. ladanifer and 2 with R. spaherocarpa. In every trench soil samples were taken each 20 cm. Subsequently, all samples were sieved using different mesh

  18. Plant Behavior

    ERIC Educational Resources Information Center

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  19. Plant Immunity

    USDA-ARS?s Scientific Manuscript database

    Plants are faced with defending themselves against a multitude of pathogens, including bacteria, fungi, viruses, nematodes, etc. Immunity is multi-layered and complex. Plants can induce defenses when they recognize small peptides, proteins or double-stranded RNA associated with pathogens. Recognitio...

  20. Plant Identification.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 12 Audubon Nature Bulletins, providing teachers and students with informational reading on plants. The bulletins include these titles: The Parade of Spring Wild Flowers, Wild Flowers of Our Prairies, Seeds and How They Travel, Poison Ivy and Other Poisonous Plants, The Forest Community, Common Trees and Their…

  1. Plant Behavior

    ERIC Educational Resources Information Center

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  2. Carnivorous Plants.

    ERIC Educational Resources Information Center

    Canipe, Stephen

    This biology lesson on carnivorous (insectivorous) plants is designed to supplement the textbook in the areas of plant diversity, ecology, and distribution. An introduction provides general background information for use as lecture material by the teacher or as reading and/or study material for students. The introduction also includes…

  3. Carnivorous Plants.

    ERIC Educational Resources Information Center

    Canipe, Stephen

    This biology lesson on carnivorous (insectivorous) plants is designed to supplement the textbook in the areas of plant diversity, ecology, and distribution. An introduction provides general background information for use as lecture material by the teacher or as reading and/or study material for students. The introduction also includes…

  4. Plant Identification.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 12 Audubon Nature Bulletins, providing teachers and students with informational reading on plants. The bulletins include these titles: The Parade of Spring Wild Flowers, Wild Flowers of Our Prairies, Seeds and How They Travel, Poison Ivy and Other Poisonous Plants, The Forest Community, Common Trees and Their…

  5. First evaluation steps of a new method for dietary intake estimation regarding a list of key food groups in adults and in different sociodemographic and health-related behaviour strata.

    PubMed

    Béjar, Luis M

    2017-10-01

    A new method known as 'current-day dietary recall' (current-day recall) is based on an application for mobile phones called 'electronic 12 h dietary recall' (e-12HR). This new method was designed to rank participants into categories of habitual intake regarding a series of key food groups. The present study compared current-day recall against a previously validated short paper FFQ. Participants recorded the consumption of selected food groups using e-12HR during twenty-eight consecutive days and then filled out a short paper FFQ at the end of the study period. To evaluate the association and agreement between both methods, Spearman's correlation coefficients (SCC), cross-classification analysis and weighted kappa statistics (κ w) were used. Andalusia, Spain, Southern Europe. University students and employees over the age of 18 years. One hundred and eighty-seven participants completed the study (64·2 % female, 35·8 % male). For all particpants, for all food group intakes, the mean SCC was 0·70 (SCC≥0·62 were observed for all strata); the mean percentage of participants cross-classified into categories of 'exact agreement+adjacent' was 90·1 % (percentages≥87·8 % were observed for all strata); and the mean κ w was 0·55 (κ w≥0·53 in ten of the twelve strata). For the whole sample and for all strata thereof, the current-day recall has good agreement with the previously validated short paper FFQ for assessing food group intakes, rendering it a useful method for ranking individuals.

  6. Detrital zircon record of Paleozoic and Mesozoic meta-sedimentary strata in the eastern part of the Baoshan block: Implications of their provenance and the tectonic evolution of the southeastern margin of the Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Li, Dapeng; Chen, Yuelong; Hou, Kejun; Lu, Zhen; Cui, Di

    2015-06-01

    The Baoshan block is one of the important members in the southeastern margin of the Tibetan Plateau. Cambrian to Jurassic (meta-) sedimentary strata and their metamorphic counterparts were well preserved in the eastern part of the Baoshan block. Zircon U-Pb dating, trace elements, and Hf isotope data for both the Cambrian to Jurassic (meta-) sedimentary sequences and the Lincang granite were used to deduce the provenance of sediments and crustal affinity with eastern Gondwanaland. The Lincang granite outcropped in the Fengqing area is typical S-type, with crystallization age of ~ 230 Ma and narrow range of zircon εHf(t) values from - 15.5 to - 10. Detrital zircons from Paleozoic strata range in age from Archean to early Paleozoic, with age peaks at ~ 2.5, ~ 0.95, and ~ 0.6 Ga. Triassic age peak (~ 230 Ma) was also detected in the Jurassic strata. Detrital zircon εHf(t) values exhibit a wide range from negative to positive for each of the four major age groups, showing the host magma of zircons from these groups have diverse sources. The Baoshan block should be along the Indian margin as the Qiangtang, Tengchong and Simao-Indochina blocks in Early Paleozoic based on the provenance analyses. Sediment inputs eroded from both the Lincang granite and the coeval igneous rocks in the Baoshan and Gongshan blocks were the dominant contributions to the Jurassic strata after the amalgation of the Baoshan and Simao-Indochina blocks. Tectonic processes linking dispersion of the Baoshan-Sibumasu terrane from the Gondwana supercontinent to the collision with the Simao-Indochina block and the deposition of the Cambrian to Jurassic sedimentary sequences were reconstructed.

  7. Plant minichromosomes.

    PubMed

    Birchler, James A; Graham, Nathaniel D; Swyers, Nathan C; Cody, Jon P; McCaw, Morgan E

    2016-02-01

    Plant minichromosomes have the potential for stacking multiple traits on a separate entity from the remainder of the genome. Transgenes carried on an independent chromosome would facilitate conferring many new properties to plants and using minichromosomes as genetic tools. The favored method for producing plant minichromosomes is telomere-mediated chromosomal truncation because the epigenetic nature of centromere function prevents using centromere sequences to confer the ability to organize a kinetochore when reintroduced into plant cells. Because haploid induction procedures are not always complete in eliminating one parental genome, chromosomes from the inducer lines are often present in plants that are otherwise haploid. This fact suggests that minichromosomes could be combined with doubled haploid breeding to transfer stacked traits more easily to multiple lines and to use minichromosomes for massive scale genome editing.

  8. Plant secretomics

    PubMed Central

    Tanveer, Tehreem; Shaheen, Kanwal; Parveen, Sajida; Kazi, Alvina Gul; Ahmad, Parvaiz

    2014-01-01

    Plant secretomes are the proteins secreted by the plant cells and are involved in the maintenance of cell wall structure, relationship between host and pathogen, communication between different cells in the plant, etc. Amalgamation of methodologies like bioinformatics, biochemical, and proteomics are used to separate, classify, and outline secretomes by means of harmonizing in planta systems and in vitro suspension cultured cell system (SSCs). We summed up and explained the meaning of secretome, methods used for the identification and isolation of secreted proteins from extracellular space and methods for the assessment of purity of secretome proteins in this review. Two D PAGE method and HPLC based methods for the analysis together with different bioinformatics tools used for the prediction of secretome proteins are also discussed. Biological significance of secretome proteins under different environmental stresses, i.e., salt stress, drought stress, oxidative stress, etc., defense responses and plant interactions with environment are also explained in detail. PMID:25763623

  9. The subduction-accretion history of the Bangong-Nujiang Ocean: Constraints from provenance and geochronology of the Mesozoic strata near Gaize, central Tibet

    NASA Astrophysics Data System (ADS)

    Li, Shun; Ding, Lin; Guilmette, Carl; Fu, Jiajun; Xu, Qiang; Yue, Yahui; Henrique-Pinto, Renato

    2017-04-01

    The Mesozoic strata, within the Bangong-Nujiang suture zone in central Tibet, recorded critical information about the subduction-accretion processes of the Bangong-Nujiang Ocean prior to the Lhasa-Qiangtang collision. This paper reports detailed field observations, petrographic descriptions, sandstone detrital zircon U-Pb ages and Hf isotopic analyses from an accretionary complex (preserved as Mugagangri Group) and the unconformably overlying Shamuluo Formation near Gaize. The youngest detrital zircon ages, together with other age constraints from literature, suggest that the Mugagangri Group was deposited during late Triassic-early Jurassic, while the Shamuluo Formation was deposited during late Jurassic-early Cretaceous. Based on the differences in lithology, age and provenance, the Mugagangri Group is subdivided into the upper, middle and lower subunits. These units are younging structurally downward/southward, consistent with models of progressive off-scrapping and accretion in a southward-facing subduction complex. The upper subunit, comprising mainly quartz-sandstone and siliceous mud/shale, was deposited in abyssal plain environment close to the Qiangtang passive margin during late Triassic, with sediments derived from the southern Qiangtang block. The middle and lower subunits comprise mainly lithic-quartz-sandstone and mud/shale, containing abundant ultramafic/ophiolitic fragments. The middle subunit, of late Triassic-early Jurassic age, records a transition in tectono-depositional setting from abyssal plain to trench-wedge basin, with sudden influx of sediments sourced from the central Qiangtang metamorphic belt and northern Qiangtang magmatic belt. The appearance of ultramafic/ophiolitic fragments in the middle subunit reflects the subduction initiation. The lower subunit was deposited in a trench-wedge basin during early Jurassic, with influx of Jurassic-aged zircons originating from the newly active southern Qiangtang magmatic arc. The lower subunit

  10. Zircon (U-Th)/He thermochronometric constraints on the exhumation of 187Os enriched Lesser Himalayan strata of northwest India and implications for Cenozoic seawater chemistry

    NASA Astrophysics Data System (ADS)

    Colleps, C. L.; McKenzie, R.; Stockli, D. F.; Webb, A. G.; Horton, B. K.; Singh, B. P.

    2016-12-01

    Despite extensive documentation from the Himalayan orogenic system that shifts in global seawater radiogenic Os and Sr are highly dependent on the weathering of chemically anomalous Himalayan lithologies, marine 187Os/188Os and 87Sr/86Sr records are still utilized as proxies to track global silicate weathering intensities responsible for CO2 drawdown and climatic cooling through deep time. Here we present new thermochronometric evidence from the Lesser Himalaya of northwest India to further challenge this common utility of these seawater records. Cambrian black shales of the outer Lesser Himalaya (oLH) of northwest India are anomalously enriched in radiogenic Os, and the unroofing of these rocks has been proposed to drive an observed rapid increase in marine 187Os/188Os at 16 Ma. We collected new zircon (U-Th)/He (ZHe) data from Lesser Himalayan strata of the thrust belt and from Miocene foreland basin deposits to resolve the exhumational evolution of northwest India and to directly constrain the timing of 187Os enriched black shale unroofing that tests this proposition. Bedrock ZHe results from the Mussoorie syncline show uniform ZHe ages of 16 Ma throughout the entire 2-3 km oLH stratigraphic package and within a 2 km vertical difference in elevation. oLH rocks near Lansdowne yielded ZHe ages between 16-19 Ma with no strong correlation with elevation. Detrital ZHe results show a prominent unimodal influx of 16-17 Ma grains deposited in the foreland basin at this same time. Our results suggest initial unroofing and rapid exhumation of oLH rocks at 16 Ma, and we postulate that this is due to in-sequence, southward propagation of thrusting away from the Main Central Thrust to the Tons Thrust. Our data support a northward shift in exhumation after movement along the Tons Thrust due to initiation of inner Lesser Himalayan duplexing to the north between 15-11 Ma. Coupled with mass balance box modeling, these results provide profound evidence that oLH black shale

  11. An integrated geological/geophysical study of Upper Pennsylvanian strata in northeast Kansas: Uses of ground-penetrating radar for stratigraphic imaging

    NASA Astrophysics Data System (ADS)

    Martinez, Alexander

    proved a basis for predicting rock properties (e.g., hydraulic permeability and water saturation). GPR, a valuable tool for investigating shallow subsurface strata, can provide more information than the geometry of stratigraphic bedding features (e.g., bounding surfaces). Inclusion and integration of geological, petrophysical, and geophysical information with GPR data can provide the basis for detailed interpretation of GPR attributes and reflection character, and insight into spatial changes in lithology and petrophysical properties.

  12. Epigenetic dolomitization of the Přaídolí formation (Upper Silurian), the Barrandian basin, Czech Republic: implications for burial history of Lower Paleozoic strata

    NASA Astrophysics Data System (ADS)

    Suchý, V.; Rozkošný, I.; Žák, K.; Franců, J.

    1996-06-01

    approximately 3-km-thick sedimentary overburden of presumably post-Givetian strata, no longer preserved in the basin, appears to be the most likely interpretation. This interpretaion may imply that the magnitude of post-Variscan erosion in the Barrandian area was substantially greater than previously thought.

  13. Epigenetic dolomitization of the Přídolí formation (Upper Silurian), the Barrandian basin, Czech Republic: implications for burial history of Lower Paleozoic strata

    NASA Astrophysics Data System (ADS)

    Suchý, V.; Rozkošný, I.; Žák, K.; Franců, J.

    -km-thick sedimentary overburden of presumably post-Givetian strata, no longer preserved in the basin, appears to be the most likely interpretation. This interpretaion may imply that the magnitude of post-Variscan erosion in the Barrandian area was substantially greater than previously thought.

  14. The stepwise increase of continental weathering in the Ediacaran and early Cambrian: evidenced from radiogenic Sr isotope excursion in the strata at Three Gorges, South China.

    NASA Astrophysics Data System (ADS)

    Sawaki, Y.; Maruyama, S.

    2014-12-01

    The Ediacaran to Cambrian period records one of the most dramatic biological episodes in Earth's history. The weathering influx from continents is thought to be a major influence on the change in composition of ancient seawater and on biological evolution. Its flux can be constrained from the 87Sr/86Sr ratio of ancient carbonate rocks. However, the scarcity of well-preserved outcrops of Ediacaran rocks still leaves ambiguity in decoding ambient surface environmental changes and biological evolution. The Ediacaran strata in South China are almost continuously exposed, comprise mainly carbonate rocks with subordinate black shales, and contain many fossils. Therefore, they are suitable for study of a link between environmental and biological changes in the Ediacaran. We conducted on-land drilling from Liantuo, via Nantuo, Doushantuo, Dengying and Yanjiahe to Shuijingtuo formations at four sites in the Three Gorges area to obtain continuous, fresh samples. We analyzed radiogenic Sr isotope of the fresh carbonate rocks with a MC-ICP-MS at Kyoto University. The 87Sr/86Sr excursion preserved in the drilled samples displays a smooth curve and three large positive shifts in the Ediacaran. The first large positive excursion occurred together with negative δ13C and positive δ18O excursions. We interpret that global regression due to global cooling enhanced the oxidative decay of exposed marine organic sediments and continental weathering. The second large positive shift of 87Sr/86Sr firstly accompanied a positive δ13C excursion, and continued through the Shuram negative δ13C excursion. The higher 87Sr/86Sr values are the first compelling evidence for enhanced continental weathering in the Ediacaran, which was responsible for the large δ13C anomaly through the re-mineralization of the dissolved organic carbon (DOC) reservoir by more active sulfate reduction due to a higher sulfate influx. The 87Sr/86Sr ratios display a large positive anomaly just below the PC/C boundary

  15. Free convective controls on sequestration of salts into low-permeability strata: Insights from sand tank laboratory experiments and numerical modelling

    NASA Astrophysics Data System (ADS)

    Simmons, C. T.; Post, V.

    2008-12-01

    Vertical reflux of dense brines may occur in hydrogeologic situations including seawater intrusion, transgression-regression cycles, leachate migration from landfills and brine reflux beneath salt lakes. The critical control that geologic heterogeneity plays in the free convective process is still an area which requires significant exploration. To date, no studies have been published that focus on the effect that discrete low- permeability structures have on the free convection process at the scale of individual lenses. The precise local scale solute transport mechanisms that affect solute exchange between the layers of lower and higher permeability have not been reported. Using sand tank experiments and numerical models, we explore local scale solute transport processes associated with free convection in the region both surrounding and within discrete low-permeability strata. Different permeability geometries and contrasts between high- and low- permeability regions are explored. Results show that the free convective processes are inherently complex and not intuitively obvious. In the high-permeability region, salinization was rapid and occurred predominantly by free convective flow around the low-permeability blocks, a process we refer to as 'interlayer convection'. Fresh water originally present within the overall domain considered became trapped both below and within the low-permeability structures. A free convection flow field also became concurrently established within the low-permeability lenses, a process we refer to as 'intralayer convection'. This smaller sublayer scale process is driven by both larger scale interlayer convection and by the buoyancy of the fresh water within the low permeability lenses. It was found that upward vertical flow retards salinization of the lenses as these buoyant freshwater displacements oppose the downward penetration of dissolved salts by diffusion and free convection from above. Due to the presence of vertical upward flow

  16. Effects of an exotic plant invasion on native understory plants in a tropical dry forest.

    PubMed

    Prasad, Ayesha E

    2010-06-01

    The dry forests of southern India, which are endangered tropical ecosystems and among the world's most important tiger (Panthera tigris) habitats, are extensively invaded by exotic plants. Yet, experimental studies exploring the impacts of these invasions on native plants in these forests are scarce. Consequently, little is known about associated implications for the long-term conservation of tigers and other biodiversity in these habitats. I studied the impacts of the exotic plant Lantana camara on understory vegetation in a dry-forest tiger habitat in southern India. I compared the richness, composition, and abundance of tree seedlings, herbs, and shrubs and the abundance of grass among plots in which Lantana was cleared or left standing. These plots were distributed across two blocks-livestock free and livestock grazed. Removal of Lantana had an immediate positive effect on herb-shrub richness in the livestock-free block, but had no effect on that of tree seedlings in either livestock block. Tree-seedling and herb-shrub composition differed significantly between Lantana treatment and livestock block, and Lantana removal significantly decreased survival of tree seedlings. Nevertheless, the absence of trees, in any stage between seedling and adult, indicates that Lantana may stall tree regeneration. Lantana removal decreased the abundance of all understory strata, probably because forage plants beneath Lantana are less accessible to herbivores, and plants in Lantana-free open plots experienced greater herbivory. Reduced access to forage in invaded habitats could negatively affect ungulate populations and ultimately compromise the ability of these forests to sustain prey-dependent large carnivores. Additional research focused on understanding and mitigating threats posed by exotic plants may be crucial to the long-term protection of these forests as viable tiger habitats.

  17. Beryllium surface levels in a military ammunition plant.

    PubMed

    Sanderson, Wayne T; Leonard, Stephanie; Ott, Darrin; Fuortes, Laurence; Field, William

    2008-07-01

    This study evaluated the presence of beryllium surface contamination in a U.S. conventional munitions plant as an indicator of possible past beryllium airborne and skin exposure and used these measurements to classify job categories by potential level of exposure. Surface samples were collected from production and nonproduction areas of the plant and at regional industrial reference sites with no known history of beryllium use. Surface samples of premoistened wiping material were analyzed for beryllium mass content using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and results expressed as micrograms of beryllium per 100 square centimeters (micro g/100 cm(2)). Beryllium was detected in 87% of samples collected at the munitions plant and in 72% of the samples collected at regional reference sites. Two munitions plant samples from areas near sanders and grinders were above 3.0 micro g/100 cm(2) (U.S. Department of Energy surface contamination limit). The highest surface level found at the reference sites was 0.44 micro g/100 cm(2). Workers in areas where beryllium-containing alloy tools were sanded or ground, but not other work areas, may have been exposed to airborne beryllium concentrations above levels encountered in other industries where metal work is conducted. Surface sampling provided information useful for categorizing munitions plant jobs by level of past beryllium airborne and skin exposure and, subsequently, for identifying employees within exposure strata to be screened for beryllium sensitization.

  18. Novel solid-phase extraction protocol for 11-nor-9-carboxy-delta9-tetrahydrocannabinol from urine samples employing a polymeric mixed-mode cation-exchange resin, Strata-X-C, suitable for gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry analysis.

    PubMed

    Huq, Shahana; Dixon, Art; Kelly, Kory; Kallury, Krishna M R

    2005-05-06

    A novel solid-phase extraction (SPE) method was developed for extraction and cleanup of 11-nor-9-carboxy-delta9-tetrahydrocannabinol (THC-COOH), the major metabolite of the active principle of marijuana, delta9-tetrahydrocannabinol, from urine samples. The protocol utilizes a polymeric mixed-mode cationic sorbent, Strata-X-C, which exhibits strong retention for the metabolite facilitating a more rigorous organic wash to eliminate matrix components/endogenous materials. Acetonitrile containing acetic acid was used as the elution solvent and is compatible with both LC-MS and GC-MS modes of analysis. The hydrophobic retention of Strata-X-C was demonstrated to be higher than a neutral polymeric sorbent, Strata-X, of the same backbone but devoid of the cation-exchange moiety (sulfonic acid), by LC studies employing homologous paraben probes. Simultaneously, the polar (non-ionic) interaction capability of Strata-X-C is also greater than that of Strata-X, as assessed through regioisomeric nitrophenol probes. These two features enable the metabolite to be retained strongly on Strata-X-C. Good linearity and precision was obtained for THC-COOH by GC-MS analysis of its trimethylsilyl derivative in the range 1-50 ng. A simplified room temperature instantaneous derivatization procedure was developed that is suitable for high-throughput screening of THC-COOH.

  19. Plant intelligence.

    PubMed

    Trewavas, Anthony

    2005-09-01

    Intelligent behavior is a complex adaptive phenomenon that has evolved to enable organisms to deal with variable environmental circumstances. Maximizing fitness requires skill in foraging for necessary resources (food) in competitive circumstances and is probably the activity in which intelligent behavior is most easily seen. Biologists suggest that intelligence encompasses the characteristics of detailed sensory perception, information processing, learning, memory, choice, optimisation of resource sequestration with minimal outlay, self-recognition, and foresight by predictive modeling. All these properties are concerned with a capacity for problem solving in recurrent and novel situations. Here I review the evidence that individual plant species exhibit all of these intelligent behavioral capabilities but do so through phenotypic plasticity, not movement. Furthermore it is in the competitive foraging for resources that most of these intelligent attributes have been detected. Plants should therefore be regarded as prototypical intelligent organisms, a concept that has considerable consequences for investigations of whole plant communication, computation and signal transduction.

  20. Plant intelligence

    NASA Astrophysics Data System (ADS)

    Trewavas, Anthony

    2005-09-01

    Intelligent behavior is a complex adaptive phenomenon that has evolved to enable organisms to deal with variable environmental circumstances. Maximizing fitness requires skill in foraging for necessary resources (food) in competitive circumstances and is probably the activity in which intelligent behavior is most easily seen. Biologists suggest that intelligence encompasses the characteristics of detailed sensory perception, information processing, learning, memory, choice, optimisation of resource sequestration with minimal outlay, self-recognition, and foresight by predictive modeling. All these properties are concerned with a capacity for problem solving in recurrent and novel situations. Here I review the evidence that individual plant species exhibit all of these intelligent behavioral capabilities but do so through phenotypic plasticity, not movement. Furthermore it is in the competitive foraging for resources that most of these intelligent attributes have been detected. Plants should therefore be regarded as prototypical intelligent organisms, a concept that has considerable consequences for investigations of whole plant communication, computation and signal transduction.

  1. The Spar Lake strata-Bound Cu-Ag deposit formed across a mixing zone between trapped natural gas and metals-bearing brine

    USGS Publications Warehouse

    Hayes, Timothy S.; Landis, Gary P.; Whelan, Joseph F.; Rye, Robert O.; Moscati, Richard J.

    2012-01-01

    Ore formation at the Spar Lake red bed-associated strata-bound Cu deposit took place across a mixing and reaction zone between a hot oxidized metals-transporting brine and a reservoir of “sour” (H2S-bearing) natural gas trapped in the host sandstones. Fluid inclusion volatile analyses have very high CH4 concentrations (≥1 mol % in most samples), and a sample from the fringe of the deposit has between 18 and 36 mol % CH4. The ratio of CH4/CO2 in fluid inclusions appears to vary regularly across the deposit, with the lowest CH4/CO2 ratios from high-grade chalcocite-bearing ore, and the highest from the chalcopyrite-bearing fringe. The helium R/Ra isotope ratios (0.23–0.98) and concentrations define a mixture between crustal and atmospheric helium. The volatiles in fluid inclusions (CH4, CO2, H2S, SO2, H2, H2O, and other organic gases) and values of fO2 and temperature calculated from the volatiles data all show gradations across the deposit that are completely consistent with such a mixing and reaction zone. Other volatiles from the fluid inclusions (HCl, HF, 3He, Msup>4He, N2, Ar) characterize the brine and give evidence for only shallow crustal fluids with no magmatic influences. The brine entered the gas reservoir from below and along the axis of the deposit and migrated out along bedding to the southwest, northeast, and northwest. Metals-transporting brines may have been fed into the host sandstones from the East Fault, but that remains uncertain. Abundant ore-stage Fe and Mn calcite cements from the reduced fringe have δ13C values as low as −18.4‰, and many values less than −10‰, which indicate that significant carbonate was generated by oxidation of organic carbon from the natural gas. The zone of calcite cements with very low δ13C values approximately envelopes chalcocite-bearing ore. Sulfur isotope data of Cu, Pb, and Fe sulfides and barite indicate derivation of roughly half of the orebody sulfide directly from sour gas H2S. That sour gas H

  2. Paleosealevels and strata formation in the Gulf of Lion during the Plioquaternary : from field evidence to stratigraphic numerical modeling : what has been done, what will be done.

    NASA Astrophysics Data System (ADS)

    Rabineau, M.

    2004-12-01

    Observation and analysis of sedimentary strata, identification of sequences within the series enable the reconstruction of paleoenvironments and paleogeographies that describe the spatio-temporal evolution of sediment deposition. Eustasy, tectonic and sediment flux are the three main factors that control variations in accommodation and therefore geometries of sequences. However deciphering between the factors is not an easy task and stratigraphic simulation can be a tool to test different geological scenario and try reproduce numerically the observed geometries in a sedimentary basin. The Gulf of Lion is particularly well suited to undertake such an approach with field observation and numerical modelling. In particular, the Gulf of Lion offers a perfect natural laboratory for sea level calibration of glacial maxima for Plioquaternary climatic cycles because : (a) the Mediterranean Sea has been connected to the global ocean throughout Plio-Quaternary time, so that sea level variations are directly linked to Arctic and Antarctic ice caps fluctuations. (b) The Gulf of Lions is a young margin with subsidence still underway at present that continually creates a large amount of accommodation to be filled by sediments. (c) During the Last Glacial Maximum, mountain glaciers covered a large part of the Alps, and smaller parts of the Pyrenees and the Massif Central. However, neither the drainage basins nor the shelf were covered by ice. Moreover, the Gulf of Lions is situated sufficiently far from former ice sheets for significant glacio-isostasy of the margin to be excluded. (d) The presence of mountain glaciers led to important erosion and scouring providing an important source of sediments to be deposited in the Gulf of Lions. This approach applied for the late Quaternary already showed that the last five sequences recorded on the outer shelf were related to 100,000 years climatic cycles (MIS12 to MIS2). Preliminary results from the recent and successful PROMESS project

  3. Birth and demise of the Rheic Ocean magmatic arc(s): Combined U-Pb and Hf isotope analyses in detrital zircon from SW Iberia siliciclastic strata

    NASA Astrophysics Data System (ADS)

    Pereira, M. F.; Gutíerrez-Alonso, G.; Murphy, J. B.; Drost, K.; Gama, C.; Silva, J. B.

    2017-05-01

    Frasnian sedimentation occurred through the opening of a back-arc basin formed along the Laurussian active margin during Rheic Ocean subduction, as has been recently proposed for the Rhenohercynian Zone in Central Europe. Detrital zircon ages in the Frasnian siliciclastic rocks indicate provenance in the Meguma terrane, Avalonia and Devonian Rheic Ocean arc(s). As a result of back-arc basin inversion, the Frasnian formations underwent deformation, metamorphism and denudation and were unconformably overlain by Famennian to Visean siliciclastic strata (including the Phyllite-Quartzite Formation of the South Portuguese Zone). The Latest Devonian-Early Carboniferous detritus were probably shed to the Pulo do Lobo Zone (Represa and Santa Iria formations) by recycling of Devonian siliciclastic rocks, from the South Portuguese Zone (Meguma terrane) and from a new distinct source with Baltica/Laurentia derivation (preserved in the Horta da Torre Formation and Alajar Mélange).

  4. Paleomagnetic Results of Permo-Carboniferous Volcanic-sedimentary Strata in Mid-eastern Inner Mongolia, China: Implications for Tectonic Evolution of the Eastern CAOB

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Huang, B.; Zhao, J.; Bai, Q.; Zhang, Y.; Zhou, T.

    2015-12-01

    There has been hotly debating over the closure time of the eastern Paleo-Asian Ocean and the tectonic evolution of the eastern CAOB (Central Asian Orogenic Belt) for decades. To better puzzle out this controversy, we carried out a detailed paleomagnetic study on the Permo-Carboniferous volcanic-sedimentary strata in mid-eastern Inner Mongolia, northeast of China. More than 820 samples were collected from 81 sites and titanium-poor magnetite and hematite are proved as the principal magnetic carriers. (1)In Kingan Block, 9 sites of volcanic rocks from Dashizhai Formation (P1) were calculated to get a mean magnetic direction Dg/Ig = 285.5°/77.4°, kg = 68.2, α95 = 6.8° before and Ds/Is = 206.5°/48.2°, ks = 100.8, α95 = 5.5°, N = 9 after bedding correction, which suggests a paleolatitude of 34.5°±5°N. Both the positive fold test and reversal test suggest a pre-folding magnetization and thus may indicate a primary remanence. (2)Three volcanic sections of Baoligaomiao Formation (C3-P1) from Uliastai Passive Margin were sampled and a mean magnetic direction derived from 16 sites is Dg/Ig = 30.1°/31.8°, kg = 16.3, α95 = 9.8° before and Ds/Is = 65.6°/58.1°, ks = 39.8, α95 = 6.1°, N = 16 after bedding correction. The corresponding paleomagnetic pole Plat. /Plong = 43.1° N/186.7°E, A95=8° suggests a paleolatitude of 38.7°±6.3°N. A primary remanence is confirmed by positive fold test. (3) In the northern margin of NCB (North China Block), a ChRM is successfully isolated from 6 sites of basaltic rocks in Elitu Formation (P2) as Dg/Ig = 351.1°/67.2°, kg = 2.1, α95 = 71.8° before and Ds/Is = 351.1°/29.1°, ks = 32.7, α95 = 71.8°, N = 16 after bedding correction, and thus yielded a paleomagnetic pole as Plat. /Plong = 63.1° N/313.5°E, A95=9.5°, which suggests a paleolatitude of 17.2°±7.2°N. A positive fold test and reversal test indicate that the remanence should be primary. The paleomagetic pole of Kingan Block and Uliastai Passive Margin are

  5. Manganese concentrations in the soil and air in the vicinity of a closed manganese alloy production plant.

    PubMed

    Boudissa, Soraya M; Lambert, Jean; Müller, Caroline; Kennedy, Greg; Gareau, Lise; Zayed, Joseph

    2006-05-15

    In Montreal (Canada), the mean annual atmospheric Mn concentrations between 1981 and 1990 were stable, followed by a decrease of almost 50% from 1990 to 1992. The reason for such a decrease in Mn is probably the shutdown of a large manganese alloy production plant in Beauharnois, approximately 25 km from Montreal. The objective of this study is to assess the level of air and soil contamination by Mn in the vicinity of this ferroalloy plant more than 10 years after its closure. Air and soil were sampled over 5 days at two and three sites, respectively. Site 1 was located 10 m NE of the closed plant, in the direction of the prevailing SW-NE winds. Sites 2 and 3 were at 50 and 800 m SE from the plant. Air samples were collected in order to determine total (MnT) and respirable (MnR). Soil samples were taken in the surface and subsurface strata. The results show that site 1 is extremely polluted with a mean Mn concentration in surface strata of 2,66,000+/-45,000 ppm and 2,83,000+/-23,000 ppm in the subsurface strata, while the average MnT and MnR are 21.9+/-13.7 and 3.5+/-3.9 microg/m(3), respectively. The explanation for this contamination is direct deposition on the soil of solid Mn-rich residue and atmospheric erosion of Mn particles. The situation should be remediated by the public authority with high priority.

  6. Toxic plants

    USDA-ARS?s Scientific Manuscript database

    Reproductive performance is the single most important economic animal trait to the livestock industry and is reported to be 5 and 10 times more significant than carcass quality and growth traits respectively. Poisonous plants impact livestock reproductive function in a major way and have been shown...

  7. PLANT DIVERSITY

    EPA Science Inventory

    Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

  8. Plant intelligence

    PubMed Central

    Lipavská, Helena; Žárský, Viktor

    2009-01-01

    The concept of plant intelligence, as proposed by Anthony Trewavas, has raised considerable discussion. However, plant intelligence remains loosely defined; often it is either perceived as practically synonymous to Darwinian fitness, or reduced to a mere decorative metaphor. A more strict view can be taken, emphasizing necessary prerequisites such as memory and learning, which requires clarifying the definition of memory itself. To qualify as memories, traces of past events have to be not only stored, but also actively accessed. We propose a criterion for eliminating false candidates of possible plant intelligence phenomena in this stricter sense: an “intelligent” behavior must involve a component that can be approximated by a plausible algorithmic model involving recourse to stored information about past states of the individual or its environment. Re-evaluation of previously presented examples of plant intelligence shows that only some of them pass our test. “You were hurt?” Kumiko said, looking at the scar. Sally looked down. “Yeah.” “Why didn't you have it removed?” “Sometimes it's good to remember.” “Being hurt?” “Being stupid.”—(W. Gibson: Mona Lisa Overdrive) PMID:19816094

  9. PLANT DIVERSITY

    EPA Science Inventory

    Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

  10. I. Plants

    Treesearch

    Dean Pearson; Steve Sutherland; Jack Butler; Jane Smith; Carolyn Sieg

    2011-01-01

    Exotic plants dramatically impact natural communities and disrupt ecosystem services (Mack and others 2000). Although the bulk of current impacts are caused by relatively few exotic species, many additional exotics that are currently established at low levels are increasing in density and distribution and present substantial imminent threats. Additionally, new exotic...

  11. Spatial Distribution and Sampling Plans for Grapevine Plant Canopy-Inhabiting Scaphoideus titanus (Hemiptera: Cicadellidae) Nymphs.

    PubMed

    Rigamonti, Ivo E; Brambilla, Carla; Colleoni, Emanuele; Jermini, Mauro; Trivellone, Valeria; Baumgärtner, Johann

    2016-04-01

    The paper deals with the study of the spatial distribution and the design of sampling plans for estimating nymph densities of the grape leafhopper Scaphoideus titanus Ball in vine plant canopies. In a reference vineyard sampled for model parameterization, leaf samples were repeatedly taken according to a multistage, stratified, random sampling procedure, and data were subjected to an ANOVA. There were no significant differences in density neither among the strata within the vineyard nor between the two strata with basal and apical leaves. The significant differences between densities on trunk and productive shoots led to the adoption of two-stage (leaves and plants) and three-stage (leaves, shoots, and plants) sampling plans for trunk shoots- and productive shoots-inhabiting individuals, respectively. The mean crowding to mean relationship used to analyze the nymphs spatial distribution revealed aggregated distributions. In both the enumerative and the sequential enumerative sampling plans, the number of leaves of trunk shoots, and of leaves and shoots of productive shoots, was kept constant while the number of plants varied. In additional vineyards data were collected and used to test the applicability of the distribution model and the sampling plans. The tests confirmed the applicability 1) of the mean crowding to mean regression model on the plant and leaf stages for representing trunk shoot-inhabiting distributions, and on the plant, shoot, and leaf stages for productive shoot-inhabiting nymphs, 2) of the enumerative sampling plan, and 3) of the sequential enumerative sampling plan. In general, sequential enumerative sampling was more cost efficient than enumerative sampling.

  12. Audubon Plant Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Plants and Flowers," an adult leaders' guide, and a large wall chart picturing 37 wildflowers and describing 23 major plant families. The student reader presents these main topics: The Plant Kingdom, The Wonderful World of Plants, Plants Without Flowers, Flowering Plants, Plants Make Food…

  13. Audubon Plant Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Plants and Flowers," an adult leaders' guide, and a large wall chart picturing 37 wildflowers and describing 23 major plant families. The student reader presents these main topics: The Plant Kingdom, The Wonderful World of Plants, Plants Without Flowers, Flowering Plants, Plants Make Food…

  14. Plant Chemiluminescence

    PubMed Central

    Abeles, Fred B.; Leather, Gerald R.; Forrence, Leonard E.

    1978-01-01

    Light production by plants was confirmed by measuring chemiluminescence from root and stem tissue of peas (Pisum sativum), beans (Phaseolus vulgaris), and corn (Zea mays) in a modified scintillation spectrophotometer. Chemiluminescence was inhibited by treating pea roots with boiling ethanol or by placing them in a N2 gas phase. Chemiluminescence was increased by an O2 gas phase or by the addition of luminol. NaN3 and NaCN blocked both in vitro and in vivo chemiluminescence. It is postulated that the source of light is the hydrogen peroxide-peroxidase enzyme system. It is known that this system is responsible for chemiluminescence in leukocytes and it seems likely that a similar system occurs in plants. PMID:16660587

  15. Overview of the influence of syn-sedimentary tectonics and palaeo-fluvial systems on coal seam and sand body characteristics in the Westphalian C strata, Campine Basin, Belgium

    USGS Publications Warehouse

    Dreesen, Roland; Bossiroy, Dominique; Dusar, Michiel; Flores, R.M.; Verkaeren, Paul; Whateley, M. K. G.; Spears, D.A.

    1995-01-01

    The Westphalian C strata found in the northeastern part of the former Belgian coal district (Campine Basin), which is part of an extensive northwest European paralic coal basin, are considered. The thickness and lateral continuity of the Westphalian C coal seams vary considerably stratigraphically and areally. Sedimentological facies analysis of borehole cores indicates that the deposition of Westphalian C coal-bearing strata was controlled by fluvial depositional systems whose architectures were ruled by local subsidence rates. The local subsidence rates may be related to major faults, which were intermittently reactivated during deposition. Lateral changes in coal seam groups are also reflected by marked variations of their seismic signatures. Westphalian C fluvial depositional systems include moderate to low sinuosity braided and anastomosed river systems. Stable tectonic conditions on upthrown, fault-bounded platforms favoured deposition by braided rivers and the associated development of relatively thick, laterally continuous coal seams in raised mires. In contrast, rapidly subsiding downthrown fault blocks favoured aggradation, probably by anastomosed rivers and the development of relatively thin, highly discontinuous coal seams in topogenous mires.

  16. Plant adaptogens.

    PubMed

    Wagner, H; Nörr, H; Winterhoff, H

    1994-06-01

    The term adaptogen has not yet been accepted in medicine. This is probably due to the difficulties in discriminating adaptogenic drugs from immunostimulators, anabolic drugs, nootropic drugs, and tonics. There can be not doubt, however, that, at least in animal experiments, there are plant drugs capable of modulating distinct phases of the adaptation syndrome as defined by Seyle. These drugs either reduce stress reactions in the alarm phase or retard / prevent the exhaustion phase and thus provide a certain degree of protection against long-term stress. The small number of drugs the antistress activity of which has been proven or reported includes, among others, the plant drugs Ginseng, Eleutherococcus, Withania, Ocimum, Rhodiola, and Codonopsis. This review summarizes the major findings of pharmacological tests and human studies carried out with these drugs. Currently used assay systems allowing detection of antistress activities are also reported. At present the most likely candidates responsible for the putative antistress activity of plant drugs are special steroids, phenylprogane compounds and lignanes, respectively. Apart from influencing activities of the pituitary-adrenal axis and inducing stress proteins, many adaptogens also possess immunomodulatory and / or anabolic activities. Copyright © 1994 Gustav Fischer Verlag, Stuttgart · Jena · New York. Published by Elsevier GmbH.. All rights reserved.

  17. The Essence of "Plantness."

    ERIC Educational Resources Information Center

    Darley, W. Marshall

    1990-01-01

    Major differences between plants and animals are presented. Discussed are autotrophs and heterotrophs, plant growth and development, gas exchange, the evolution of plants, ecosystem components, the alleged inferiority of plants, and fungi. (CW)

  18. Plants: Novel Developmental Processes.

    ERIC Educational Resources Information Center

    Goldberg, Robert B.

    1988-01-01

    Describes the diversity of plants. Outlines novel developmental and complex genetic processes that are specific to plants. Identifies approaches that can be used to solve problems in plant biology. Cites the advantages of using higher plants for experimental systems. (RT)

  19. The Essence of "Plantness."

    ERIC Educational Resources Information Center

    Darley, W. Marshall

    1990-01-01

    Major differences between plants and animals are presented. Discussed are autotrophs and heterotrophs, plant growth and development, gas exchange, the evolution of plants, ecosystem components, the alleged inferiority of plants, and fungi. (CW)

  20. Plant fertilizer poisoning

    MedlinePlus

    Plant fertilizers and household plant foods are used to improve plant growth. Poisoning can occur if someone swallows these products. Plant fertilizers are mildly poisonous if small amounts are swallowed. ...

  1. Plants: Novel Developmental Processes.

    ERIC Educational Resources Information Center

    Goldberg, Robert B.

    1988-01-01

    Describes the diversity of plants. Outlines novel developmental and complex genetic processes that are specific to plants. Identifies approaches that can be used to solve problems in plant biology. Cites the advantages of using higher plants for experimental systems. (RT)

  2. Plant cooperation.

    PubMed

    Dudley, Susan A

    2015-09-25

    The study of plant behaviour will be aided by conceptual approaches and terminology for cooperation, altruism and helping. The plant literature has a rich discussion of helping between species while the animal literature has an extensive and somewhat contentious discussion of within-species helping. Here, I identify and synthesize concepts, terminology and some practical methodology for speaking about helping in plant populations and measuring the costs and benefits. I use Lehmann and Keller's (2006) classification scheme for animal helping and McIntire and Fajardo's (2014) synthesis of facilitation to provide starting points for classifying the mechanisms of how and why organisms help each other. Contextual theory is discussed as a mechanism for understanding and measuring the fitness consequences of helping. I synthesize helping into four categories. The act of helping can be costly to the helper. If the helper gains indirect fitness by helping relatives but loses direct fitness, this is altruism, and it only occurs within species. Helpers can exchange costly help, which is called mutualism when between species, and reciprocation when within a species. The act of helping can directly benefit the helper as well as the recipient, either as an epiphenomenon resulting from behaviours under natural selection for other reasons, or because the helper is creating a mutual benefit, such as satiating predators or supporting a mutualism. Facilitation between species by stress amelioration, creation of novel ecosystems and habitat complexity often meets the definition of epiphenomenon helping. Within species, this kind of helping is called by-product mutualism. If the helping is under selection to create a mutual benefit shared by others, between species this is facilitation with service sharing or access to resources and within species, direct benefits by mutual benefits. These classifications provide a clear starting point for addressing the subject of helping behaviours.

  3. Plant cooperation

    PubMed Central

    Dudley, Susan A.

    2015-01-01

    The study of plant behaviour will be aided by conceptual approaches and terminology for cooperation, altruism and helping. The plant literature has a rich discussion of helping between species while the animal literature has an extensive and somewhat contentious discussion of within-species helping. Here, I identify and synthesize concepts, terminology and some practical methodology for speaking about helping in plant populations and measuring the costs and benefits. I use Lehmann and Keller's (2006) classification scheme for animal helping and McIntire and Fajardo's (2014) synthesis of facilitation to provide starting points for classifying the mechanisms of how and why organisms help each other. Contextual theory is discussed as a mechanism for understanding and measuring the fitness consequences of helping. I synthesize helping into four categories. The act of helping can be costly to the helper. If the helper gains indirect fitness by helping relatives but loses direct fitness, this is altruism, and it only occurs within species. Helpers can exchange costly help, which is called mutualism when between species, and reciprocation when within a species. The act of helping can directly benefit the helper as well as the recipient, either as an epiphenomenon resulting from behaviours under natural selection for other reasons, or because the helper is creating a mutual benefit, such as satiating predators or supporting a mutualism. Facilitation between species by stress amelioration, creation of novel ecosystems and habitat complexity often meets the definition of epiphenomenon helping. Within species, this kind of helping is called by-product mutualism. If the helping is under selection to create a mutual benefit shared by others, between species this is facilitation with service sharing or access to resources and within species, direct benefits by mutual benefits. These classifications provide a clear starting point for addressing the subject of helping behaviours

  4. Plants. Environmental Education Curriculum.

    ERIC Educational Resources Information Center

    Topeka Public Schools, KS.

    The study of plants is often limited to studying plant structure with little emphasis on the vital role plants play in our natural system and the variety of ways man uses plants. This unit, designed for intermediate level elementary students, reviews basic plant structure, discusses roles of plants in nature's system, illustrates plant…

  5. Multi-Crop Specific Area Frame Stratification Based on Geospatial Crop Planting Frequency Data Layers

    NASA Astrophysics Data System (ADS)

    Boryan, C. G.; Yang, Z.; Willis, P.; Di, L.

    2016-12-01

    Area sampling frames (ASFs) are the basis of many statistical programs around the world. When an ASF's stratification is based on generalized percent cultivation, the ASF usually cannot identify the planting location of specific crops targeted for agricultural surveys. To improve the accuracy, objectivity and efficiency of crop survey estimates, an automated stratification method based on geospatial crop planting frequency data is proposed. The Crop Planting Frequency Data Layers are crop specific geospatial data sets derived from multi-year Cropland Data Layers. Therefore, the ASF stratification based on the crop planting frequency data is crop specific. This paper investigates using 2008-2013 geospatial Crop Frequency Data Layers to create a novel multi-crop specific stratification for South Dakota, U.S. The crop specific ASF stratification is developed based on crop frequency statistics calculated at the primary sampling unit (PSU) level based on the corn, soybean and wheat planting frequency data layers, three major crops in South Dakota. Strata are formed using a k means clustering algorithm. It is observed that the crop frequency based ASF stratification predicts corn, soybean and wheat planting patterns well as verified by 2014 Farm Service Agency (FSA) Common Land Unit (CLU) and 578 administrative data. This finding demonstrates that the novel multi-crop specific stratification based on crop planting frequency data is crop type independent and applicable to all major crops. Further, these results indicate that the new multi-crop specific ASF stratification has great potential to improve ASF accuracy, efficiency and crop estimates.

  6. The biochemistry of environmental heavy metal uptake by plants: implications for the food chain.

    PubMed

    Peralta-Videa, Jose R; Lopez, Martha Laura; Narayan, Mahesh; Saupe, Geoffrey; Gardea-Torresdey, Jorge

    2009-01-01

    Plants absorb a number of elements from soil, some of which have no known biological function and some are known to be toxic at low concentrations. As plants constitute the foundation of the food chain, some concerns have been raised about the possibility of toxic concentrations of certain elements being transported from plants to higher strata of the food chain. Special attention has been given to the uptake and biotransformation mechanisms occurring in plants and its role in bioaccumulation and impact on consumers, especially human beings. While this review draws particular attention to metal accumulation in edible plants, researched studies of certain wild plants and their consumers are included. Furthermore, this review focuses on plant uptake of the toxic elements arsenic, cadmium, chromium, mercury, and lead and their possible transfer to the food chain. These elements were selected because they are well-established as being toxic for living systems and their effects in humans have been widely documented. Arsenic is known to promote cancer of the bladder, lung, and skin and can be acquired, for example, through the consumption of As-contaminated rice. Cadmium can attack kidney, liver, bone, and it also affects the female reproduction system. Cadmium also can be found in rice. Chromium can produce cancer, and humans can be exposed through smoking and eating Cr-laden vegetables. Lead and mercury are well known neurotoxins that can be consumed via seafood, vegetables and rice.

  7. Population dynamics and within-plant distribution of the mite Calacarus flagelliseta (Acari: Eriophyidae) on papaya in Hawaii.

    PubMed

    Fournier, Valerie; Rosenheim, Jay A; Brodeur, Jacques; Johnson, Marshall W

    2004-10-01

    An important element in developing a management strategy for a new pest is the study of its seasonal dynamics and within-plant distribution. Here, we studied the mite Calacarus flagelliseta Fletchmann, De Moraes & Barbosa on papaya, Papaya carica L. (Caricaceae), in Hawaii to quantify 1) patterns of seasonal abundance, 2) its distribution across different vertical strata of the papaya canopy, and 3) shifts in its use of the upper versus the lower surfaces of papaya leaves. Nondestructive sampling conducted in two papaya plantings revealed that 1) populations of C. flagelliseta peak during the summer; 2) mites are most abundant in the middle and lower strata of the plant canopy, and least abundant on the youngest leaves found in the upper canopy; and 3) mites are found more predominantly on the upper leaf surfaces when overall population density peaks, suggesting that individuals move from the lower to the upper leaf surfaces when food resources on the lower leaf surface have been exploited by conspecifics. These results have significant implications for the development of sampling plans for C. flagelliseta in papaya.

  8. Characteristics of coal mine overburden important to plant growth

    SciTech Connect

    McFee, W.W.; Byrnes, W.R.; Stockton, J.G.

    1981-09-01

    This investigation was conducted to determine physical and chemical properties of mineland overburden, to evaluate plant growth in these materials, and to identify properties of overburden materials before mining that may serve as predictors of potential plant growth. Eighteen overburden materials from five surface coal mines in the Illinois coal basin of southwestern Indiana were sampled and analyzed for 20 physical and chemical properties. Twelve were unconsolidated materials, including A and B horizons, lacustrine sediments, and glacial tills, and six were rock strata that break and weather easily. Growth potential for overburden materials, with and without sewage sludge and fertilizer amendments, was evaluated in greenhouse pot culture using alfalfa, wheat, and white pine. Oats yield, and survival and growth of Virginia pine and yellow-poplar were evaluated for 10 materials in outdoor containers. Regression analysis of plant growth against chemical and physical properties of the overburden materials did not reveal properties that could be consistently used in a formula approach to predicting plant growth potential of the materials. Electrical conductivity of the material extract and water storage capacity was most frequently significantly related to growth. High plant tissue levels of B, Fe, Mn, and Al suggested toxicity problems on some materials. The general ranking of overburden materials evaluated for plant growth potential was lacustrine sediment greater than or equal to A horizons > B horizons = glacial tills greater than or equal to brown shale > sandstone > gray shale > black fissile shales; however, physical properties unfavorable to extraction and replacement of lacustrine material may limit its use under field conditions. Addition of sewage sludge resulted in vastly improved growth of wheat, and to a lesser extent alfalfa, on most materials in the greenhouse.

  9. [Characteristics of canopy plant substratum in a low land humid tropical forest (Upper Orinoco, Venezuela)].

    PubMed

    Hernández-Rosas, José Ibrahin

    2004-01-01

    By international agreement (Austria-Venezuela) a tower crane was installed near Surumoni river, Upper Orinoco, for canopy research in a tropical rain forest. From the 1.5 ha crane-accessible area of the forest, an experimental plot was selected for assessment of the canopy plants' aerial substrates and to determine their relationship with spatial distribution, presence or absence of vascular plants, and some of the strategies used in their ecological space. In the middle and lower canopy strata myrmecophytic associations appear, where the conformation of the aerial substrates determines the establishment and maintenance of these associations. The high content of nutrients of these aerial substrata represents a reservoir for the forest, where the mirmecophytic activity is determining. A higher fertility of aerial substrates of the ants gardens can be related to a higher number of vascular epiphytes present in these gardens.

  10. Strata-bound Fe-Co-Cu-Au-Bi-Y-REE deposits of the Idaho Cobalt Belt: Multistage hydrothermal mineralization in a magmatic-related iron oxide copper-gold system

    USGS Publications Warehouse

    Slack, John F.

    2012-01-01

    Mineralogical and geochemical studies of strata-bound Fe-Co-Cu-Au-Bi-Y-rare-earth element (REE) deposits of the Idaho cobalt belt in east-central Idaho provide evidence of multistage epigenetic mineralization by magmatic-hydrothermal processes in an iron oxide copper-gold (IOCG) system. Deposits of the Idaho cobalt belt comprise three types: (1) strata-bound sulfide lenses in the Blackbird district, which are cobaltite and, less commonly, chalcopyrite rich with locally abundant gold, native bismuth, bismuthinite, xenotime, allanite, monazite, and the Be-rich silicate gadolinite-(Y), with sparse uraninite, stannite, and Bi tellurides, in a gangue of quartz, chlorite, biotite, muscovite, garnet, tourmaline, chloritoid, and/or siderite, with locally abundant fluorapatite or magnetite; (2) discordant tourmalinized breccias in the Blackbird district that in places have concentrations of cobaltite, chalcopyrite, gold, and xenotime; and (3) strata-bound magnetite-rich lenses in the Iron Creek area, which contain cobaltiferous pyrite and locally sparse chalcopyrite or xenotime. Most sulfide-rich deposits in the Blackbird district are enclosed by strata-bound lenses composed mainly of Cl-rich Fe biotite; some deposits have quartz-rich envelopes.Whole-rock analyses of 48 Co- and/or Cu-rich samples show high concentrations of Au (up to 26.8 ppm), Bi (up to 9.16 wt %), Y (up to 0.83 wt %), ∑REEs (up to 2.56 wt %), Ni (up to 6,780 ppm), and Be (up to 1,180 ppm), with locally elevated U (up to 124 ppm) and Sn (up to 133 ppm); Zn and Pb contents are uniformly low (≤821 and ≤61 ppm, respectively). Varimax factor analysis of bulk compositions of these samples reveals geochemically distinct element groupings that reflect statistical associations of monazite, allanite, and xenotime; biotite and gold; detrital minerals; chalcopyrite and sparse stannite; quartz; and cobaltite with sparse selenides and tellurides. Significantly, Cu is statistically separate from Co and As

  11. Subsurface-controlled geological maps for the Y-12 plant and adjacent areas of Bear Creek Valley

    SciTech Connect

    King, H.L.; Haase, C.S.

    1987-04-01

    Bear Creek Valley in the vicinity of the US Department of Energy Y-12 Plant is underlain by Middle to Late Cambrian strata of the Conasauga Group. The group consists of interbedded limestones, shales, mudstones, and siltstones, and it can be divided into six discrete formations. Bear Creek Valley is bordered on the north by Pine Ridge, which is underlain by sandstones, siltstones, and shales of the Rome Formation, and on the south by Chestnut Ridge, which is underlain by dolostones of the Knox Group. Subsurface-controlled geological maps illustrating stratigraphic data and formational contacts for the formations within the Conasauga Group have been prepared for the Y-12 Plant vicinity and selected areas in Bear Creek Valley westward from the plant. The maps are consistent with all available surface and subsurface data for areas where sufficient data exist to make map construction feasible. 13 refs.

  12. 3D geometry of growth strata in a fault-propagation fold: insights into space-time evolution of the Crevillente Fault (Abanilla-Alicante sector), Betic Cordillera, Spain

    NASA Astrophysics Data System (ADS)

    Martin-Rojas, I.; Alfaro, P.; Estévez, A.

    2015-07-01

    This work presents a 3D geometric model of growth strata cropping out in a fault-propagation fold associated with the Crevillente Fault (Abanilla-Alicante sector) from the Bajo Segura Basin (eastern Betic Cordillera, southern Spain). The analysis of this 3D model enables us to unravel the along-strike and along-section variations of the growth strata, providing constraints to assess the fold development, and hence, the fault kinematic evolution in space and time. We postulate that the observed along-strike dip variations are related to lateral variation in fault displacement. Along-section variations of the progressive unconformity opening angles indicate greater fault slip in the upper Tortonian-Messinian time span; from the Messinian on, quantitative analysis of the unconformity indicate a constant or lower tectonic activity of the Crevillente Fault (Abanilla-Alicante sector); the minor abundance of striated pebbles in the Pliocene-Quaternary units could be interpreted as a decrease in the stress magnitude and consequently in the tectonic activity of the fault. At a regional scale, comparison of the growth successions cropping out in the northern and southern limits of the Bajo Segura Basin points to a southward migration of deformation in the basin. This means that the Bajo Segura Fault became active after the Crevillente Fault (Abanilla-Alicante sector), for which activity on the latter was probably decreasing according to our data. Consequently, we propose that the seismic hazard at the northern limit of the Bajo Segura Basin should be lower than at the southern limit.

  13. Enhanced provenance interpretation using combined U-Pb and (U-Th)/He double dating of detrital zircon grains from lower Miocene strata, proximal Gulf of Mexico Basin, North America

    NASA Astrophysics Data System (ADS)

    Xu, Jie; Stockli, Daniel F.; Snedden, John W.

    2017-10-01

    Detrital zircon U-Pb analysis is an effective approach for investigating sediment provenance by relating crystallization age to potential crystalline source terranes. Studies of large passive margin basins, such as the Gulf of Mexico Basin, that have received sediment from multiple terranes with non-unique crystallization ages or sedimentary strata, benefit from additional constraints to better elucidate provenance interpretation. In this study, U-Pb and (U-Th)/He double dating analyses on single zircons from the lower Miocene sandstones in the northern Gulf of Mexico Basin reveal a detailed history of sediment source evolution. U-Pb age data indicate that most zircon originated from five major crystalline provinces, including the Western Cordillera Arc (<250 Ma), the Appalachian-Ouachita orogen (500-260 Ma), the Grenville (1300-950 Ma) orogen, the Mid-Continent Granite-Rhyolite (1500-1300 Ma), and the Yavapai-Mazatzal (1800-1600 Ma) terranes as well as sparse Pan-African (700-500 Ma) and Canadian Shield (>1800 Ma) terranes. Zircon (U-Th)/He ages record tectonic cooling and exhumation in the U.S. since the Mesoproterozoic related to the Grenville to Laramide Orogenies. The combined crystallization and cooling information from single zircon double dating can differentiate volcanic and plutonic zircons. Importantly, the U-Pb-He double dating approach allows for the differentiation between multiple possible crystallization-age sources on the basis of their subsequent tectonic evolution. In particular, for Grenville zircons that are present in all of lower Miocene samples, four distinct zircon U-Pb-He age combinations are recognizable that can be traced back to four different possible sources. The integrated U-Pb and (U-Th)/He data eliminate some ambiguities and improves the provenance interpretation for the lower Miocene strata in the northern Gulf of Mexico Basin and illustrate the applicability of this approach for other large-scale basins to reconstruct sediment

  14. Plants on Display

    ERIC Educational Resources Information Center

    Lawniczak, Stefanie; Gerber, D. Timothy; Beck, Judy

    2004-01-01

    Food, medicine, clothing--much of what people encounter every day comes from plants or plant products. However, plants often do not get as much attention in the K-12 curriculum as they deserve. Because of the essential role plants play in peoples lives, it is important to include standards-based plant units in the elementary science curriculum.…

  15. Plant host finding by parasitic plants: A new perspective on plant to plant communication

    Treesearch

    Mark C. Mescher; Justin B. Runyon; Consuelo M. De Moraes

    2006-01-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-...

  16. Plants on Display

    ERIC Educational Resources Information Center

    Lawniczak, Stefanie; Gerber, D. Timothy; Beck, Judy

    2004-01-01

    Food, medicine, clothing--much of what people encounter every day comes from plants or plant products. However, plants often do not get as much attention in the K-12 curriculum as they deserve. Because of the essential role plants play in peoples lives, it is important to include standards-based plant units in the elementary science curriculum.…

  17. Model for the incorporation of plant detritus within clastic accumulating interdistributary bays

    SciTech Connect

    Gastaldo, R.A.; McCarroll, S.M.; Douglass, D.P.

    1985-01-01

    Plant-bearing clastic lithologies interpreted as interdistributary bay deposits are reported from rocks Devonian to Holocene in age. Often, these strata preserve accumulations of discrete, laterally continuous leaf beds or coaly horizons. Investigations within two modern inter-distributary bays in the lower delta plain of the Mobile Delta, Alabama have provided insight into the phytotaphonomic processes responsible for the generation of carbonaceous lithologies, coaly horizons and laterally continuous leaf beds. Delvan and Chacalooche Bays lie adjacent to the Tensaw River distributary channel and differ in the mode of clastic and plant detrital accumulation. Delvan Bay, lying west of the distributary channel, is accumulating detritus solely by overbank deposition. Chacaloochee Bay, lying east of the channel, presently is accumulating detritus by active crevasse-splay activity. Plant detritus is accumulating as transported assemblages in both bays, but the mode of preservation differs. In Delvan Bay, the organic component is highly degraded and incorporated within the clastic component resulting in a carbonaceous silt. Little identifiable plant detritus can be recovered. On the other hand, the organic component in Chacaloochee Bay is accumulating in locally restricted allochthonous peat deposits up to 2 m in thickness, and discrete leaf beds generated by flooding events. In addition, autochthonous plant accumulations occur on subaerially and aerially exposed portions of the crevasse. The resultant distribution of plant remains is a complicated array of transported and non-transported organics.

  18. Differences in forest plant functional trait distributions across land-use and productivity gradients.

    PubMed

    Mayfield, Margaret M; Dwyer, John M; Chalmandrier, Loïc; Wells, Jessie A; Bonser, Stephen P; Catterall, Carla P; DeClerck, Fabrice; Ding, Yi; Fraterrigo, Jennifer M; Metcalfe, Daniel J; Queiroz, Cibele; Vesk, Peter A; Morgan, John W

    2013-07-01

    Plant functional traits are commonly used as proxies for plant responses to environmental challenges, yet few studies have explored how functional trait distributions differ across gradients of land-use change. By comparing trait distributions in intact forests with those across land-use change gradients, we can improve our understanding of the ways land-use change alters the diversity and functioning of plant communities. We examined how the variation and distribution of trait values for seven plant functional traits differ between reference natural forest and three types of land-use conversion (pasture, old-field, or "legacy" sites-regrowth following logging), landscape productivity (NPP) and vegetation strata (tree or non-tree "understory"), in a meta-analysis of studies from 15 landscapes across five continents. Although trait variation often differed between land-uses within a landscape, these patterns were rarely consistent across landscapes. The variance and distribution of traits were more likely to differ consistently between natural forest and land-use conversion categories for understory (non-tree) plants than for trees. Landscape productivity did not significantly alter the difference in trait variance between natural forest and land-use conversion categories for any trait except dispersal. Our results suggest that even for traits well linked to plant environmental response strategies, broad classes of land-use change and landscape productivity are not generally useful indicators of the mechanisms driving compositional changes in human-modified forest systems.

  19. The plant microbiome

    PubMed Central

    2013-01-01

    Plant genomes contribute to the structure and function of the plant microbiome, a key determinant of plant health and productivity. High-throughput technologies are revealing interactions between these complex communities and their hosts in unprecedented detail. PMID:23805896

  20. Poinsettia plant exposure

    MedlinePlus

    Christmas flower poisoning; Lobster plant poisoning; Painted leaf poisoning ... Leaves, stem, sap of the poinsettia plant ... Poinsettia plant exposure can affect many parts of the body. EYES (IF DIRECT CONTACT OCCURS) Burning Redness STOMACH AND ...

  1. Teaching Plant Reproduction.

    ERIC Educational Resources Information Center

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  2. Plants in Space

    NASA Image and Video Library

    This student plant growth investigation on the International Space Station compares plant growth on the ground with plant growth in space. Brassica rapa seeds, commonly known as a turnip mustard, w...

  3. Teaching Plant Reproduction.

    ERIC Educational Resources Information Center

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  4. LDL-cholesterol-lowering effect of plant sterols and stanols across different dose ranges: a meta-analysis of randomised controlled studies.

    PubMed

    Ras, Rouyanne T; Geleijnse, Johanna M; Trautwein, Elke A

    2014-07-28

    Phytosterols (PS, comprising plant sterols and plant stanols) have been proven to lower LDL-cholesterol concentrations. The dose-response relationship for this effect has been evaluated in several meta-analyses by calculating averages for different dose ranges or by applying continuous dose-response functions. Both approaches have advantages and disadvantages. So far, the calculation of averages for different dose ranges has not been done for plant sterols and stanols separately. The objective of the present meta-analysis was to investigate the combined and separate effects of plant sterols and stanols when classified into different dose ranges. Studies were searched and selected based on predefined criteria. Relevant data were extracted. Average LDL-cholesterol effects were calculated when studies were categorised by dose, according to random-effects models while using the variance as weighing factor. This was done for plant sterols and stanols combined and separately. In total, 124 studies (201 strata) were included. Plant sterols and stanols were administered in 129 and fifty-nine strata, respectively; the remaining used a mix of both. The average PS dose was 2.1 (range 0.2-9.0) g/d. PS intakes of 0.6-3.3 g/d were found to gradually reduce LDL-cholesterol concentrations by, on average, 6-12%. When plant sterols and stanols were analysed separately, clear and comparable dose-response relationships were observed. Studies carried out with PS doses exceeding 4 g/d were not pooled, as these were scarce and scattered across a wide range of doses. In conclusion, the LDL-cholesterol-lowering effect of both plant sterols and stanols continues to increase up to intakes of approximately 3 g/d to an average effect of 12%.

  5. Students' Ideas about Plants and Plant Growth

    ERIC Educational Resources Information Center

    Barman, Charles R.; Stein, Mary; McNair, Shannan; Barman, Natalie S.

    2006-01-01

    Because the National Science Education Standards (1996) outline specific things K-8 students should know about plants, and previous data indicated that elementary students had difficulty understanding some major ideas about plants and plant growth, the authors of this article thought it appropriate to initiate an investigation to determine the…

  6. Students' Ideas about Plants and Plant Growth

    ERIC Educational Resources Information Center

    Barman, Charles R.; Stein, Mary; McNair, Shannan; Barman, Natalie S.

    2006-01-01

    Because the National Science Education Standards (1996) outline specific things K-8 students should know about plants, and previous data indicated that elementary students had difficulty understanding some major ideas about plants and plant growth, the authors of this article thought it appropriate to initiate an investigation to determine the…

  7. Cosmogenic Nuclides 10Be-21Ne Burial Dating of Middle Miocene Sedimentary Formation of the Hongliu Valley in Southern Ningxia Basin: A Case of Isotopic Geochronology Study for the Cenozoic Sedimentary Strata

    NASA Astrophysics Data System (ADS)

    Ma, Yan; Zhang, Huiping; Wang, Weitao; Pang, Jianzhang; Zheng, Dewen

    2016-04-01

    Chronology studies for the Cenozoic sedimentary strata based on the magnetostratigraphy cannot afford the unique chronological sequences in the absence of absolute ages from biostratigraphy or volcanic ash chronology. In situ-produced cosmogenic nuclides provide a powerful tool for the sediment dating based on the time-dependent concentration ratio of two nuclides, which are produced in the same mineral but with different half-lives. Thereinto,10Be-26Al is the most widely used nuclide pairs, of which the available dating range spans the Plio-Pleistocene. But the coupling of 10Be with the stable nuclide 21Ne would significantly improve the burial dating range up to the middle Miocene, which is promising in revolutionizing the chronology study for the Late Cenozoic terrestrial sedimentary sequences. We have applied 10Be-21Ne pair for dating the middle Miocene sediments of the Hongliu Valley in southern Ningxia basin. Two major features of the sediments are involved in our study: (1) sediments originated from the steady erosion of the source area, and (2) the burial depth of our sample after deposition is time dependent due to the gradual accumulation of sediments into basin. The post-burial nuclide production is estimated to be less than 3%, including the contribution by muon interactions, of the total nuclide concentrations measured in our sample. Our 10Be-21Ne analysis demonstrates the age of the burial sample is 12.4(+0.6/-0.4) Ma, and the erosion rate at the source area is 0.26±0.01 cm ka-1. The sample's burial age is consistent with the age constraint set by the Hongliugou Formation (16.7-5.4 Ma) which we collected the sample in. Vertebrate fossils of Platybelodon tongxinensis with an age between 12 and 15 Ma exhumated along with our sample further verifies the reliability of our dating results for the middle Miocene sediments.This study has shown the improved age range of cosmogenic-nuclide burial dating method by incorporating the stable nuclide 21Ne, and has

  8. Lithofacies and conodonts of Carboniferous strata in the Ivotuk Hills, western Brooks Range, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1992

    USGS Publications Warehouse

    Dumoulin, Julie A.; Harris, Anita G.

    1993-01-01

    Carboniferous strata in the Ivotuk Hills, in the western Brooks Range fold and thrust belt, consist of about 45 m of dark-gray shale, mudstone, dolostone, and spiculitic chert (upper part of the Kayak Shale, Endicott Group) and at least 225 m of light- to dark-gray dolostone, chert, and minor shale (Lisburne Group). The Kayak Shale was deposited chiefly below wave base; subordinate beds of dolomitic bioclastic packstone probably formed as storm deposits. The Kayak contains conodonts of Early Mississippian (early Osagean) age. The Lisburne Group in the Ivotuk Hills can be divided into three subunits on the basis of bedding style and lithology. The lower and upper units are thin-bedded to laminated, consist chiefly of fine-grained dolostone and spiculite and subordinate dolomitized bioclastic packstone. The middle unit is massive and resistant and is made up mostly of crinoidal packstone and lesser bryozoan wackestone. The lower and middle units of the Lisburne Group yield conodonts of early Late Mississippian (late Meramecian) age; a sample from the upper unit produced latest Late Mississippian (late Chesterian) conodonts.The Kayak Shale in the Ivotuk Hills is in general similar to the Kayak elsewhere in the Brooks Range, but also has some lithologic and faunal similarities to the Kuna Formation of the Lisburne Group. The Kayak was probably deposited in a middle to outer platform or shelf setting in somewhat deeper water than that in which most of the Kayak accumulated, but under more oxygenated conditions than those typical of Kuna environments.Sedimentologic data and conodont biofacies indicate that the Lisburne Group in the Ivotuk Hills accumulated primarily in normal marine, middle to outer platform or shelf settings. The section correlates well in age and lithology with the Lisburne at Lisburne Ridge, about 40 km to the west. Repeated thrust panels of Carboniferous strata encountered in the Lisburne Test Well No. 1, drilled 1.5 km northeast of our study area in

  9. Plant Biology Science Projects.

    ERIC Educational Resources Information Center

    Hershey, David R.

    This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

  10. New baseload power plants

    SciTech Connect

    Not Available

    1994-04-01

    This is a listing of 221 baseload power plant units currently in the planning stage. The list shows the plant owner, capacity, fuel, engineering firm, constructor, major equipment suppliers (steam generator, turbogenerator, and flue gas desulfurization system), partner, and date the plant is to be online. This data is a result of a survey by the journal of power plant owners.

  11. Polyhydroxyalkanoate synthesis in plants

    DOEpatents

    Srienc, Friedrich; Somers, David A.; Hahn, J. J.; Eschenlauer, Arthur C.

    2000-01-01

    Novel transgenic plants and plant cells are capable of biosynthesis of polyhydroxyalkanoate (PHA). Heterologous enzymes involved in PHA biosynthesis, particularly PHA polymerase, are targeted to the peroxisome of a transgenic plant. Transgenic plant materials that biosynthesize short chain length monomer PHAs in the absence of heterologous .beta.-ketothiolase and acetoacetyl-CoA reductase are also disclosed.

  12. Plants' essential chemical elements

    Treesearch

    Kevin T. Smith

    2007-01-01

    Every garden center and hardware store sells fertilizer guaranteed to "feed" plants. In a strict sense, we can't feed plants. Food contains an energy source. Green plants capture solar energy and make their own food through photosynthesis! Photosynthesis and other metabolic processes require chemical elements in appropriate doses for plants to survive...

  13. Plant Biology Science Projects.

    ERIC Educational Resources Information Center

    Hershey, David R.

    This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

  14. Plant Growth Regulators.

    ERIC Educational Resources Information Center

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  15. Plant Growth Regulators.

    ERIC Educational Resources Information Center

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  16. Ethylene insensitive plants

    DOEpatents

    Ecker, Joseph R.; Nehring, Ramlah; McGrath, Robert B.

    2007-05-22

    Nucleic acid and polypeptide sequences are described which relate to an EIN6 gene, a gene involved in the plant ethylene response. Plant transformation vectors and transgenic plants are described which display an altered ethylene-dependent phenotype due to altered expression of EIN6 in transformed plants.

  17. Field test of short-notice random inspections for inventory-change verification at a low-enriched-uranium fuel-fabrication plant

    SciTech Connect

    Fishbone, L.G. |; Moussalli, G.; Naegele, G.

    1995-05-01

    An approach of short-notice random inspections (SNRIs) for inventory-change verification can enhance the effectiveness and efficiency of international safeguards at natural or low-enriched uranium (LEU) fuel fabrication plants. According to this approach, the plant operator declares the contents of nuclear material items before knowing if an inspection will occur to verify them. Additionally, items about which declarations are newly made should remain available for verification for an agreed time. Then a statistical inference can be made from verification results for items verified during SNRIs to the entire populations, i.e. the entire strata, even if inspectors were not present when many items were received or produced. A six-month field test of the feasibility of such SNRIs took place at the Westinghouse Electric Corporation Commercial Nuclear Fuel Division during 1993. Westinghouse personnel made daily declarations about both feed and product items, uranium hexafluoride cylinders and finished fuel assemblies, using a custom-designed computer ``mailbox``. Safeguards inspectors from the IAEA conducted eight SNRIs to verify these declarations. They arrived unannounced at the plant, in most cases immediately after travel from Canada, where the IAEA maintains a regional office. Items from both strata were verified during the SNRIs by meant of nondestructive assay equipment.

  18. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  19. Pathogen Phytosensing: Plants to Report Plant Pathogens.

    PubMed

    Mazarei, Mitra; Teplova, Irina; Hajimorad, M Reza; Stewart, C Neal

    2008-04-14

    Real-time systems that provide evidence of pathogen contamination in crops can be an important new line of early defense in agricultural centers. Plants possess defense mechanisms to protect against pathogen attack. Inducible plant defense is controlled by signal transduction pathways, inducible promoters and cis-regulatory elements corresponding to key genes involved in defense, and pathogen-specific responses. Identified inducible promoters and cis-acting elements could be utilized in plant sentinels, or 'phytosensors', by fusing these to reporter genes to produce plants with altered phenotypes in response to the presence of pathogens. Here, we have employed cis-acting elements from promoter regions of pathogen inducible genes as well as those responsive to the plant defense signal molecules salicylic acid, jasmonic acid, and ethylene. Synthetic promoters were constructed by combining various regulatory elements supplemented with the enhancer elements from the Cauliflower mosaic virus (CaMV) 35S promoter to increase basal level of the GUS expression. The inducibility of each synthetic promoter was first assessed in transient expression assays using Arabidopsis thaliana protoplasts and then examined for efficacy in stably transgenic Arabidopsis and tobacco plants. Histochemical and fluorometric GUS expression analyses showed that both transgenic Arabidopsis and tobacco plants responded to elicitor and phytohormone treatments with increased GUS expression when compared to untreated plants. Pathogen-inducible phytosensor studies were initiated by analyzing the sensitivity of the synthetic promoters against virus infection. Transgenic tobacco plants infected with Alfalfa mosaic virus showed an increase in GUS expression when compared to mock-inoculated control plants, whereas Tobacco mosaic virus infection caused no changes in GUS expression. Further research, using these transgenic plants against a range of different pathogens with the regulation of detectable

  20. Collision-induced tectonism along the northwestern margin of the Indian subcontinent as recorded in the Upper Paleocene to Middle Eocene strata of central Pakistan (Kirthar and Sulaiman Ranges)

    USGS Publications Warehouse

    Warwick, P.D.; Johnson, E.A.; Khan, I.H.

    1998-01-01

    Outcrop data from the Upper Paleocene to Middle Eocene Ghazij Formation of central Pakistan provide information about the depositional environments, source areas, and paleogeographic and tectonic settings along the northwestern margin of the Indian subcontinent during the closing of the Tethys Ocean. In this region, in the lower part of the exposed stratigraphic sequence, are various marine carbonate-shelf deposits (Jurassic to Upper Paleocene). Overlying these strata is the Ghazij, which consists of marine mudstone (lower part), paralic sandstone and mudstone (middle part), and terrestrial mudstone and conglomerate (upper part). Petrographic examination of sandstone samples from the middle and upper parts reveals that rock fragments of the underlying carbonate-shelf deposits are dominant; also present are volcanic rock fragments and chromite grains. Paleocurrent measurements from the middle and upper parts suggest that source areas were located northwest of the study area. We postulate that the source areas were uplifted by the collision of the subcontinent with a landmass during the final stages of the closing of the Tethys Ocean. Middle Eocene carbonate-shelf deposits that overlie the Ghazij record a return to marine conditions prior to the Miocene to Pleistocene sediment influx denoting the main collision with Eurasia.

  1. Beginning Plant Biotechnology Laboratories Using Fast Plants.

    ERIC Educational Resources Information Center

    Williams, Mike

    This set of 16 laboratory activities is designed to illustrate the life cycle of Brassicae plants from seeds in pots to pods in 40 days. At certain points along the production cycle of the central core of labs, there are related lateral labs to provide additional learning opportunities employing this family of plants, referred to as "fast…

  2. Thrips management program for plants for planting

    USDA-ARS?s Scientific Manuscript database

    Thrips Management includes sanitation, exclusion, chemical control and biological control. Sanitation. Remove weeds, old plant debris, and growing medium from within and around the greenhouse. Eliminate old stock plants as these are a source of thrips and viruses. Removing old flowers may reduce the...

  3. Origin and Evolution of The Early- Silurian Land Vascular Plants: Evidence From Biomarkers

    NASA Astrophysics Data System (ADS)

    Jin, R.

    2016-12-01

    Origin and early evolution of land vascular plants, is one of the most intriguing hotspots in the life science research. During the 1970s and 1980s,Pinnatiramosus qianensis was found in early-Silurian strata in guizhou of south China.43 years have passed. But so far, the biological characteristics and belonging of the age of this unique plant have been debated again and again, up in the air.Biomarkers have a good stability in the process of organic evolution, no more or less changed, so they have a special `function of mark'. While biomarkers can provide information about organic matter of hydrocarbon source rock (the source), the period of deposition and burial (diagenesis) environmental conditions, and many other aspects of information.This paper obtained the sedimentary environment, source of organic matter input and other relevant information, through extracting and analyzing biomarkers of the 26 samples in the late Ordovician to early Silurian strata in NorthGuizhou areas. According to the results, Pr/Ph of late Ordovician Meitan Fm-early Silurian Hanjiadian Fm is high.It manifests more pristane, characterized by reductive environment. At the bottom of the Hanjiadian Fm, Pr/Ph has a volatility.Some huge environmental changes may have taken place in the corresponding period. N-alkanes do not have parity advantage or has even carbon advantage slightly.The peak carbon is mainly in low carbon number.(C21 + C22)/(C28 + C29) is high.Aquatic organisms is a major source of organic matter during this period,C21-/C22+ is low.This may be caused by the relatively serious loss of light hydrocarbon during the separation of components. In the Hanjiadian Fm,information of C29/C27 sterane ratios and oleanane index showed a trend of rising at the same time, indicating that during this period, there was a gradual increase input in the number of higher plants.The stable carbon isotope of saturated hydrocarbon and aromatic hydrocarbon in the Hanjiadian Fm also gradually become

  4. Plant Phenotype Characterization System

    SciTech Connect

    Daniel W McDonald; Ronald B Michaels

    2005-09-09

    This report is the final scientific report for the DOE Inventions and Innovations Project: Plant Phenotype Characterization System, DE-FG36-04GO14334. The period of performance was September 30, 2004 through July 15, 2005. The project objective is to demonstrate the viability of a new scientific instrument concept for the study of plant root systems. The root systems of plants are thought to be important in plant yield and thus important to DOE goals in renewable energy sources. The scientific study and understanding of plant root systems is hampered by the difficulty in observing root activity and the inadequacy of existing root study instrumentation options. We have demonstrated a high throughput, non-invasive, high resolution technique for visualizing plant root systems in-situ. Our approach is based upon low-energy x-ray radiography and the use of containers and substrates (artificial soil) which are virtually transparent to x-rays. The system allows us to germinate and grow plant specimens in our containers and substrates and to generate x-ray images of the developing root system over time. The same plant can be imaged at different times in its development. The system can be used for root studies in plant physiology, plant morphology, plant breeding, plant functional genomics and plant genotype screening.

  5. Geologic mapping of the air intake shaft at the Waste Isolation Pilot Plant

    SciTech Connect

    Holt, R.M.; Powers, D.W. )

    1990-12-01

    The air intake shaft (AS) was geologically mapped from the surface to the Waste Isolation Pilot Plant (WIPP) facility horizon. The entire shaft section including the Mescalero Caliche, Gatuna Formation, Santa Rosa Formation, Dewey Lake Redbeds, Rustler Formation, and Salado Formation was geologically described. The air intake shaft (AS) at the Waste Isolation Pilot Plant (WIPP) site was constructed to provide a pathway for fresh air into the underground repository and maintain the desired pressure balances for proper underground ventilation. It was up-reamed to minimize construction-related damage to the wall rock. The upper portion of the shaft was lined with slip-formed concrete, while the lower part of the shaft, from approximately 903 ft below top of concrete at the surface, was unlined. As part of WIPP site characterization activities, the AS was geologically mapped. The shaft construction method, up-reaming, created a nearly ideal surface for geologic description. Small-scale textures usually best seen on slabbed core were easily distinguished on the shaft wall, while larger scale textures not generally revealed in core were well displayed. During the mapping, newly recognized textures were interpreted in order to refine depositional and post-depositional models of the units mapped. The objectives of the geologic mapping were to: (1) provide confirmation and documentation of strata overlying the WIPP facility horizon; (2) provide detailed information of the geologic conditions in strata critical to repository sealing and operations; (3) provide technical basis for field adjustments and modification of key and aquifer seal design, based upon the observed geology; (4) provide geological data for the selection of instrument borehole locations; (5) and characterize the geology at geomechanical instrument locations to assist in data interpretation. 40 refs., 27 figs., 1 tab.

  6. Plant Pathogenic Fungi.

    PubMed

    Doehlemann, Gunther; Ökmen, Bilal; Zhu, Wenjun; Sharon, Amir

    2017-01-01

    Fungi are among the dominant causal agents of plant diseases. To colonize plants and cause disease, pathogenic fungi use diverse strategies. Some fungi kill their hosts and feed on dead material (necrotrophs), while others colonize the living tissue (biotrophs). For successful invasion of plant organs, pathogenic development is tightly regulated and specialized infection structures are formed. To further colonize hosts and establish disease, fungal pathogens deploy a plethora of virulence factors. Depending on the infection strategy, virulence factors perform different functions. While basically all pathogens interfere with primary plant defense, necrotrophs secrete toxins to kill plant tissue. In contrast, biotrophs utilize effector molecules to suppress plant cell death and manipulate plant metabolism in favor of the pathogen. This article provides an overview of plant pathogenic fungal species and the strategies they use to cause disease.

  7. Flooding and Plant Growth

    PubMed Central

    VISSER, E. J. W.; VOESENEK, L. A. C. J.; VARTAPETIAN, B. B.; JACKSON, M. B.

    2003-01-01

    This Special Issue is based on the 7th Conference of the International Society for Plant Anaerobiosis (ISPA), held in Nijmegen, The Netherlands, 12–16 June 2001. The papers describe and analyse many of the responses that plants display when subjected to waterlogging of the soil or deeper submergence. These responses may be injurious or adaptive, and are discussed at various levels of organizational complexity ranging from ecosystem processes, through individual plants to single cells. The research incorporates molecular biology and genetics, cell physiology, biochemistry, hormone physiology, whole plant physiology, plant demography and ecology. The study of the damage to young rice plants caused by submergence, especially as experienced in the rainfed lowlands of Asia, is comprehensively addressed. This work integrates various specialized approaches ranging from agronomy to molecular genetics, and demonstrates how plant biology can be harnessed to improve stress tolerance in an important crop species while simultaneously improving basic understanding of tolerance mechanisms and plant processes.

  8. Plant centromere compositions

    DOEpatents

    Mach, Jennifer M [Chicago, IL; Zieler, Helge [Del Mar, CA; Jin, RongGuan [Chesterfield, MO; Keith, Kevin [Three Forks, MT; Copenhaver, Gregory P [Chapel Hill, NC; Preuss, Daphne [Chicago, IL

    2011-08-02

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  9. Plant centromere compositions

    DOEpatents

    Mach, Jennifer; Zieler, Helge; Jin, RongGuan; Keith, Kevin; Copenhaver, Gregory; Preuss, Daphne

    2007-06-05

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  10. Plant centromere compositions

    DOEpatents

    Keith, Kevin; Copenhaver, Gregory; Preuss, Daphne

    2006-10-10

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  11. Plant centromere compositions

    DOEpatents

    Mach,; Jennifer M. , Zieler; Helge, Jin [Del Mar, CA; RongGuan, Keith [Chesterfield, MO; Kevin, Copenhaver [Three Forks, MT; Gregory P. , Preuss; Daphne, [Chicago, IL

    2011-11-22

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  12. Plant centromere compositions

    DOEpatents

    Mach, Jennifer; Zieler, Helge; Jin, James; Keith, Kevin; Copenhaver, Gregory; Preuss, Daphne

    2006-06-26

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  13. Aspects of Plant Intelligence

    PubMed Central

    TREWAVAS, ANTHONY

    2003-01-01

    Intelligence is not a term commonly used when plants are discussed. However, I believe that this is an omission based not on a true assessment of the ability of plants to compute complex aspects of their environment, but solely a reflection of a sessile lifestyle. This article, which is admittedly controversial, attempts to raise many issues that surround this area. To commence use of the term intelligence with regard to plant behaviour will lead to a better understanding of the complexity of plant signal transduction and the discrimination and sensitivity with which plants construct images of their environment, and raises critical questions concerning how plants compute responses at the whole‐plant level. Approaches to investigating learning and memory in plants will also be considered. PMID:12740212

  14. Plant centromere compositions

    DOEpatents

    Mach, Jennifer; Zieler, Helge; Jin, James; Keith, Kevin; Copenhaver, Gregory; Preuss, Daphne

    2007-06-05

    The present invention provides for the nucleic acid sequences of plant centromeres. This will permit construction of stably inherited recombinant DNA constructs and minichromosomes which can serve as vectors for the construction of transgenic plant and animal cells.

  15. On Plant Names.

    ERIC Educational Resources Information Center

    Colton, Ronald W.

    1979-01-01

    Discusses the scientific and common names of numerous plants and the satisfaction children derive from mastering them. Includes drawings which illustrate the connections between plant structures and their names. (MA)

  16. Divergent genetic strata in five Bahamian islands.

    PubMed

    Simms, Tanya M; Barrett, Dianne A; McCartney, Quinn; Herrera, Rene J

    2012-01-01

    Based on historical records, the genetic landscape of the Bahamian archipelago is presumed to be complex and to exhibit island-specific characteristics, yet the genetic composition of the island chain, which could corroborate or refute these past accounts, remains poorly defined. As such, the current investigation was undertaken to genetically characterize 5 Bahamian populations representing the Northwest (Grand Bahama and Abaco) and Central (Eleuthera, Exuma and Long Island) Bahamas across the 15 autosomal Identifiler loci routinely employed in forensic analyses. Altogether, our findings suggest that Bahamians are a genetically heterogeneous group, with each island sampled receiving differential contributions from African, European, East Asian and Native American sources. Even though the strongest genetic signal in all 5 collections emanates from continental Africa, inter-island differentiation is noted in both the Structure and admixture analyses. The presence of alleles not in common among the 5 insular populations also signals genetic heterogeneity among the islands of the archipelago. This is especially the case when considering the Long Island population, which exhibits statistically significant genetic differences in relation to the other Bahamian collections and the New World groups of African descent (Afro-American and Afro-Caribbean) in the G-test pair-wise comparisons, even after application of the Bonferroni adjustment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Propensity Score Matching within Prognostic Strata

    ERIC Educational Resources Information Center

    Kelcey, Ben

    2013-01-01

    A central issue in nonexperimental studies is identifying comparable individuals to remove selection bias. One common way to address this selection bias is through propensity score (PS) matching. PS methods use a model of the treatment assignment to reduce the dimensionality of the covariate space and identify comparable individuals. parallel to…

  18. Rock-Strata Names Go on Computer

    ERIC Educational Resources Information Center

    Cohee, George V.

    1973-01-01

    Reports that the United States Geological Survey has recently prepared computer print-outs of the rock-stratigraphic names in good usage in published references in the United States, using the standard stratigraphic code of the American Association of Petroleum Geologists. A sample of the print-out is provided with explanatory notes. (JR)

  19. Power Plant Systems Analysis

    NASA Technical Reports Server (NTRS)

    Williams, J. R.; Yang, Y. Y.

    1973-01-01

    Three basic thermodynamic cycles of advanced nuclear MHD power plant systems are studied. The effect of reactor exit temperature and space radiator temperature on the overall thermal efficiency of a regenerative turbine compressor power plant system is shown. The effect of MHD pressure ratio on plant efficiency is also described, along with the dependence of MHD power output, compressor power requirement, turbine power output, mass flow rate of H2, and overall plant efficiency on the reactor exit temperature for a specific configuration.

  20. New baseload power plants

    SciTech Connect

    Not Available

    1993-04-01

    This is a tabulation of the results of this magazines survey of current plans for new baseload power plants. The table lists the unit name, capacity, fuel, engineering firm, constructor, suppliers for steam generator, turbine generator and flue gas desulfurization equipment, date due on-line, and any non-utility participants. The table includes fossil-fuel plants, nuclear plants, geothermal, biomass and hydroelectric plants.

  1. National Plant Genome Initiative

    DTIC Science & Technology

    2005-01-01

    JAN 2005 2. REPORT TYPE 3. DATES COVERED 00-00-2005 to 00-00-2005 4. TITLE AND SUBTITLE National Plant Genome Initiative. Progress Report 5a...refl ected in future Administration budgets. Cover Photo: National Plant Genome Initiative Progress Report January 2005 National Science and...Technology Council Committee on Science Interagency Working Group on Plant Genomes [Blank Page] Interagency Working Group on Plant Genomes Committee on

  2. Plant design: Integrating Plant and Equipment Models

    SciTech Connect

    Sloan, David; Fiveland, Woody; Zitney, S.E.; Osawe, Maxwell

    2007-08-01

    Like power plant engineers, process plant engineers must design generating units to operate efficiently, cleanly, and profitably despite fluctuating costs for raw materials and fuels. To do so, they increasingly create virtual plants to enable evaluation of design concepts without the expense of building pilot-scale or demonstration facilities. Existing computational models describe an entire plant either as a network of simplified equipment models or as a single, very detailed equipment model. The Advanced Process Engineering Co-Simulator (APECS) project (Figure 5) sponsored by the U.S. Department of Energy's National Energy Technology Laboratory (NETL) seeks to bridge the gap between models by integrating plant modeling and equipment modeling software. The goal of the effort is to provide greater insight into the performance of proposed plant designs. The software integration was done using the process-industry standard CAPE-OPEN (Computer Aided Process Engineering–Open), or CO interface. Several demonstration cases based on operating power plants confirm the viability of this co-simulation approach.

  3. Plants on the Move

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2005-01-01

    Living things respond to a stimulus, which is a change in the surroundings. Some common stimuli are noises, smells, and things the people see or feel, such as a change in temperature. Animals often respond to a stimulus by moving. Because plants can't move around in the same way animals do, plants have to respond in a different way. Plants can…

  4. TRANSGENIC PLANT CONTAINMENT

    EPA Science Inventory

    The new technology using plant genetics to produce chemicals, pharmaceuticals, and therapeuitics in a wide array of new plant forms requires sufficient testing to ensure that these new plant introductions are benign in the environment. A recent effort to provide necessary guidan...

  5. Diagnosing plant problems

    Treesearch

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  6. TRANSGENIC PLANT CONTAINMENT

    EPA Science Inventory

    The new technology using plant genetics to produce chemicals, pharmaceuticals, and therapeuitics in a wide array of new plant forms requires sufficient testing to ensure that these new plant introductions are benign in the environment. A recent effort to provide necessary guidan...

  7. Plants and people

    Treesearch

    Kathryn Lynch

    2012-01-01

    Salal! Salmonberries! Sword ferns! The Northwest is home to a great number of native plant species that humans have used for centuries. Sadly, many local children are unaware of the history and culture connecting people and plants. Yet, from the beginning of time, plants have provided us food, medicine, and material for clothing, shelter, transportation, decoration,...

  8. Cycling Through Plants

    ERIC Educational Resources Information Center

    Cavallo, Ann

    2005-01-01

    Children notice seeds and plants every day. But do they really understand what seeds are and how they are related to plants? Have they ever observed what is inside the seed? What happens to the "things" inside a seed when it grows? What do plants need to grow, and what do they need to stay healthy? Through a sequence of three related learning…

  9. Plants on the Move

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2005-01-01

    Living things respond to a stimulus, which is a change in the surroundings. Some common stimuli are noises, smells, and things the people see or feel, such as a change in temperature. Animals often respond to a stimulus by moving. Because plants can't move around in the same way animals do, plants have to respond in a different way. Plants can…

  10. Fundaments of plant cybernetics.

    PubMed

    Zucconi, F

    2001-01-01

    A systemic approach is proposed for analyzing plants' physiological organization and cybernesis. To this end, the plant is inspected as a system, starting from the integration of crown and root systems, and its impact on a number of basic epigenetic events. The approach proves to be axiomatic and facilitates the definition of the principles behind the plant's autonomous control of growth and reproduction.

  11. Plant bugs on alfalfa

    USDA-ARS?s Scientific Manuscript database

    This paper treats the most important plant bugs, or Miridae, found on alfalfa in North America. It is estimated that more than 10 species of plant bugs have the potential to develop on this important forage legume. Of these, the alfalfa plant bug (Adelphocoris lineolatus), pale legume bug (Lygus e...

  12. Oak Tree Planting Project

    Treesearch

    Sherryl L. Nives; William D. Tietje; William H. Weitkamp

    1991-01-01

    An Oak Tree Planting Project was conducted during 1989/90 in San Luis Obispo County by the Integrated Hardwood Range Management Program (IHRMP)/Central Coast. The local media and an IHRMP workshop were used to publicize the Planting Project and give information on the status of oaks (Quercus spp.) in California and oak planting techniques. Outreach...

  13. Plant or Animal?

    ERIC Educational Resources Information Center

    Bowman, Frank; Matthews, Catherine E.

    1996-01-01

    Presents activities that use marine organisms with plant-like appearances to help students build classification skills and illustrate some of the less obvious differences between plants and animals. Compares mechanisms by which sessile plants and animals deal with common problems such as obtaining energy, defending themselves, successfully…

  14. Recognizing Plant Defense Priming.

    PubMed

    Martinez-Medina, Ainhoa; Flors, Victor; Heil, Martin; Mauch-Mani, Brigitte; Pieterse, Corné M J; Pozo, Maria J; Ton, Jurriaan; van Dam, Nicole M; Conrath, Uwe

    2016-10-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in plants.

  15. Advanced Plant Habitat (APH)

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E. (Compiler); Levine, Howard G.; Reed, David W.

    2016-01-01

    The Advanced Plant Habitat (APH) hardware will be a large growth volume plant habitat, capable of hosting multigenerational studies, in which environmental variables (e.g., temperature, relative humidity, carbon dioxide level light intensity and spectral quality) can be tracked and controlled in support of whole plant physiological testing and Bio-regenerative Life Support System investigations.

  16. Plants of the Bayshore.

    ERIC Educational Resources Information Center

    Bachle, Leo; And Others

    This field guide gives pictures and descriptions of plants that can be found along the San Francisco Bayshore, especially along the Hayward shoreline. The plants are divided into three categories, those of the mud-flat zone, the drier zone, and the levee zone. Eighteen plants are represented in all. The guide is designed to be used alone, with an…

  17. Regional native plant strategies

    Treesearch

    Wendell G. Hassell

    1999-01-01

    Because of increasing public interest in native plants, regional groups have been cooperating to develop native species. The Federal Native Plants Initiative was formed in 1994 to coordinate and encourage the development and use of native plants. The program they developed includes public involvement, organizational structure, technical work groups, implementation...

  18. Iron stress in plants.

    PubMed

    Connolly, Erin L; Guerinot, Mary

    2002-07-30

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches

  19. Statistically Valid Planting Trials

    Treesearch

    C. B. Briscoe

    1961-01-01

    More than 100 million tree seedlings are planted each year in Latin America, and at least ten time'that many should be planted Rational control and development of a program of such magnitude require establishing and interpreting carefully planned trial plantings which will yield statistically valid answers to real and important questions. Unfortunately, many...

  20. Cycling Through Plants

    ERIC Educational Resources Information Center

    Cavallo, Ann

    2005-01-01

    Children notice seeds and plants every day. But do they really understand what seeds are and how they are related to plants? Have they ever observed what is inside the seed? What happens to the "things" inside a seed when it grows? What do plants need to grow, and what do they need to stay healthy? Through a sequence of three related learning…

  1. Power Plant Cycling Costs

    SciTech Connect

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  2. Understanding complex structures in fold-and-thrust belts. Integration of geometric and growth strata analyses, paleomagnetism, AMS and analogue models in the Western termination of the Southern Pyrenees

    NASA Astrophysics Data System (ADS)

    Pueyo, Emilio L.; Sánchez, Elisa; Oliva-Urcia, Belén; José Ramón, Ma

    2014-05-01

    Classic 2D approaches have helped the understanding of the geometry and kinematics of fold-and-thrust belts belts (FAT belts) but are insufficient to unravel many natural cases. This is because deformation is 3D from the geometric point of view and, thus, cylindrical features may be considered as a simplification. On the other hand, deformation kinematics is usually complex, diachronic and poliphasic in real cases. Therefore, FAT belts have to be always considered in 4D. In this sense, the Southern Pyrenees is a perfect location to study the evolution of FAT belts because of the exceptional outcropping conditions of growth strata, the proven diachronic kinematics and the non-coaxial interference of deformation events. Within the vast catalogue of complex structures that includes superposed folding, conical and plunging folds, oblique thrust ramps, etc here, we have selected the westernmost termination of the South Pyrenean sole thrust to illustrate how the integration of geometric and kinematic analysis can help unraveling complex structures in FAT belts. The San Marzal pericline (4 km2 surface extension) is the lateral termination of the Sto. Domingo deca-kilometric fold. San Marzal looks like a large 70° plunging cylindrical structure. However the large magnitude (≡ 60-70°) of vertical axis rotations accommodated between its flanks cannot be explained without a conical geometry. In this work we will show how the structural analysis performed on this structure has disentangled its complex geometry. This analyses comprises several hundreds of bedding data, joints and veins and more than 150 standard paleomagnetic and AMS sites. Besides, we will show how the kinematic information derived from magnetostratigraphic sections (more than 8 km of sampled profiles) has helped to constraint the folding and rotation ages and velocities. Finally, all these complex geometric and kinematic features have inspired us to build an analogue model where we can explore the 3D

  3. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, scientists are preparing the science carrier, or base, of the Advanced Plant Habitat (APH). A growing substrate called arcillite has been packed down in the base and coverings are being secured to seal the base. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  4. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, scientists prepare Apogee wheat seeds for the science carrier, or base, of the Advanced Plant Habitat (APH). A growing substrate called arcillite was packed down in the base and coverings were secured on top of the base. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  5. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, scientists prepared the science carrier, or base, of the Advanced Plant Habitat (APH). A growing substrate called arcillite was packed down in the base and coverings were secured on top of the base. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  6. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Dr. Oscar Monje, a research scientist, pours a growing substrate called arcillite in the science carrier, or base, of the Advanced Plant Habitat (APH) inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  7. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Dr. Oscar Monje, a research scientist, packs a growing substrate called arcillite in the science carrier, or base, of the Advanced Plant Habitat (APH) inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  8. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Dr. Oscar Monje, a research scientist, packs a growing substrate called arcillite in the science carrier, or base, of the Advanced Plant Habitat (APH) inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. Seated at right is Susan Manning-Roach, a quality assurance specialist on the Engineering Services Contract. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  9. Advanced Plant Habitat - Packing and Planting Seeds

    NASA Image and Video Library

    2017-02-15

    Inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a scientist inserts Apogee wheat seeds into the science carrier, or base, of the Advanced Plant Habitat (APH). A growing substrate called arcillite was packed down in the base and coverings were secured on top of the base. Developed by NASA and ORBITEC of Madison, Wisconsin, the APH is the largest plant chamber built for the agency. It is a fully automated plant growth facility that will be used to conduct bioscience research on the International Space Station. The APH will be delivered to the space station aboard future Commercial Resupply Services missions.

  10. Steroid plant hormones: effects outside plant kingdom.

    PubMed

    Zhabinskii, Vladimir N; Khripach, Natalia B; Khripach, Vladimir A

    2015-05-01

    Brassinosteroids (BS) are the first group of steroid-hormonal compounds isolated from and acting in plants. Among numerous physiological effects of BS growth stimulation and adaptogenic activities are especially remarkable. In this review, we provide evidence that BS possess similar types of activity also beyond plant kingdom at concentrations comparable with those for plants. This finding allows looking at steroids from a new point of view: how common are the mechanisms of steroid bioregulation in different types of organisms from protozoa to higher animals.