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Sample records for cordillera se spain

  1. Spatial gradient of chemical weathering and its coupling with physical erosion in the soils of the Betic Cordillera (SE Spain)

    NASA Astrophysics Data System (ADS)

    Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Ameijeiras-Mariño, Yolanda; Kubik, Peter

    2015-04-01

    The production and denudation of soil material are controlled by chemical weathering and physical erosion which influence one another. Better understanding and quantification of this relationship is critical to understand biogeochemical cycles in the critical zone. The intense silicate weathering that is taking place in young mountain ranges is often cited to be a negative feedback that involves a long-term reduction of the atmospheric CO2 and the temperature cooling. However the possible (de)coupling between weathering and erosion is not fully understood for the moment and could reduce the effect of the feedback. This study is conducted in the eastern Betic Cordillera located in southeast Spain. The Betic Cordillera is composed by several mountains ranges or so-called Sierras that are oriented E-W to SE-NW and rise to 2000m.a.s.l. The Sierras differ in topographic setting, tectonic activity, and slightly in climate and vegetation. The mountain ranges located in the northwest, such as the Sierra Estancias, have the lowest uplift rates ( ~20-30 mm/kyr); while those in the southeast, such as the Sierra Cabrera, have the highest uplift rates ( >150mm/kyr). The sampling was realised into four small catchments located in three different Sierras. In each of them, two to three soil profiles were excavated on exposed ridgetops, and samples were taken by depth slices. The long-term denudation rate at the sites is inferred from in-situ 10Be CRN measurements. The chemical weathering intensity is constrained using a mass balance approach that is based on the concentration of immobile elements throughout the soil profile (CDF). Our results show that the soil depth decreases with an increase of the denudation rates. Chemical weathering accounts for 5 to 35% of the total mass lost due to denudation. Higher chemical weathering intensities (CDFs) are observed in sites with lower denudation rates (and vice versa). The data suggest that chemical weathering intensities are strongly

  2. Paleoseismic and geomorphologic evidence of recent tectonic activity of the Pozohondo Fault (Betic Cordillera, SE Spain)

    USGS Publications Warehouse

    Rodríguez-Pascua, M.A.; Pérez-López, R.; Garduño-Monroy, V.H.; Giner-Robles, J.L.; Silva, P.G.; Perucha-Atienza, M.A.; Hernández-Madrigal, V.M.; Bischoff, J.

    2012-01-01

    Instrumental and historical seismicity in the Albacete province (External Prebetic Zone) has been scarcely recorded. However, major strike-slip faults showing NW-SE trending provide geomorphologic and paleoseismic evidence of recent tectonic activity (Late Pleistocene to Present). Moreover, these faults are consistently well oriented under the present stress tensor and therefore, they can trigger earthquakes of magnitude greater than M6, according to the lengths of surface ruptures and active segments recognized in fieldwork. Present landscape nearby the village of Hellin (SE of Albacete) is determined by the recent activity of the Pozohondo Fault (FPH), a NW-SE right-lateral fault with 90 km in length. In this study, we have calculated the Late Quaternary tectonic sliprate of the FPH from geomorphological, sedimentological, archaeoseimological, and paleoseismological approaches. All of these data suggest that the FPH runs with a minimum slip-rate of 0.1 mm/yr during the last 100 kyrs (Upper Pleistocene-Holocene). In addition, we have recognized the last two major paleoearthquakes associated to this fault. Magnitudes of these paleoearthquakes were gretarer than M6 and their recurrence intervals ranged from 6600 to 8600 yrs for the seismic cycle of FPH. The last earthquake was dated between the 1st and 6th centuries, though two earthquakes could be interpreted in this wide time interval, one at the FPH and other from a far field source. Results obtained here, suggest an increasing of the tectonic activity of the Pozohondo Fault during the last 10,000 yrs.

  3. A cross section of the eastern Betic Cordillera (SE Spain) according field data and a seismic reflection profile

    NASA Astrophysics Data System (ADS)

    Jabaloy-Sánchez, A.; Fernández-Fernández, E. M.; González-Lodeiro, F.

    2007-04-01

    The BT3 multichannel seismic profile was acquired by the C.G.G. (Compagnie General de Géophysique) in 1977 for hydrocarbon exploration in the eastern Betic Cordillera. REXIMseis Ltd scanned and vectorized a paper copy and then performed post-stack processing, including coherence filtering and deconvolution. The receiver functions of a broad-band seismic station located near the village of Vélez Rubio, at the SE end of the profile, were analysed by Julia et al. [Julia, J., Mancilla, F., Morales, J., 2005. Seismic signature of intracrustal magmatic intrusions in the Eastern Betics (Internal Zone), SE Iberia, Geophysical Research Letters 32, L16304, doi:10.1029/2005GL023274.] to determine the structure of the underlying crust. We have used these Vp data to convert the profile to depth. The profile has a mean SE-NW trend, with a SE-Section 44 km in length followed by a NW-Section 20 km in length. The record includes the first 4 s (twtt), which corresponds to 11 km. Two main areas can be seen in the profile. At the SE-end, a band of high-amplitude discontinuous reflectors dips towards the north. The band is 100 to 200 ms thick, increasing even more northwards. This band reaches the surface at the top of the Maláguide Complex (the upper complex of the Internal Zones). Above these reflectors, an area with chaotic seismic facies and no reflectors corresponds to the outcrops of the olistostromes and turbidites of the Solana Formation, and it is in turn overlain by discontinuous reflectors of the Subbetic rocks. At the NW-end of the profile, a set of high-amplitude continuous reflectors with SE dips point to the location of the Prebetic. Below this section, oblique reflectors of intermediate amplitude indicate the Variscan basement. Over the Prebetic, we have marked the basal thrusts of the Intermediate Units and the Subbetic. Using this seismic data, as well as field observations, we propose a geological cross-section of the upper crust of the eastern Betic Cordillera

  4. Hydrothermal activity and its paleoecological implications in the latest Miocene to Middle Pleistocene lacustrine environments of the Baza Basin (Betic Cordillera, SE Spain)

    NASA Astrophysics Data System (ADS)

    García-Aguilar, José Manuel; Guerra-Merchán, Antonio; Serrano, Francisco; Palmqvist, Paul; Flores-Moya, Antonio; Martínez-Navarro, Bienvenido

    2014-07-01

    The continental sedimentary record of the Baza Basin (Guadix-Baza Depression, Betic Cordillera, SE Spain) shows six sedimentary units of lacustrine origin deposited from the latest Miocene to the Middle Pleistocene. Depending on the interval considered, the lacustrine deposits are mainly composed of marls, carbonates or gypsiferous evaporites, showing lithological, mineralogical and geochemical features (i.e., magnesium, strontium and sulfur contents, celestine deposits and travertine growths) that are evidence of intense, tectonically-induced hydrothermal activity. According to the high concentrations of strontium and sulfur as well as the abundance of travertines and magnesium clays, the supply of hot waters was greater during the Zanclean, the Gelasian and the Calabrian, as a result of tectonic activity. Hydrothermal activity has continued until the present time and is responsible of the hot springs that are nowadays active in the Guadix-Baza Depression. The paleoenvironmental consequences of these sublacustrine hot springs were that during some intervals the lakes maintained a relatively permanent water table, not subject to periodic desiccations in the dry season, and warmer temperatures throughout the year. This resulted in a high level of organic productivity, especially for the Calabrian, which allowed the development of a rich and well diversified mammalian community, similar to those of modern African savannas with tree patches. In this mild environment, the permanent water sheet favored the presence of drought intolerant megaherbivores such as the giant extinct hippo Hippopotamus antiquus. The high standing crop biomass of ungulates resulted in the availability of abundant carcasses for scavengers such as hyenas and hominins, which explains the very high densities of skeletal remains preserved in the sediments distributed along the lake surroundings.

  5. A reassessment of the evidence for hydrothermal activity in the Neogene-Quaternary lacustrine environments of the Baza basin (Betic Cordillera, SE Spain) and its paleoecological implications

    NASA Astrophysics Data System (ADS)

    García-Aguilar, José Manuel; Guerra-Merchán, Antonio; Serrano, Francisco; Flores-Moya, Antonio; Delgado-Huertas, Antonio; Espigares, M. Patrocinio; Ros-Montoya, Sergio; Martínez-Navarro, Bienvenido; Palmqvist, Paul

    2015-03-01

    In a recent paper, García-Aguilar et al. (2014) reported on lithological, mineralogical and geochemical evidence of intense, tectonically-induced hydrothermal activity during the continental sedimentary infilling of the Baza basin, a postorogenic, intramontane area developed on the boundary between the Internal and External Zones of the Betic Cordillera, Southeast Spain (Fig. 1). This evidence includes the finding of sulfur contents, magnesium clays, fluorspar and celestine deposits, thermogene stromatolites and travertine growths in the latest Miocene (Turolian) to Middle Pleistocene lacustrine sediments and is particularly concentrated at certain stages and places (e.g. at Calabrian times in the Orce area).

  6. Flow in the shallow mantle in the westernmost Mediterranean: insights from xenoliths in Plio-Pleistocene alkali basalts from the eastern Betic Cordillera (SE Spain)

    NASA Astrophysics Data System (ADS)

    Konc, Zoltán; Hidas, Károly; Garrido, Carlos J.; Tommasi, Andréa; Vauchez, Alain; Padrón Navarta, José Alberto; Marchesi, Claudio; Acosta-Vigil, Antonio; Szabó, Csaba; Varas-Reus, Maria Isabel

    2016-04-01

    Peridotite mantle xenoliths in Plio-Pleistocene alkali basalts of the eastern Betic Cordillera (Cartagena area, Murcia, SE Spain) provide a snapshot of the structure and composition of the lithospheric mantle at the northern limb of the Alpine Betic-Rif arched belt in the westernmost Mediterranean. The xenoliths are spinel and plagioclase lherzolite with minor harzburgite and wehrlite, displaying porphyroclastic to equigranular textures. Regardless of composition and texture, the Crystal Preferred Orientation (CPO) of olivine shows an axial-[100] pattern characterized by a strong alignment of [100]-axes near or parallel to the peridotite lineation and a girdle distribution of [010]-axes with a maximum normal to the peridotite foliation. This CPO pattern is consistent with ductile deformation accommodated by dislocation creep with dominant activation of the high temperature {0kl}[100] olivine slip system, indicative of deformation by simple shear or combinations of simple shear and pure shear with a transtensional component. Calculated seismic properties are characterized by fast propagation of P-waves and polarization of fast S-waves parallel to olivine [100]-axis, indicating the flow direction. SKS and Pn anisotropy in the eastern Betics can be explained by a lithospheric mantle peridotite with similar fabric to the one displayed by the studied mantle xenoliths. Considering the limited thickness of the mantle lithosphere in the Betics (40-80 km), the measured azimuths and delays of SKS waves in the eastern Betics are consistent with a steeply dipping mantle foliation and a subhorizontal lineation with ENE strike. This geometry of the lithospheric fabrics implies active or frozen mantle flow with a dominantly strike-slip component subparallel to the paleo-Iberian margin. Synkinematic overprinting of mineral assemblages from the garnet-spinel to the plagioclase facies demonstrates 36-40 km uplift continuously accommodated by ductile shear thinning of the

  7. Evolution of near-surface ramp-flat-ramp normal faults and implication during intramontane basin formation in the eastern Betic Cordillera (the Huércal-Overa Basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Pedrera, Antonio; Galindo-ZaldíVar, Jesús; Lamas, Francisco; Ruiz-ConstáN, Ana

    2012-08-01

    The nucleation, propagation, and associated folding of ramp-flat-ramp normal faults were analyzed from field examples developed in a brittle/ductile multilayer sequence of the Huércal-Overa Basin (SE Spain). Gently dipping sandy silt layers, which display a low cohesive strength (C0 = 7 kPa, μ= 34°), favor the development of extensional detachments. A tectonic origin instead of a possible gravitational origin is supported by the perpendicularity between the paleoslope direction of the fluvial-deltaic environment inferred from imbricated pebbles, and the senses of movement deduced from fault slicken-lines. The link between high-angle normal faults (HANFs) —formed at different levels in the layered sequence— with horizontal fault segments comes to develop ramp-flat-ramp normal faults with associated roll-over in the hanging wall. Observed extensional duplexes are formed by parallel detachments connected through synthetic Riedel faults. These Riedel faults would produce the back-rotation of the individual blocks (horses), i.e., extensional folding of the originally subhorizontal layers. There is no correlation between the analyzed ramp-flat-ramp normal faults, accommodating south-southeastward extension during Serravallian-lower Tortonian, and either the regional Alpujarride/Nevado-Filabride west-directed extensional shear zone or the top-to-the-north detachments within Alpujarride units, which are clearly sealed by Serravallian-lower Tortonian sediments. Therefore, the studied normal faults are restricted to the brittle/ductile multilayer fluvio/deltaic sequence and accommodate moderate late extension instead of belonging to a large crustal extensional system connected with a regional detachment at depth. Therefore, the basin formed in a moderate crustal thickness context where small and medium-scale extensional systems were subordinate structures. These natural examples support the development of low-angle normal faults at very shallow crustal levels in

  8. Contrasting Modern and 10Be- derived erosion rates for the Southern Betic Cordillera, Spain

    NASA Astrophysics Data System (ADS)

    Bellin, N.; Vanacker, V.; Kubik, P.

    2012-04-01

    In Europe, Southeast Spain was identified as one of the regions with major treat of desertification in the context of future land use and climate change. During the last years, significant progress has been made to understand spatial patterns of modern erosion rates in these semi-arid degraded environments. Numerous European projects have contributed to the collection of modern erosion data at different spatial scales for Southeast Spain. However, these data are rarely analysed in the context of long-term changes in vegetation, climate and human occupation. In this paper, we present Modern and Holocene denudation rates for small river basins (1 to 10 km2) located in the Spanish Betic Cordillera. Long-term erosion data were derived from cosmogenic nuclide analyses of river-borne sediment. Modern erosion data were quantified through analysis of sediment deposition volumes behind check dams, and represent average erosion rates over the last 10 to 40 years. Modern erosion rates are surprisingly low (mean erosion rate = 0.048 mm y-1; n=36). They indicate that the steep, sparsely vegetated hillslopes in the Betic Cordillera cannot directly be associated with high erosion rates. 10Be -derived erosion rates integrate over the last 37500 to 3500 years, and are roughly of the same magnitude. They range from 0.013 to 0.243 mm y-1 (mean denudation rate = 0.062 mm y-1 ± 0.054; n=20). Our data suggest that the modern erosion rates are similar to the long-term erosion rates in this area. This result is in contrast with the numerous reports on human-accelerated modern erosion rates for Southeast Spain. Interestingly, our new data on long-term erosion rates show a clear spatial pattern, with higher erosion rates in the Sierra Cabrera and lower erosion rates in Sierra de las Estancias, and Sierra Torrecilla. Preliminary geomorphometric analyses suggest that the spatial variation that we observe in long-term erosion rates is related to the gradient in uplift rates of the Betic

  9. CO2-rich thermomineral groundwater in the Betic Cordilleras, southeastern Spain: Genesis and tectonic implications

    NASA Astrophysics Data System (ADS)

    Cerón, J. C.; Martín-Vallejo, M.; García-Rossell, L.

    The CO2-rich thermal groundwater in the Betic Cordilleras in Spain has been studied with regard to the geological and hydrogeological setting, physical and chemical characteristics, and 13C-isotope content. The study area is about 60km northeast of Almería city, in southeastern Spain. The thermomineral waters are plentiful and are related to regional geothermal anomalies. Temperatures of 20 -41°C, high bicarbonate concentrations (183-1824mg/L), and high amounts of PCO2 (<1.1bar) characterize the groundwater. CO2 spatial variations are related to proximity to the Carboneras, Palomares, and Guadalentín fault systems, which may be the surface representation of the zone of crustal thinning and magmatism. δ13C values probably indicate a deep source for the CO2, either the mantle or perhaps carbonate rocks in the metamorphic substratum. The high amount of CO2 in the groundwater causes problems in wells and severely restricts water usage. The hydrothermal features of this area are probably related to neotectonic activity. Résumé Les eaux thermales à teneurs élevées en CO2 des Cordillères Bétiques ont étéétudiées, spécialement en ce qui concerne les aspects géologiques et hydrogéologiques, leurs caractéristiques physiques et chimiques, et leurs teneurs en 13C. La zone d'étude est située à 60km environ au nord-est de la ville d'Almería, au sud-est de l'Espagne. Les eaux thermominérales sont nombreuses et sont en relation avec les anomalies géothermales régionales. L'eau souterraine a une température comprise entre 20-41°C, une concentration élevée en bicarbonates (entre 183 et 1824mg/L), et PCO2élevée (<1.1bars). Les variations spaciales de CO2 sont en rapport avec la proximité des systèmes de failles de Carboneras, Palomares et Guadalentin, et peuvent être la manifestation en surface d'une zone d'amincissement cortical. Les données de δ13C indiquent un apport probable d'origine profonde de CO2, éventuellement du manteau et/ou des

  10. Space-time evolution of a growth fold (Betic Cordillera, Spain). Evidences from 3D geometrical modelling

    NASA Astrophysics Data System (ADS)

    Martin-Rojas, Ivan; Alfaro, Pedro; Estévez, Antonio

    2014-05-01

    We present a study that encompasses several software tools (iGIS©, ArcGIS©, Autocad©, etc.) and data (geological mapping, high resolution digital topographic data, high resolution aerial photographs, etc.) to create a detailed 3D geometric model of an active fault propagation growth fold. This 3D model clearly shows structural features of the analysed fold, as well as growth relationships and sedimentary patterns. The results obtained permit us to discuss the kinematics and structural evolution of the fold and the fault in time and space. The study fault propagation fold is the Crevillente syncline. This fold represents the northern limit of the Bajo Segura Basin, an intermontane basin in the Eastern Betic Cordillera (SE Spain) developed from upper Miocene on. 3D features of the Crevillente syncline, including growth pattern, indicate that limb rotation and, consequently, fault activity was higher during Messinian than during Tortonian; consequently, fault activity was also higher. From Pliocene on our data point that limb rotation and fault activity steadies or probably decreases. This in time evolution of the Crevillente syncline is not the same all along the structure; actually the 3D geometric model indicates that observed lateral heterogeneity is related to along strike variation of fault displacement.

  11. Remelting of nanogranites in peritectic garnet from granulites of Jubrique, Betic Cordillera, Southern Spain

    NASA Astrophysics Data System (ADS)

    Barich, Amel; Bartoli, Omar; Acosta-Vigil, Antonio; Poli, Stefano; Cesare, Bernardo; Garrido, Carlos J.

    2014-05-01

    Peritectic minerals in migmatites can trap droplets of melt that form via incongruent melting reactions during crustal anatexis [1]. In most cases, these melts crystallize and form nanogranites upon slow cooling of the anatectic terrane [2]. To obtain information on the primary compositions of crustal melts, including volatile concentrations in melt and information on fluid regimes, nanogranites must be remelted and rehomogenized before analysis [3]. A new occurrence of nanogranites was recently reported in granulitic gneisses at the bottom of the prograde metamorphic sequence of Jubrique, located on top of the Ronda peridotite slab (Betic Cordillera, S Spain) [4]. These nanogranites are trapped in garnet porphyroblasts. They show partially irregular to well facetted negative crystal shapes, and have variable size from ~5-10 μm to several tens of μm or even ~200 μm in diameter. They appear at the core and rim of large Grt crystals, and are composed of rare glass, daughter Qz, Pl, Kfs, Bt and Ms, and solid inclusions of Ky and less frequently Gr, Hc, Rt, Ilm, Zrn and Mnz. Ky was the main solid phase that favored the trapping of melt inclusions (MI) by poisoning crystal surfaces during Grt growth. The presence of Ky+Rt within MI, and their occurrence in the high-P cores of Grt, suggest that partial melting in the gneisses initiated at relatively high P conditions, and that most Grt in these rocks crystallized in the presence of melt. To recover the major and trace element composition of the primary melt during anatexis, we performed remelting experiments on chips of MI-bearing Grt separated from a sample of gneiss at Jubrique, using a piston cylinder apparatus. Experiments were run at 800, 825 and 850° C, 15 Kbar and dry conditions (i.e. no added H2O) for 24 hrs. Preliminary results of the first experiment at 850º show that nanogranites have been successfully remelted; they all contain glass regardless of their textural position, i.e. at the core and rim of

  12. Neogene uplift of the eastern Betic Cordillera (Spain) : new constraints from low-temperature thermochronology and stream profile analysis

    NASA Astrophysics Data System (ADS)

    Janowski, Marianne; Loget, Nicolas; Gautheron, Cécile; Meyer, Bertrand; Van Den Driessche, Jean; Babault, Julien

    2015-04-01

    The Betic Cordillera (south Spain), forms the western european ending of the peri-Mediterranean alpine belts. In the eastern Betics, uplift of the cordillera and the peripheral neogene marine basins results from recent tectonic processes (shortening linked to Africa-Eurasia convergence, dynamic topography associated with Alboran slab evolution). These processes are connected to the Alboran domain tectonic inversion subsequent to the Miocene thinning stage and exhumation of metamorphic domes. These metamorphic domes now correspond to the highest topographies in the area (e.g. Sierra Nevada, Sierra de Gador) surrounded by the neogene basins. Based on a geomorphological study of the eastern Betics, and a LT thermochronology analysis focused on the Sierra de Gador, our aim is to bring new constraints on the late-neogene topography evolution. Apatite (U-Th)/He analysis was performed on samples from the Alpujarride Complex of the Sierra de Gador and reveals an AHe cooling age of ~ 9 Ma. Thermal modeling of the Alpujarride Complex, based on the new AHe and published data (AFT, ZFT and Ar/Ar on muscovite), was performed using QTQt software. The thermal model shows a very fast cooling of ~ 120°C/Ma between 20 and 16 Ma associated with Miocene thinning, then a brutal stop in the cooling path between 16 and 10 Ma when the temperature remains approximately at 65°C and may be linked to a peneplanation event. Low-relief surfaces (detected by relief spatial analysis and field mapping) preserved at the summit of the Sierra de Gador could be related to this event. Surfacing is constrained by uncomfortably late-tortonian inner platform deposits on the top of the Sierra de Gador. Post-Tortonian non-resetting indicates (i) the thickness of these platform deposits has not been significant, and (ii) tortonian tectonic inversion of the domain is not expressed in the exhumation signal. On the other hand, we performed a stream profile analysis to investigate large scale neogene uplift

  13. Emplacement of the Cabezo María lamproite volcano (Miocene, SE Spain)

    NASA Astrophysics Data System (ADS)

    Gernon, Thomas M.; Spence, Samuel; Trueman, Clive N.; Taylor, Rex N.; Rohling, Eelco; J. Hatter, Stuart; Harding, Ian C.

    2015-06-01

    Lamproite volcanoes are uncommon in the geological record but are exceptionally well preserved in the Betic Cordilleras of SE Spain, where they erupted during the Late Miocene (Tortonian to Messinian stages). The parent melts are thought to have been channelled through major lithospheric faults to erupt at or near the faulted margins of Neogene sedimentary basins. Lamproite magmas are thought to be relatively CO2-poor (<1 wt %) and are typically characterised by an effusive eruption style and the development of lava lakes and scoria cones. Cabezo María is a relatively small (˜550 m diameter) lamproite volcano that was emplaced within the shallow-water marine-influenced Vera Basin. The lamproites are compositionally similar to those of the Roman Province and generally less potassic (K2O<5 wt%) than other (ultra-) potassic rocks in SE Spain (e.g. Cancarix, Fortuna). The initial eruption stages were dominated by explosive magma-water interactions and the formation of peperites. These are characterised by angular fragments of glassy lamproite lavas (and isolated lobes) incorporated in sediments, locally showing the effects of thermal metamorphism. Further, elutriation pipes and `jigsaw-fit' textures are observed in the peperites. The lavas and peperites are overlain by outward-dipping well-stratified scoria deposits defining part of a cinder cone, which is inferred to have emerged above sea level. Steep internal contacts with inward-dipping, structureless breccias likely represent the inner wall deposits of a central conduit. The deposits are cross-cut by late-stage dykes, which supplied fissure eruptions of geochemically similar lavas capping the scoria cone. The transition from explosive to effusive behaviour may reflect the decreased availability of water, possibly due to downward migration of the feeder conduit below the level of water-saturated sediments.

  14. Microstructures and petrology of melt inclusions in the anatectic sequence of Jubrique (Betic Cordillera, S Spain): Implications for crustal anatexis

    NASA Astrophysics Data System (ADS)

    Barich, Amel; Acosta-Vigil, Antonio; Garrido, Carlos J.; Cesare, Bernardo; Tajčmanová, Lucie; Bartoli, Omar

    2014-10-01

    We report a new occurrence of melt inclusions in polymetamorphic granulitic gneisses of the Jubrique unit, a complete though strongly thinned crustal section located above the Ronda peridotite slab (Betic Cordillera, S Spain). The gneissic sequence is composed of mylonitic gneisses at the bottom and in contact with the peridotites, and porphyroblastic gneisses on top. Mylonitic gneisses are strongly deformed rocks with abundant garnet and rare biotite. Except for the presence of melt inclusions, microstructures indicating the former presence of melt are rare or absent. Upwards in the sequence, garnet decreases whereas biotite increases in modal proportion. Melt inclusions are present from cores to rims of garnets throughout the entire sequence. Most of the former melt inclusions are now totally crystallized and correspond to nanogranites, whereas some of them are partially made of glass or, more rarely, are totally glassy. They show negative crystal shapes and range in size from ≈ 5 to 200 μm, with a mean size of ≈ 30-40 μm. Daughter phases in nanogranites and partially crystallized melt inclusions include quartz, feldspars, biotite and muscovite; accidental minerals include kyanite, graphite, zircon, monazite, rutile and ilmenite; glass has a granitic composition. Melt inclusions are mostly similar throughout all the gneissic sequence. Some fluid inclusions, of possible primary origin, are spatially associated with melt inclusions, indicating that at some point during the suprasolidus history of these rocks granitic melt and fluid coexisted. Thermodynamic modeling and conventional thermobarometry of mylonitic gneisses provide peak conditions of ≈ 850 °C and 12-14 kbar, corresponding to cores of large garnets with inclusions of kyanite and rutile. Post-peak conditions of ≈ 800-850 °C and 5-6 kbar are represented by rim regions of large garnets with inclusions of sillimanite and ilmenite, cordierite-quartz-biotite coronas replacing garnet rims, and the

  15. Microstructures and Petrology of Melt Inclusions in the Anatectic Sequence of Jubrique (Betic Cordillera, S Spain): Implications for Crustal Anatexis

    NASA Astrophysics Data System (ADS)

    Acosta-vigil, A.; Barich, A.; Garrido, C. J.; Cesare, B.; Tajčmanová, L.; Bartoli, O.

    2014-12-01

    We report a new occurrence of melt inclusions in polymetamorphic granulitic gneisses of the Jubrique unit, a complete though thinned crustal section located above the Ronda peridotite slab (Betic Cordillera, S Spain). The gneissic sequence is composed of mylonitic gneisses at the bottom and porphyroblastic gneisses on top. Mylonitic gneisses are strongly deformed rocks with abundant garnet and rare biotite. Except for the presence of melt inclusions, microstructures indicating the former presence of melt are rare or absent. Upwards in the sequence garnet decreases whereas biotite increases in proportion. Melt inclusions are present from cores to rims of garnets throughout the entire sequence. Most of the former melt inclusions are now totally crystallized and correspond to nanogranites, whereas some of them are partially made of glass or, more rarely, are totally glassy. They show negative crystal shapes and range in size from ≈5 to 200 micrometers, with a mean size of ≈30-40 micrometers. Daughter phases in nanogranites and partially crystallized melt inclusions include quartz, feldspars, biotite and muscovite; accidental minerals include kyanite, graphite, zircon, monazite, rutile and ilmenite; glass has a granitic composition. Melt inclusions are mostly similar throughout all the gneissic sequence. Some fluid inclusions, of possible primary origin, are spatially associated with melt inclusions, indicating that at some point during the suprasolidus history of these rocks granitic melt and fluid coexisted. Thermodynamic modeling and conventional thermobarometry of mylonitic gneisses provide peak conditions of ≈850 ºC and 12-14 kbar, corresponding to cores of large garnets with inclusions of kyanite and rutile. Post-peak conditions of ≈800-850 ºC and 5-6 kbar are represented by rim regions of large garnets with inclusions of sillimanite and ilmenite, cordierite-quartz-biotite coronas replacing garnet rims, and the matrix with oriented sillimanite. Previous

  16. Benthic foraminiferal biostratigraphy of the Aalenian-Bajocian (Middle Jurassic) boundary in the Barranco de Agua Larga section (Betic Cordillera, southern Spain)

    NASA Astrophysics Data System (ADS)

    Silva, Sílvia; Canales, María Luisa; Sandoval, José; Henriques, Maria Helena

    2016-04-01

    This work describes the benthic foraminiferal assemblages recorded across the Aalenian - Bajocian boundary in the Barranco de Agua Larga section (Betic Cordillera, SE of Spain), where the ammonite record has enabled the recognition of the Gigantea Subzone in the Bradfordensis Zone (Middle Aalenian), the Concavum and Limitatum subzones in the Concavum Zone (Upper Aalenian) and the Discites Zone (Lower Bajocian). This reference section is characterized by an alternation of limestones and marly limestones corresponding to distal marine environmental conditions, where a total of 17 samples have been collected. They have provided abundant and diverse foraminiferal assemblages, constituted by well-preserved specimens displaying close similarities to those already described for the Jurassic carbonate platforms of the Boreal Realm. From the study of the samples, a total of 3139 specimens have been obtained, corresponding to 5 suborders, 11 families, 25 genus and 80 species. The representatives of the Suborder Lagenina are the most abundant, Vaginulinidae is the most abundant family and Lenticulina is the most abundant genus. From a specific level, the most abundant species are Thurammina jurensis (Franke), Lenticulina muensteri (Roemer) and Prodentalina pseudocommunis (Franke). The occurrence of Astacolus dorbignyi (Roemer) in the Gigantea Subzone has enabled the recognition of the Astacolus dorbignyi Zone. The first occurrence of Lenticulina quenstedti (Gümbel) in the Concavum Subzone has allowed the recognition of the Lenticulina quenstedti Zone. In Barranco de Agua Larga section this species co-occur with Ramulina spandeli Paalzow, the index fossil used in the establishment of the Ramulina spandeli Zone. This zone was defined in the lower part of the Discites Zone in the Murtinheira section (the Bajocian GSSP) and related to distal platform conditions. In the Iberian Basin the Ramulina spandeli Zone was recognized in the Hontoria del Pinar section, but not in the

  17. Seismic transpressive basement faults and monocline development in a foreland basin (Eastern Guadalquivir, SE Spain)

    NASA Astrophysics Data System (ADS)

    Pedrera, A.; Ruiz-Constán, A.; Marín-Lechado, C.; Galindo-Zaldívar, J.; González, A.; Peláez, J. A.

    2013-12-01

    We examine the late Tortonian to present-day deformation of an active seismic sector of the eastern Iberian foreland basement of the Betic Cordillera, in southern Spain. Transpressive faults affecting Paleozoic basement offset up to Triassic rocks. Late Triassic clays and evaporites constitute a décollement level decoupling the basement rocks and a ~100 m thick cover of Jurassic carbonates. Monoclines trending NE-SW to ENE-WSW deform the Jurassic cover driven by the propagation of high-angle transpressive right-lateral basement faults. They favor the migration of clays and evaporites toward the propagated fault tip, i.e., the core of the anticline, resulting in fluid overpressure, fluid flow, and precipitation of fibrous gypsum parallel to a vertical σ3. The overall geometry of the studied monoclines, as well as the intense deformation within the clays and evaporites, reproduces three-layer discrete element models entailing a weak middle unit sandwiched between strong layers. Late Tortonian syn-folding sediments recorded the initial stages of the fault-propagation folding. Equivalent unexposed transpressive structures and associated monoclines reactivated under the present-day NW-SE convergence are recognized and analyzed in the Sabiote-Torreperogil region, using seismic reflection, gravity, and borehole data. A seismic series of more than 2100 low-magnitude earthquakes was recorded within a very limited area of the basement of this sector from October 2012 to May 2013. Seismic activity within a major NE-SW trending transpressive basement fault plane stimulated rupture along a subsidiary E-W (~N95°E) strike-slip relay fault. The biggest event (mbLg 3.9, MW 3.7) occurred at the junction between them in a transpressive relay sector.

  18. The Eastern delta-fan deposits on the Granada Basin as tectonic indicators of the Sierra Nevada uplift (Betic Cordillera, South Spain)

    NASA Astrophysics Data System (ADS)

    Roldán, Francisco Javier; Azañon, Jose Miguel; Mateos, Rosa Maria

    2014-05-01

    Sierra Nevada uplift and with original NE-SW normal left-lateral fault system associated with a compatible ESE-WNW normal fault system. The asymmetrical morphologies of the two delta-fan bodies confirm this configuration as tectonic induced deposits. References Braga, J.C., Martín, J.M. and Alcalá, B. (1990). Coral reefs in coarse-terrigenous sedimentary environments (Upper Tortonian, Granada Basin, southern Spain). Sedimentary Geology, 66, pp 135-150. Clark, S.J.P.and Dempster, T.J. (2009). The record of tectonic denudation and erosion in an emerging orogen: an apatite fission-track study of the Sierra Nevada, southern Spain. Journal of the Geological Society, London, Vol. 166, pp. 87-100. Dabrio, C.J., Fernández, J., Peña, J., Ruíz-Bustos, A. y Sanz de Galdeano, C. (1978). Rasgos sedimentarios de los conglomerados miocénicos del borde noreste de la Depresión de Granada. Estudios Geológicos, 34, pp 89-97. García-García, F., Fernández, J., Viseras, C. and Soria, J.M. (2006). Architecture and sedimentary facies evolution in a delta stack controlled by fault growth (Betic Cordillera, southern Spain, late Tortonian). Sedimentary Geology, 185, pp. 79-92. García-García, F., Viseras, C. and Fernández, J. (1999). Organización secuencial de abanicos deltaicos controlados por la tectónica (Tortoniense superior, cuenca de Granada, Cordillera Bética). Rev. Soc. Geol. España, 12 (2): 199-208.

  19. Metasedimentary and igneous xenoliths from Tallante (Betic Cordillera, Spain): Inferences on crust-mantle interactions and clues for post-collisional volcanism magma sources

    NASA Astrophysics Data System (ADS)

    Bianchini, Gianluca; Braga, Roberto; Langone, Antonio; Natali, Claudio; Tiepolo, Massimo

    2015-04-01

    The deep seated xenolith association exhumed in the Pliocenic volcano of Tallante (Betic Cordillera, Spain) includes protogranular mantle peridotites, felsic (metasedimentary) crustal rocks, as well as cumulus igneous rocks such as norites and amphibole (± phlogopite)-clinopyroxenites. The whole xenolith suite equilibrated at the same pressure (0.7-0.9 GPa) representing the local crust-mantle boundary (MOHO) characterized by extreme lithological heterogeneity. This heterogeneity resulted from orogenic processes that induced the juxtaposition of crustal rocks (variably depleted in fusible components) within mantle domains including metasomes, as it is commonly observed in orogenic mantle massifs of the Mediterranean area. In this contribution, we report new mineral compositions of igneous parageneses recorded in these xenoliths, and we present Sr-Nd isotope data on both igneous and metasedimentary xenoliths that integrate those from the literature. Sr-Nd isotopes coherently indicate a restitic character of the metasedimentary xenoliths, which according to model ages were affected by partial melting in Paleozoic times. Sr-Nd isotopic errorchrons on the igneous xenoliths, on the other hand, qualitatively indicate Tertiary ages, which are corroborated by U-Pb zircon datings of one norite xenolith and two composite xenoliths having zircon-bearing norite veinlets. The new data are discussed proposing that MOHO lithologies of Tallante could provide significant source compositions for the genesis of the Neogene volcanics of the Betic area, which included calcalkaline lavas as well as more potassic products such as lamproites.

  20. Neotectonics and morphotectonics of the southern Almería region (Betic Cordillera-Spain) kinematic implications

    NASA Astrophysics Data System (ADS)

    Martínez-Díaz, José J.; Hernández-Enrile, J. L.

    Most previous studies related to the recent tectonic development of southeastern Betic Cordillera, and in particular the south of Almería, agree with the kinematic variety that can be observed in the post-Miocene structures at different scales. This variety is difficult to explain if we consider only the regional stress field related to the convergence of the Eurasian and African plates that remained relatively steady over the last 9 Ma. This work proposes a block tectonics with horizontal and vertical relative movements driven by strike-slip movements of major faults to explain the variety of kinematics observed in the area from Middle Miocene to present. The combined activity of the Alpujarras fault zone (dextral strike-slip) and the Carboneras fault zone (sinistral strike-slip) induces, within the major block bounded by them, the squeezing of minor pre-existing fault bounded crustal blocks. This process generates traction areas inside the escaping block, which are linked with the existence of gradients of westward movement rate. This tectonics can explain some of the structures related with the extensional tectonics predominant in the south of Almería province and the development of the minor and major morphostructures driven by faults with different kinematics. The tectonics of blocks proposed is useful to give a coherent interpretation of apparently incoherent local structural data into a regional and homogeneous compressional stress field.

  1. Upper Pleistocene - Holocene activity of the Carrascoy Fault (Murcia, SE Spain): preliminary results from paleoseismological research.

    NASA Astrophysics Data System (ADS)

    Martin-Banda, Raquel; Garcia-Mayordomo, Julian; Insua-Arevalo, Juan M.; Salazar, Angel; Rodriguez-Escudero, Emilio; Alvarez-Gomez, Jose A.; Martinez-Diaz, Jose J.; Herrero, Maria J.; Medialdea, Alicia

    2014-05-01

    The Carrascoy Fault is located in the Internal Zones of the Betic Cordillera (Southern Spain). In particular, the Carrascoy Fault is one of the major faults forming the Eastern Betic Shear Zone, the main structure accommodating the convergence between Nubian and Eurasian plates in the westernmost Mediterranean. So far, the Carrascoy Fault has been defined as a left-lateral strike-slip fault. It extends for at least 31 km in a NE-SW trend from the village of Zeneta (Murcia) at its northeastern tip, to the Cañaricos village, controlling the northern edge of the Carrascoy Range and its linkage to the Guadalentin Depression towards the southwest. This is an area of moderate seismic activity, but densely populated, the capital of the region, Murcia, being settled very close to the fault. Hence, the knowledge of the structure and kinematics of the Carrascoy Fault is essential for assessing reliably the seismic hazard of the region. We present a detailed-scale geological and geomorphological map along the fault zone created from a LIDAR DEM combined with fieldwork, and geological and geophysical information. Furthermore, a number of trenches have been dug across the fault at different locations providing insights in the fault most recent activity as well as paleoseismic data. Preliminary results suggest that the Cararscoy Fault has recently changed its kinematic showing a near pure reverse motion. According to this, the fault can be divided into two distinct segments, the eastern one: Zeneta - Fuensanta, and the western one: Fuensanta - Cañaricos, each one having its own characteristic style and geodynamics. Some new active strands of the fault locate at the foot of the very first relief towards the North of the older strand, forming the current southern border of the Guadalentin Depression. These new faults show an increasingly reverse component westwards, so that the Fuensanta - Cañaricos segment is constituted by thrusts, which are blind at its western end

  2. Diagenetic evolution of Tortonian temperate carbonates close to evaporites in the Granada Basin (SE Spain)

    NASA Astrophysics Data System (ADS)

    López-Quirós, A.; Barbier, M.; Martín, J. M.; Puga-Bernabéu, Á.; Guichet, X.

    2016-04-01

    The Granada Basin (SE Spain) is a small basin located in the central part of the Betic Cordillera, structured as such in the late Tortonian and initially connected to the Atlantic Ocean and to the Mediterranean Sea. During the late Tortonian, normal marine conditions prevailed, leading to the deposition of skeletal carbonate sediments on platforms around structural highs. The marine connections were later interrupted, first to the Atlantic Ocean and then to the Mediterranean Sea, and a thick evaporite sequence, marking the transition from marine to continental conditions, was deposited during the latest Tortonian. In this work, the diagenetic evolution of the Tortonian temperate carbonates (TTC), underlying and close to the evaporite bodies, is revealed and discussed. The diagenetic study includes petrographic analyses (conventional petrography, cathodoluminescence, and fluorescence), geochemical analyses (major, minor and trace elements, and δ13C and δ18O stable isotopes), and microthermometry of fluid inclusions. In the TTC, marine diagenetic processes such as micritization and fibrous calcite-cement precipitation and mechanical compaction took place during or just after deposition (Eogenesis). An initial burial event (Mesogenesis 1) is characterized by: 1) stabilization of the temperate-water carbonates by freshwater, and 2) porosity occlusion via precipitation of low-Mg bladed and syntaxial/mosaic calcite cements. The TTC were then subaerially exposed (or got close to the surface) during evaporite deposition and underwent pedogenesis, Mg-smectite infiltration, and pyrite formation (Telogenesis 1). Subsequent brine-related diagenetic alterations, such as dolomitization and silica, halite, and sylvite replacements of carbonate grains occurred during a second burial episode (Mesogenesis 2) concomitant with the Messinian lacustrine deposition, this being followed by chemical compaction (stylolite formation). Finally, the area was uplifted and the TTC exhumed

  3. Geomorphological impacts of an extreme flood in SE Spain

    NASA Astrophysics Data System (ADS)

    Hooke, J. M.

    2016-06-01

    Long-term field studies in semiarid ephemeral streams are rare. These geomorphic data are essential for understanding the nature of the processes in order to develop modelling for risk assessments and management. An extreme flood event on 28 September 2012 affected the Murcia region of SE Spain, including long-tem monitoring sites on two fluvial systems in the Guadalentín basin, the Nogalte and Torrealvilla. Detailed morphological data were collected before and immediately after the event; and the amount of morphological change, erosion, and deposition have been related to peak flow conditions at the sites. On the Nogalte channel, peak flow reached 2500 m3 s- 1 at the downstream end of the catchment in less than 1 h. The event had a recurrence interval of > 50 years based on rainfall records and damage to old irrigation structures. The major effect in the braided, gravel channel of the Nogalte was net aggradation, with massive deposition in large flat bars. The measured changes in bankfull capacity were highly correlated with most hydraulic variables. Net changes in cut-and-fill in cross sections on the Nogalte were highly related to peak discharge and stream power but much less so to measures of hydraulic force (velocity, shear stress, unit stream power). Relationships of amount of erosion to hydraulic variables were much weaker than for amount of deposition, which was largely scaled to channel size and flow energy. Changes on the Torrealvilla were much less than on the Nogalte, and net erosion occurred at all sites. Sites on the Nogalte channel in schist exhibited higher deposition than those of the Torrealvilla sites on marl for the same hydraulic values. Overall, less morphological change took place in the extreme event on the Nogalte than predicted from some published hydraulic relations, probably reflecting the high sediment supply and the hydrological characteristics of the event. The results demonstrate the high degree of adjustment of these channels to

  4. Extensional Detachment faulting in melange rocks. Plurikilometres migration by W the External Zone (Cordillera Bética, Spain)

    NASA Astrophysics Data System (ADS)

    Roldán, Francisco Javier; Azañon, Jose Miguel; Rodríguez, Jose; Mateos, Rosa Maria

    2014-05-01

    The synthesis and correlation of units carried out in the continuous geological map (Roldán et al., 2012), has revealed a fragmentation of the carbonate outcrops belong to the Subbetic Domain (García-Hernández et al., 1980). Subbetic NW verging thrust and fold axial traces have not lateral continuity and Jurassic carbonate outscrops appear as klippes on the olistotromic unit. These ductile structures that can be observed in the internal structure of these jurassic blocks are unrelated to the brittle-ductile deformation bands observed at the basal pelitic levels. Basal detachments are rooted in: a) the Olistostromic unit, a Upper Langhian-Lower Serravallian breccia constituted by gypsum-bearing clay and marls; b) Cretaceous-Tertiary marly sedimentary rocks (Rodríguez-Fernández, et al., 2013) . In both kind of rocks, cataclastic structures allows to infer a top-to-the WSW displacement. Paleostress measurements, made on these detachments levels, are compatible with a extensional regime (Roldán et al., 2012). At the same time, the analysis and interpretation of subsurface data (seismic surveys and borehole testing) shows that the Subbetic Domain (External Subbetic, Molina 1987) are affected by westward low-angle normal faults. A balanced cross-section, based on morphological and cartographic data in the area between Sierra de Cabra and Sierra de Alta Coloma (Valdepeñas de Jaén), shows plurikilometric displacements which has been produced during Late Serravallian-Early Tortonian times. References: García-Hernández, M., López-Garrido, A.C., Rivas, P., Sanz de Galdeano, C., Vera, J.A. (1980): Mesozoic paleogeographic evolution of the zones of the Betic Cordillera. Geol. Mijnb. 59 (2). 155-168. Molina, J.M. (1987). Análisis de facies del Mesozoico en el Subbético. Tesis Doctoral, Univ. Granada. 518 p. Rodríguez-Fernández, J., Roldán, F. J., Azañón, J.M. y García-Cortés, A. (2013). El colapso gravitacional del frente orogénico a lpino en el Dominio Subb

  5. The composition of nanogranitoids in migmatites overlying the Ronda peridotites (Betic Cordillera, S Spain): the anatectic history of a polymetamorphic basement

    NASA Astrophysics Data System (ADS)

    Acosta-Vigil, Antonio; Barich, Amel; Omar, Bartoli; Garrido, Carlos J.; Cesare, Bernardo; Remusat, Laurent; Poli, Stefano; Raepsaet, Caroline

    2016-04-01

    The study of the composition of primary melts during anatexis of high-pressure granulitic migmatites is relevant to understand the generation and differentiation of continental crust. Peritectic minerals in migmatites can trap dropless of melt that forms via incongruent melting reactions during crustal anatexis. These melt inclusions commonly crystallize and form nanogranitoids upon slow cooling of the anatectic terrane. To obtain the primary compositions of crustal melts recorded in these nanogranitoids, including volatile concentrations and information on fluid regimes, they must be remelted and rehomogenize before analysis. A new occurrence of nanogranitoids was recently reported in garnets of mylonitic metapelitic gneisses (former high pressure granulitic migmatites) at the bottom of the prograde metamorphic sequence of Jubrique, located on top of the Ronda peridotite slab (Betic Cordillera, S Spain). Nanogranitoids within separated chips of cores and rims of large garnets from these migmatites were remelted at 15 kbar and 850, 825 or 800 °C and dry (without added H2O), during 24 hours, using a piston cylinder apparatus. Although all experiments show glass (former melt) within melt inclusions, the extent of rehomogenization depends on the experimental temperature. Experiments at 850-825 °C show abundant disequilibrium microstructures, whereas those at 800 °C show a relatively high proportion of rehomogenized nanogranitoids, indicating that anatexis and entrapment of melt inclusions in these rocks was likely close to 800 °C. Electron microprobe and NanoSIMS analyses show that experimental glasses are leucogranitoid and peraluminous, though define two distinct compositional groups. Type I corresponds to K-rich, Ca- and H2O-poor leucogranitic melts, whereas type II represents K-poor, Ca- and H2O-rich granodioritic to tonalitic melts. Type I and II melt inclusions are found in most cases at the cores and rims of large garnets, respectively. We tentatively

  6. Using nanogranitoids and phase equilibria modeling to unravel anatexis in the crustal footwall of the Ronda peridotites (Betic Cordillera, S Spain)

    NASA Astrophysics Data System (ADS)

    Bartoli, Omar; Acosta-Vigil, Antonio; Tajčmanová, Lucie; Cesare, Bernardo; Bodnar, Robert J.

    2016-07-01

    Anatexis in the crustal footwall of Ronda peridotites (Betic Cordillera, S Spain) is apparently related to the hot emplacement of this mantle slab over metasedimentary rocks. In this study, we combine the analysis of melt inclusions (MI) and phase equilibria calculations on quartzo-feldspathic mylonites (former migmatites) occurring at the contact with the mantle rocks, in the region of Sierra Alpujata (Ojén unit). The goal is to better characterize anatexis in these rocks and to provide new constraints on the geodynamic evolution of the crustal footwall. Such data are important for understanding the mechanisms of crustal emplacement of the mantle slice. The quartzo-feldspathic mylonites are characterized by the mineral assemblage Qtz + Pl + Kfs + Sil + Grt + Ilm + Bt ± Ap ± Gr. Clusters of MI are observed both at the core and toward the rim of peritectic garnet. In each cluster, MI range from totally glassy to nanogranitoids, consisting of Qtz + Kfs + Bt + Ms + Pl aggregates. The trapped melt is leucogranitic and peraluminous with variable Na2O/K2O values and low H2O contents (≈ 2-4 wt%). Phase equilibria modeling in the MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2-TiO2-O2-C (MnNCaKFMASHTOC) system with graphite-saturated fluid constrains the P-T conditions of melting at ≈ 6 kbar, ≈ 820 °C. MI data support the fluid-absent character of melting. The investigated MI represent the primary anatectic melts produced during prograde anatexis of the host rocks via biotite dehydration melting. Field, compositional, and textural observations indicate that mylonitic migmatites represent strongly deformed former diatexites. The comparison between the new data and some recently published information on migmatites located further from the contact with the peridotites and toward the bottom of the crustal footwall, raises some important issues which question the previously proposed geodynamic models for this region. Among them, (i) the crustal footwall at Sierra Alpujata

  7. Late Quaternary large-scale rotational slides induced by river incision: The Arroyo de Gor area (Guadix basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Azañón, José M.; Azor, Antonio; Pérez-Peña, J. Vicente; Carrillo, José M.

    2005-07-01

    The Arroyo de Gor is a highly incised stream (up to 200 m) that has eroded into the Pliocene-Pleistocene infill of the Guadix basin in the Betic cordillera (SE Spain). This paper concentrates on a particular reach of this stream, namely the Cenascuras-Gorafe reach, where abundant inactive rotational slides can be recognized on both hillslopes of the canyon-shaped valley. The rotational slides have surface areas of 5-15 ha and volumes of mobilized material of 5-15 Hm 3. These rotational slides can be recognized by their main scarps, which are still well featured at both margins of the valley, as well as by the counter hillslope rotation of the strata in their bodies. The surfaces of rupture are concave, their width being greater than their length, i.e. the landslides are elongated in a direction perpendicular to the landsliding displacement and parallel to the stream. At depth, the surfaces of rupture developed on fine-grained sediments (mostly clays) underlying the conglomerates and sands affected by the rotational slides. The clays at the surface of rupture are smectite-rich and show several features produced by the landsliding, such as striations and sigmoidal-shaped structures. The Cenascuras-Gorafe canyon has been developed by a combination of entrenchment, fracturing and landsliding. Initial deep entrenchment of the stream is attributed to a base-level lowering related to the capture of the former endorheic basin by the Gualdalquivir river in the late Pleistocene. This river incision created a canyon with subvertical unstable walls, which due to gravitational instability would give way to vertical open tension cracks some distance from the canyon edge. The tension cracks would end at depths equal to the base of the canyon, which also coincides with the contact between the conglomerates and the underlying clays. The rotational slides are thought to have occurred during heavy rains by a combination of piping, which would have lengthened the tension cracks, and

  8. Levelling profiles and a GPS network to monitor the active folding and faulting deformation in the Campo de Dalias (Betic Cordillera, southeastern Spain).

    PubMed

    Marín-Lechado, Carlos; Galindo-Zaldívar, Jesús; Gil, Antonio José; Borque, María Jesús; de Lacy, María Clara; Pedrera, Antonio; López-Garrido, Angel Carlos; Alfaro, Pedro; García-Tortosa, Francisco; Ramos, Maria Isabel; Rodríguez-Caderot, Gracia; Rodríguez-Fernández, José; Ruiz-Constán, Ana; de Galdeano-Equiza, Carlos Sanz

    2010-01-01

    The Campo de Dalias is an area with relevant seismicity associated to the active tectonic deformations of the southern boundary of the Betic Cordillera. A non-permanent GPS network was installed to monitor, for the first time, the fault- and fold-related activity. In addition, two high precision levelling profiles were measured twice over a one-year period across the Balanegra Fault, one of the most active faults recognized in the area. The absence of significant movement of the main fault surface suggests seismogenic behaviour. The possible recurrence interval may be between 100 and 300 y. The repetitive GPS and high precision levelling monitoring of the fault surface during a long time period may help us to determine future fault behaviour with regard to the existence (or not) of a creep component, the accumulation of elastic deformation before faulting, and implications of the fold-fault relationship. PMID:22319309

  9. Levelling Profiles and a GPS Network to Monitor the Active Folding and Faulting Deformation in the Campo de Dalias (Betic Cordillera, Southeastern Spain)

    PubMed Central

    Marín-Lechado, Carlos; Galindo-Zaldívar, Jesús; Gil, Antonio José; Borque, María Jesús; de Lacy, María Clara; Pedrera, Antonio; López-Garrido, Angel Carlos; Alfaro, Pedro; García-Tortosa, Francisco; Ramos, Maria Isabel; Rodríguez-Caderot, Gracia; Rodríguez-Fernández, José; Ruiz-Constán, Ana; de Galdeano-Equiza, Carlos Sanz

    2010-01-01

    The Campo de Dalias is an area with relevant seismicity associated to the active tectonic deformations of the southern boundary of the Betic Cordillera. A non-permanent GPS network was installed to monitor, for the first time, the fault- and fold-related activity. In addition, two high precision levelling profiles were measured twice over a one-year period across the Balanegra Fault, one of the most active faults recognized in the area. The absence of significant movement of the main fault surface suggests seismogenic behaviour. The possible recurrence interval may be between 100 and 300 y. The repetitive GPS and high precision levelling monitoring of the fault surface during a long time period may help us to determine future fault behaviour with regard to the existence (or not) of a creep component, the accumulation of elastic deformation before faulting, and implications of the fold-fault relationship. PMID:22319309

  10. Lithofacies, diagenetic spectra and sedimentary cycles of messinian (Late Miocene) evaporites in SE Spain

    NASA Astrophysics Data System (ADS)

    Michalzik, Dieter

    1996-11-01

    Messinian evaporites have been deposited within a number of connected basins that formed the so-called 'Betic Strait' in SE Spain during the Late Miocene. Pre-, syn- and postevaporitic sedimentary successions may well be compared with other strata of the same age surrounding the Mediterranean Sea. There is no evidence for a cataract-like connection of these basins with a strong unidirectional flow regime before and during the formation of Messinian evaporites as previously suggested. The most frequently occurring gypsum lithofacies presumably related to shallow-water depositional environments are crystalline selenitic gypsum ('grass-like gypsum'), laminated gypsum and cross-bedded gypsarenite. Only few real sabkha type chicken wire alabastrine gypsum have been identified. Evenly laminated gypsum together with graded gypsarenites (turbidites), gypsrudites (debrites) and slumps is restricted to basins or parts of basins with considerable paleoslopes. Evidence for diagenetic overprinting is abundant in all outcrop areas studied. This includes the formation of giant gypsum twin crystals, 'super cones' and alabastrine nodular gypsum. The formation of Messinian evaporites in SE Spain is thought to be controlled by a superimposed third-order sea-level lowstand. Smaller sedimentary units fall well into the range of fourth- to sixth-order cyclic and rhythmic successions. They are clearly related to basin dynamics or to autogenetic processes of the local facies zone (facies dynamics). None of the smaller-scale cycles (fourth and higher order), as observed in outcrops, are related to high-frequency eustasy.

  11. Backarc basin inversion and subcontinental mantle emplacement in the crust: kilometre-scale folding and shearing at the base of the proto-Alborán lithospheric mantle (Betic Cordillera, southern Spain)

    NASA Astrophysics Data System (ADS)

    Hidas, Károly; Garrido, Carlos J.; Guillermo, Booth-Rea; Martínez-Martínez, José M.; Konc, Zotán; Frets, Erwin; Marchesi, Claudio

    2013-04-01

    To constrain the latest evolutionary stages and mechanisms of exhumation and emplacement of subcontinental peridotites in the westernmost Mediterranean, we present here a detailed structural study of the transition from granular spinel peridotite to plagioclase tectonite in the western Ronda Peridotite (Betic Cordillera, southern Spain). We show that the plagioclase tectonite foliation represents an axial surface particularly well developed in the reverse limb of a downward facing moderately plunging and moderately inclined synform at the base of the Ronda massif. The fold limbs are cut by several mylonitic and ultramylonitic shear zones with top-to-the-SW sense of shear. After restoring the middle to late Miocene vertical-axis palaeomagnetic rotation and the early Miocene tectonic tilting of the massif, these studied structures record southward directed kinematics. We propose a geodynamic model in which folding and shearing of an attenuated mantle lithosphere occurred by backarc basin inversion during late Oligocene (23-25 Ma) southward collision of the Alborán Domain with the palaeo-Maghrebian passive margin, leading to the intracrustal emplacement of peridotites in the earliest Miocene (21-23 Ma).

  12. Spreading of pollutants from alkaline mine drainage. Rodalquilar mining district (SE Spain).

    PubMed

    González, V; García, I; del Moral, F; de Haro, S; Sánchez, J A; Simón, M

    2012-09-15

    In the Rodalquilar mining district of SE Spain, a total of 46 soil samples that were between 0 and 20 cm in depth were taken from the tailings dump, stream sediments, and surfaces that were presumably were unaffected by mining. In each soil sample, organic carbon content, pH, particle size distribution and total and soluble trace element content were analysed. Pollutants were scattered by runoff from two source areas: tailings from Au mining (Sn, Sb, As and Se) and wastes from Pb mining (Pb, Cu and Zn). Sn, Pb, and Sb were spread mostly in the solid phase of the runoff, while Cu, Zn, As and Se were spread in both the solid and soluble phases of the runoff. The pollutants with the highest soluble concentrations were As and Se, which were scattered at greater distances from the source. Some evidence suggests that tailings from Au mining could also be scattered by wind, but no farther than 1500 m from the source.

  13. Evidence of a large deep conductive body within the basement of the Guadalquivir foreland Basin (Betic Cordillera, S-Spain) from tipper vector modelling: Tectonic implications

    NASA Astrophysics Data System (ADS)

    González-Castillo, L.; Galindo-Zaldívar, J.; Junge, A.; Martínez-Moreno, F. J.; Löwer, A.; Sanz de Galdeano, C.; Pedrera, A.; López-Garrido, A. C.; Ruiz-Constán, A.; Ruano, P.; Martínez-Martos, M.

    2015-11-01

    The Betic Cordillera is an Alpine belt formed by the interaction of the Eurasian and African plates and the westward motion of the Alboran Domain. Long Period Magnetotelluric observations at 26 sites in its westernmost part provide induction arrows that have been compared with 3D forward models including bathymetry and major geological bodies. The results highlight the presence of a major conductive body (0.05 Ω m) unknown to date and located within the basement of the Guadalquivir foreland basin. Aeromagnetic and field magnetic measurements further support the occurrence of magnetic anomalies related to the top of this anomalous body. This major structure is interpreted as an intermediate or basic igneous rock, with a high proportion of metallic mineralization. Its origin is discussed in the framework of the regional geological setting, possibly produced in the southern Iberian Variscan Massif by a huge concentration of volcanogenic massive sulphide (VMS) in the prolongation of the Iberian Pyrite Belt during Devonian-early Carboniferous times. Another possibility is that the conductive anomaly is due to magmatic intrusions associated with the Mesozoic fragmentation of Southern Iberia and the opening of the Tethys.

  14. Late Neogene-Recent uplift of the Cabo de Gata volcanic province, Almerı´a, SE Spain

    NASA Astrophysics Data System (ADS)

    Martín, José M.; Braga, Juan C.; Betzler, Christian

    2003-02-01

    Cabo de Gata is a Miocene volcanic province in the Betic Cordillera in southeastern Spain. The distribution of coastal deposits in the successive marine sedimentary units overlying the last volcanic episode (about 7.5 Ma old) has been used to reconstruct the post-volcanic palaeogeographic evolution of the region during the Late Neogene. The current elevation of well-dated shoreline marker rocks has been used to estimate uplift amount and rates. Since the late Tortonian, a N45°E-aligned (the strike of the Carboneras fault system) topographic relief was emergent in the Cabo de Gata region. The extension and height of this island increased throughout the late Neogene. Smaller, independent islands were emergent and finally became connected to the main island during the Messinian. The Carboneras and Agua Amarga Pliocene sub-basins were the last two marine basins prior to the final emergence of the region. Since the last volcanic eruption (ca. 7.5 Ma), maximum uplift of sedimentary rocks in Cabo de Gata has taken place on the western margin of the N45°E-aligned palaeorelief. The altitude of the shoreline marker rocks in the successive sedimentary units decreases eastwards to the present-day coast and northwards of the Rambla del Plomo. Uplift rates since deposition remain nearly constant for the successive Messinian rocks and decrease slightly for the lower Pliocene outcrops. Most of the uplift took place before the Pliocene while the main island enlarged. Uplift amounts and rates since deposition of the upper Neogene sedimentary units in the Cabo de Gata area are similar to the ones estimated for laterally equivalent units in the eastern Betic basins (approximately 50 m/Ma). Despite its volcanic nature and the occurrence of the Carboneras fault system, the Cabo de Gata probably became elevated as a consequence of regional uplift in connection with the rest of the Betic Cordillera.

  15. Seismic local site effects characterization in the Andarax River Valley (SE Spain) from ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Carmona, Enrique; García-Jerez, Antonio; Luzón, Francisco; Sánchez-Martos, Francisco; Sánchez-Sesma, Francisco J.; Piña, José

    2014-05-01

    This work is focused on the characterization of seismic local effects in the Low Andarax River Valley (SE Spain). The Low Andarax River valley is located in an active seismic region, with the higher seismic hazard values in Spain. The landform is composed mainly by sedimentary materials which increase its seismic hazard due to the amplification of the seismic inputs and spectral resonances. We study seismic local effects in the Low Andarax River by analyzing the Horizontal-to-Vertical Spectral Ratio (HVSR) of ambient noise records. The noise data were recorded during two field campaigns in 2012 and 2013. There have been a total of 374 noise measurements with 15 and 30 minutes duration. The acquisition was performed with a Digital Broadband Seismometer Guralp CMG-6TD. The distance between measurements was about 200 meters, covering an area around 40 km2. There have been 6 significant peak frequencies between 0.3 Hz and 5 Hz. It was possible to find interesting areas with similar spectral peaks that coincide with zones with similar microgravimetric anomalies at the alluvial valley. It is also observed a decrease in the frequency peaks from West to East suggesting increased sediment layer. We also compute the soil models at those sites where geotechnical information is available, assuming that the seismic noise is diffuse. We invert the HVSR for these places using horizontally layered models and in the imaginary part the Green functions at the source. It is observed that the S wave velocity inverted models are consistent with the known geotechnical information obtained from drilled boreholes. We identify the elastodynamic properties of the limestone-dolomite materials with a formation of phyllites and quartzite that form the basement of the depression, and those properties of the Miocene and Pliocene detrital deposits (marls, sandy silts, sands and conglomerates) that fill the valley. These results together with the observed resonant frequencies along the Andarax

  16. Quantitative petrogenetic constraints on the Pliocene alkali basaltic volcanism of the SE Spain Volcanic Province

    NASA Astrophysics Data System (ADS)

    Cebriá, J. M.; López-Ruiz, J.; Carmona, J.; Doblas, M.

    2009-09-01

    Alkali basalts of Pliocene age are the last episode of volcanism in the SE Spain Volcanic Province, postdating a complex series of Miocene calc-alkaline to ultrapotassic rocks. This volcanism is represented by small outcrops and vents NW of Cartagena that has been interpreted as a volcanic episode similar to the contemporaneous monogenetic alkaline basaltic volcanism of the Iberian Peninsula and Western/Central Europe. However, their geochemical signature is characterised by relatively higher 87Sr/ 86Sr ratios as well as distinct trace element anomalies which, at different scale, are only found in the spatially related calc-alkaline to ultrapotassic volcanism. Quantitative modelling of these data demonstrate that the geochemical signature of the Pliocene alkali basalts of Cartagena can be explained by the interaction between primitive melts generated from a sublithospheric mantle source similar to that identified for other volcanic regions of Spain, and liquids derived from the overlying lithospheric mantle. This interaction implies that the alkali basalts show some geochemical features only observed in mantle lithosphere-derived melts (e.g. Sr isotope enrichment and Th-U-Pb positive anomalies), while retaining an overall geochemical signature similar to other Iberian basalts (e.g. Rb-K negative anomalies). This model also implies that beneath the SEVP, enriched (metasomatized) portions were still present within the lithospheric mantle after the Miocene magmatic episodes. Comparison of this model with those already developed for other alkaline basaltic volcanic regions of western/central Europe supports the idea that the interaction of primitive magmas derived from a common sublithospheric mantle source with liquids derived from the overlying regionally heterogeneous lithospheric mantle is a relatively frequent scenario in the European realm.

  17. 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.

  18. Reconstruction of past climate variability in SE Spain between 14 and 8 ka

    NASA Astrophysics Data System (ADS)

    Budsky, Alexander; Scholz, Denis; Mertz-Kraus, Regina; Christoph, Spötl; Gibert, Luis; Jochum, Klaus Peter; Andreae, Meinrat O.

    2016-04-01

    In comparison to the large climatic oscillations during the Pleistocene, Holocene climate only underwent minor changes. Nevertheless, cyclic climate changes also occurred during the Holocene. The Bond events, represented by the presence of cold, ice-bearing waters from the north of Iceland as far south as the latitude of Britain, occurred at a cyclicity of about 1500 a and were particularly pronounced during the Early Holocene. However, their climatic impact on the terrestrial realm was not consistent over Europe, in particular with respect to changes in precipitation. Here we present a precisely dated high-resolution flowstone record from Cueva Victoria, SE Spain, a site well suited to study the competing influence of the Atlantic and Mediterranean Sea on the southern Iberian Peninsula. We sampled several flowstones with a thickness of up to 60 cm. 230Th/U-dating has shown that these deposits mainly formed during relatively warm climate intervals of the Middle and Late Pleistocene, i.e. interglacials and interstadials (Budsky et al., 2015; Gibert et al., 2016). Here we focus on a short (11 cm) flowstone sequence from the Holocene with a high temporal resolution (centennial for stable isotopes and annual for trace elements). The flowstone grew between 14 and ca. 8 ka b2k. The decreasing trend of the δ18O and δ13C values as well as of several trace elements between 12 and 11 ka b2k reflects an increase in temperature and precipitation at the beginning of the Holocene. In particular, Sr and Mg show a trend towards low and stable values. Subsequently, from 10.5 to 8 ka b2k, the δ13C values show a high variability (-11 to -4), whereas the δ18O values are rather stable (between -6 and -7). Maxima in δ13C are interpreted as drier conditions in response to Bond events. These events possibly led to a change of the atmospheric circulation, affecting the vegetation in SE Spain, which evolved towards an open C3 vegetation at ca. 8 ka b2k concomitant with drier conditions

  19. Metal bioaccumulation pattern by Cotylorhiza tuberculata (Cnidaria, Scyphozoa) in the Mar Menor coastal lagoon (SE Spain).

    PubMed

    Muñoz-Vera, Ana; García, Gregorio; García-Sánchez, Antonio

    2015-12-01

    Coastal lagoons are ecosystems highly vulnerable to human impacts because of their situation between terrestrial and marine environment. Mar Menor coastal lagoon is one of the largest lagoons of the Mediterranean Sea, placed in SE Spain and subjected to major human impacts, in particular the mining of metal sulphides. As a consequence, metal concentration in water column and sediments of this ecosystem is usually higher than in other areas. For monitoring ecosystem health, the present study has assessed the ability of Cotylorhiza tuberculata for bioaccumulating metals from sea water. Up to 65 individuals were sampled at 8 different sampling stations during the summer of 2012. Although the concentration values for different elements considered were moderate (Pb: 0.04-29.50 ppm, Zn: 2.27-93.44 ppm, Cd: 0-0.67 ppm, As: 0.56-130.31 ppm) by dry weight of the jellyfish tissues (bell and oral arms combined), bioconcentration levels in relation to seawater metal concentration were extremely high. In any case, the use or disposal of these organisms should consider their metal content because of their potential environmental and health implications. PMID:26250818

  20. Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain).

    PubMed

    Pérez-Luque, Antonio Jesús; Bonet, Francisco Javier; Pérez-Pérez, Ramón; Rut Aspizua; Lorite, Juan; Zamora, Regino

    2014-01-01

    The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain). The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened) from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic inventory was created to gather useful information for the proper management of Pinus plantations in Sierra Nevada. This is the only dataset that shows a comprehensive view of the forest flora in Sierra Nevada. This is the reason why it is being used to assess the biodiversity in the very dense pine plantations on this massif. With this dataset, managers have improved their ability to decide where to apply forest treatments in order to avoid biodiversity loss. The dataset forms part of the Sierra Nevada Global Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:24843285

  1. Metal bioaccumulation pattern by Cotylorhiza tuberculata (Cnidaria, Scyphozoa) in the Mar Menor coastal lagoon (SE Spain).

    PubMed

    Muñoz-Vera, Ana; García, Gregorio; García-Sánchez, Antonio

    2015-12-01

    Coastal lagoons are ecosystems highly vulnerable to human impacts because of their situation between terrestrial and marine environment. Mar Menor coastal lagoon is one of the largest lagoons of the Mediterranean Sea, placed in SE Spain and subjected to major human impacts, in particular the mining of metal sulphides. As a consequence, metal concentration in water column and sediments of this ecosystem is usually higher than in other areas. For monitoring ecosystem health, the present study has assessed the ability of Cotylorhiza tuberculata for bioaccumulating metals from sea water. Up to 65 individuals were sampled at 8 different sampling stations during the summer of 2012. Although the concentration values for different elements considered were moderate (Pb: 0.04-29.50 ppm, Zn: 2.27-93.44 ppm, Cd: 0-0.67 ppm, As: 0.56-130.31 ppm) by dry weight of the jellyfish tissues (bell and oral arms combined), bioconcentration levels in relation to seawater metal concentration were extremely high. In any case, the use or disposal of these organisms should consider their metal content because of their potential environmental and health implications.

  2. Mesoscale climatic simulation of surface air temperature cooling by highly reflective greenhouses in SE Spain.

    PubMed

    Campra, Pablo; Millstein, Dev

    2013-01-01

    A long-term local cooling trend in surface air temperature has been monitored at the largest concentration of reflective greenhouses in the world, at the Province of Almeria, SE Spain, associated with a dramatic increase in surface albedo in the area. The availability of reliable long-term climatic field data at this site offers a unique opportunity to test the skill of mesoscale meteorological models describing and predicting the impacts of land use change on local climate. Using the Weather Research and Forecast (WRF) mesoscale model, we have run a sensitivity experiment to simulate the impact of the observed surface albedo change on monthly and annual surface air temperatures. The model output showed a mean annual cooling of 0.25 °C associated with a 0.09 albedo increase, and a reduction of 22.8 W m(-2) of net incoming solar radiation at surface. Mean reduction of summer daily maximum temperatures was 0.49 °C, with the largest single-day decrease equal to 1.3 °C. WRF output was evaluated and compared with observations. A mean annual warm bias (MBE) of 0.42 °C was estimated. High correlation coefficients (R(2) > 0.9) were found between modeled and observed values. This study has particular interest in the assessment of the potential for urban temperature cooling by cool roofs deployment projects, as well as in the evaluation of mesoscale climatic models performance. PMID:24074145

  3. Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain).

    PubMed

    Pérez-Luque, Antonio Jesús; Bonet, Francisco Javier; Pérez-Pérez, Ramón; Rut Aspizua; Lorite, Juan; Zamora, Regino

    2014-01-01

    The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain). The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened) from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic inventory was created to gather useful information for the proper management of Pinus plantations in Sierra Nevada. This is the only dataset that shows a comprehensive view of the forest flora in Sierra Nevada. This is the reason why it is being used to assess the biodiversity in the very dense pine plantations on this massif. With this dataset, managers have improved their ability to decide where to apply forest treatments in order to avoid biodiversity loss. The dataset forms part of the Sierra Nevada Global Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

  4. Silicification of carbonate clasts in a marine environment (Upper Miocene, Vera Basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Martín Penela, Antonio J.; Barragán, Guillermo

    1995-06-01

    Upper Miocene marine sediments in the Vera Basin (SE Spain) contain abundant silicified marble pebbles and bivalves. The silicification of these marble pebbles and bivalves represents one of the stages of their sedimentary history, associated with small fluctuations in relative sea level. During the late Tortonian alluvial fan deposits containing the marble pebbles were invaded by the sea, which caused reworking of the pebbles and the establishment of a marine biota in the environment. After shallow burial numerous marble pebbles and bivalve remains were silicified. Both types of clasts were partially replaced by opal-CT or quartz from opaline silica derived from dissolution of skeletal debris. The silicified zones (rinds) now consist of quartzine or quartz. Silicification of the clasts must have taken place under shallow burial conditions during early diagenesis, while pyrite formed in favourable anoxic sites. Iron oxides also precipitated during early diagenesis, but after silicification. Finally, part of the deposits containing the silicified clasts were transported by gravitational mass flows and redeposited in deeper areas of the basin. If the hypothesis proposed for the diagenetic process is correct, it indicates that the uncommon silicification of carbonate clasts does not only occur in continental environments, in which it has previously been described.

  5. Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain)

    PubMed Central

    Pérez-Luque, Antonio Jesús; Bonet, Francisco Javier; Pérez-Pérez, Ramón; Rut Aspizua; Lorite, Juan; Zamora, Regino

    2014-01-01

    Abstract The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain). The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened) from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic inventory was created to gather useful information for the proper management of Pinus plantations in Sierra Nevada. This is the only dataset that shows a comprehensive view of the forest flora in Sierra Nevada. This is the reason why it is being used to assess the biodiversity in the very dense pine plantations on this massif. With this dataset, managers have improved their ability to decide where to apply forest treatments in order to avoid biodiversity loss. The dataset forms part of the Sierra Nevada Global Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:24843285

  6. Influence of local and regional Mediterranean meteorology on SO₂ ground-level concentrations in SE Spain.

    PubMed

    Santacatalina, Milagros; Carratalá, Adoración; Mantilla, Enrique

    2011-06-01

    This work presents the results of a 4-year study on sulfur dioxide (SO(2)) ground-level concentrations in an area of southeastern Spain, the L'Alacantí region, where the cement industry is important and coke use extends to other industries as well. The main source of SO(2) emissions in the area was found to be a the Lepold cement plant (one of the two cement plants in the area). The high levels of SO(2) probably extend back to 1920 when this plant began operations. Both local and Mediterranean-scale meteorological processes influence the SO(2) ground-level concentration and together explain the dispersion dynamics of this pollutant. The location and topography of the study zone result in NW Atlantic advections and E-SE sea breezes being the dominant atmospheric circulation patterns in the area. Under stable meteorological conditions, minor local circulations are also relevant to the SO(2) concentration levels. The high frequency of local circulations determines a concentration pattern that changes during the day, with impacts occurring preferentially in a W-NW direction from the source at midday (sea breeze and strong thermal mixture), and in a SE direction at night. This causes the SO(2) concentrations to present well-defined diurnal cycles with well-differentiated shapes depending on the location of the sampling station relative to the source. The dependence of SO(2) 10 min levels on the wind origin and speed throughout the day has been evaluated by studying statistical parameters including P95, P50 and arithmetic mean. Exceedances occur under specific dispersion conditions at distances less than 1 km from the source. However, the source is traceable at larger distances and the levels are higher than typical urban ones. P95 was used as an estimator of the occurrence of larger levels or impacts. Leeward of NW winds and the source, at night and in early morning, P95 levels are comprised between 30 and 55 µg m(-3). In contrast, with SE winds and at midday, P95

  7. Spain.

    PubMed

    1985-03-01

    Spain is a constitutional monarchy with a population of 38.3 million growing at .5%/year. The most striking topographical features are the high plateaus and internal compartmentalization by mountain and river barriers. Nearly 3/4 of the country is arid. The Iberian peninsula was the scene of successive invasions and warfare for centuries. Phoenicians, Greeks, Carthaginians, Moors, Celts, Romans, and Visigoths all invaded at some time. The present language, religion, and laws stem from the Roman Period. The Reconquest from the North African Moors lasted over 700 years until they were driven out in 1492. The unification of present day Spain was complete by 1512. A period of dictatorial rule from 1923-31 ended with establishment of the Second Republic which saw increasing political polarization culminating in the Spanish Civil War. Franco's victory in 1939 was followed by official neutrality but pro-Axis policies during World War II. Spain's economy began to recover during the 1950s, but large scale modernization and development did not occur until the 1960s. Prince Juan Carlos de Borbon y Borbon, Franco's personally designated heir, assumed the title of king and chief of state with Franco's death in 1975. Franco's last prime minister was replaced in July 1976 in order to speed the pace of post-Franco liberalization. Spain's 1st parliamentary elections since 1936 were held in 1977, and a new constitution protecting human and civil rights and granting due process was overwhelmingly approved in 1978. The constitution also authorized creation of regional autonomous governments. By the mid-1970s, Spain had developed a strong and diversified industrial sector and a thriving tourist industry. From 1975-83, there were 8 years of double-digit inflation, an average growth rate of 1.5% in real terms, and an increase in unemployment from about 4.7% to 18.4%. By 1984 there was substantial improvement in inflation and the balance of payments. Goals of current government economic

  8. Spain.

    PubMed

    1985-03-01

    Spain is a constitutional monarchy with a population of 38.3 million growing at .5%/year. The most striking topographical features are the high plateaus and internal compartmentalization by mountain and river barriers. Nearly 3/4 of the country is arid. The Iberian peninsula was the scene of successive invasions and warfare for centuries. Phoenicians, Greeks, Carthaginians, Moors, Celts, Romans, and Visigoths all invaded at some time. The present language, religion, and laws stem from the Roman Period. The Reconquest from the North African Moors lasted over 700 years until they were driven out in 1492. The unification of present day Spain was complete by 1512. A period of dictatorial rule from 1923-31 ended with establishment of the Second Republic which saw increasing political polarization culminating in the Spanish Civil War. Franco's victory in 1939 was followed by official neutrality but pro-Axis policies during World War II. Spain's economy began to recover during the 1950s, but large scale modernization and development did not occur until the 1960s. Prince Juan Carlos de Borbon y Borbon, Franco's personally designated heir, assumed the title of king and chief of state with Franco's death in 1975. Franco's last prime minister was replaced in July 1976 in order to speed the pace of post-Franco liberalization. Spain's 1st parliamentary elections since 1936 were held in 1977, and a new constitution protecting human and civil rights and granting due process was overwhelmingly approved in 1978. The constitution also authorized creation of regional autonomous governments. By the mid-1970s, Spain had developed a strong and diversified industrial sector and a thriving tourist industry. From 1975-83, there were 8 years of double-digit inflation, an average growth rate of 1.5% in real terms, and an increase in unemployment from about 4.7% to 18.4%. By 1984 there was substantial improvement in inflation and the balance of payments. Goals of current government economic

  9. Processes and Geomorphological Impacts of an Extreme Flash Flood Event in SE Spain

    NASA Astrophysics Data System (ADS)

    Hooke, J.

    2015-12-01

    A major flash flood event took place on 28 September, 2012 in SE Spain, resulting in 10 fatalities and much damage to infrastructure regionally. The flood affected long-term monitoring sites in two catchments in which morphological changes and flow dynamics of these ephemeral channels were being measured. Thus detailed data on channel state prior to the flood were available. The flood event in the Nogalte catchment was extreme in its peak flow, rate of rise and unit runoff. The catchment has steep relief and much bare soil under almond groves, resulting in high sediment supply. The channel is confined in places, but mostly wide and braided, composed of loose gravel and occupying much of the valley floor. Flow was spatially continuous, with high connectivity throughout the catchment. The flood effects were net depositional in the monitored sites, with massive sedimentation on the channel bars. Vegetation was destroyed. Bank erosion and destruction of embankments took place in some locations. Hydraulic calculations indicate very high velocities, stream power and Froude numbers. Modelling and field evidence demonstrate extremely high sediment competence and sediment loadings. The influence of the event dynamics on processes and net outcomes is discussed. The impacts are compared with other events in this and neighbouring catchments. Overall, the event in the Nogalte did not alter the morphology markedly in spite of its extreme characteristics. It is suggested that these valley floors are adapted to this type of flash flood but that flows of such force and magnitude need to be allowed for in management in such an environment.

  10. ERT studies on tailings ponds of the Sierra Minera Cartagena-La Union, SE Spain (Invited)

    NASA Astrophysics Data System (ADS)

    Martinez-Pagan, P.; Faz-Cano, A.; Rosales-Aranda, M. R.

    2009-12-01

    The Sierra Minera Cartagena - La Union (SE Spain) is a huge area that has been mined for centuries. That mining extraction activity was particularly enormous in the second half of the twentieth century. By the early 1980’s almost all mineral deposits of this area had been depleted and the mineral processing plants had left 80 tailings ponds of different shape and height as a result of their activity. At the present, these former mining areas are close to important urban and industrial centers, where the tailings ponds are potential points of environmental and geotechnical concerns among others. In the 1972, there was also an important collapse of a tailings pond after a strong stormy event. Because of that, nowadays, there are several researcher groups working on the area with the goal of improving the environmental, geotechnical, safety, and use conditions of the tailings ponds. In this framework, the electrical resistivity tomography (ERT) method was used to obtain complementary information from the inner of the tailings ponds itself. Due to the high electrical resistivity contrast between the tailings and the hard-rock the geo-electrical methods became very useful in getting information about the bedrock geometry. In addition, where the tailing ponds have not been built up with a more complex interne structure (Figure 1) then it has been possible to obtain their construction history based on the grain distribution which is related in some extent to the electrical resistivity. In some cases, based on the fact of the presence of big cracks into the pond as pathways (Figure 2) where the mine acid waters are infiltrated easily, the use of ERT technique has proved its usefulness in highlighting them. Moreover, the ERT method can be an interesting tool in tailings ponds remediation works by delimiting the acid areas on the surface characterized by low electrical resistivity values.

  11. Risk assessment and restoration possibilities of some abandoned mining ponds in Murcia Region, SE Spain

    NASA Astrophysics Data System (ADS)

    Faz, Angel; Acosta, Jose A.; Martinez-Martinez, Silvia; Carmona, Dora M.; Zornoza, Raul; Kabas, Sebla; Bech, Jaume

    2010-05-01

    In Murcia Region, SE Spain, there are 85 tailing ponds due to intensive mining activities that occurred during last century, especially in Sierra Minera de Cartagena-La Union. Although mining activity was abandoned several decades ago, those tailing ponds with high amounts of heavy metals still remain in the area. The ponds, due to their composition and location, may create environmental risks of geochemical pollution, negatively affecting soil, water, and plant, animal, and human populations, as well as infrastructures. The main objective of this research is to evaluate the restoration possibilities of two representative mining ponds in order to minimize the risk for human and ecosystems. To achieve this objective, two tailing ponds generated by mining activities were selected, El Lirio and El Gorguel. These ponds are representative of the rest of existent ponds in Sierra Minera de Cartagena-La Unión, with similar problems and characteristics. Several techniques and studies were applied to the tailing ponds for their characterization, including: geophysics, geotechnics, geochemical, geological, hydrological, and vegetation studies. In addition, effects of particulate size in the distribution of heavy metals will be used to assess the risk of dispersion of these metals in finest particles. Once the ponds were characterized, they were divided in several sectors in order to apply different amendments (pig slurry and marble waste) to reduce the risk of metal mobility and improve soil quality for a future phytostabilization. It is known that organic amendments promote soil development processes, microbial diversity, and finally, soil ecosystem restoration to a state of self-sustainability. By comparing the results before and after applications we will be able to evaluate the effect of the different amendments on soil quality and their effectively on risk reduction. Finally, plant metal-tolerant species are used to restore vegetation in the ponds, thereby decreasing

  12. Zn mobility and geochemistry in surface sulfide mining soils from SE Spain.

    PubMed

    Garcia, G; Peñas, J M; Manteca, J I

    2008-03-01

    The extraction of metallic minerals and the mineral dressing operations in concentrators produced a high impact in soils and sediments. Heavy metals in soils constitute a high risk of pollution, not only for mining areas, but also for agriculture and villages placed in subsidiary areas. This research has been focused on the assessment of the real environmental and health hazards of Zn in relation to geochemistry and metal mobility in surface soils from a mining area in SE Spain, under semiarid weather conditions. Mineralogy of the studied soils revealed major presence of quartz, but also of other silicates, sulfates, carbonates, and sulfides. Regarding Zn minerals, the presence of sphalerite as the main Zn sulfide, and of goslarite as Zn sulfate, and of smithsonite as Zn carbonate should be highlighted. Soil pH ranged between 4.4 and 4.9 and the electrical conductivity between 55 and 85 microS/cm. By using the sequential extraction procedure, the achieved results show that zinc is not only mainly associated to primary but also to secondary sulfides. Total concentration of the non-available fractions rises up to 98.45% of total Zn in the studied soils. On the other hand, available Zn fraction did not exceed more than 1.55% in percentage and less than 2000 ppm in absolute terms, and when referred to more easily available fraction (water-soluble and exchangeable fractions), these values are not more than 0.44% and then 800 ppm. Therefore, although there is a significant pollution level in this area, immediate hazard for the environment can be assessed as moderate. Finally it should be highlighted that these surface soils have undergone concentration processes of sphalerite, whose mechanisms should be related to the ascending flow of capillary water and the dragging of sphalerite crystals and Zn salts by electrokinetic and colloidal processes These processes seem to occur based on environmental pollution by wind and water erosion, and therefore directly associated to

  13. Plio-Pleistocene continental paleoclimate record from the Zújar section, Guadix-Baza Basin (SE Spain)

    NASA Astrophysics Data System (ADS)

    Matson, S. D.; Gibert, L.; Scott, G. R.; Fox, D. L.

    2014-12-01

    The intramontane Guadix-Baza Basin (SE Spain) preserves an extensive record of Neogene continental sedimentation during an interval of important global climatic and ecologic changes, including the onset Northern Hemisphere glaciation and the evolution of grassland biomes on several continents. Several localities within this basin represent mammal biostratigraphic reference sections for the Plio-Pleistocene of Western Europe, and have been the focus of much previous bio-, magneto-, and cyclostratigraphic work. Here we report new stratigraphic and geochemical results from one of these reference sections near the village of Zújar in the central part of the Guadix-Baza Basin. We interpret Plio-Pleistocene climatic history from lacustrine and pedogenic sediments at Zújar, based on new paleomagnetic results coupled with stable carbon and oxygen isotopic (δ13C and δ18O) analyses of carbonate and bulk organic matter, thin-section petrography, cathodoluminescence and scanning electron microscopy, and semi-quantitative X-ray diffraction. Paleoclimatic variability in the Zújar section is reflected in the highly variable composition of carbonate-rich beds, which fluctuate between nearly pure micritic calcite and dolomite but commonly display mixed carbonate phases. The δ18O values of these carbonates are also highly variable (-8.2 to +1.9‰ VPDB) and are strongly correlated with dolomite content (r2 = 0.79). The δ13C values are less variable (-8.8‰ to -4.2‰ VPDB) and are similar between calcite- and dolomite-rich samples. We interpret periods of wet climate and lake-level highstand from calcite-dominated beds with variable δ13C values and low (-7 to -8‰ VPDB), invariant δ18O values that likely represent equilibrium calcite precipitation from minimally evolved lake source waters. Several mixed-carbonate beds display covariant δ13C and δ18O, representing evaporative enrichment of lake waters during more arid periods. We interpret maximum aridity and lake

  14. Astrochronology for the Messinian Sorbas basin (SE Spain) and orbital (precessional) forcing for evaporite cyclicity

    NASA Astrophysics Data System (ADS)

    Krijgsman, W.; Fortuin, A. R.; Hilgen, F. J.; Sierro, F. J.

    2001-04-01

    The Sorbas basin of SE Spain contains one of the most complete sedimentary successions of the Mediterranean reflecting the increasing salinity during the Messinian salinity crisis. A detailed cyclostratigraphic study of these successions allows a correlation of the sedimentary cycle patterns to astronomical target curves. Here, we present an astrochronological framework for the Messinian of the central part of the Sorbas basin. This framework will form a solid basis for high-resolution correlations to the marginal carbonate facies and to the Central Mediterranean area. The early Messinian Abad Member contains 55 precession induced sedimentary cycles marked by homogeneous marl-opal-rich bed alternations in the 'Lower Abad' and by homogeneous marl-sapropel alternations in the 'Upper Abad'. Astronomical tuning results in an age of 5.96 Ma for the transition to the Yesares evaporites and thus for the onset of the 'Messinian salinity crisis'. The marl-sapropel cycles of the 'Upper Abad' are replaced by gypsum-sapropel cycles (14) in the Yesares Member, indicating that the evaporite cyclicity is related to precession controlled oscillations in (circum) Mediterranean climate as well. As a consequence, gypsum beds correspond to precession maxima (insolation minima) and relatively dry climate, sapropelitic marls to precession minima (insolation maxima) and relatively wet climate. An alternative (glacio-eustatic) obliquity control for evaporite cyclicity can be excluded because the number of sedimentary cycles with a reversed polarity is too high. Sedimentation during the Abad, Yesares, and the overlying coastal sequences of the Sorbas Member, took place in a continuously marine environment, indicating that marine conditions in the Sorbas basin prevailed at least until 5.60-5.54 Ma. According to our scenario, deposition of the Yesares and Sorbas Member took place synchronously with deposition of the 'Lower Evaporites' in the Central Mediterranean. Finally, the continental

  15. Amendments and mulches improve the biological quality of soils degraded by mining activities in SE Spain

    NASA Astrophysics Data System (ADS)

    Luna Ramos, Lourdes; Miralles Mellado, Isabel; Hernández Fernández, María Teresa; García Izquierdo, Carlos; Solé Benet, Albert

    2014-05-01

    Mining and quarrying activities generate negative visual impacts in the landscape and a loss of environmental quality. Substrate properties at the end of mining are in general not suitable for plant growth, even native ones. In an experimental soil restoration in limestone quarries from Sierra de Gádor (Almería), SE Spain, the effect of organic amendment (sewage sludge, compost from the organic fraction of domestic waste or non-amendment) combined or not with two different kind of mulches (fine gravel, chopped forest residue) was tested by triplicate in 5 x 5 m plots with the aim to improve soil/substrate properties and to reduce evaporation and erosion. In each experimental plot 75 native plants (Stipa tenacissima, Anthyllis terniflora and Anthyllis cytisoides) were planted. Effects of adding organic amendments and mulches on some soil microbiological and biochemical parameters (microbial biomass carbon, basal respiration and different enzymatic activities, such as dehydrogenase, phosphatase, β-glucosidase and urease) were analyzed 5 years after the start of the experiment. Vegetation growth was also monitored. The two-way ANOVA, using as factors amendment and mulch, showed a significant positive influence of organic amendments on microbial biomass (Cmic), basal respiration and some enzymatic activities related to the cycles of C and N. The highest values of these parameters were obtained with compost. The influence of the mulch factor and its interactions with the amendment factor on the measured variables did not follow a clear trend with respect the measured parameters. Mulching did not improved significantly (p<0.05) the positive effect of organic amendments on Cmic although Cmic values increased with the incorporation of "forest chopped residue" and decreased with gravel incorporation. In general, both type of mulch decreased or have no effect on the microbial activity detected in the amended soils, with the only exception of the forest chopped residue

  16. Salinity effect of irrigation with treated wastewater in basal soil respiration in SE of Spain

    NASA Astrophysics Data System (ADS)

    Morugan, A.; Garcia-Orenes, F.; Mataix-Solera, J.

    2012-04-01

    The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. Wastewater use in agriculture is not a new practice, all over the world this reuse has been common practice for a long time, but the concept is of greater importance currently because of the global water crisis. Replacement of freshwater by treated wastewater is seen as an important conservation strategy contributing to agricultural production, substantial benefits can derive from using this nutrient-rich waste water but there can also be a negative impact. For this reason it is necessary to know precisely the composition of water before applying it to the soil in order to guarantee minimal impact in terms of contamination and salinization. In this work we have been studying, for more than three years, different parameters in calcareous soils irrigated with treated wastewater in an agricultural Mediterranean area located at Biar (Alicante, SE Spain), with a crop of grape (Vitis labrusca). Three types of waters were used for the irrigation of the soil: fresh water (control) (TC), and treated wastewater from secondary (T2) and tertiary treatment (T3). Three different doses of irrigation have been applied to fit the efficiency of the irrigation to the crop and soil type during the study period. A soil sampling was carried out every four months. We show the results of the evolution of basal soil respiration (BSR), and its relationship with other parameters. We observed a similar pattern of behavior for BSR between treatments, a decrease at the first eighteen months of irrigation and an increase at the end of study. In our study case, the variations of BSR obtained for all the treatments seem to be closely related to the dose and frequency of irrigation and the related soil wetting and drying cycles. However, the results showed a negative correlation between BSR and

  17. Palaeoflood estimates of Pleistocene coarse grained river terrace landforms (Río Almanzora, SE Spain)

    NASA Astrophysics Data System (ADS)

    Stokes, Martin; Griffiths, James S.; Mather, Anne

    2012-05-01

    A series of palaeoflood estimation techniques are applied to an inset sequence of Middle to Late Pleistocene river terrace landforms associated with the Río Almanzora, SE Spain. The study area is a 7 km-long transverse reach, where 4 terrace levels (Level 1 = highest and oldest, Level 4 = lowest and youngest) document some 200 m of incision across an uplifted basement block during the Pleistocene. For the broader region, river terrace aggradation is attributed to increased sediment supply during glacial to interglacial transitions (Level 1 = Marine oxygen isotope stages [MOIS] 12/11, L2 = 10/9, L3 = 8/7 and L4 = 6/5). Within the transverse reach, terrace Levels 2, 3 and 4 are characterised by coarse boulder-rich gravels (Dmax = 2.5 m) organised into 3-5 m-high cross-beds. Level 4 is characterised by a series of km-scale abandoned meander loops, with Levels 2 and 3 showing evidence for similar degraded high sinuosity forms. The fluvial setting is interpreted as a braided river environment, with lateral and longitudinal gravel barforms. Using field-derived sedimentary (boulder size etc) and morphological (width, slope etc) features, flow competence- and regime-based methods were applied. Palaeoflood estimates varied from 40 to 2859 m3/s, with mean maximum discharges showing an increase through time (L2 = 278, L3 = 413, L4 = 1361 m3/s). Palaeoflood estimates were compared to flood events associated with the ephemeral modern Río Almanzora (catchment = 2500 km2) to establish whether palaeoflood values were reasonable estimations. A 46-year (1963-2009) modern flood gauge record shows infrequent flood events with discharges typically < 40 m3/s. A rare flood event in 1973 (5680 m3/s) provides an upper value for comparison with the palaeoflood estimates. Although estimates appear reasonable they should be considered as minimum values due to 1) some disparities between flow depths derived from the palaeoflood equations (0.7-4 m) and field-based evidence (3-5 m-high cross

  18. Offshore remobilization processes and deposits in low-energy temperate-water carbonate-ramp systems: Examples from the Neogene basins of the Betic Cordillera (SE Spain)

    NASA Astrophysics Data System (ADS)

    Puga-Bernabéu, Ángel; Martín, José M.; Braga, Juan C.; Aguirre, Julio

    2014-05-01

    General facies models developed for modern and ancient Mediterranean temperate-water carbonates in the last two decades have shown that the style of deposition on outer-ramp, slope, and basin environments in low-energy areas such as the Mediterranean Sea differs overall from that of high-energy open-ocean areas, given the wider variety of smaller-scale topographic and hydrodynamic conditions in the former setting. However, these depositional models generally lack relevant information about sedimentary processes, transport mechanisms and controlling factors on offshore sediment redeposition, which are potential sources of information for sequence stratigraphic, palaeoclimate and exploration studies. Several examples from the Neogene Betic basins of the western Mediterranean region have been selected to integrate the processes and controlling factors on the offshore sediment transport and the resulting deposits. Additional published data from other Mediterranean localities have also been considered.

  19. Mineralogical study of stream waters and efflorescent salts in Sierra Minera, SE Spain

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Garcia-Lorenzo, Maria luz; Martinez-Sanchez, Maria Jose; Hernandez, Carmen; Hernandez-Cordoba, Manuel

    2015-04-01

    Trace elements contained in the residues from mining and metallurgical operations are often dispersed by wind and/or water after their disposal. These areas have severe erosion problems caused by water run-off in which soil and mine spoil texture, landscape topography and regional and microclimate play an important role. Water pollution by dissolved metals in mining areas has mainly been associated with the oxidation of sulphide-bearing minerals exposed to weathering conditions, resulting in low quality effluents of acidic pH and containing a high level of dissolved metals. The studied area, Sierra Minera, is close to the mining region of La Unión (Murcia, SE Spain). This area constituted an important mining centre for more than 2500 years, ceasing activity in 1991. The ore deposits of this zone have iron, lead and zinc as the main metal components. Studied area showed a lot of contaminations sources, formed by mining steriles, waste piles and foundry residues. As a consequence of the long period of mining activity, large volumes of wastes were generated during the mineral concentration and smelting processes. Historically, these wastes were dumped into watercourses, filling riverbeds and contaminating their surroundings. 40 sediment samples were collected from the area affected by mining exploitations, and at increasing distances from the contamination sources in 4 zones In addition, 36 surficial water samples were collected after a rain episode The Zn and Fe content was determined by flame atomic absorption spectrometry (FAAS). The Pb and Cd content was determined by electrothermal atomization atomic absorption spectrometry (ETAAS). The As content was measured by atomic fluorescence spectrometry using an automated continuous flow hydride generation spectrometer and Al content was determined by ICP-MS. Mineralogical composition of the samples was made by X Ray Diffraction (XRD) analysis using Cu-Kα radiation with a PW3040 Philips Diffractometer. Zone A: Water

  20. Use of Biomass Ash as a stabilization agent for expansive marly soils (SE Spain)

    NASA Astrophysics Data System (ADS)

    Ureña, C.; Azañón, J. M.; Caro, J. M.; Irigaray, C.; Corpas, F.; Ramirez, A.; Rivas, F.; Salazar, L. M.; Mochón, I.

    2012-04-01

    In recent years, several biomass power plants have been installed in Southeastern Spain to reuse olive oil industry residues. This energy production tries to reduce the high costs associated with fossil fuels, but without entering into direct competition to traditional food crops. The waste management in these biomass energy plants is still an issue since there are non-flammable materials which remains after incineration in the form of ashes. In Southeastern Spain there is also a great amount of clayey and marly soils whose volume is very sensitive to changes in climate conditions, making them unsuitable for civil engineering. We propose the use of biomass ash (both fly ash and bottom ash) as a stabilization agent for expansive soils in order to improve the efficiency of construction processes by using locally available materials. In this work biomass ashes from a biomass power plant in Southeastern Spain have been used to stabilize 6 samples of local marly soil. Those 6 samples of expansive soil were mixed with different dosages of biomass ash (2%, 4% and 7%) to create 18 specimens of treated soil, which were submitted to Proctor, Atterberg Limits, pH and Free Swell Index tests, following Spanish Standards UNE by AENOR. X-Ray Diffraction (XRD) tests by powder method were also carried out, using a diffractometer Philips X'Pert-MPD. The results obtained for the original untreated marly soil were: PI = 34.6; Free Swell = 12.5; pH = 8. By adding biomass ash the value of the plasticity index (PI) became slightly lower although it was not low enough as to obtain a non-plastic soil (PI under 25). However, there were dramatical decreases of free swell index (FSI) after the stabilization treatment: FSI < 8.18 (2% biomass); FSI < 6.15 (4% biomass); FSI < 4.18 (7% biomass); These results suggest that treated soil is quite less susceptible than the original soil to moisture changes. The pH of the mixes after adding biomass ash rose from 8 to 11±1 leading to an alkaline

  1. Identification of the origin of salts in an agricultural area of SE Spain

    NASA Astrophysics Data System (ADS)

    Acosta, Jose A.; Faz, Angel; Kalbitz, Karsten; Jansen, Boris; Silvia, Martinez-Martinez

    2010-05-01

    In spite of soil salinity having been widely studied in many part of the world, origin of salinity has not been addresses in detail in some of the most productive agricultural areas of Europe (e.g. southeast of Spain). According to the European Commission, salinization affects about 1 to 3 million ha of the area of the European Union and Candidate Countries. In Europe, most of the salt-affected land surfaces are concentrated in the Mediterranean basin. In Spain, about 3% of the 3.5 million hectares of irrigated land are severely affected by salts and another 15% is at serious risk of imminent salinization. Due to the limited water resources in southeast of Spain, water with marginal quality is used for irrigation. The use of this water has led to degradation, reduction of the land's production capacity and soil salinization. The main aim of the present study was to identify the origin of the salts involved in such salinization, using classical and multivariable statistical techniques. In order to achieve this objective, surface soil samples were collected in January and July 2009 at 48 sites located in a representative lemon production area close to City of Murcia, covering a surface area of 44 km2. Soil pH, electrical conductivity, ionic composition, total organic matter, equivalent calcium carbonate, cation exchange capacity and particle size distribution were determined. The Pearson correlation coefficient, r, was used to measure the relationship between two quantitative variables and principal components analysis was used to study the correlations among anions and cations and their grouping into several factors. Results indicated that the high electrical conductivity found in the study area indeed comes from poor quality irrigation water used for agriculture. Anions and cations responsible of the salinity were chlorides, sulphates, calcium, magnesium and sodium. Mismanagement of water and traditional irrigation system resulted in salt build-up in the soil

  2. The role of desalinisation to address aquifer overdraft in SE Spain.

    PubMed

    Martínez-Granados, David; Calatrava, Javier

    2014-11-01

    Aquifer overdraft is a major environmental and water management problem in Southeast Spain. In some areas, availability of desalinised seawater resources is being expanding, which provides an opportunity to address this problem at a lower social and economic cost. We analyse the economic impact of using several instruments to address the problem of non-renewable groundwater pumping in the aquifers of the Guadalentín basin: an environmental tax on groundwater use, the buyback of groundwater rights and the subsidization of desalinised resources. Their impact is assessed using a mathematical programming model that maximises the farm net margin resulting from the use of the available water resources for irrigation in the area. Our results show that, in the current situation of water availability, all the alternatives have significant economic impacts. Moreover, the first two alternatives would be unfeasible from a political point of view. The existence of abundant, though expensive, desalinised water resources in the foreseen future would reduce, but not eliminate, the negative economic impact of such instruments. Furthermore, water demand is so high in this area that even strongly subsidising desalinised water in exchange for reducing the use of groundwater would not allow to eliminate aquifer overdraft.

  3. The role of desalinisation to address aquifer overdraft in SE Spain.

    PubMed

    Martínez-Granados, David; Calatrava, Javier

    2014-11-01

    Aquifer overdraft is a major environmental and water management problem in Southeast Spain. In some areas, availability of desalinised seawater resources is being expanding, which provides an opportunity to address this problem at a lower social and economic cost. We analyse the economic impact of using several instruments to address the problem of non-renewable groundwater pumping in the aquifers of the Guadalentín basin: an environmental tax on groundwater use, the buyback of groundwater rights and the subsidization of desalinised resources. Their impact is assessed using a mathematical programming model that maximises the farm net margin resulting from the use of the available water resources for irrigation in the area. Our results show that, in the current situation of water availability, all the alternatives have significant economic impacts. Moreover, the first two alternatives would be unfeasible from a political point of view. The existence of abundant, though expensive, desalinised water resources in the foreseen future would reduce, but not eliminate, the negative economic impact of such instruments. Furthermore, water demand is so high in this area that even strongly subsidising desalinised water in exchange for reducing the use of groundwater would not allow to eliminate aquifer overdraft. PMID:24973613

  4. Heavy metals relationship in arable and greenhouse soils of SE Spain using a geostatistical analysis

    NASA Astrophysics Data System (ADS)

    Gil, Carlos; Joaquin Ramos-Miras, Jose; Rodríguez Martín, Jose Antonio; Boluda, Rafael; Roca, Núria; Bech, Jaume

    2013-04-01

    This study compares heavy metals contents and the main edaphic parameters in greenhouse soils from the W Almería region one of the most productive agricultural systems in Europe, with agricultural soils (arable soils) in western Andalusia, SW Spain. Heavy metals input in agricultural soils mainly occur through pesticides and phytosanitary control products. The hazardousness of the studied elements (Cr, Ni, Pb, Cu, Zn and Cd) is particularly relevant in soils used for intensive greenhouse farming where such agricultural practices, which centre on maximising production, end up with products that finally enter the human food chain directly. Here we explore a total of 199 greenhouse soils and 142 arable soils, representing two scales of variation in this Mediterranean area. Despite their similar edaphic characteristics, the main differences between arable soils and greenhouse soils lie in nutrients contents (P and K) and in certain heavy metals (Cd, Pb and Zn), which reflect widespread use of pesticides in greenhouse farming. One of the most toxic metals is Cd given its mobility, whose concentrations triple in greenhouse soils, although it does not exceed the limits set by Spanish legislation. We conclude that despite anthropic heavy metals input, the association patterns of these elements were similar on the two spatial variability scales. Cd, Pb and Zn contents, and partly those of Cu, are related with agricultural practices. On the short spatial scale, grouping these heavy metals shows very high contents in greenhouse soils in the central northern area of the W Almería region. On the other hand, the associations of Cr and Ni suggest a lithogenic influence combined with a pedogenic effect on spatial maps. This natural origin input becomes more marked on the long spatial scale (arable soils) where the main Cr and Ni contents are found in the vicinity of the Gádor Mountain Range.

  5. Seismic microzonation and velocity models of El Ejido area (SE Spain) from the diffuse-field H/V method

    NASA Astrophysics Data System (ADS)

    García-Jerez, Antonio; Seivane, Helena; Navarro, Manuel; Piña-Flores, José; Luzón, Francisco; Vidal, Francisco; Posadas, Antonio M.; Aranda, Carolina

    2016-04-01

    El Ejido town is located in the Campo de Dalías coastal plain (Almería province, SE Spain), emplaced in one of the most seismically active regions of Spain. The municipality has 84000 inhabitants and presented a high growth rate during the last twenty years. The most recent intense seismic activity occurred close to this town was in 1993 and 1994, with events of Mb = 4.9 and Mb = 5.0, respectively. To provide a basis for site-specific hazard analysis, we first carried out a seismic microzonation of this town in terms of predominant periods and geotechnical properties. The predominant periods map was obtained from ambient noise observations on a grid of 250 x 250 m in the main urban area, and sparser measurements on the outskirts. These broad-band records, of about 20 minutes long each, were analyzed by using the horizontal-to-vertical spectral ratio technique (H/V). Dispersion curves obtained from two array measurements of ambient noise and borehole data provided additional geophysical information. All the surveyed points in the town were found to have relatively long predominant periods ranging from 0.8 to 2.3 s and growing towards the SE. Secondary high-frequency (> 2Hz) peaks were found at about the 10% of the points only. On the other hand, Vs30 values of 550 - 650 m/s were estimated from the array records, corresponding to cemented sediments and medium-hard rocks. The local S-wave velocity structure has been inverted from the H/V curves for a subset of the measurement sites. We used an innovative full-wavefield method based on the diffuse-wavefield approximation (Sánchez-Sesma et al., 2011) combined with the simulated annealing algorithm. Shallow seismic velocities and deep boreholes data were used as constraints. The results show that the low-frequency resonances are related with the impedance contrast between several hundred meters of medium-hard sedimentary rocks (marls and calcarenites) with the stiffer basement of the basin, which dips to the SE. These

  6. Arsenic background and baseline values in soils from Murcia Region (SE, Spain)

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, C.; Martínez-Sánchez, , M. J.; García-Lorenzo, M. L.; Molina, J.; Tudela, M. L.; Mantilla, W.

    2009-04-01

    Arsenic is a strongly chalcophile, and is partitioned into a variety of sulphide and sulpharsenide minerals, notably arsenopyrite FeAsS, but also realgar and orpiment.It is also widely present as an accessory element in other sulphide minerals such as galena, pyrite and sphalerite. The objective of this study was to determine the arsenic background and baseline level in soils from the Region of Murcia (Southeast, Spain) and to study the possible relationship between mineralogical composition and arsenic concentration. Sampling sites were selected in areas subjected to high and similar agricultural activity or abandoned agricultural soils with natural vegetation, that are not subjected to particular point contamination sources. A total of 490 samples were collected, and the mineralogical composition and the arsenic content were determined. Samples were analysed for arsenic content by atomic fluorescence spectrometry (AFS). Background and baseline values could be determined for each geological unit, because of its unique and differentiating geochemical pattern. For some samples, the soils were influenced by the erosion of surrounding mountains, which belong to different geologic units and, as a consequence, background and baseline value determination was more difficult. Four different groups were established based on significant relationship with the mineralogical composition in soil samples, using discriminant analysis. The results showed that the concentration of arsenic is correlated with the mineralogical composition. Thus, arsenic level is positively correlated with the phylosilicate content. In summary, the background level, showed as the median was 6.65 mg kg-1 and the baseline level, showed as mean+ 2*Std. deviation, was 21.14 mg kg-1. Since the As content varied as a function of the mineralogical group, baselines of arsenic could be established for the four mineralogical groups as follows: 49.59 mg kg-1 for group 1, 12.57 mg kg-1 for group 2, 11.14 mg kg-1

  7. Environmental impact from mountainous olive orchards under different soil-management systems (SE Spain).

    PubMed

    Francia Martínez, José R; Durán Zuazo, Víctor H; Martínez Raya, Armando

    2006-04-01

    Soil erosion, runoff and nutrient-loss patterns over a two-year period (1999-2000) were monitored in erosion plots on a mountainside with olive (Olea europaea cv. Picual) trees under three different types of soil management: (1) non-tillage with barley (Hordeum vulgare) strips of 4 m width (BS); (2) conventional tillage (CT); (3) non-tillage without plant strips (NT). The erosion plots, located in Lanjaron (Alpujarras) on the southern flank of the Sierra Nevada Mountains in south-eastern Spain, had 30% slope at an altitude of 565 m and 192 m(2) (24x8 m) in area. The highest erosion and runoff values, ranging from 10.5 to 40.7 t ha(-1) yr(-1) and from 26.5 to 51.5 mm yr(-1), respectively, over the entire study period, were measured under NT. In CT, erosion ranged from 1.0 to 10.4 t ha(-1) yr(-1) and runoff from 6.7 to 15.2 mm yr(-1), while under BS, erosion ranged from 1.7 to 2.4 t ha(-1) yr(-1) and runoff from 19.6 to 20.0 mm yr(-1). It is concluded that the BS and CT reduced the soil erosion by 92% and 78%, with respect to the NT, and the runoff by 49% and 72%, respectively. The total NPK losses (sediments and runoff) from BS averaged 0.87, 0.07 and 0.72 kg ha(-1), from CT 1.82, 0.11 and 0.97 kg ha(-1) and from NT 3.15, 0.29 and 2.45 kg ha(-1), respectively. In addition, nutrient concentrations in the surface runoff were higher than the recommended level for standard water quality for N-NO(3), N-NH(4) and soluble P, particularly from NT and CT. These results support the recommendation of non-tillage with barley strips for sloped agricultural land in order to reduce erosion and pollution.

  8. Pliocene Transgression in the Western Mediterranean Sea: Strontium Isotopes from Cuevas Del Almanzora (Se Spain)

    NASA Astrophysics Data System (ADS)

    Müller, Daniel W.

    1993-02-01

    The deposition of marine sediments in the deep Mediterranean basins following the Messinian salinity crisis ("Zanclean Deluge") began at 4.9 Ma and continued until normal marine conditions prevailed at 4.6 Ma. The Betic Strait of southeast Spain, the Rif Strait of northern Morocco, and the Strait of Gibraltar have been postulated as possible entry ways for the marine waters into the Mediterranean. Two possible explanations have been offered for the timing of the deposition of marine hemipelagic marls in the Vera Basin (Cuevas del Almanzora section) within the Betic Strait: (1) early Pliocene, representing the "Zanclean Deluge" (Cita et al., 1980), (2) Messinian (˜5.7 Ma), representing the last marine stage before the Messinian salinity crisis (Benson and Rakic-El Bied, 1991; Benson et al., 1991). The strontium isotopic ratio on mixed assemblages of foraminifers from these marine marls was determined in order to assess their ages. The average 87Sr/86Sr (0.709033±24) of the seven measured samples is, compared to the base of the Miocene/Pliocene boundary stratotype at Capo Rossello, Sicily, higher by 38 × 10-6 and yields an age of 4.6±0.5 Ma when compared to the established open ocean Sr seawater curve. The determined age indicates that (1) the first 3.6 m of marine deposits of the Cuevas del Almanzora section sensu Cita et al. (1980) including the passage zone are Pliocene, (2) the earliest marine Pliocene might not be represented at Cuevas del Almanzora indicating that this marginal basin at the edge of the Mediterranean Sea, yet within the former Betic Strait, was filled progressively by a marine transgression originating from the Mediterranean Sea around 4.6 Ma. The absence of lowermost Pliocene sediments could suggest that the Betic Strait did not serve as a conduit for the water masses entering the Mediterranean basins during the early Pliocene; and (3) the presence of an early evolutionary stage of Globorotalia margaritae in the Moroccan Bou Regreg section

  9. Amino acid racemization dating of Upper Pleistocene - Holocene terrestrial gastropods from a Mediterranean region (Murcia, SE Spain)

    NASA Astrophysics Data System (ADS)

    Garcia-Mayordomo, Julian; Ortiz, Jose E.; Torres, Trinidad; Insua-Arevalo, Juan M.; Martinez-Diaz, Jose J.; Altolaguirre, Yul; Canales-Fernandez, Maria L.; Martin-Banda, Raquel

    2014-05-01

    The amino acid racemization method has become a widely used geochronological tool for dating Quaternary deposits. The method is based on the fact that living organisms contain only L-amino acids which gradually racemize into D-amino acids after death. Thus, the D/L ratio increases with time after death until it is equal to 1, that is, when equilibrium is reached. Gastropod shells are particularly useful for amino acid racemization dating. Because the amino acid racemization method is not a numerical dating method in isolation, it needs to be calibrated, mainly with radiometric dating methods. The racemization process is genus- and temperature-dependent. In this work we present a preliminary analysis that compares the radiometric age estimated from different dating methods of a number of gastropods recovered in localities from Murcia (Southeastern Spain), with the age obtained through the amino acid racemization method. Taking advantage of recent paleoseismological research in the Murcia region (SE Spain), 28 gastropods specimens were collected from different trenches dug in young Quaternary alluvial deposits. The specimens were subsequently classified and then analyzed according to the standards protocols of the Biomolecular Stratigraphy Laboratory (UPM, Madrid School of Mines). The species found were Otala lactea, Iberus gualterianus, Sphincterochila candidissima and Theba pisana. The D/L ratios of aspartic acid, leucine, phenylalanine and glutamic acid were determined, and the corresponding average age of each specimen was calculated introducing the D/L values in the age calculation algorithm of Torres et al. (1997) for gastropods of central and southern Spain. The racemization age for each locality was then compared to the radiometric age of the deposit where the specimens were collected. To this respect, the samples were classified in different groups considering the reliability on the age control method. The most reliable sample consists only on dates obtained

  10. Estimation of the tectonic slip-rate from Quaternary lacustrine facies within the intraplate Albacete province (SE of Spain)

    USGS Publications Warehouse

    Rodriguez-Pascua, M. A.; Bischoff, J.; Garduno-Monroy, Victor H.; Pérez-López, R.; Giner-Robles, J.L.; Israde-Alcántara, I.; Calvo, J.P.; Williams, Ross W.

    2009-01-01

    The Quaternary lacustrine basin of Cordovilla (CB) represents one of the most active tectonic areas of the Prebetic Zone (Albacete, SE of Spain). The Quaternary sedimentary deposits of this basin are mainly endoreic lacustrine carbonate and alluvial deposits, developed in a semi-arid climate (Pleistocene-present). The basin is a NW-SE-elongated graben bounded by a major right-lateral oblique-fault, the Pozohondo Fault. This fault trends NW-SE, with an approximate trace of 55 km, and is composed of various segments which are identified by fault scarps. In order to establish the slip-rate of the most active segment of the Pozohondo Fault, called the Cordovilla segment, we carried out a detailed study of the affected Quaternary lacustrine deposits. We found that the lacustrine facies could be related to episodic moderate paleoearthquakes. The slip-rate is calculated to be 0.05 and 0.09 mm/yr, using radiometric dating for the vertical offsets of the lacustrine facies. A trenching study at the northern part of the Cordovilla segment revealed two events caused by paleoearthquakes, with the most recent expressed as an oblique-fault off-setting a poorly-developed soil. The magnitude of the last event was greater than 6, using various empirical relationships for the fault displacement and the surface-length rupture. We estimate episodic activity across the Cordovilla segment, to be characterized by moderate-sized paleoearthquakes (M6), which is in agreement with the tectonic context of an intraplate zone of the Iberian plate. ?? 2009 Elsevier B.V.

  11. Experimental studies of supercritical bedforms applied to coarse-grained turbidite deposits of the Tabernas Basin (SE Spain, late Miocene)

    NASA Astrophysics Data System (ADS)

    Cartigny, Matthieu; Postma, George; Kleverlaan, Kick

    2014-05-01

    Modern submarine canyon floors are often covered with bedform patterns linked to supercritical turbidity currents, while recognition of sedimentary structures associated with such bedforms in outcrops are rare. On the basis of experimental work on bed morphodynamics and flow structure of high-density turbidity currents, a 3-dimensional bedform stability diagram and related sedimentary facies diagram have been constructed. To allow scaling of this diagram to natural flows, four non-dimensional parameters are used: 1) densimetric Froude number, 2) modified mobility parameter, 3) dimensionless grain size and 4) basal sediment concentration. Each bedform and basal sediment concentration is then linked to a characteristic facies type. Numerical and theoretical models from the literature and observations from modern turbidite depositional systems are used to estimate characteristic sizes of the bedforms for different flow types. The model is applied to the turbidite fan systems of the Tabernas Basin (SE Spain, late Miocene) and discussed along existing classical models of high density turbidity current deposits. It is concluded that the vertical sequence of supercritical bedforms have been described in these models, yet to date have never been recognized as bedforms in outcrop, presumably because of their large size that easily exceeds the dimensions of commonly available outcrop. On the basis both experimental work and outcrop studies in the Tabernas Basin (SE Spain) a conceptual three-dimensional bedform diagram for recognition of cyclic steps in outcrop is constructed. Experimental data indicates that depositional processes on the stoss-side of a cyclic step are controlled by hydraulic jump, which temporarily stalls the flow and by subsequent waxing of the flow up to supercritical again. The hydraulic jump produces large scours with soft sediment deformation (flames) preserved in Bouma Ta, while near horizontal, massive to stratified top-cut-out turbidite beds are

  12. Biophysical and socioeconomic impacts of soil and water conservation measures. An evaluation of Sustainable Land Management in SE Spain.

    NASA Astrophysics Data System (ADS)

    de Vente, J.; Solé-Benet, A.; López, J.; Boix-Fayos, C.

    2012-04-01

    In close collaboration with stakeholders promising soil and water conservation measures were selected as part of the EU funded DESIRE project. These measures were monitored for nearly three years at an experimental farm in the upper Guadalentin (SE-Spain). Four Sustainable Land Management (SLM) measures were implemented on rainfed almonds: a) reduced tillage, b) green manure, c) straw mulch, d) traditional water harvesting. A fifth measure (e) reduced tillage of cereals, was compared to conventional mouldboard tillage. Here, we present monitoring results according to biophysical and socioeconomic criteria. SLM measures a, b and e, aim to reduce soil and water loss through runoff. Therefore, for each measure three replica erosion-runoff plots and a control plot were installed to monitor soil and water loss and soil moisture content at two depths. SLM measures c and d aim to increase soil water content by preventing soil evaporation and adding additional water by water harvesting respectively. In these fields, the volume of harvested water was registered and soil water content was monitored. In all experiments, farm operation costs and crop harvest were monitored as well. In the almond fields, green manure and reduced tillage significantly reduced soil and water loss as compared to the control plot with normal tillage operations. Also for the cereal field, results show lower erosion rates under reduced tillage as compared to traditional tillage operation. In two successive years, the highest almond harvest was found in the field with water harvesting (d), followed by the green manure field (b), though no significant differences were found in soil water content with their control plots. Mulching did not show a significant effect on soil water content or harvest. Four of the selected SLM options showed a positive effect on the protection of soil and water resources, and were beneficial for crop yield. Whereas, reduced tillage also results in lower production costs, the

  13. Climate change adaptation via targeted ecosystem service provision: a sustainable land management strategy for the Segura catchment (SE Spain)

    NASA Astrophysics Data System (ADS)

    Zagaria, Cecilia; de Vente, Joris; Perez-Cutillas, Pedro

    2014-05-01

    Topical research investigating climate, land-use and management scenarios in the Segura catchment (SE Spain), depicts a landscape at high-risk of, quite literally, deserting agriculture. Land degradation in the semi-arid region of SE Spain is characterized by water shortage, high erosion rates and salinization, increasingly exacerbated by climatic changes, scarce vegetation cover and detrimental farming practices. Future climate scenarios predict increases in aridity, variability and intensity of rainfall events, leading to increasing pressure on scarce soil and water resources. This study conceptualized the impending crisis of agro-ecological systems of the Segura basin (18800 km2) as a crisis of ecosystem service deterioration. In light of existing land degradation drivers and future climate scenarios, the potential of Sustainable Land Management (SLM) strategies was evaluated to target three priority ecosystem services (water provision, sediment retention and carbon sequestration) as a means to achieve climate change adaptation and mitigation. A preceding thorough process of stakeholder engagement (as part of the EU funded DESIRE project) indicated five SLM technologies for potential implementation, all with a focus upon reducing soil erosion, increasing soil water holding capacity and soil organic matter content. These technologies have been tested for over four years in local experimental field plots, and have provided results on the local effects upon individual environmental parameters. Despite the growing emphasis witnessed in literature upon the context-specificity which characterizes adaptation solutions, the frequent analysis at the field scale is limited in both scope and utility. There is a need to investigate the effects of adaptive SLM solutions at wider, regional scales. Thus, this study modeled the cumulative effect of each of the five selected SLM technologies with InVEST, a spatial analyst tool designed for ecosystem service quantification and

  14. Evaporite sedimentation in a tectonically active basin: The lacustrine Las Minas Gypsum unit (Late Tortonian, SE Spain)

    NASA Astrophysics Data System (ADS)

    Ortí, Federico; Rosell, Laura; Gibert, Lluís; Moragas, Mar; Playà, Elisabet; Inglès, Montserrat; Rouchy, Jean Marie; Calvo, José Pedro; Gimeno, Domingo

    2014-08-01

    Evaporite successions may undergo significant lithostratigraphic changes laterally and vertically in tectonically-active basins. The Las Minas Gypsum, a lacustrine unit of Late Tortonian age and up to 160 m thick in the Las Minas-Camarillas basin (SE Spain), consists of a number of shallowing-upward cycles. Each cycle is made up of a lower interval with marl and carbonate, and an upper interval with gypsum. In the upper interval, the base displays carbonate-gypsum laminites (couplets, yearly microcycles) showing a large variability of textures and fabrics; gypsum textures are cumulates and bottom-grown crystals. Laminites are overlain by selenitic gypsum. The carbonate is a primary dolomite induced by sulphate-reducing bacterial activity. Native sulphur was formed in early diagenesis and during exhumation was partly transformed into late diagenetic gypsum. The isotopic compositions of gypsum suggest that the sulphate mainly derived from chemical recycling of Triassic evaporites; however, marine sulphate was probably supplied by episodic marine incursions. A perennial saline lake characterized by irregular bottom topography and depositional settings with variable subsidence ratios is interpreted. In addition to climate, saline diapirism, Neogene volcanism, synsedimentary faulting and seismicity influenced the evaporitic deposition. Las Minas-Camarillas basin is an example of how in tectonically active zones different factors interplay to produce significant variability of the evaporitic sedimentation and cyclicity.

  15. Boxwork and ferromanganese coatings in hypogenic caves: An example from Sima de la Higuera Cave (Murcia, SE Spain)

    NASA Astrophysics Data System (ADS)

    Gázquez, Fernando; Calaforra, José-María; Rull, Fernando

    2012-12-01

    This paper examines the greyish-blue deposits that were recently discovered in the lower levels of the Sima de la Higuera Cave (Murcia, SE Spain) which occur as patinas over the walls and ceilings, as well as coating boxwork formations. Their mineralogy was determined using XRD and micro-Raman spectroscopy, while EDX microanalysis was used to determine their elemental composition. The mineralogical analyses revealed the presence of Mn oxides (todorokite and pyrolusite) and Fe with a low degree of crystallinity, whereas EDX microprobe showed elevated concentrations of Mn (38.2 wt.%), Fe (15.2 wt.%) and Pb (8.1 wt.%). The ferromanganese oxyhydroxides occur as botryoidal aggregates overlying blades of calcite that have a visibly sugary texture. The speleogenetic model proposed describes (1) an initial phase of precipitation of hydrothermal calcite veins (of hypogenic origin) within the fissures of the host rock under phreatic conditions and (2) a subsequent vadose phase involving preferential corrosion of the carbonate host rock caused by lowering of the pH resulting from CO2 diffusion in condensed water and oxidation of Fe and Mn under aerobic conditions, probably mediated by microorganisms. It is this later phase that gave rise to the boxwork. The boxwork of the Sima de la Higuera Cave is a singular example of a formation that is generated by dissolution-corrosion of the rock due to acidification caused by oxidation of iron and manganese.

  16. Long-term erosion rate measurements in gypsum caves of Sorbas (SE Spain) by the Micro-Erosion Meter method

    NASA Astrophysics Data System (ADS)

    Sanna, Laura; De Waele, Jo; Calaforra, José Maria; Forti, Paolo

    2015-01-01

    The present work deals with the results of long-term micro-erosion measurements in the most important gypsum cave of Spain, the Cueva del Agua (Sorbas, Almeria, SE Spain). Nineteen MEM stations were positioned in 1992 in a wide range of morphological and environmental settings (gypsum floors and walls, carbonate speleothems, dry conduits and vadose passages) inside and outside the cave, on gypsum and carbonate bedrocks and exposed to variable degree of humidity, different air flow and hydrodynamic conditions. Four different sets of stations have been investigated: (1) the main cave entrance (Las Viñicas spring); (2) the main river passage; (3) the abandoned Laboratory tunnel; and (4) the external gypsum surface. Data over a period of about 18 years are available. The average lowering rates vary from 0.014 to 0.016 mm yr- 1 near the main entrance and in the Laboratory tunnel, to 0.022 mm - 1 on gypsum floors and 0.028 mm yr- 1 on carbonate flowstones. The denudation data from the external gypsum stations are quite regular with a rate of 0.170 mm yr- 1. The observations allowed the collecting of important information concerning the feeding of the karst aquifer not only by infiltrating rainwater, but under present climate conditions also by water condensation of moist air flow. This contribution to the overall karst processes in the Cueva del Agua basin represents over 20% of the total chemical dissolution of the karst area and more than 50% of the speleogenetically removed gypsum in the cave system, thus representing all but a secondary role in speleogenesis. Condensation-corrosion is most active along the medium walls, being slower at the roof and almost absent close to the floor. This creates typical corrosion morphologies such as cupola, while gypsum flowers develop where evaporation dominates. This approach also shows quantitatively the morphological implications of condensation-corrosion processes in gypsum karst systems in arid zones, responsible for an

  17. Extreme storms during the last 6500 years from lagoonal sedimentary archives in the Mar Menor (SE Spain)

    NASA Astrophysics Data System (ADS)

    Dezileau, Laurent; Pérez-Ruzafa, Angel; Blanchemanche, Philippe; Degeai, Jean-Philippe; Raji, Otmane; Martinez, Philippe; Marcos, Concepcion; Von Grafenstein, Ulrich

    2016-06-01

    Storms and tsunamis, which may seriously endanger human society, are amongst the most devastating marine catastrophes that can occur in coastal areas. Many such events are known and have been reported for the Mediterranean, a region where high-frequency occurrences of these extreme events coincides with some of the most densely populated coastal areas in the world. In a sediment core from the Mar Menor (SE Spain), we discovered eight coarse-grained layers which document marine incursions during periods of intense storm activity or tsunami events. Based on radiocarbon dating, these extreme events occurred around 5250, 4000, 3600, 3010, 2300, 1350, 650, and 80 years cal BP. No comparable events have been observed during the 20th and 21st centuries. The results indicate little likelihood of a tsunami origin for these coarse-grained layers, although historical tsunami events are recorded in this region. These periods of surge events seem to coincide with the coldest periods in Europe during the late Holocene, suggesting a control by a climatic mechanism for periods of increased storm activity. Spectral analyses performed on the sand percentage revealed four major periodicities of 1228 ± 327, 732 ± 80, 562 ± 58, and 319 ± 16 years. Amongst the well-known proxies that have revealed a millennial-scale climate variability during the Holocene, the ice-rafted debris (IRD) indices in the North Atlantic developed by Bond et al. (1997, 2001) present a cyclicity of 1470 ± 500 years, which matches the 1228 ± 327-year periodicity evidenced in the Mar Menor, considering the respective uncertainties in the periodicities. Thus, an in-phase storm activity in the western Mediterranean is found with the coldest periods in Europe and with the North Atlantic thermohaline circulation. However, further investigations, such as additional coring and high-resolution coastal imagery, are needed to better constrain the main cause of these multiple events.

  18. Categorical Indicator Kriging for assessing the risk of groundwater nitrate pollution: the case of Vega de Granada aquifer (SE Spain).

    PubMed

    Chica-Olmo, Mario; Luque-Espinar, Juan Antonio; Rodriguez-Galiano, Victor; Pardo-Igúzquiza, Eulogio; Chica-Rivas, Lucía

    2014-02-01

    Groundwater nitrate pollution associated with agricultural activity is an important environmental problem in the management of this natural resource, as acknowledged by the European Water Framework Directive. Therefore, specific measures aimed to control the risk of water pollution by nitrates must be implemented to minimise its impact on the environment and potential risk to human health. The spatial probability distribution of nitrate contents exceeding a threshold or limit value, established within the quality standard, will be helpful to managers and decision-makers. A methodology based on non-parametric and non-linear methods of Indicator Kriging was used in the elaboration of a nitrate pollution categorical map for the aquifer of Vega de Granada (SE Spain). The map has been obtained from the local estimation of the probability that a nitrate content in an unsampled location belongs to one of the three categories established by the European Water Framework Directive: CL. 1 good quality [Min - 37.5 ppm], CL. 2 intermediate quality [37.5-50 ppm] and CL. 3 poor quality [50 ppm - Max]. The obtained results show that the areas exceeding nitrate concentrations of 50 ppm, poor quality waters, occupy more than 50% of the aquifer area. A great proportion of the area's municipalities are located in these poor quality water areas. The intermediate quality and good quality areas correspond to 21% and 28%, respectively, but with the highest population density. These results are coherent with the experimental data, which show an average nitrate concentration value of 72 ppm, significantly higher than the quality standard limit of 50 ppm. Consequently, the results suggest the importance of planning actions in order to control and monitor aquifer nitrate pollution.

  19. An assessment of the influence of sulfidic mine wastes on rainwater quality in a semiarid climate (SE Spain)

    NASA Astrophysics Data System (ADS)

    Alcolea, A.; Fernández-López, C.; Vázquez, M.; Caparrós, A.; Ibarra, I.; García, C.; Zarroca, M.; Rodríguez, R.

    2015-04-01

    This study assessed the influence of the Sierra Minera de Cartagena - La Unión mining wastes on the surrounding areas, due to the sediment transport in the atmosphere. Monitoring of 15 weather stations located in the Campo de Cartagena land (SE Spain) was performed in the period December, 2004-March, 2008. A total of 920 rainfall water samples were collected and analyzed in this study. The network of weather stations covered a wide range of soil use and human activities (industrial, urban, agricultural, and mining sites). The physicochemical characterization involved determination of pH, EC, major ions, and the metals of interest in the soluble fraction of rainwater. Precipitations had an alkaline pH (7.0-7.9) and, compared to World Health Organization guidelines for drinking-water quality, samples were characterized by low EC (76-930 μS/cm), Ni (0.1-8 μg/L), Cu (3-88 μg/L), As (0.04-2 μg/L), Na+ (3-16 mg/L), K+ (0.41-30 mg/L), Ca2+ (6-51 mg/L), Mg2+ (up to 5 mg/L), Cl- (4-23 mg/L), NO3- (1-30 mg/L), and SO42- (4-35 mg/L) values. In certain locations, Zn, Cd, and Pb exceeded the guideline limits. A downward trend of H+, Zn, Cd, and Pb concentrations in total depositions was observed while the distance to the area affected by mining activities increased in the first 20 km. Rainwater quality was found to be just subtly affected by the metal-sulfide abandoned minesites, but without presenting a current threat to neither public health nor natural ecosystem. Nevertheless, greater attention should be paid in the future projections of climate change, where a significant increase in aridity may favor the atmospheric transport of pollutant particles.

  20. Geochemical background of zinc, cadmium and mercury in anthropically influenced soils in a semi-arid zone (SE, Spain)

    NASA Astrophysics Data System (ADS)

    García-Lorenzo, M. L.; Pérez-Sirvent, C.; Martínez-Sánchez, M. J.; Molina, J.; Tudela, M. L.; Hernández-Córdoba, M.

    2009-04-01

    This work seeks to establish the geochemical background for three potentially toxic trace elements (Zn, Cd and Hg) in a pilot zone included in the DesertNet project in the province of Murcia. The studied area, known as Campo de Cartagena, Murcia (SE Spain) is an area of intensive agriculture and has been much affected over the years by anthropic activity. The zone can be considered an experimental pilot zone for establishing background levels in agricultural soils. Sixty four samples were collected and corresponded to areas subjected to high and similar agricultural activity or soils with natural vegetation, which correspond to abandoned agricultural areas. The Zn content was determined by flame atomic absorption spectrometry. The Cd content was determined by electrothermal atomization atomic absorption spectrometry and mercury content was determined by atomic fluorescence spectrometry. Geostatistical analysis consisting of kriging and mapping was performed using the geostatistical analyst extension of ArcGIS 8.3. Zinc values ranged from 10 mg kg-1 to 151 mg kg-1, with an average value of 45 mg kg-1. Cadmium values ranged between 0.1 mg kg-1 and 0.9mg kg-1, with a mean value of 0.3 mg kg-1 and mercury values ranged from 0.1 mg kg-1 to 2.3 mg kg-1, with a mean value of 0.5 mg kg-1. At a national level, the Spanish Royal Decree 9/2005 proposes toxicological and statistical approaches to establish background values. According to the statistical approach, background values consist of the median value for the selected element. The background values for Zn, Cd and Hg in the studied area were 40 mg kg-1 for Zn, 0.3 mg kg-1 for Cd and 0.4 mg kg-1 for Hg.

  1. Paleoecological and paleoenvironmental changes during the continental Middle-Late Permian transition at the SE Iberian Ranges, Spain

    NASA Astrophysics Data System (ADS)

    De la Horra, R.; Galán-Abellán, A. B.; López-Gómez, J.; Sheldon, N. D.; Barrenechea, J. F.; Luque, F. J.; Arche, A.; Benito, M. I.

    2012-08-01

    The Middle and Late Permian are characterized by a pair of mass-extinction events that are recorded in both marine and continental environments. Here, we present the first continental western peri-Tethyan record of an extinction event located in the Middle-Late interval. In the SE Iberian Ranges, Central Spain, the transition between the Lower and Middle subunits of the Middle Permian Alcotas Formation indicates a significant paleoclimatic change from arid and semiarid conditions towards more humid conditions. Coincident with the onset of humid conditions there were changes in the sedimentology, mineralogy, and geochemistry that indicate significant environmental changes including a shift in weathering intensity and a change of fluvial style from braided to meandering systems. Near the top of the Middle Subunit, a local biotic crisis is recorded by palynomorph assemblages. Following this crisis, there is a total absence of coal beds, plant remains, and microflora that defines a barren zone in the uppermost part of the Alcotas Formation which is recorded throughout the basin. The barren zone is accompanied by a shift back to braided stream systems, but not by a return to carbonate-bearing paleosols indicative of arid or semi-arid conditions. This combination of features is consistent with other Middle-Late continental basins related with mass extinctions, so the barren zone is interpreted as the extinction interval. The regional character of the extinction interval and its proximity with the Middle-Late Permian transition could be related with the global mid-Capitanian biotic turnover described in this period of time in other marine basins. However, the common difficulties of dating with precision non-marine rocks make this relationship difficult to probe in the Iberian Basin and in other Middle-Late Permian basins. Further work, including high resolution carbon-isotope analyses and complete studies of the magnetostratigraphy, should be desirable in order to obtain

  2. Do heavy metals existing in abandoned mining sites represent a real health risk? A study case in the SE Spain.

    NASA Astrophysics Data System (ADS)

    Martinez-Sanchez, Maria Jose; Perez-Sirvent, Carmen; García-Lorenzo, Mari Luz; Martínez-López, Salvadora; Perez-Espinosa, Victor; Hernández-Cordoba, Manuel; Bech, Jaime

    2013-04-01

    Mining activities have been carried out for centuries in Sierra Minera (SE Spain) giving rise to a large number of sites distributed throughout the zone in which residues are accumulated. This communication reports studies as regards metal mobilization and analysis of the health risk that could be posed by inhalation, dermic contact or occasional ingestion of this type of sediments. Lead was used as the metal for the studies due to its particular abundance in the zone. A large number of samples were taken and general analytical determinations (pH, particle size, organic matter, equivalent calcium carbonate content and mineralogical composition) were carried out in order its characterization. An in vitro method for obtaining formation on Pb bioaccessibility in these mine waste materials was also carried out. Our results prove that mineral associations, different alteration states and sorption/desorption processes play an important role in the bioavailability of lead. In addition, it is noteworthy that the metal fraction dissolved by the proposed in vitro methodology is lower than 100%, both in the stomach and intestinal phases. Finally an assessment of the risk posed by lead is achieved. To this respect it should be noted that the IRIS database provide cancer slope factor and reference dose, as a way to assess the risk caused by arsenic, cadmium and copper but no for lead, probably due to the wide variety of real situations, and the discrepancy of the sources. The way here suggested is a novelty in this sense, and the results could be extrapolated to other similar zones and be incorporated to the general protocol of risk assessment applied to contaminated sites.

  3. Total organic carbon and humus fractions in restored soils from limestone quarries in semiarid climate, SE Spain

    NASA Astrophysics Data System (ADS)

    Luna Ramos, Lourdes; Miralles Mellado, Isabel; Ángel Domene Ruiz, Miguel; Solé Benet, Albert

    2016-04-01

    Mining activities generate erosion and loss of plant cover and soil organic matter (SOM), especially in arid and semiarid Mediterranean regions. A precondition for ecosystem restoration in such highly disturbed areas is the development of functional soils with sufficient organic matter. But the SOM quality is also important to long-term C stabilization. The resistance to biodegradation of recalcitrant organic matter fractions has been reported to depend on some intrinsic structural factors of humic acid substances and formation of amorphous organo-mineral recalcitrant complexes. In an experimental soil restoration in limestone quarries in the Sierra de Gádor (Almería), SE Spain, several combinations of organic amendments (sewage sludge and compost from domestic organic waste) and mulches (gravel and woodchip) were added in experimental plots using a factorial design. In each plot, 75 native plants (Anthyllis cytisoides, A. terniflora and Macrochloa tenacissima) were planted and five years after the start of the experiment total organic carbon (TOC), physico-chemical soil properties and organic C fractions (particulate organic matter, H3PO4-fulvic fraction, fulvic acids (FA), humic acids (HA) and humin) were analyzed. We observed significant differences between treatments related to the TOC content and the HA/FA ratio. Compost amendments increased the TOC, HA content and HA/FA ratio, even higher than in natural undisturbed soils, indicating an effective clay humus-complex pointing to progressively increasing organic matter quality. Soils with sewage sludge showed the lowest TOC and HA/FA ratio and accumulated a lower HA proportion indicating poorer organic matter quality and comparatively lower resilience than in natural soils and soils amended with compost.

  4. Thinning effects on litterfall remaining after 8 years and improved stand resilience in Aleppo pine afforestation (SE Spain).

    PubMed

    Jiménez, M N; Navarro, F B

    2016-03-15

    Monthly litterfall was monitored over a 3-year period in afforested Aleppo pines in the Mediterranean semiarid SE Spain with the aim of determining the long-term response of pines to reductions in tree competition and how this forest practice might influence stand resilience. Three thinning intensities applied 5 years earlier were evaluated (T75 = 75% of the basal area removed, T60 = 60% and T48 = 48%), both at the stand and at the tree level. On average, the total annual litterfall varied between 1.30 Mg ha(-1) yr(-1) (±0.24 SE) in T75 and 3.28 Mg ha(-1) yr(-1) (±0.78 SE) in the unthinned control. At the stand level, monthly differences among the treatments were found over time in the needles (F = 11.09, df = 3, P = 0.0009) and woody fraction (F = 4.36, df = 3, P = 0.0269) following the thinning gradient: T0 (control)>T48 > T60 > T75, and for the total amount of needles (χ(2) = 9.33, P = 0.025) and twigs (χ(2) = 9.11, P = 0.027) recorded at the end of the study period. High amounts of twig and needle fall were recorded during summer and beginning of autumn, whereas the main miscellanea inputs were registered during the spring, coinciding with the fall of nests and frass from caterpillar outbreaks. At the tree level, the total litterfall fluctuated between 1.5 kg tree yr(-1) in T0 (2nd yr) and 7.0 kg tree yr(-1) in T75 (3rd yr), although mean annual statistical differences among the treatments were found only for the first year of monitoring. However, needle fall was higher for larger pines (T75) than for the smaller ones in control (T0) when the data were analysed over the 3-year-period (F = 3.64, df = 3, P = 0.0247), and the same happened for the woody fraction (F = 3.63, df = 3, P = 0.0250). By contrast, pine trees in the unthinned control registered needle-fall rates (measured as kg m(-2) tree(-1)) that were similar to or higher than those of pine trees in thinned stands, suggesting that defoliation

  5. Geodetic slip rate estimates for the Alhama de Murcia and Carboneras faults in the SE Betics, Spain

    NASA Astrophysics Data System (ADS)

    Khazaradze, Giorgi; Echeverria, Anna; Masana, Eulàlia

    2016-04-01

    The Alhama de Murcia and the Carboneras faults are the most prominent geologic structures within the Eastern Betic Shear Zone (EBSZ), located in SE Spain. Using continuous and campaign GPS observations conducted during the last decade, we were able to confirm the continuing tectonic activity of these faults by quantifying their geodetic slip-rates and comparing the estimated values with the geological (including paleoseismological) observations. We find that the bulk of the observed deformation is concentrated around the Alhama de Murcia (AMF) and the Palomares (PF) faults. The geodetic horizontal slip rate (reverse-sinistral) of 1.5±0.3 mm/yr calculated for the AMF and PF fault system is in good agreement with geological observations at the AMF, as well as, the focal mechanism of the 2011 Lorca earthquake, suggesting a main role of the AMF. We also find that the geodetic slip rate of the Carboneras fault zone (CFZ) is almost purely sinistral strike-slip with a rate of 1.3±0.2 mm/yr along N48° direction, very similar to 1.1 mm/yr geologic slip-rate, estimated from recent onshore and offshore paleoseismic and geomorphologic studies. The fact the geodetic and the geologic slip-rates are similar at the AMF and CF faults, suggests that both faults have been tectonically active since Quaternary, slipping at approximately at constant rate of 1.1 to 1.8 mm/yr. Since the existing GPS data cannot discern whether the CFZ is slipping seismically or aseismically, we have intended to relate the on-going seismic activity to the slip-rates estimated using GPS. For this reason we compared seismic and geodetic strain rates, where the latter are larger than seismic strain rates, suggesting the presence of aseismic processes in the area. Nevertheless, due to the large earthquake recurrence intervals, we may be underestimating the seismic strain rates. The direction of the P and T average stress axes are in good agreement with geodetic principal strain rate axes. To summarize, in

  6. Sedimentary and diagenetic markers of the restriction in a marine basin: the Lorca Basin (SE Spain) during the Messinian

    NASA Astrophysics Data System (ADS)

    Rouchy, J. M.; Taberner, C.; Blanc-Valleron, M.-M.; Sprovieri, R.; Russell, M.; Pierre, C.; Di Stefano, E.; Pueyo, J. J.; Caruso, A.; Dinarès-Turell, J.; Gomis-Coll, E.; Wolff, G. A.; Cespuglio, G.; Ditchfield, P.; Pestrea, S.; Combourieu-Nebout, N.; Santisteban, C.; Grimalt, J. O.

    1998-10-01

    The Lorca Basin (southeastern Spain) is part of a chain of small marginal Neogene basins located in the structurally active Betic area. The Upper Miocene (Messinian) sequence is composed of a thick diatomite-bearing series (Tripoli Unit) overlain by the Main Evaporites, analogous to the classical succession that records the main events during the Salinity Crisis in the Mediterranean region. The shallow restricted conditions of this region amplified the sedimentary responses to local and global forcings. An integrated approach using sedimentology, micropalaeontology, stable isotope geochemistry and organic geochemistry has been applied to the Tortonian/Messinian succession of the Lorca Basin, in order to obtain a continuous record of the environmental changes. The sediments record two major events which affected the whole Mediterranean: (1) high levels of productivity that led to the formation of the diatomite-bearing deposits in the early Messinian (Tripoli); and (2) the Messinian Salinity Crisis with its two major stages, represented by the Halite and Gypsum Units, both mainly precipitated from marine-derived brines. The rapid reflooding of the Mediterranean by normal marine waters at the base of the Pliocene did not reach the Lorca Basin, nor other basins of this part of the Betic area. Instead, continental sediments were deposited as a consequence of the regional uplift of SE Iberia, which started close to the Messinian/Pliocene boundary. The most prominent feature of this basin concerns the record of its restriction by the time of the deposition of the Tripoli Unit, which led to intercalations of precursor evaporitic layers, consisting of Ca-sulphate deposited in sub-aqueous and sabkha conditions, interbedded with diatomites. This alternation of evaporites and diatomites proves that the Lorca Basin was periodically restricted and reflooded by marine waters, a possible cause for this being relative sea-level fluctuations in the Mediterranean. This strengthens

  7. Interannual variability of Net Ecosystem CO2 Exchange and its component fluxes in a subalpine Mediterranean ecosystem (SE Spain)

    NASA Astrophysics Data System (ADS)

    Chamizo, Sonia; Serrano-Ortiz, Penélope; Sánchez-Cañete, Enrique P.; Domingo, Francisco; Arnau-Rosalén, Eva; Oyonarte, Cecilio; Pérez-Priego, Óscar; López-Ballesteros, Ana; Kowalski, Andrew S.

    2015-04-01

    Recent decades under climate change have seen increasing interest in quantifying the carbon (C) balance of different terrestrial ecosystems, and their behavior as sources or sinks of C. Both CO2 exchange between terrestrial ecosystems and the atmosphere and identification of its drivers are key to understanding land-surface feedbacks to climate change. The eddy covariance (EC) technique allows measurements of net ecosystem C exchange (NEE) from short to long time scales. In addition, flux partitioning models can extract the components of net CO2 fluxes, including both biological processes of photosynthesis or gross primary production (GPP) and respiration (Reco), and also abiotic drivers like subsoil CO2 ventilation (VE), which is of particular relevance in semiarid environments. The importance of abiotic processes together with the strong interannual variability of precipitation, which strongly affects CO2 fluxes, complicates the accurate characterization of the C balance in semiarid landscapes. In this study, we examine 10 years of interannual variability of NEE and its components at a subalpine karstic plateau, El Llano de los Juanes, in the Sierra de Gádor (Almería, SE Spain). Results show annual NEE ranging from 55 g C m-2 (net emission) to -54 g C m-2 (net uptake). Among C flux components, GPP was the greatest contributing 42-57% of summed component magnitudes, while contributions by Reco and VE ranged from 27 to 46% and from 3 to 18%, respectively. Annual precipitation during the studied period exhibited high interannual variability, ranging from 210 mm to 1374 mm. Annual precipitation explained 50% of the variance in Reco, 59% of that in GPP, and 56% for VE. While Reco and GPP were positively correlated with annual precipitation (correlation coefficient, R, of 0.71 and 0.77, respectively), VE showed negative correlation with this driver (R = -0.74). During the driest year (2004-2005), annual GPP and Reco reached their lowest values, while contribution of

  8. Transplant experiments to examine the habitat exclusivity of lichen dominated soil crust communities in the El Cautivo badlands, SE Spain

    NASA Astrophysics Data System (ADS)

    Bevan, J.; Alexander, R.; Lazaro-Suau, R.

    2012-04-01

    Successive episodes of erosion into late Miocene marls have produced the complex, deeply incised topography of the El Cautivo badlands in Almería, SE Spain. Phanerogamic vegetation is sparse in this extreme semi-arid environment and biological soil crusts constitute the predominant cover on all surfaces except those with active erosion. The soil crusts comprise a diverse range of lichen-dominated communities, which previous work (Bevan, 2008) has indicated can be separated into four main types, each characterised by one or a small number of lichen species. Distribution patterns of these main crust types appear to reflect (micro)topographic and microclimatic variability at the site with each community type occupying a specific habitat. The main crust types are identified as BC, a brown crust typically containing Endocarpon pusillum, Collema spp, Fulgensia spp and Placynthium nigrum, and DC, SC, LC, three white crusts characterised respectively by Diploschistes diacapsis, Squamarina lentigera and Lepraria crassissima. Previous work at the site (Bevan, 2008) has revealed associations between the distribution of these four crust types and a number of microclimatic variables, in particular insolation and temperature. BC tends to occur in the most exposed parts of the site where insolation and surface temperatures reach their highest levels and humidity and soil moisture tends to be low. LC appears more restricted to shaded sites with lower insolation and temperature and higher humidity and soil moisture. DC and SC occupy intermediate ranges of these variables. In order to test the degree to which the apparent habitat preferences of the crust types are obligatory or preferential a series of transplant experiments were devised. Replicate samples representative of each of the four crust types were reciprocally transplanted into areas dominated by each of the other types and also into an area previously eroded and bare. Each location had the following groups of plots: a

  9. Effect of partial melting on Vp and Vs in crustal enclaves from Mazarrón (SE Spain)

    NASA Astrophysics Data System (ADS)

    Ferri, Fabio; Burlini, Luigi; Cesare, Bernardo

    2016-03-01

    The combination of compressional and shear wave velocity is an important tool in discriminating rock types and identifying residing melts within the continental crust. Here we report the laboratory measurements for Vp and Vs obtained in varying conditions up to those exceeding the beginning of melting (950 °C at 500 MPa confining pressure) on two residual garnet-biotite-sillimanite-cordierite-spinel metapelitic enclaves recovered from the Neogene dacites of Mazarrón (SE Spain). The enclaves preserve widespread interstitial rhyolitic glass as evidence of primary melt extraction. At 500 MPa, the experimental Vp ranges from 7.21 ÷ 7.46 km s- 1 at room temperature to 5.44 km/s at 950 °C. The mean Vs is 4.5 km/s at room temperature with shear-wave splitting of 0.25 ÷ 0.3 km/s, measured along three mutually orthogonal directions. When temperature increases, the Vs evidences a reversible slope change at about 650 °C, and the shear-wave splitting reduces to zero (isotropic material) at 850-950 °C, where the sample Vs is ~ 3.0 km/s. The Vp anisotropy is 7-10% up to 700 °C increasing to ~ 20% at 950 °C, while the Vs anisotropy continuously decreases with temperature from 5% to 7% at room temperature to zero at 950 °C. No mineral reactions are observed up to 650-700 °C; however, microstructure equilibrates due to the relaxation of the primary glass at the glass transition temperature. Between 850 °C and 950 °C, a new melting reaction is observed producing biotite + spinel + ilmenite + plagioclase + melt. At melting, the rock becomes isotropic for Vs, and Poisson's ratio increases to 0.30. Our seismic data show that the seismic signature of high grade metapelitic rocks is similar to that of mafic materials. The evolution of Vp and Vs at melting conditions is compatible with the geophysical data of the area, supporting the hypothesis of the current existence of anatectic melts at intermediate depths of the Alborán domain.

  10. Lichenometry dating of rock collapse related to the great Lisbon Earthquake (1755) at the SE part of Spain

    NASA Astrophysics Data System (ADS)

    Perez-Lopez, Raul; Rodriguez-Pascua, Miguel Angel; Silva, Pablo G.; Bischoff, James L.; Owen, Lewis A.; Giner-Robles, Jorge L.; Díez-Herrero, Andres

    2010-05-01

    "De una montaña, se desprendió una parte" (A large part of a mountain has fallen down). This sentence was extracted from an ancient text written at the end of the 18th Century, in relation with the great Earthquake of Lisbon in 1755 (Martínez-Solares, 2001), and describing the rock collapse recorded near the small town of Agramón, 50 km southeastward of Albacete city (SE of Spain). Up to now, archaeologists have suggested this rock collapse to the archaeological site of "El Tolmo de Minateda", a small butte (420 m long) of calcarenitic sandstone bedrock with a flat top and scarped cliffs (20m high) bordering the butte. This ancient city was habited by several civilizations from Bronze Ages to modern times (i.e. Iberians, Roman, Visigoths, Muslims, Medieval ages, etc.). The landscape of this area is characterized by a flat terrain with isolated relict structural buttes consisting of Late Neogene marine sandstones created by differential erosion. The site exhibits three different stages of massive rock collapse. The oldest is located at the north of the site while the younger is located at the south part of the site and affecting Visigothic stone carved tombs. Archaeologists have postulated that the youngest of these was triggered by the Lisbon earthquake of 1755. We have carried out a lichenometric analysis over the free-faces of the rock blocks, with the aim of testing the postulate. For our purpose, we have calculated the calibrated growth curve for Aspicilia Radiosa (Hoff.), which yields a linear growth of 0.2425 mm per yr (R2 = 0.97, N=20). This growth rate was determined for the time interval from 800 BP yrs to the present by two different approaches: (1) rates obtained from cemetery measurements (200 yrs BP) and (2) rates determined from well-dated archaeological monuments (200-800 yrs BP). Our analysis revealed that the age of the rock-falling was in the year 1754 AD ±4. Thus, our results confirm that this collapse of ca. 5000 m3 of volume was triggered

  11. Constraining controls on carbonate sequences with high-resolution chronostratigraphy: Upper Miocene, Cabo de Gata region, SE Spain

    USGS Publications Warehouse

    Montgomery, P.; Farr, M.R.; Franseen, E.K.; Goldstein, R.H.

    2001-01-01

    A high-resolution chronostratigraphy has been developed for Miocene shallow-water carbonate strata in the Cabo de Gata region of SE Spain for evaluation of local, regional and global factors that controlled platform architecture prior to and during the Messinian salinity crisis. Paleomagnetic data were collected from strata at three localities. Mean natural remanent magnetization (NRM) ranges between 1.53 ?? 10-8 and 5.2 ?? 10-3 Am2/kg. Incremental thermal and alternating field demagnetization isolated the characteristic remanent magnetization (ChRM). Rock magnetic studies show that the dominant magnetic mineral is magnetite, but mixtures of magnetite and hematite occur. A composite chronostratigraphy was derived from five stratigraphic sections. Regional stratigraphic data, biostratigraphic data, and an 40Ar/39Ar date of 8.5 ?? 0.1 Ma, for an interbedded volcanic flow, place the strata in geomagnetic polarity Chrons C4r to C3r. Sequence-stratigraphic and diagenetic evidence indicate a major unconformity at the base of depositional sequence (DS)3 that contains a prograding reef complex, suggesting that approximately 250 000 yr of record (Subchrons C3Br.2r to 3Br.1r) are missing near the Messinian-Tortonian boundary. Correlation to the GPTS shows that the studied strata represent five third- to fourth-order DSs. Basal units are temperate to subtropical ramps (DS1A, DS1B, DS2); these are overlain by subtropical to tropical reefal platforms (DS3), which are capped by subtropical to tropical cyclic carbonates (Terminal Carbonate Complex, TCC). Correlation of the Cabo de Gata record to the Melilla area of Morocco, and the Sorbas basin of Spain indicate that early - Late Tortonian ramp strata from these areas are partially time-equivalent. Similar strata are extensively developed in the Western Mediterranean and likely were influenced by a cool climate or influx of nutrients during an overall rise in global sea-level. After ramp deposition, a sequence boundary (SB3) in

  12. Quantitative controls on location and architecture of carbonate depositional sequences: upper miocene, cabo de gata region, se Spain

    USGS Publications Warehouse

    Franseen, E.K.; Goldstein, R.H.; Farr, M.R.

    1998-01-01

    Sequence stratigraphy, pinning-point relative sea-level curves, and magnetostratigraphy provide the quantitative data necessary to understand how rates of sea-level change and different substrate paleoslopes are dominant controls on accumulation rate, carbonate depositional sequence location, and internal architecture. Five third-order (1-10 my) and fourth-order (0.1-1.0 my) upper Miocene carbonate depositional sequences (DS1A, DS1B, DS2, DS3, TCC) formed with superimposed higher-frequency sea-level cycles in an archipelago setting in SE Spain. Overall, our study indicates when areas of high substrate slope (> 15??) are in shallow water, independent of climate, the location and internal architecture of carbonate deposits are not directly linked to sea-level position but, instead, are controlled by location of gently sloping substrates and processes of bypass. In contrast, if carbonate sediments are generated where substrates of low slope ( 15.6 cm/ky to ??? 2 cm/ky and overall relative sea level rose at rates of 17-21.4 cm/ky. Higher frequency sea-level rates were about 111 to more than 260 cm/ky, producing onlapping, fining- (deepening-) upward cycles. Decreasing accumulation rates resulted from decreasing surface area for shallow-water sediment production, drowning of shallow-water substrates, and complex sediment dispersal related to the archipelago setting. Typical systems tract and parasequence development should not be expected in "bypass ramp" settings; facies of onlapping strata do not track base level and are likely to be significantly different compared to onlapping strata associated with coastal onlap. Basal and upper DS2 reef megabreccias (indicating the transition from cool to warmer climatic conditions) were eroded from steep upslope positions and redeposited downslope onto areas of gentle substrate during rapid sea-level falls (> 22.7 cm/ky) of short duration. Such rapid sea-level falls and presence of steep slopes are not conducive to formation of

  13. Quantitative controls on location and architecture of carbonate depositional sequences: Upper miocene, cabo de gata region, SE Spain

    USGS Publications Warehouse

    Franseen, E.K.; Goldstein, R.H.; Farr, M.R.

    1997-01-01

    Sequence stratigraphy, pinning-point relative sea-level curves, and magnetostratigraphy provide the quantitative data necessary to understand how rates of sea-level change and different substrate paleoslopes are dominant controls on accumulation rate, carbonate depositional sequence location, and internal architecture. Five third-order (1-10 my) and fourth-order (0.1-1.0 my) upper Miocene carbonate depositional sequences (DS1A, DS1B, DS2, DS3, TCC) formed with superimposed higher-frequency sea-level cycles in an archipelago setting in SE Spain. Overall, our study indicates when areas of high substrate slope (> 15??) are in shallow water, independent of climate, the location and internal architecture of carbonate deposits are not directly linked to sea-level position but, instead, are controlled by location of gently sloping substrates and processes of bypass. In contrast, if carbonate sediments are generated where substrates of low slope ( 15.6 cm/ky to ??? 2 cm/ky and overall relative sea level rose at rates of 17-21.4 cm/ky. Higher frequency sea-level rates were about 111 to more than 260 cm/ky, producing onlapping, fining- (deepening-) upward cycles. Decreasing accumulation rates resulted from decreasing surface area for shallow-water sediment production, drowning of shallow-water substrates, and complex sediment dispersal related to the archipelago setting. Typical systems tract and parasequence development should not be expected in "bypass ramp" settings; facies of onlapping strata do not track base level and are likely to be significantly different compared to onlapping strata associated with coastal onlap. Basal and upper DS2 reef megabreccias (indicating the transition from cool to warmer climatic conditions) were eroded from steep upslope positions and redeposited downslope onto areas of gentle substrate during rapid sea-level falls (> 22.7 cm/ky) of short duration. Such rapid sea-level falls and presence of steep slopes are not conducive to formation of

  14. Spectral detection of different types of soil crusts under intact and disturbance conditions in semiarid environments from SE Spain.

    NASA Astrophysics Data System (ADS)

    Chamizo, S.; Stevens, A.; Cantón, Y.; Domingo, F.; van Wesemael, B.

    2009-04-01

    Biological Soil Crusts (BSCs) consist of an association of soil particles with cyanobacteria, algae, microfungi, liverworts, bryophytes and lichens creating a cohesive thin horizontal layer on the soil surface. They have a widespread distribution in arid and semiarid regions, which comprise over 40% of the world's land surface. BSCs play an important role on hydrological and ecological functioning of arid and semiarid ecosystems since they influence all components of hydrological balance (runoff, rainfall capture, infiltration, evaporation, water retention capacity) and erosion. It is well known that BSCs at local scale reduce water erosion by protecting soil against raindrop impact. However, their effects have to be evaluated at different spatial scales, because in many cases BSCs lead to an increase of runoff and downslope erosion or water harvesting from crusted areas to nourish adjacent vegetated areas. Moreover, BSCs are easily damaged by livestock or human activities and the disturbance usually has great significance for the coverage and the composition of the community of the BSCs, the developmental stage of the BSC and their effects on hydrology and erosion. So, to accurately predict runoff and erosion processes, the spatial distribution of soil crust types and their disturbance conditions should be included in models. To map soil crusting at large scales, the use of their spectral characteristics can be a useful method. The objectives of this work are i) to analyze the spectral characteristics of different crust types (physical and biological soil crusts), also corresponding to different crust development stages, in two semiarid areas in SE Spain, El Cautivo (in the Tabernas Desert) and Amoladeras (in the Natural Park Cabo de Gata-Níjar), ii) to demonstrate the efficiency of diffuse reflectance spectroscopy, especially in the visible part of the spectrum, for classifying different crust types and different crust disturbance conditions. Spectral

  15. Lower Aptian Sequence at Madoz (SE Spain) in Relation to Cretaceous Anoxic Event-1a (OAE- 1a)

    NASA Astrophysics Data System (ADS)

    Gaona-Narvaez, T.; Maurrasse, F. J.; Lamolda, M. A.

    2008-05-01

    The Aptian stage at Madoz in the Sierra de Aralar, NE Spain, shows contrasting lithological succession of intercalated clastic-rich intervals and rudist-rich limestone beds varying between Medium Olive Gray (5Y 5/1) and Olive Gray (5Y 4/1). They are subdivided into different sub-units (Duvernois et al., 1972; Cherchi & Schroeder, 1998) with unit 1, as well as subunits 2a and 2b of "Madoz Limestone" are placed within the Lower Aptian Palorbitolina lenticularis Zone. Their stratigraphic level corresponds at least to the Deshayesites deshayesi ammonite zone, based on the presence of the nominate taxon in clastic Unit 1. Sub-unit 2b includes a distinct 180-cm thick black (Medium to Dark Gray, -N4 to N3) shale layer toward the close of the upper Lower Aptian. Detailed microfacies analysis was carried out on the Lower Aptian interval in order to characterize the different lithofacies and their possible relationship to Cretaceous OAE-1a. Subunit 2a is 20m thick and its microfacies consists of sparse and packed biomicrites, moderate to poorly sorted fine calcirudites and calcarenites composed of 40 - 50% remains of corals, predominantly non-rudist bivalves, echinoids, bryozoans, benthic foraminifera and calcareous algae indicative of well oxygenated conditions. Matrix and bioclasts are highly affected by neomorphism and growing of micritic envelopes is frequent. Superjacent subunit 2b is also 20m thick, but is lithologically very variable and consists of interbeds of indurated biomicrite with 30 - 50 % fossil fragments dominated by orbitolinids, and echinoids, non-rudist bivalves, benthic foraminifers, and algae as secondary components. These beds also contain 15 - 25 % mostly silt-size quartz grains, and clays. Other indurated biomicrite beds within subunit 2b contain 1 - 20 % fragments of non-rudist bivalves, echinoids, other benthic foraminifers, and algae, but orbitolinids are scarce. Terrigenous components make up 10 - 25 % of the matrix. Subunit 2b also includes soft

  16. Architecture analysis of a river flood-dominated delta during an overall sea-level rise (early Pliocene, SE Spain)

    NASA Astrophysics Data System (ADS)

    García-García, F.; Corbí, H.; Soria, J. M.; Viseras, C.

    2011-05-01

    The sedimentary record of delta-front to prodelta transition that developed during the early Pliocene (Bajo Segura Basin, peri-Mediterranean Betic Cordillera Basin) represents an unusual infilling of an incised valley cutting downwards into late Messinian pelagic marls. The complete delta succession, less than 65 m thick, consists of four upwardly fining and thinning sequences several metres thick. Each sequence consists of basal conglomeratic and coarse-grained sandstone beds (delta-front deposits) evolving upwards to alternating sandstones and silty-marl beds (prodelta deposits). The retrogradational stratal succession pattern is interpreted as having been deposited during an overall sea-level rise. Facies association is characterised by quasi- to planar-laminated sandstones and pebbly sandstones alternating with clast-supported boulders to pebbles, sheet-like climbing cross-laminated sandstones with abundant plant remains, and epsilon cross-stratified and channelized gravels and sandstones. These are interpreted as having been deposited by highly concentrated flows interpreted as hyperpycnal turbidity flows from high (cohesionless debris flows and sinuous submarine channels) to moderate (sheet-like climbing cross-laminated sandstones) discharge river-flood events. Slabs of sediment from unstable banks, outsized clasts which roll onto thin beds from channel mouths, slumps and intraformational breccias in delta front are other signatures (including a lack of bored clasts) which indicate high-energy and rapid deposition at the river mouth, encouraging the delta-front gravitational instability failures. Major changes in the discharge of the river-fed delta could have been caused by brief catastrophic, heavy-precipitation events coupled with quasi-stationary convective orographic rainfall typical of the modern Mediterranean.

  17. Habitat Fragmentation in Arid Zones: A Case Study of Linaria nigricans Under Land Use Changes (SE Spain)

    NASA Astrophysics Data System (ADS)

    Peñas, Julio; Benito, Blas; Lorite, Juan; Ballesteros, Miguel; Cañadas, Eva María; Martinez-Ortega, Montserrat

    2011-07-01

    Habitat fragmentation due to human activities is one of the most important causes of biodiversity loss. In Mediterranean areas the species have co-evolved with traditional farming, which has recently been replaced for more severe and aggressive practices. We use a methodological approach that enables the evaluation of the impact that agriculture and land use changes have for the conservation of sensitive species. As model species, we selected Linaria nigricans, a critically endangered plant from arid and semiarid ecosystems in south-eastern Spain. A chronosequence of the evolution of the suitable habitat for the species over more than 50 years has been reconstructed and several geometrical fragmentation indices have been calculated. A new index called fragmentation cadence (FC) is proposed to quantify the historical evolution of habitat fragmentation regardless of the habitat size. The application of this index has provided objective forecasting of the changes of each remnant population of L. nigricans. The results indicate that greenhouses and construction activities (mainly for tourist purposes) exert a strong impact on the populations of this endangered species. The habitat depletion showed peaks that constitute the destruction of 85% of the initial area in only 20 years for some populations of L. nigricans. According to the forecast established by the model, a rapid extinction could take place and some populations may disappear as early as the year 2030. Fragmentation-cadence analysis can help identify population units of primary concern for its conservation, by means of the adoption of improved management and regulatory measures.

  18. Physico-chemical evolution of groundwater in tectonically active areas. Application to the Leana hot spring (Murcia Region, SE Spain)

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Hornero, J.; Trujillo, C.

    2016-09-01

    Seismic events can affect the physico-chemical characteristics of groundwater. These anomalies are of a pre-seismic, co-seismic and post-seismic nature and correspond to pulse variations, sudden increases and decreases without return to initial values and upward or downward changes in trend. Continuous and in situ conductivity and temperature monitoring and periodic water sampling at a hot spring associated with neotectonic activity are of great interest for establishing predictive methods. This method is limited to the seismic activity affecting the fracturing system with which the hot spring is associated. The Region of Murcia and surroundings (southeast Spain) was selected as the study area for exploring the nature of these influences on groundwater. A hot spring in the Leana spa (Murcia) was equipped and monitored during the period 2006-2008, allowing for the in situ determination of conductivity and temperature as well as of major and minor constituents at the laboratory. Due to its proximity and related with fault network, we suggest that 86 % of earthquakes located between 0 and 10 km may affect in situ parameters of groundwater, and 75 % may affect laboratory determinations. This percentage drops in more distant zones. Of all earthquakes that seem to influence groundwater, 55 % of the in situ parameter anomalies and 53 % of laboratory were of a pre-seismic nature.

  19. Magnetostratigraphy of the Orce region (Baza Basin), SE Spain: New chronologies for Early Pleistocene faunas and hominid occupation sites

    NASA Astrophysics Data System (ADS)

    Scott, G. R.; Gibert, Ll.; Gibert, J.

    2007-02-01

    The Orce fossil quarries, in the Baza Basin of southeastern Spain, are a rich source of Early Pleistocene Palaeolithic tools and vertebrate remains. Geologic fieldwork during the last decade has placed these fossiliferous strata within the context of a thick Neogene continental sequence. Detailed lithostratigraphic and magnetostratigraphic results indicate that at least the upper 60 m of this sequence are of Early Pleistocene age. The quarried strata (Venta Micena, Barranco León and Fuentenueva-3) are from a narrow time span (<100 ka) starting before 1.3 Ma. A new, lower excavation at ˜1.5 Ma (Fuentenueva-1 quarry) has a distinctly older fauna. These Orce strata provide a high resolution, Early Pleistocene record of grassland fauna that shows the end of Mammal Neogene fauna (MN17) in the Fuentenueva-1 site (with Gazella borbonica, Equus stenonis) and the beginning of more characteristic Pleistocene fauna in the Venta Micena site (with Hippopotamus antiquus, Equus granatensis, Homo sp.). Thus far, no evidence for human occupation has been found within the earlier Fuentenueva-1 quarry, although many of the same terminal MN17 species have been found with hominids on the other side of Europe at the Dmanisi site (earliest Pleistocene) in the Republic of Georgia.

  20. Mapping local microseismicity using short-term tripartite small array installations — Case study: Coy region (SE Spain)

    NASA Astrophysics Data System (ADS)

    Häge, Martin; Joswig, Manfred

    2009-06-01

    One major tectonic feature in the southern part of Spain is the Crevillente Fault Zone (CFZ) which can be traced over 600 km. A short-term microseismic feasibility study was carried out in the area around Coy to investigate the seismic activity of the CFZ by mapping the local seismicity distribution. The area under investigation is of high interest because three moderate earthquakes have occurred nearby since 1999. The measurements were performed with two small arrays, whereas one array was relocated every day to increase the spatial resolution. In the measurement period of 14 nights, including 4 daytime records, 189 events in the magnitude range - 1.8 ≤ ML ≤ 1.3 were detected, of them 133 events could also be located. According to the bulletin of the Instituto Geográfico Nacional, the local network recorded 1 event in the area under investigation in the same period. The results of this short-term measurement show an increased detectability by using small arrays for event recording and prove that there is a high rate of microseismicity below the detection threshold of the local network. For event location, the regional velocity model had to be adapted to our small scale, short epicentral distance application by reducing vP to 4 km/s using a homogenous half space model. The distribution of the events does not indicate a seismic activity along the CFZ. It is rather concentrated to the south around the epicentral zone of the La Paca earthquake that occurred 114 days before our measurement campaign. Some events show a high waveform similarity. They can be attributed to the same fault segment.

  1. Assessment of African and local wind-blown dust contributions at three rural sites in SE Spain: aerosol size distribution

    NASA Astrophysics Data System (ADS)

    Orza, J. A. G.; Cabello, M.; Lidón, V.; Martínez, J.

    2009-04-01

    Aerosol number size distribution and meteorological parameters were measured at three rural sites in semiarid southeastern Spain. Number concentrations of suspended particles in 31 size bins between 0.25 and 32 m diameter were continuosly recorded with a GRIMM 190 aerosol spectrometer at: (i) a rural background (RB) location in a perennial tussock grassland, from July to October 2006; (ii) a rural site surrounded by abandoned croplands, and influenced by mineral industries and by a small paved road having a small traffic load located 30 m to the East (RA), from June to December 2007; and (iii) a rural (R) location in an agricultural plot previously cleared and then lightly leveled and compacted for future lemon-tree cultivation, from February to June 2008. Events of long range transport from North Africa to the study area (African dust outbreaks, ADOs) were identified by aerosol transport models, back-trajectories and satellite imagery. There is an increase in the concentration of particles larger than 2 m with increasing wind speed while the concentrations decrease for smaller particles at the RB and R sites. At the RA location, that increase is observed for particles in the range 1.6 - 3.5 m (the precise value depends on the wind speed) when there are West winds. Particulate resuspension is found to occur at all wind speeds, although wind threshold values can be identified by a sharp increase in particle concentrations for a range of particle sizes. Light winds entrain large particles while stronger winds additionally entrain particles of smaller size (down to 2.5 m for the highest winds). The size distributions present maxima at 1.6 and 3 m on days with ADO. Concentration for almost every particle size is higher on ADOs than on days without such events, due in part to the associated meteorological situation. This work was partially supported by the Spanish Ministerio de Educación y Ciencia under grant CGL2004-04419 (RESUSPENSE Project).

  2. Recent (0-8 Ma) tectonics and exhumation processes in Cordilleras Blanca and Negra, Central Peru: Constraints from (U-Th)/He dating

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Robert, Xavier; Gautheron, Cécile; Audin, Laurence

    2014-05-01

    The Central Andes are a classical example of topography building in front of an oceanic subduction. However, many first order questions are still debated: How do subduction processes and observed tectonic uplift interact along the Andean margin? What is the impact of tectonic, magmatism and climate on exhumation? The Cordilleras Blanca (6768 m) and Negra (5181 m), in north Central Peru, belong to the highest Andean reliefs. Both ranges trend parallel to the subduction zone and are separated by the NW-SE Rio Santa valley. The Cordillera Blanca pluton formed in an active subduction context at 8-5 Ma and renders an abnormal magmatic activity over a planar subduction. In contrast with the Cordillera Blanca, the Cordillera Negra is an older relief, which evolution and exhumation history has never been studied. A remarkable ~200 km-long normal fault system showing ~4500 m of vertical displacement since 5 Ma edges the western flank of the Cordillera Blanca. This region is a perfect target to study the impact of magmatism and subduction processes on exhumation. We perform a morphotectonic study on both cordilleras coupled with low-temperature thermochronology apatite (U-Th)/He dating to quantify these processes. Geomorphic parameters and altitude contrasts between these two ranges indicate a differential uplift. The Cordillera Negra displays a smooth and asymmetric relief from the West to the East whereas the Cordillera Blanca shows higher and sharper relief with North/South and East/West contrasts. We obtain apatite (U-Th)/He ages for twenty samples located along vertical and horizontal profiles at different latitudes of the Cordilleras Blanca and Negra. The (U-Th)/He ages range from 13.4 ± 1.3 to 5.6 ± 0.6 Ma in the Cordillera Negra and range from 11.8 ± 1.2 to 2.0 ± 0.2 Ma in the Cordillera Blanca. We use them as inputs in QTQt tools for time-temperature reconstructions and thus to constrain the exhumation history. Whole ages evidence a more regional exhumation than

  3. Heterogeneous extension and the role of transfer faults in the development of the southeastern Betic basins (SE Spain)

    NASA Astrophysics Data System (ADS)

    Giaconia, F.; Booth-Rea, G.; Martínez-Martínez, J. M.; Azañón, J. M.; Storti, F.; Artoni, A.

    2014-12-01

    Large strike-slip faults in the eastern Betics are interpreted to have developed in a transcurrent setting in response to 4-6 mm/yr of Africa-Iberia NW-SE convergence. However, here we show that some of these faults are transfer faults accommodating heterogeneous late Miocene extension. The North Cabrera dextral fault and other E-W to NE-SW strike-slip faults in the Sorbas basin were transfer faults produced under SW-NE extension. These faults together with related normal faults form the main boundaries of two sedimentary depocenters active between the Serravallian and the Tortonian. The older North Cabrera depocenter extended between the Serravallian and the early Tortonian (approximately 13.8 to 9 Ma), while the younger Gacía depocenter formed in response to late Tortonian extension (approximately 9 to 7.5 Ma). The latter formed to the west of the North Cabrera depocenter by a listric fan of normal faults with SW directed transport that are linked by dextral and sinistral transfer fault segments. These faults root on a low-angle detachment cutting into the exhumed high-pressure Nevado-Filabride complex rocks at ~0.8 km depth. The present work reveals that (1) this extension was partially coeval with and kinematically linked to sinistral displacement along the Carboneras fault farther south in the Níjar basin; (2) this westward directed extension produced elongated core complexes and tilted blocks to the north of the Carboneras fault and magmatic accretion upon thinned continental crust to the south, probably in response to slab tearing or detachment and associated edge delamination of the Iberian continental lithospheric mantle beneath the Betics.

  4. The economic value of conjoint local management in water resources: Results from a contingent valuation in the Boquerón aquifer (Albacete, SE Spain).

    PubMed

    Rupérez-Moreno, Carmen; Pérez-Sánchez, Julio; Senent-Aparicio, Javier; del Pilar Flores-Asenjo, Maria

    2015-11-01

    In the field of water resources management, the Water Framework Directive is the first directive to adopt an ecosystem approach, establishing principles and economic tools for an integrated management of water resources to protect, conserve and restore all water bodies. The incorporation of local authorities in this management involves quality benefits that are perceived by users in an effective and lasting way. The purpose of this paper is to present the economic value of the environmental recovery of the overexploited Boquerón aquifer in Hellín (Albacete, SE Spain) and all of its associated ecosystems. This aquifer operates as a regulating reservoir for the surface waters of the Hellín Canal. The contingent valuation method (CVM) applied in this environmental assessment of the aquifer showed that its non-use value was €147,470 per year, due to the high environmental awareness of the Hellín people, which is enough to ensure the survival of the ecosystems linked to the aquifer.

  5. Combining radon, short-lived radium isotopes and hydrodynamic modeling to assess submarine groundwater discharge from an anthropized semiarid watershed to a Mediterranean lagoon (Mar Menor, SE Spain)

    NASA Astrophysics Data System (ADS)

    Baudron, Paul; Cockenpot, Sabine; Lopez-Castejon, Francisco; Radakovitch, Olivier; Gilabert, Javier; Mayer, Adriano; Garcia-Arostegui, José Luis; Martinez-Vicente, David; Leduc, Christian; Claude, Christelle

    2015-06-01

    In highly anthropized watersheds, surface water tributaries may carry unexpected high quantities of radon and radium to coastal lagoons. Investigating submarine groundwater discharge (SGD) with radionuclide tracers is therefore a complex task. In order to quantify SGD and decipher the influence of the different water sources, we combined a radon (222Rn) and short-lived radium (223Ra, 224Ra) survey with the hydrodynamic modeling of a lagoon. We applied it to the Mar Menor lagoon (SE Spain) where surface water tributaries and undocumented emissaries carry water from groundwater drainage and brines from groundwater desalinization. We identified the areas of influence of the plume of radionuclides from the river, located major areas of SGD and proposed a location for two submarine emissaries. Porewater, i.e. interstitial water from underlying sediments, was found to be the most representative SGD end member, compared to continental groundwater collected from piezometers. Mass balances in winter and summer seasons provided yearly SGD fluxes of water of 0.4-2.2 ṡ 108 m3/y (222Rn), 4.4-19.0 ṡ 108 m3/y (224Ra) and 1.3 ṡ 108 m3/y (223Ra, measured in winter only). Tidal pumping was identified as a main driver for recirculated saline groundwater, while fresh submarine groundwater discharge from the aquifer ranged between 2% and 23% of total SGD.

  6. The beach placer iron deposit of Portman Bay, Murcia, SE Spain: the result of 33 years of tailings disposal (1957-1990) to the Mediterranean seaside

    NASA Astrophysics Data System (ADS)

    Manteca, José Ignacio; López García, José Ángel; Oyarzun, Roberto; Carmona, Carlos

    2014-08-01

    Between 1957 and 1990, the Peñarroya Mining and Metallurgical Company (SMMPE) disposed about 60 million tonnes of tailings materials directly to the Mediterranean Sea. A substantial part of it (12.5 Mt) was dragged back by the sea currents progressively infilling the Portman Bay (Murcia, SE Spain), thus making the shoreline advance between 500 and 600 m seaward. The Roberto froth flotation plant processed mineral from manto-type deposits belonging to the Sierra de Cartagena-La Unión lead-zinc district. One of the mineral assemblages present in these deposits comprises greenalite, magnetite, sulfides, carbonates, and silica. Despite that magnetite recovery was undertaken by SMMPE between 1959 and 1967, we estimate that magnetite contained in the tailings hosts a substantial resource that could be as large as 2.3 Mt of iron ore. The ore contains magnetite ± hematite ± siderite. Tidal waves and sea currents led to gravimetric classification of the tailings material, with concentration of the dense iron oxides in the sandy fractions, eventually forming a coastal placer iron deposit. A major problem for magnetic separation is the intimate intergrowth between magnetite, hematite, and siderite. Besides, the sands contain large concentrations of Pb (0.27 %), Zn (0.72 %), and As (559 ppm).

  7. Sulphide-mining impacts in the physical environment: Sierra de Cartagena-La Unión (SE Spain) case study

    NASA Astrophysics Data System (ADS)

    Robles-Arenas, V. M.; Rodríguez, R.; García, C.; Manteca, J. I.; Candela, L.

    2006-10-01

    The environmental impact and potential-risk assessment of an abandoned sulphide-mining site in a semiarid climate is presented here, by the study case of Sierra de Cartagena-La Unión (SE Spain), a 2,500-year-old mining district extending over an area of 100 km2. The regional map illustrates the existence of 12 open-pits, 1,902 mining wells, 2,351 waste deposits, including 89 tailing dams and waste rock derived from mining processes. Mine wastes occupy an area of 9 km2 and have an approximate volume of 200 Mm3. Mineralogical, physical and chemical data distinguish nine different types of mine and metallurgical waste. According to the concentration of sulphate and heavy metals in sediment, soil, rainwater, surface water and groundwater samples, it is possible to conclude that the impact of mine activities occurs not only in the immediate mining area (100 km2), but also in the surrounding areas (an affected area of 1,000 km2 approximately). The hydrochemical data show that groundwater, runoff water and some rainwater samples exceed Spanish and European water quality guideline values for water supply. The main geochemical process recognised is sulphide-mineral oxidation and later-generated sulphate dissolution by groundwater and runoff. Runoff and wind are the major mechanisms of metals and sulphate transport in the study area and adjacent zones.

  8. Regional subsidence modelling in Murcia city (SE Spain) using 1-D vertical finite element analysis and 2-D interpolation of ground surface displacements

    NASA Astrophysics Data System (ADS)

    Tessitore, S.; Fernández-Merodo, J. A.; Herrera, G.; Tomás, R.; Ramondini, M.; Sanabria, M.; Duro, J.; Mulas, J.; Calcaterra, D.

    2015-11-01

    Subsidence is a hazard that may have natural or anthropogenic origin causing important economic losses. The area of Murcia city (SE Spain) has been affected by subsidence due to groundwater overexploitation since the year 1992. The main observed historical piezometric level declines occurred in the periods 1982-1984, 1992-1995 and 2004-2008 and showed a close correlation with the temporal evolution of ground displacements. Since 2008, the pressure recovery in the aquifer has led to an uplift of the ground surface that has been detected by the extensometers. In the present work an elastic hydro-mechanical finite element code has been used to compute the subsidence time series for 24 geotechnical boreholes, prescribing the measured groundwater table evolution. The achieved results have been compared with the displacements estimated through an advanced DInSAR technique and measured by the extensometers. These spatio-temporal comparisons have showed that, in spite of the limited geomechanical data available, the model has turned out to satisfactorily reproduce the subsidence phenomenon affecting Murcia City. The model will allow the prediction of future induced deformations and the consequences of any piezometric level variation in the study area.

  9. Mud volcanism and authigenic carbonates related to methane-rich fluids migration in the late Neogene marls of S.E. Spain

    NASA Astrophysics Data System (ADS)

    Pierre, C.; Blanc-Valleron, M. M.; Rouchy, J. M.

    2015-12-01

    Methane-rich fluids that are generated at depth in organic-rich deposits migrate within the sediments to the seafloor where they are expelled to form mud volcanoes or pockmarks. Moreover, these migrating fluids are involved in diagenetic processes as authigenic carbonate formation and they may participate to gas hydrate formation. These features are well-known in the present-day continental margins but their fossil records are relatively scarce. The outcropping Tortonian and Messinian marls in S.E. Spain basins (Lorca, Fortuna, Columbares, Huercal Overa) contain abundant authigenic dolomite nodules. The oxygen and carbon isotopic compositions of these dolomites exhibit wide ranges (-1.4 < δ18O < +5.6 ; -25.6 < δ13C < +9.3) indicating that carbonate precipitation occurred within the marly sediments due to circulation of fluids modified by gas hydrates formation/dissociation, where anaerobic oxidation of methane and methanogenesis were active. In the Huercal Overa basin, there is a well-preserved mud volcano intruding vertically the Messinian marls. These two features, methane derived authigenic dolomites and mud volcanism, are testifying of the intense methane-rich fluid migration in the marly deposits of the western Mediterranean basins during the late Neogene, which was the time of major paleoenvironmental changes in the Mediterranean sea climaxing during the Messinian salinity crisis.

  10. Chronology for the Cueva Victoria fossil site (SE Spain): Evidence for Early Pleistocene Afro-Iberian dispersals.

    PubMed

    Gibert, Luis; Scott, Gary R; Scholz, Denis; Budsky, Alexander; Ferràndez, Carles; Ribot, Francesc; Martin, Robert A; Lería, María

    2016-01-01

    Cueva Victoria has provided remains of more than 90 species of fossil vertebrates, including a hominin phalanx, and the only specimens of the African cercopithecid Theropithecus oswaldi in Europe. To constrain the age of the vertebrate remains we used paleomagnetism, vertebrate biostratigraphy and (230)Th/U dating. Normal polarity was identified in the non-fossiliferous lowest and highest stratigraphic units (red clay and capping flowstones) while reverse polarity was found in the intermediate stratigraphic unit (fossiliferous breccia). A lower polarity change occurred during the deposition of the decalcification clay, when the cave was closed and karstification was active. A second polarity change occurred during the capping flowstone formation, when the upper galleries were filled with breccia. The mammal association indicates a post-Jaramillo age, which allows us to correlate this upper reversal with the Brunhes-Matuyama boundary (0.78 Ma). Consequently, the lower reversal (N-R) is interpreted as the end of the Jaramillo magnetochron (0.99 Ma). These ages bracket the age of the fossiliferous breccia between 0.99 and 0.78 Ma, suggesting that the capping flowstone was formed during the wet Marine Isotopic Stage 19, which includes the Brunhes-Matuyama boundary. Fossil remains of Theropithecus have been only found in situ ∼1 m below the B/M boundary, which allows us to place the arrival of Theropithecus to Cueva Victoria at ∼0.9-0.85 Ma. The fauna of Cueva Victoria lived during a period of important climatic change, known as the Early-Middle Pleistocene Climatic Transition. The occurrence of the oldest European Acheulean tools at the contemporaneous nearby site of Cueva Negra suggest an African dispersal into SE Iberia through the Strait of Gibraltar during MIS 22, when sea-level was ∼100 m below its present position, allowing the passage into Europe of, at least, Theropithecus and Homo bearing Acheulean technology. PMID:26581114

  11. Triclinic Transpression in brittle shear zones evaluated via combined numerical and analogue modeling: the case of The Torcal de Antequera Massif, SE Spain.

    NASA Astrophysics Data System (ADS)

    Barcos, Leticia; Díaz-Azpiroz, Manuel; Faccenna, Claudio; Balanyá, Juan Carlos; Expósito, Inmaculada; Giménez-Bonilla, Alejandro

    2013-04-01

    Numerical kinematic models have been widely used to understand the parameters controlling the generation and evolution of ductile transpression zones. However, these models are based on continuum mechanics and therefore, are not as useful to analyse deformation partitioning and strain within brittle-ductile transpression zones. The combination of numerical and analogue models will potentially provide an effective approach for a better understanding of these processes and, to a broader extent, of high strain zones in general. In the present work, we follow a combined numerical and analogue approach to analyse a brittle dextral transpressive shear zone. The Torcal de Antequera Massif (TAM) is part of a roughly E-W oriented shear zone at the NE end of the Western Gibraltar Arc (Betic Cordillera). This shear zone presents, according to their structural and kinematic features, two types of domains i) Domain type 1 is located at both TAM margins, and is characterized by strike-slip structures subparallel to the main TAM boundaries (E-W). ii) Domain type 2 corresponds to the TAM inner part, and it presents SE-vergent open folds and reverse shear zones, as well as normal faults accommodating fold axis parallel extension. Both domains have been studied separately applying a model of triclinic transpression with inclined extrusion. The kinematic parameters obtained in this study (?, ? and Wk) allows us to constrain geometrical transpression parameters. As such, the angle of oblique convergence (α, the horizontal angle between the displacement vector and the strike of the shear zone) ranges between 10-17° (simple shear dominated) for domain type 1 and between 31-35° (coaxial dominated) for domain type 2. According to the results obtained from the numerical model and in order to validate its possible utility in brittle shear zones we develop two analogue models with α values representative of both domains defined in the TAM: 15° for type 1 and 30° for type 2. In the

  12. Environmental assessment of the arsenic-rich, Rodalquilar gold-(copper-lead-zinc) mining district, SE Spain: data from soils and vegetation

    NASA Astrophysics Data System (ADS)

    Oyarzun, Roberto; Cubas, Paloma; Higueras, Pablo; Lillo, Javier; Llanos, Willians

    2009-08-01

    The Rodalquilar mineral deposits (SE Spain) were formed in Miocene time in relation to caldera volcanic episodes and dome emplacement phenomena. Two types of ore deposits are recognized: (1) the El Cinto epithermal, Au-As high sulphidation vein and breccia type; and (2) peripheral low sulphidation epithermal Pb-Zn-Cu-(Au) veins. The first metallurgical plants for gold extraction were set up in the 1920s and used amalgamation. Cyanide leaching began in the 1930s and the operations lasted until the mid 1960s. The latter left a huge pile of ~900,000-1,250,000 m3 of abandoned As-rich tailings adjacent to the town of Rodalquilar. A frustrated initiative to reactivate the El Cinto mines took place in the late 1980s and left a heap leaching pile of ~120,000 m3. Adverse mineralogical and structural conditions favoured metal and metalloid dispersion from the ore bodies into soils and sediments, whereas mining and metallurgical operations considerably aggravated contamination. We present geochemical data for soils, tailings and wild plant species. Compared to world and local baselines, both the tailings and soils of Rodalquilar are highly enriched in As (mean concentrations of 950 and 180 μg g-1, respectively). Regarding plants, only the concentrations of As, Bi and Sb in Asparagus horridus, Launaea arborescens, Salsola genistoides, and Stipa tenacissima are above the local baselines. Bioaccumulation factors in these species are generally lower in the tailings, which may be related to an exclusion strategy for metal tolerance. The statistical analysis of geochemical data from soils and plants allows recognition of two well-differentiated clusters of elements (As-Bi-Sb-Se-Sn-Te and Cd-Cu-Hg-Pb-Zn), which ultimately reflect the strong chemical influence of both El Cinto and peripheral deposits mineral assemblages.

  13. Late Variscan magmatism in the Nevado-Filábride Complex: U-Pb geochronologic evidence for the pre-Mesozoic nature of the deepest Betic complex (SE Spain)

    NASA Astrophysics Data System (ADS)

    Gómez-Pugnaire, M. T.; Rubatto, D.; Fernández-Soler, J. M.; Jabaloy, A.; López-Sánchez-Vizcaíno, V.; González-Lodeiro, F.; Galindo-Zaldívar, J.; Padrón-Navarta, J. A.

    2012-08-01

    Orthogneisses crop out in different lithostratigraphic positions throughout the Nevado-Filábride metamorphic Complex (Betic Cordillera, southern Spain). Their abundance offers the opportunity to establish its origin and to date the ages of acid magmatism and of early deposition ages of metasedimentary host rocks of the orthogneisses, in this complex metamorphosed and deformed during the Alpine Orogeny. Petrography and bulk-rock chemistry indicate that the orthoderivates samples are peraluminous tourmaline leucogranites and strongly peraluminous biotite gneisses. Compositional similarity in different outcrops points to common genetic relationships. Although the studied gneisses are affected by metamorphic and deformational processes their compositional variations may be explained by differing degrees of crustal melting, source heterogeneity or minor feldspar fractionation. Variation in REE contents is attributed to accessory minerals fractionation. The geochemical data show that the protoliths originated by low degree of partial melting of biotite-rich, muscovite-plagioclase-bearing metasediments. U-Pb SHRIMP dating of magmatic zircons from six samples yielded ages between ~ 282 ± 5 and 295 ± 3 Ma. Their ages and chemical composition indicate that these intrusive bodies strongly resemble the peraluminous, post-tectonic, leucogranites widespread in the Variscan Orogen, particularly those produced by crustal partial melting of the Central Iberian Zone. Zircons in host pelitic metasediments provide older ages ranging from ~ 336 to 2.050 Ma. They testify to the recycling of Early Carboniferous and older granites, which are found in the Central Iberian zones of the Iberian Massif. The new geochronological data combined with detailed field observations allow drafting a new chronostratigraphy of the Nevado-Filábride Complex. Traditionally proposed Triassic ages for the metasedimentary upper series of the complex are not consistent with the ages reported here, which

  14. A descriptive and quantitative approach regarding erosion and development of landforms on abandoned mine tailings: New insights and environmental implications from SE Spain

    NASA Astrophysics Data System (ADS)

    Martín Duque, J. F.; Zapico, I.; Oyarzun, R.; López García, J. A.; Cubas, P.

    2015-06-01

    - 1 y- 1, which matches well typical values for erosion of mined areas, commonly above 100 Mg (MT) ha- 1 y- 1. Abandoned mine tailing deposits are extremely common in the semiarid scenarios of the SW USA, Australia, Chile, and Peru. Given the similarities of these scenarios with SE Spain, the example from Mazarrón may provide useful new insights regarding the erosion and geomorphic evolution of such tailing deposits. These matters should be addressed in key environmental actions such as mine closure plans and land reclamation projects. A solution may come via restoration of these deposits through landform design involving the building up of stable mature landscapes, which in turn can withstand erosion much more easily.

  15. Preliminary results in larger benthic foraminifera assemblage in a mixed siliciclastic-carbonate platform from the Upper Cretaceous of the External Prebetic Domain (Valencia province, SE Spain)

    NASA Astrophysics Data System (ADS)

    Robles-Salcedo, Raquel; Vicedo, Vicent

    2016-04-01

    In the External Prebetic Domain (Betic Mountain Range, Valencia province, SE Spain) it is difficult to find good outcrops to study larger benthic foraminifera (LBF), particularly in the Upper Cretaceous deposits, because of three main reasons. During the Upper Cretaceous, the complex paleogeography in the northern Prebetic Domain developed a complex system of shallow-water platforms. This is directly linked to the complexity in the distribution of the facies observed nowadays, which may change drastically in lateral, closely related outcrops having a special negative impact in the lateral extension of stratigraphical levels containing LBF. The second reason is the nature of the shallow water environments in which the larger foraminifera lived. The local continental influence derived in the establishment of very complex mixed platforms. Thus, there is not a complete register through carbonate rocks, but an alternation of microconglomerates, sandstones, calcarenites and carbonates that can be observed in the stratigraphic series of the Upper Cretaceous. This affects negatively in observing changes in the evolutionary trends of taxa. The third reason difficulting the study of LBF in northern localities of the Prebetic Domain is diagenetic. Dolomitization affects a huge part of the Mesozoic rocks deleting all fossil microfauna in the affected rocks. Such three reasons are behind the difficulty in developing correlations and having a comprehensive understanding of the biostratigraphy and phylogeny of the taxa involved. However, after several field trips developed in the northern Prebetic area, an excellent reference section for the study of the LBF in the Prebetic Domain has been identified in the surroundings of the Pinet village (Valencia province). Here, a relatively continuous section with scarce dolomitization and good conditions of accessibility exists. The larger foraminifera assemblages appering in the Pinet section will be compared with other paleobiogeographic

  16. Fan-surface dynamics and biogenic calcrete development: Interactions during ultimate phases of fan evolution in the semiarid SE Spain (Murcia)

    NASA Astrophysics Data System (ADS)

    Alonso-Zarza, Ana M.; Silva, Pablo G.; Goy, José L.; Zazo, Cari

    1998-08-01

    Pleistocene alluvial fan surfaces of the Campo de Cartagena-Mar Menor Basin (Murcia, SE Spain) are capped by thick mature calcretes. Calcrete profiles consist mainly of six different horizons: prismatic, chalky, nodular, massive, laminar and coated-gravels. Petrographic study of the calcretes has shown the occurrence of features such as alveolar septal structures, calcified filaments, coated grains, spherulites, calcified root cells and calcispheres that indicate the biogenic origin of the calcretes, mainly induced by plant root related microbial activity. The calcretes studied were formed initially in the soil and represented the K horizon. Development of the calcrete profiles took place in six main stages and was driven by multiple phases of soil formation, erosion and reworking. The relationships between these processes caused the formation of different calcrete profiles in proximal and distal fan areas. In the distal areas, which are controlled by limited distal fan aggradation, episodic sediment input, buried previously developed calcretes and generated new space for calcrete growth by plants growing in the overlying unconsolidated materials. This allowed the renewal of calcrete formation and it led to the development of complex composite profiles which are thicker than in proximal areas, where surface stabilisation and/or dissection enabled calcrete reworking and brecciation. These processes of erosion, sedimentation, reworking and renewed calcrete formation initiated by vegetation were repeated through time. They explain the complex macro- and microstructures of these calcretes and indicate that calcrete development, even reaching mature stages, can start before the fan surface is completely abandoned, but it requires episodic sedimentation. Eventually, distal fan aggradation and continuous calcrete development throughout the entire fan surface, led to the ultimate fan surface induration, controlling subsequent landscape evolution. So, fan surface calcretes

  17. The Cartagena-La Unión mining district (SE Spain): a review of environmental problems and emerging phytoremediation solutions after fifteen years research.

    PubMed

    Conesa, Héctor M; Schulin, Rainer

    2010-06-01

    After mining in the Cartagena-La Unión Mining District (SE Spain) was discontinued in 1992, various studies have shown that large amounts of toxic metals continue to be transferred with the spread of unstabilized mining wastes to the nearby ecosystems. Local creeks seem to be important pathways carrying eroded materials from the headwaters to the nearby coastal areas of the Mediterranean Sea. Studies have shown the presence of high metal concentrations in the sediments of riverbeds and in river mouths and adjacent coastal marshes (e.g. 500 mg kg(-1) As; 12 000 mg kg(-1) Pb). Also, some nearby agricultural areas are affected (up to 10 mg kg(-1) Pb in lettuce leaves). Metal transfer into biota has been demonstrated in creek sediments in relation to benthic organisms (up to 222 mg kg(-1) Pb in molluscs). The mining wastes in the area are spontaneously colonized by native plant species. On the tailings, most of the plant species are grasses (e.g. Lygeum spartum, Piptatherum miliaceum); in polluted salt marshes, halophytic species dominate (e.g. Arthrocnemum macrostachyum). Metal uptake by plants is in general low (10 mg kg(-1) for Cu; <200 mg kg(-1) Pb; <500 mg kg(-1) Zn). Preliminary tests have shown the suitability of amendments (e.g. lime, fertilizer, pig manure) to improve the establishment of certain vegetation on the tailings. Phytostabilization appears to be a promising technology to decrease erosion in the tailings. However, tailings must be individually analysed in order to determine their geostructural stability, as in addition, mechanical stabilization will be needed in some cases to prevent collapse.

  18. Use of Bioassay test for the environmental evaluation of mining residues and their leachates: the singular case of the Portman Bay (SE, Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, Maria Jose; García-Lorenzo, Maria Luz; Pérez-Sirvent, Carmen; Molina, Jose; Tudela, Maria Luz; Hernández-Córdoba, Manuel

    2010-05-01

    The aim of the present study was to evaluate the toxicity of sediments and their pore-water extracts from sites contaminated by mining activities using two assays: bacteria and plants. The acute toxicity in pore-waters was determined using the Microtox® bioassay, which uses the naturally luminescent marine bacterium Vibrio fischeri. Phytotoxicity in soil samples was tested by way of the seed germination and root elongation technique in three plant species, Sorghum saccharatum, Sinapis alba and Lepidium sativum. The aim of applying these assays is to establish a method for evaluating the real risks within a risk analysis process, considering both present and future risks, bearing in mind that the uses to which soil is put (urban, recreational or industrial) may change. In the zone studied, mining activities have led to heavy metal contamination with the risk of runoff and wind dispersion of the contaminated material. For this study, 6 sediment samples were collected from Portman Bay (Murcia, SE Spain). The soil extract was prepared by saturation with distilled water and allowing it to stand for four hours. Then, the soil was subjected to a vacuum pressure to extract the soil solution through filter paper. The Zn and Fe content was determined by flame atomic absorption spectrometry (FAAS). The Pb, Cd and Cu content was determined by electrothermal atomization atomic absorption spectrometry (ETAAS). The As content was analysed by atomic fluorescence spectrometry using an automated continuous flow hydride generation (As-AFS) spectrometer. Total Pb concentration varied from 600 to 2500 ppm, with a mean value of 1200 ppm. The average content of Zn was 5300 ppm. The mean concentration of Cd and Cu was 23 and 59 ppm, respectively. Total As concentrations varied from 180 to 470 ppm, with an average value 280 ppm. Finally, the total Fe content ranged from 37% to 47%, with an average value of 40%. Pore-water samples showed neutral pH values and average electrical

  19. Bioavailability of metals in soils and sedimentes affected by old mining actitvities. The study case of the Portman bay (SE, Spain)

    NASA Astrophysics Data System (ADS)

    Martinez-Sanchez, Maria Jose; Agudo, Ines; Banegas, Ascension; Garcia-Lorenzo, Maria Luz; Gonzalez-Ciudad, Eva; Perez-Espinosa, Victor; Martinez-Lopez, Salvadora; Martinez, Lucia; Perz-Sirvent, Carmen

    2010-05-01

    A study on metal (Zn, Pb, Cd, Cu and As) mobilization and analysis of the health risk represented by ingestion from contaminated sediments in Portman Bay (SE Spain) was carried out. This zone has suffered a great impact from mining activity, since million tons of mine tailings were dumped into the bay for a long period, giving as a result the filling of the bay with them. The long-term deposition of metals in soils and sediments can lead to their accumulation and transport, while their toxicity depends on the mobility and bioavailability of a significant fraction of the metals. The ingestion of contaminated soil particles by grazing animals or young children may well represent a special exposure pathway for Pb, Cd and other hazardous metals. The aim of this study was to determine the bioaccessibility of Zn, Pb, Cd, Cu and As ,and the extent to which bioaccessibility is influenced by mineralogy in materials from this mining site as an indicator of the potential risk that metals pose to both environmental and human health. General analytical determinations (pH, particle size, organic matter, equivalent calcium carbonate content and mineralogical composition) were carried out to characterize the samples. The mineralogical composition was studied by X-ray diffraction (XRD), using a Philips PW3040 diffractometer with Cu-Kα. To determine the total metal content, the samples were digested in a Milestone ETHOS PLUS microwave, Zn, Pb, Cu and Cd contents were determined by electrothermal atomization atomic absorption spectrometry, while As was analysed by HG- AFS using an automated continuous flow hydride generation spectrometer. To assess bioaccessibility, the gastric solution was prepared according to the Standard Operating Procedure (SOP) developed by the Solubility/Bioavailability Research Consortium (SBRC). The mineralogical composition, corresponds to materials which have suffered a supergenic oxidation process which has been influenced by the presence of sea water

  20. Multifunctional greenway approach for landscape planning and reclamation of a post-mining district: Cartagena-La Unión, SE Spain

    NASA Astrophysics Data System (ADS)

    Acosta, Jose A.; Faz, Ángel; Zornoza, Raúl; Martínez-Martínez, Silvia; Kabas, Sebla; Bech, Jaume

    2015-04-01

    Fragmented structures create metaphorical wounds in the landscape altering the ecological and cultural processes associated with it, as it can be seen in many mine areas. Therefore it is advisable to organize the reclamation plan in the beginning of mine operating to provide spatial and functional integration of the landscape based on scientific arguments and with all possible legal and administrative means, which is generally the case of the Strategic Environmental Assessment. However, there are many abandon mine areas where no reclamation plan has been carried out, such as the case of Mining District of Sierra Minera Cartagena-La Unión, SE Spain. In these cases it is vital to respond in a sustainable manner for healing the landscape wounds of post-mining activities. Reclamation activities of a post-mining district includes not only the mine soils also all land uses around them, for this reason on necessary create practical solutions for returning the functions of ecologic and cultural processes of the area. Greenway approach shows the main veins which are crucial for keeping alive and sustaining the mentioned processes of the area. Therefore the main objectives of this study are to 1) develop an integrated local greenway network to be able to preserve significant resources and values of the district, and to 2) develop this greenway network as a part of reclamation process for degraded areas. Landscape assessments revealed the most valuable and potential connectivity resources of the area. These clustering and linear patterns of resource concentrations include mountain range and valleys, natural drainage network, legally protected areas and cultural-historical resources. Conservation areas, cultural-educational resources of post-mining activities and the riverbeds have been the main building stones for the greenway corridor. The multifunctional greenway approach serves as landscape reclamation and planning tool in a degraded area by showing the priority zones for

  1. The influence of competition between lichen colonization and erosion on the evolution of soil surfaces in the Tabernas badlands (SE Spain) and its landscape effects

    NASA Astrophysics Data System (ADS)

    Lázaro, R.; Cantón, Y.; Solé-Benet, A.; Bevan, J.; Alexander, R.; Sancho, L. G.; Puigdefábregas, J.

    2008-12-01

    Badlands often contain a mosaic of soil surface types with contrasting hydrological behaviour which drives their short term geomorphic evolution. The Tabernas badlands, in semiarid SE Spain, show a complex mosaic of bare ground, biological soil crusts and plant covered patches, and high variability of covers and morphologies. Previous work has identified the surfaces that act as sources of runoff and sediments and those that act as sinks; the pathways of runoff between surfaces, and the runoff and erosion at catchment scale. However, surfaces without vascular plants, can be quite dynamic, with important effects on geomorphic processes. This work aims to generate hypotheses about the dynamics of both bare soil (34% of the area) and biological soil crusts (33%), and to provide a first estimation of the growth rate of terricolous lichens (as increase of coverage) and their geomorphological implications. The dynamics of ten representative soil surfaces were photographically monitored over 13 years, recording the cover and pattern of bare soil and of the two main kinds of biological soil crust: 'brown crust' and 'white crust'. Erosion/deposition were measured by erosion pins in unbounded plots, and the hydrological and erosional behaviour monitored in bounded plots under natural and simulated rainfall. Biological colonization and crust growth were studied from 2004 within cleared plots in four crust communities. Microclimate was continuously monitored in each community. After 13 years, net erosion was recorded only in previously eroded slopes and divides. Vegetated sites and those covered by biological soil crust remained more or less invariant or recorded sedimentation. In all white crust surfaces, whole crust cover increased by 3% on average, while macrolichen cover increased by nearly 30%. Within the driest brown crust, macrolichen cover increased by 7%, while the whole crust decreased by 3%. According to previous work, lichen cover, particularly of white crust, is

  2. Guatemela: preliminary zircon ages from central cordillera.

    PubMed

    Gomberg, D N; Banks, P O; McBirney, A R

    1968-10-01

    Concordia resolution of uranium-lead analyses of zircons from rocks of the Guatemalan Cordillera indicates a period of plutonism, and perhaps metamorphism, in late Paleozoic times (345 +/- 20 million years). Gneisses of the Chuacus Series yield an age of 1075 +/- 25 million years which may be either the age of a source terrain for the original sediments, or the age of principal metamorphism. Zircons from a Paleozoic granite intruding the gneisses appear to contain inherited or contaminating material acquired during the process of magma generation or emplacement, or both.

  3. Coupling data from U-series and 10Be CRN to evaluate soil steady-state in the Betic Cordillera

    NASA Astrophysics Data System (ADS)

    Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Granet, Mathieu; Chabaux, François

    2015-04-01

    The regolith mantel is produced by weathering of bedrock through physical and biochemical processes. At the same time, the upper part of the regolith is eroded by gravity mass movements, water and wind erosion. Feedback's between production and erosion of soil material are important for soil development, and are essential to reach long-term steady-state in soil chemical and physical properties. Nowadays, long-term denudation rates of regolith can be quantified by using in-situ cosmogenic nuclides (CRN). If the soil thickness remains constant over sufficiently long time, soil production rates can be determined. However, the a priori assumption of long-term steady-state can be questionable in highly dynamic environments. In this study, we present analytical data from two independent isotopic techniques, in-situ cosmogenic nuclides and Uranium series disequilibrium. The disequilibrium of Uranium isotopes (238U, 234U, 230Th, 226Ra) is an alternative method that allows assessing soil formation rates through isotopic analysis of weathering products. Nine soil profiles were sampled in three different mountain ranges of the Betic Cordillera (SE Spain): Sierra Estancias, Filabres, Cabrera. All soils overly fractured mica schist and are very thin (< 60cm). In each soil profile, we sampled 4 to 6 depth slices in the soil profile, the soil-bedrock interface and (weathered) bedrock. Three of the nine soil profiles were sampled for U-series isotope measurements at EOST (University of Strasbourg). The surface denudation rates (CRN) are about the same in the Sierra Estancias and Filabres (26 ± 10 mm/ky) and increase up to 103 ± 47 mm/ky in the Sierra Cabrera. The spatial variation in soil denudation rates is in agreement with the variation in catchment-wide denudation rates presented by Bellin et al. (2014) which present the highest rates in the Sierra Cabrera (104-246mm/kyr). Moreover it roughly coincides with the pattern of long-term exhumation of the Betic Cordillera. Results

  4. Columbus's Spain.

    ERIC Educational Resources Information Center

    Soria, Jose Manuel Nieto

    1991-01-01

    Describes fifteenth-century Spain's tendencies that proved central to the Columbian enterprise: experience as a conquering and colonizing kingdom, interest in Atlantic expansion, and missionary inclination. Argues that Columbus's arrival in Spain came at the perfect time in Spanish history. Stresses Spain's long history of religious war, conquest,…

  5. Porphyry deposits of the Canadian Cordillera

    USGS Publications Warehouse

    McMillan, W.J.; Thompson, J.F.H.; Hart, C.J.R.; Johnston, S.T.

    1996-01-01

    Porphyry deposits are intrusion-related, large tonnage low grade mineral deposits with metal assemblages that may include all or some of copper, molybdenum, gold and silver. The genesis of these deposits is related to the emplacement of intermediate to felsic, hypabyssal, generally porphyritic intrusions that are commonly formed at convergent plate margins. Porphyry deposits of the Canadian Cordillera occur in association with two distinctive intrusive suites: calc-alkalic and alkalic. In the Canadian Cordillera, these deposits formed during two separate time periods: Late Triassic to Middle Jurassic (early Mesozoic), and Late Cretaceous to Eocene (Mesozoic-Cenozoic). Deposits of the early Mesozoic period occur in at least three different arc terranes (Wrangellia, Stikinia and Quesnellia) with a single deposit occurring in the oceanic assemblage of the Cache Creek terrane. These terranes were located outboard from continental North America during formation of most of their contained early Mesozoic porphyry deposits. Some of the deposits of this early period may have been emplaced during terrane collisions. Metal assemblages in deposits of the calc-alkalic suite include Mo-Cu (Brenda), Cu-Mo (Highland Valley, Gibraltar), Cu-Mo-Au-Ag (Island Copper, Schaft Creek) and Cu-Au (Kemess, Kerr).The alkalic suite deposits are characterized by a Cu-Au assemblage (Copper Mountain, Afton-Ajax, Mt. Milligan, Mount Polley, Galore Creek). Although silver is recovered from calc-alkalic and alkalic porphyry copper mining operations, silver data are seldom included in the published reserve figures. Those available are in the range of 1-2 grams per tonne (g??t-1). Alkalic suite deposits are restricted to the early Mesozoic and display distinctive petrology, alteration and mineralization that suggest a similar tectonic setting for both Quesnellia and Stikinia in Early Jurassic time. The younger deposits, late Mesozoic to Cenozoic in age, formed in an intracontinental setting, after the

  6. Crustal resistivity structure of the southwestern transect of the Rif Cordillera (Morocco)

    NASA Astrophysics Data System (ADS)

    Anahnah, Farida; Galindo-ZaldíVar, Jesús; Chalouan, Ahmed; Pous, Jaume; Ruano, Patricia; Pedrera, Antonio; Ruiz-ConstáN, Ana; Ahmamou, M'fedal; Benmakhlouf, Mohamed; Ibarra, Pedro; Asensio, Eva

    2011-12-01

    A NE-SW magnetotelluric 110 km-long profile including 18 sites was acquired across the western Rif Cordillera along the Eurasian-African plate boundary, allowing to constrain its poorly known deep structure. It extends from the Internal Zones, close to the Alboran coast, crossing the External Zones and up to the Gharb foreland basin. The periods recorded range from 0.001 s to 1000 s. The combination of magnetotelluric data with available geological data provides new insight regarding the relationship between deep and shallow crustal structures of the Rif Cordillera. Analyses of structural dimensionality suggest a preferential NW-SE direction, and a 2D joint inversion was performed. A 3D inversion extending the 2D model along the strike confirmed the reliability of this approach. The magnetotelluric model shows a heterogeneous upper crust in agreement with the geological structures observed at surface. The Internal Zones correspond to resistive (metamorphic rocks) and conductive (peridotites) bodies, while the External Zones and the foreland basin are characterized by large conductive bodies of variable thickness. A crustal detachment level separating shallow geological units from a probable variscan basement was inferred. At depth, the most relevant feature consists of large resistive bodies with a shallow irregular top, located below the frontal part of the Rif. The outcrops of exotic metapelitic, granitic and gneissic blocks in the frontal part of the Cordillera suggest that these large resistive bodies may correspond to a gneissic or granitic basement surrounded by metapelitic rocks. Late contractive thrust and diapiric processes were responsible for their uplift and shallow emplacement. The Rif constitutes an active southwestward vergent orogenic wedge, oblique to the present-day NW-SE convergent Eurasian-African plate boundary.

  7. Comparison of water-level, extensometric, DInSAR and simulation data for quantification of subsidence in Murcia City (SE Spain)

    NASA Astrophysics Data System (ADS)

    Tessitore, S.; Fernández-Merodo, J. A.; Herrera, G.; Tomás, R.; Ramondini, M.; Sanabria, M.; Duro, J.; Mulas, J.; Calcaterra, D.

    2016-05-01

    Subsidence due to groundwater overexploitation has been recognized in the metropolitan area of Murcia (25 km2) in south-eastern Spain since the early 1990s. Previous published works have focused their attention on land subsidence that occurred during the drought period between 1995 and 2008. This work first analyzes the groundwater recovery that has occurred since 2008 and then determines the kind of associated ground deformation detected by the new extensometric data. Subsequently, subsidence time series are computed on 24 geotechnical boreholes scattered throughout the study area by means of a hydro-mechanical finite element code and a linear-elastic constitutive law. A spatio-temporal interpolation of the numerically modeled surface displacements is performed over the whole domain and compared with extensometers and DInSAR-derived displacement maps in two different periods: the drought period from 2004 to 2008, and the recovery period from 2008 to 2012. In spite of the limited information on the geomechanical parameters characterizing the modelled geological formations, the proposed approach is able to discriminate areas where the soils have an elastic behavior (small differences in the comparisons) or an elasto-plastic behavior (large differences in the comparisons). This zonation enhances the understanding of the subsidence phenomenon in Murcia City and could prevent, from a quantitatively point of view, future severe subsidence due to aquifer overexploitation.

  8. Current deformation of the Betic Cordillera from a new GPS observation of the southern sector of the IBERIA95 Zero-Order Geodetic Network

    NASA Astrophysics Data System (ADS)

    Gil, Antonio J.; Galindo, Jesús; Alfaro, Pedro; de Lacy, María. Clara; Jesús Borque, María.; Franco, Juan A. Armenteros (1), Oscar; Ruano, Patricia; García Tortosa, Francisco Juan; López Garrido, Angel Carlos; Pedrera, Antonio

    2010-05-01

    The Betic Cordillera, located at the convergent plate boundary between Africa and Eurasia, is subjected to an average NNW-SSE compression and an associated orthogonal extension. In order to quantify this deformation a GPS campaign in the Southern Sector of IBERIA95 Zero-Order Geodetic Network was done in December 2008. This network was observed in 1995 by the Spanish National Geographical Institute (IGNE) and the Portuguese Institute of Cartography and Cadastre (IPCC) for the establishment of a Three-dimensional Geodetic Network in Spain and Portugal. The comparison of results in 1995 and 2009 provides one of the first geodetic results of the short-term deformation in the Betic Cordillera.

  9. Groundwater temperature patterns in the freshwater-saltwater contact zone in coastal aquifers. The Motril-Salobreña Aquifer (SE Spain)

    NASA Astrophysics Data System (ADS)

    Calvache, Maria Luisa; Duque, Carlos; Lopez-Chicano, Manuel; Martin-Rosales, Wenceslao; Sanchez-Ubeda, Juan Pedro

    2013-04-01

    The groundwater temperature in the freshwater-saltwater contact zones shows a characteristic pattern completely different from that monitored in other parts of the coastal aquifers. The temperature-depth profiles of seven wells in the Motril-Salobreña aquifer (southern Spain) were used as a basis for a comparative analysis involving various parameters to determine their relations and factors influencing the different trends. The temperature profiles show a shallow belt of variable temperature (up to 5 °C) that can reach depths in the groundwater ranging from 15 m to 45 m. There is an influence of ambient temperature on all the profiles, with a lag time of two to five months. Furthermore, there is a clear influence of the Guadalfeo River (the main source of recharge to the aquifer) reflected in a decrease in temperature coinciding with peak flow rates in the river and the highest water tables in the aquifer during the springtime when the river flow derives mainly from snowmelt from Sierra Nevada. In the autumn, there are secondary peaks in river flow rates due to rainfall, and the river temperature is higher than in spring. In this case, the groundwater temperature rises. This influence fades with distance from the river. In the summer, when the river is dry, the temperature profiles are straight, with no effect on groundwater temperature. Three of the wells, the closest ones to the coastal line, are exception. However, as there is no clear coincidence between temperature valleys and peaks in the river flow rate, making it difficult to establish a relation between the groundwater temperatures and the river recharge in these two cases. Instead, we must recur to a discharge-zone flow pattern, typical of the freshwater-saltwater contact in a coastal aquifer (Glover, 1959), that generates vertical upward fluxes due to the density contrast when is reaching the saline wedge. In this case is even more pronounced due to the fact that the Motril-Salobreña aquifer has

  10. On the physical- and socioeconomic aspects of land degradation in the Guadalentin basin (SE-Spain): Towards comprehensive understanding for effective remediation

    NASA Astrophysics Data System (ADS)

    de Vente, J.; Solé-Benet, A.; Boix-Fayos, C.; Nainggolan, D.

    2009-04-01

    During the last two decades, the Guadalentin basin in south-eastern Spain has been the study area for many national- and international studies dealing with land degradation and desertification. One of the reasons for such a broad interest in the Guadalentin basin is that land degradation is generally considered severe in large parts of the basin due to a combination of the Mediterranean climate characterised by dry summers followed by intense autumn rainfall, steep topography that marks most parts of the landscape, and fragile soils on erodible lithologies. The main types of degradation are due to soil erosion, soil surface crusting, aridity, soil organic matter decline and salinisation. Moreover, triggered by various political and socioeconomic drivers, important land use and management changes have taken place over the last centuries, which have formed an important driver for further land degradation. Examples of such changes are large-scale land abandonment, a shift from dryland cereals production to large almond plantations, large scale land levelling for irrigated horticulture and urban expansions, and several types of agricultural subsidies. Numerous publications have been produced based on works done to address land degradation in the Guadalentin. However, until now there is no concise and integrated overview of what has been done and what is still missing regarding the study of the physical- and socioeconomic aspects of land degradation and conservation. This is in fact crucial to assist policy makers in making decisions that would effectively navigate land management in the area to a sustainable way. Here, we aim to provide such an overview by listing and discussing the main studies performed in this area, and by providing an integrated synthesis of the main physical- and socioeconomic factors identified in these studies as being responsible for land degradation, with a focus on feasible soil conservation strategies. In overall, there has been a strong

  11. A multidisciplinary study for mining landscape reclamation: A study case on two tailing ponds in the Region of Murcia (SE Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Pagán, P.; Faz, A.; Acosta, J. A.; Carmona, D. M.; Martínez-Martínez, S.

    The aim of this work was to evaluate the mobility of Pb, Cu, Zn and Cd in two tailing ponds (Brunita and San Cristobal) from mine activity in the Southeast of Spain before applying reclamation measures for reducing the risk for human and environment. To achieve this objective, five profiles of electrical resistivity imaging (ERI) in Brunita, three profiles in San Cristobal, a drill-hole in each pond and undisturbed columns amended with marble waste for leaching experiments were taken. Results showed that all layers of the two ponds exceed the maximum Pb and Zn concentrations allowed by the selected European legislations. In both ponds, the mixture of tailings with natural soil is the main process involved in soil pollution under the ponds. However, due to high pH in the substrate the metals are precipitated and their solubility reduced, therefore there is not a risk of leaching to groundwater. At Brunita tailing pond electrical resistivity sections displayed some lower electrical resistivity region into the bedrock which has been described as some fault occurrence due to breaking events suffered by the tailing pond. At San Cristobal tailing pond geochemical results were consistent with data obtained by the electrical resistivity imaging (ERI) method where no evidence of faults or cracks into the bedrock and the ponds were observed. Therefore, no preferential pathways of acid mine drainages containing heavy metals were reported. Leaching experiments indicated that, after 11 weeks of leaching, amended and control columns showed comparable values of pH (∼2.3) and similar trends for Cu, Cd and Zn, with a very drastic decrease up to week 3 and thereafter the tendency was to reach near steady-state conditions. In contrast, the evolution of Pb showed that marble amended reduces significantly its concentration over time compared with the control. In accordance with the results, future reclamation action should be based on the reduction of heavy metal mobility by means of

  12. On the ecological context of the earliest human settlements in Europe: Resource availability and competition intensity in the carnivore guild of Barranco León-D and Fuente Nueva-3 (Orce, Baza Basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gómez, Guillermo; Palmqvist, Paul; Rodríguez, Jesús; Mateos, Ana; Martín-González, Jesús A.; Espigares, M. Patrocinio; Ros-Montoya, Sergio; Martínez-Navarro, Bienvenido

    2016-07-01

    With an age of ∼1.4 Ma, the Early Pleistocene archaeopaleontological sites of Barranco León and Fuente Nueva-3 (Orce, Baza Basin, SE Spain) provide the oldest evidence on human presence in Western Europe, including the finding of a deciduous tooth of Homo sp., huge lithic assemblages of Oldowan tradition and abundant cut-marks on large mammal bones. Here we use a mathematical approach based on Leslie matrices to quantify for the large mammal species preserved at the sites the biomass of primary consumers available, the distribution of meat resources among the secondary consumers and the competition intensity within the carnivore guild. The results obtained show a community of large mammals with a high diversity of secondary consumers that would satisfy slightly less than half of their dietary requirements under optimal ecological conditions. In the case of Homo sp., and considering that flesh resources were obtained through the scavenging of ungulate carcasses, the model indicates that the ecosystems of the basin could hold 10-14 individuals per 100 km2 during a year, a value that is close to the mean population density of recent hunter-gatherers. These density estimates decrease slightly when a mixed hunting-scavenging strategy is considered and even more in the case of a strict hunting behavior. In addition, the value of the species competition index obtained for Homo sp. is among the lowest of the carnivore guild. These results suggest that the hominin populations that inhabited Southeast Spain during the Early Pleistocene behaved more as opportunistic scavengers than as active predators.

  13. Late Miocene extensional tectonics in the evolution of the eastern Betics and Neogene-Quaternary basins, an example from the Sorbas basin (SE Spain).

    NASA Astrophysics Data System (ADS)

    Giaconia, Flavio; Booth-Rea, Guillermo; Martínez-Martínez, José Miguel; Azañón, José Miguel

    2013-04-01

    Neogene to Quaternary basins in the eastern Betics occur in synclines among near E/W-elongated antiformal ridges where the metamorphic basement crops out. These antiforms are related to or cut by large-scale strike-slip faults, both developed in response of the NW-SE Africa-Iberia convergence. Most literature associated the origin and evolution of the Neogene-Quaternary eastern Betics basins with this transpressional strike-slip regime. However, recent work showed the great importance of extensional tectonics in the development and evolution of these basins during the middle to late Miocene. In order to define the role of Miocene extensional tectonics in the origin and evolution of Neogene - Quaternary basins, we have carefully mapped a key area in the southeastern Betics, the western termination of Sierra Cabrera. We analyzed the age and linking relationships between brittle fault segments, and finally we constructed a balanced cross section. We identified a NW-SE listric normal fault system that was active during the Tortonian producing southwestward hanging-wall displacement. These normal faults show hard linkage relationships with E-W to N70E vertical strike-slip and oblique-slip extensional transfer faults that show both dextral and sinistral kinematics. The balanced cross section shows that listric faults probably join together into a basal detachment (about 1 km depth) inside the metamorphic basement (Nevado-Filabride complex). The fault system influenced the Tortonian sedimentary evolution of the Sorbas Basin controlling the sediments thickness. The early Tortonian sedimentary unit is missed in the hangingwall of the fault system, meanwhile the thickness of late Tortonian sediments deposited between 11 and 8 Ma change across the main faults from approximately 200 m thick in the footwall of the system to up to 800 m in the main depocentre. Furthermore, the fault system controlled the Tortonian sedimentary facies shifting from continental and deltaic

  14. Mountain front migration and drainage captures related to fault segment linkage and growth: The Polopos transpressive fault zone (southeastern Betics, SE Spain)

    NASA Astrophysics Data System (ADS)

    Giaconia, Flavio; Booth-Rea, Guillermo; Martínez-Martínez, José Miguel; Azañón, José Miguel; Pérez-Romero, Joaquín; Villegas, Irene

    2013-01-01

    The Polopos E-W- to ESE-WNW-oriented dextral-reverse fault zone is formed by the North Alhamilla reverse fault and the North and South Gafarillos dextral faults. It is a conjugate fault system of the sinistral NNE-SSW Palomares fault zone, active from the late most Tortonian (≈7 Ma) up to the late Pleistocene (≥70 ky) in the southeastern Betics. The helicoidal geometry of the fault zone permits to shift SE-directed movement along the South Cabrera reverse fault to NW-directed shortening along the North Alhamilla reverse fault via vertical Gafarillos fault segments, in between. Since the Messinian, fault activity migrated southwards forming the South Gafarillos fault and displacing the active fault-related mountain-front from the north to the south of Sierra de Polopos; whilst recent activity of the North Alhamilla reverse fault migrated westwards. The Polopos fault zone determined the differential uplift between the Sierra Alhamilla and the Tabernas-Sorbas basin promoting the middle Pleistocene capture that occurred in the southern margin of the Sorbas basin. Continued tectonic uplift of the Sierra Alhamilla-Polopos and Cabrera anticlinoria and local subsidence associated to the Palomares fault zone in the Vera basin promoted the headward erosion of the Aguas river drainage that captured the Sorbas basin during the late Pleistocene.

  15. Integrating soil water and tracer balances, numerical modelling and GIS tools to estimate regional groundwater recharge: Application to the Alcadozo Aquifer System (SE Spain).

    PubMed

    Hornero, Jorge; Manzano, Marisol; Ortega, Lucía; Custodio, Emilio

    2016-10-15

    Groundwater recharge is one of the key variables for aquifer management and also one of the most difficult to be evaluated with acceptable accuracy. This is especially relevant in semiarid areas, where the processes involved in recharge are widely variable. Uncertainty should be estimated to know how reliable recharge estimations are. Groundwater recharge has been calculated in the Alcadozo Aquifer System, under steady state conditions, at regional (aquifer) and sub-regional (spring catchment) scales applying different methods. The regional distribution of long-term average recharge values has been estimated with the chloride mass balance method using data from four rain stations and 40 groundwater samples covering almost the whole aquifer surface. A remarkable spatial variability has been found. Average annual recharge rates ranges from 20 to 243mmyear(-1) across the aquifer, with an estimated coefficient of variation between 0.16 and 0.38. The average recharge/precipitation ratio decreases from 34% in the NW to 6% in the SE, following the topographic slope. At spring-catchment scale, recharge has been estimated by modelling the soil water balance with the code Visual Balan 2.0. The results, calibrated with discharge data of the two main springs Liétor and Ayna, are 35.5 and 50mmyear(-1) respectively, with estimated coefficients of variation of 0.49 and 0.36. A sensitivity analysis showed that soil parameters influence the most the uncertainty of recharge estimations. Recharge values estimated with both methods and at two temporal and spatial scales are consistent, considering the regional variability obtained with the chloride method and the respective confidence intervals. Evaluating the uncertainties of each method eased to compare their relative results and to check their agreement, which provided confidence to the values obtained. Thus, the use of independent methods together with their uncertainties is strongly recommended to constrain the magnitude and to

  16. Integrating soil water and tracer balances, numerical modelling and GIS tools to estimate regional groundwater recharge: Application to the Alcadozo Aquifer System (SE Spain).

    PubMed

    Hornero, Jorge; Manzano, Marisol; Ortega, Lucía; Custodio, Emilio

    2016-10-15

    Groundwater recharge is one of the key variables for aquifer management and also one of the most difficult to be evaluated with acceptable accuracy. This is especially relevant in semiarid areas, where the processes involved in recharge are widely variable. Uncertainty should be estimated to know how reliable recharge estimations are. Groundwater recharge has been calculated in the Alcadozo Aquifer System, under steady state conditions, at regional (aquifer) and sub-regional (spring catchment) scales applying different methods. The regional distribution of long-term average recharge values has been estimated with the chloride mass balance method using data from four rain stations and 40 groundwater samples covering almost the whole aquifer surface. A remarkable spatial variability has been found. Average annual recharge rates ranges from 20 to 243mmyear(-1) across the aquifer, with an estimated coefficient of variation between 0.16 and 0.38. The average recharge/precipitation ratio decreases from 34% in the NW to 6% in the SE, following the topographic slope. At spring-catchment scale, recharge has been estimated by modelling the soil water balance with the code Visual Balan 2.0. The results, calibrated with discharge data of the two main springs Liétor and Ayna, are 35.5 and 50mmyear(-1) respectively, with estimated coefficients of variation of 0.49 and 0.36. A sensitivity analysis showed that soil parameters influence the most the uncertainty of recharge estimations. Recharge values estimated with both methods and at two temporal and spatial scales are consistent, considering the regional variability obtained with the chloride method and the respective confidence intervals. Evaluating the uncertainties of each method eased to compare their relative results and to check their agreement, which provided confidence to the values obtained. Thus, the use of independent methods together with their uncertainties is strongly recommended to constrain the magnitude and to

  17. Geochronology of Quaternary glaciations from the tropical Cordillera Huayhuash, Peru

    NASA Astrophysics Data System (ADS)

    Hall, Sarah R.; Farber, Daniel L.; Ramage, Joan M.; Rodbell, Donald T.; Finkel, Robert C.; Smith, Jacqueline A.; Mark, Bryan G.; Kassel, Christopher

    2009-12-01

    The Cordillera Huayhuash in the central Peruvian Andes (10.3°S, 76.9°W) is an ideal mountain range in which to study regional climate through variations in paleoglacier extents. The range trends nearly north-south with modern glaciers confined to peaks >4800 m a.s.l. Geomorphology and geochronology in the nearby Cordillera Blanca and Junin Plain reveal that the Peruvian Andes preserve a detailed record of tropical glaciation. Here, we use ASTER imagery, aerial photographs, and GPS to map and date glacial features in both the western and eastern drainages of the Cordillera Huayhuash. We have used in situ produced cosmogenic 10Be concentrations in quartz bearing erratics on moraine crests and ice-polished bedrock surfaces to develop an exposure age chronology for Pleistocene glaciation within the range. We have also collected sediment cores from moraine-dammed lakes and bogs to provide limiting 14C ages for glacial deposits. In contrast to the ranges to the north and south, most glacial features within the Cordillera Huayhuash are Lateglacial in age, however we have identified features with ages that span ˜0.2 to ˜38 ka with moraine sets marking the onset of glacier retreat at ˜0.3 ka, ˜9-10 ka, ˜13-14 ka, ˜20-22 ka, and >26 ka. The range displays a pronounced east-west variation in maximum down-valley distance from the headwall of moraine crests with considerably longer paleoglaciers in the eastern drainages. Importantly, Lateglacial paleoglaciers reached a terminal elevation of ˜4000 m a.s.l. on both sides of the Cordillera Huayhuash; suggesting that temperature may have been a dominant factor in controlling the maximum glacier extent. We suggest that valley morphology, specifically valley slope, strongly influences down-valley distance to the maximum glacier extent and potential for moraine preservation. While regionally there is an extensive record of older (>50 ka) advances to the north (Cordillera Blanca) and to the south (Junin region), the apparent

  18. An integrated multiscale paleoseismic and neotectonic approach of the Carboneras Fault Zone, SE Spain, and its marine continuation in the Alboran Sea

    NASA Astrophysics Data System (ADS)

    Moreno, X.; Masana, E.; Gracia, E.; Bartolome, R.; Lo Iacono, C.; Rodés, A.; Pallàs, R.

    2009-12-01

    . The N45 segment overlaps with the southern N60 segment in a 14 km long intersection zone characterized by prominent pressure ridges and narrow flower structures. The N60 segment links to the south with an 8 km long N45 segment showing a transtensive graben-type structure. The southern end of the CFZ is characterized by smooth strain transference through folds and pervasive subvertical NW-SE faults. Geometry and structure of the marine segments are similar to onshore structures indicating a main left-lateral movement with a reverse component. The infill of the sedimentary basins on both sides of the basement high produced by the CFZ suggests that the activity of the fault started before the Messinian (Upper Miocene). Sediment rates obtained from 14C dating of marine cores allow us to calculate dip-slip rates of the CFZ. As observed on seismic profiles, these values range from 0.14 mm/a for the last 165 ka to 0.06 mm/a if considering the whole Quaternary. A forthcoming study better controlling the age of key horizons as well as detailed study of horizontally displaced morphological features will allow us to propose more accurate vertical and horizontal slip rates.

  19. Recent large fold nucleation in the upper crust: Insight from gravity, magnetic, magnetotelluric and seismicity data (Sierra de Los Filabres-Sierra de Las Estancias, Internal Zones, Betic Cordillera)

    NASA Astrophysics Data System (ADS)

    Pedrera, Antonio; Galindo-Zaldívar, Jesús; Ruíz-Constán, Ana; Duque, Carlos; Marín-Lechado, Carlos; Serrano, Inmaculada

    2009-01-01

    Rheological heterogeneities in the upper-crust have a close relationship with the fold position where rigid bodies could constitute initial perturbations that allow the nucleation of folds. Consequently, establish the position and geometry of anomalous rocks located in the upper-crust by geophysical studies help to understand the folded structure observed on surface. New geological observations in the field, along with gravity, magnetic, magnetotelluric and seismicity data, reveal the subsurface structure in the Sierra de Los Filabres-Sierra de Las Estancias folded region part of the Alpine belt in southern Spain. The geometry of the upper crust is determined by geological field data, 2D gravity models, 2D magnetic models and 2D MT resistivity model, while seismicity evidences the location of the deep active structures. These results allow us to propose that a basic rock body at 4 to 9 km depth has determined the nucleation and development of the Sierra de Los Filabres kilometric antiform. N-vergent large late folds are subjected to a variable present-day stress field. Earthquake focal mechanisms suggest the presence in depth of a regional NW-SE compressive stress field. However, most of the seismogenetic structures do not extend up to the surface, where NW-SE and WNW-ESE outcropping active normal faults are observed, thus indicating a NE-SW extension in the upper crust simultaneous to orthogonal NW-SE compression related to reverse faults and minor folds developed in the Eastern Almanzora Corridor and in the nearby Huércal-Overa Basin. The recent and active tectonic studies of cordilleras hinterland subjected to late folding greatly benefits from the integration of surface observations together with geophysical data.

  20. Variations of the Crustal Structure in the Rif Cordillera, N-Morocco from Wide-Angle Seismic Data

    NASA Astrophysics Data System (ADS)

    Gallart, J.; Gil, A.; Diaz, J.; Carbonell, R.; Harnafi, M.; Levander, A.; Palomeras, I.; Cordoba, D.

    2012-12-01

    The Rif Cordillera, located in North Morocco forms, together with the Betic Cordillera, the Gibraltar Arc around the Alboran Sea. This asymmetric curved mountain belt originated during a Miocene continent-continent collision as a result of the westward motion of the Alboran domain between northwest Africa and Iberia. The complexity of the area favored the proposition of diverse tectonic models, poorly constrained by available geophysical data. Previous numerical models that integrate both elevation, geoid and gravity anomalies assuming local isostasy suggest a poorly marked orogenic root beneath the Rif Cordillera, whereas a recent receiver function study from Topo-Iberia project reveals large variations of at least 10 km in crustal thicknesses under northern Morocco, similarly to values obtained in station terms from a Pn tomography. In order to constrain the seismic velocity structure of the Rif Cordillera and to delineate the Moho topography, in October 2011, within the Spanish project RIFSIS complemented by the US-PICASSO one, wide-angle reflection and refraction seismic data were acquired for the first time along two 330 km-length profiles, oriented respectively N-S and E-W. The N-S line was extended northwards by a 70 km long segment in Spain, along the Betics. Southwards, this profile connects with the one recorded in 2010 across the Atlas Mountains (SIMA project), hence delineating a 700 km-long wide-angle seismic transect across the Betic-Rif-Atlas systems. Seismic energy released at 5 shot points was generated by the detonation of 1 TN of explosives and was recorded by ~ 900 Texans stations from the IRIS-PASCAL pool, with an average station spacing of about 750 m. Crustal phases Pg, PcP and PiP and Moho reflected PmP phases are clearly identified in the processed datasets. Preliminary analyses by forward modeling already reveal the existence of major variations in crustal thicknesses, especially along the E-W profile that documents differences of about 20

  1. Jurassic Magmatism and Tectonics of the North American Cordillera

    NASA Astrophysics Data System (ADS)

    Boettcher, Stefan

    The relationship of Jurassic magmatic arc rocks to the tectonic evolution of the North American Cordilleran continental margin is a principle theme of Geological Society of America Special Paper 299. The volume gives readers a comprehensive view of the early stages of magmatic arc evolution on a continental margin and is a tribute to the contributions of Richard Lee Armstrong, whose pioneering studies provide a framework for current geologic investigations of the North American Cordillera.

  2. Significance of "tethyan" fossils in the american cordillera.

    PubMed

    Newton, C R

    1988-10-21

    Equatorial faunas of the ancient Tethyan seaway, which extended from western Europe to southeastern Asia, comprise some of the most diverse marine taxa in the fossil record. Comparable or identical "Tethyan" species that occur far from the Tethyan seaway in Paleozoic and Mesozoic rocks of the North and South American Cordillera have long been considered as a major biogeographic anomaly. Two leading theories to account for the occurrence of these anomalous "Tethyan" faunas in the Cordillera are that they were transported long distances to the east on tectonic blocks(suspect terranes that originated near the Tethys) or that they migrated westward via undiscovered marine corridors through continental areas of Pangea. An alternative model is that these "Tethyan" fauna were pantropic species that extended with attenuated diversities into the eastern proto-Pacific Ocean. This pantropic model can better account for the distribution patterns of many Paleozoic and early Mesozoic "Tethyan" species in the American Cordillera and provides a steady state hypothesis against which the other models can be tested. The distribution of pre-Cretaceous "Tethyan" faunas is similar to the known pantropic distribution of many Cretaceous and Cenozoic tropical biotas. During the Cenozoic, taxa were most diverse in the Tethys and Indo-West Pacific regions but extended with attenuated diversity to many parts of the equatorial Pacific Ocean, including the west coasts of North and South America. The eastern Pacific occurrence of many Indo-West Pacific species provides a modern analog for the occurrence of many anomalous "Tethyan" fossils in the American Cordillera.

  3. Refining upon the climatic background of the Early Pleistocene hominid settlement in western Europe: Barranco León and Fuente Nueva-3 (Guadix-Baza Basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Blain, Hugues-Alexandre; Lozano-Fernández, Iván; Agustí, Jordi; Bailon, Salvador; Menéndez Granda, Leticia; Espígares Ortiz, Maria Patrocinio; Ros-Montoya, Sergios; Jiménez Arenas, Juan Manuel; Toro-Moyano, Isidro; Martínez-Navarro, Bienvenido; Sala, Robert

    2016-07-01

    The Early Pleistocene sites of Barranco León and Fuente Nueva-3 (Guadix-Baza Basin, SE Spain) have yielded thousands of Mode 1 or Oldowan lithic artifacts (both sites) and one tooth (in layer D, formerly 5 of Barranco León), today considered to be some of the earliest evidence of humans in western Europe at ca. 1.2-1.5 Ma. Previous quantitative paleoclimatic reconstructions based on herpetile assemblages indicated that, during the formation of these two sites, the mean annual temperature and mean annual precipitation were higher than they are now in the southeastern Iberian Peninsula, with lower continentality. Here, we propose new climatic reconstructions where the mean monthly temperature and precipitation and the difference between the four driest months and the four rainiest months are estimated. Climatograms are built in order to specify the distribution and variation of temperature and precipitation during the year, and the Aridity Indices of Gaussen, Lautensach-Mayer, Dantin-Revenga and De Martonne are used to characterize ombroclimatic differences. According to these new climatic parameters, rainfall distribution through the year shows considerably higher precipitation in every season except summer and early autumn, which remain drier and thus consistent with a Mediterranean climate pattern. No change is observed in the duration of the aridity period, which remains four months long. However, the value of the Aridity Index of De Martonne is higher than 20 (subhumid climate) in Barranco León and Fuente Nueva-3, whereas today it is lower than 20 (semi-arid climate), suggesting major changes in the ombroclimatic type. These results yield a more precise scenario for the paleoclimatic conditions that prevailed during the late Early Pleistocene in the Guadix-Baza Basin and permit us to contrast the ages obtained from numerical dating and biochronology. The very warm and humid climate reconstructed for both Barranco León and Fuente Nueva-3 suggests that, in

  4. Distribution of crack density parameter in Central Betic Cordillera (Southern Spain)

    NASA Astrophysics Data System (ADS)

    Serrano, Inmaculada; Torcal, Federico; Morales, José

    2014-01-01

    In this study we have used high-resolution P- and S-wave velocity results to estimate crack density (ɛ, epsilon) and saturation ratio (ξ, xi) at a depth of 2 km in an intramountain basin and surrounding regions. Detailed observations of gravity, seismic profile and geological data reveal high ɛ consistent with large sedimentary thickness and minimum ɛ coinciding with elevations arising from the basement of the basin. From the distribution of seismic measurements of ξ it is possible to identify the presence of aquifers in detrital sediments, sandstone and dolostone. However, ξ does not show significant changes for the aquifers in geological formations made up also of schists and marbles. A low ξ anomaly in the western part could be associated with Triassic evaporite and clay rocks, and high values of ξ in the southwestern part near thermal springs may be imaging the intricate system of fractures which connect at depth with aquifer rocks.

  5. The Messinian post-evaporitic deposits of the Gafares area (Almerı´a-Nı´jar basin, SE Spain). A new view of the "Lago-Mare" facies

    NASA Astrophysics Data System (ADS)

    Aguirre, Julio; Sánchez-Almazo, Isabel M.

    2004-06-01

    The exceptional exposures of the evaporitic and post-evaporitic Messinian deposits in the Gafares area (NE Almerı´a-Nı´jar basin, SE Spain) make it possible to elucidate those processes affecting this region during the critical period of the Messinian Salinity Crisis. The contact between the pre-evaporitic and the evaporitic units is an erosional unconformity. The transition from the evaporitic to the post-evaporitic units is gradual, since the gypsum beds of the evaporitic unit thin upward and the siliciclastic interbeds concomitantly thicken, thus passing gradually to the overlaying post-evaporitic unit. The presence of Globorotalia miotumida group in the last pelitic intercalation of the evaporitic unit as well as throughout the post-evaporitic one indicates a Messinian age. The post-evaporitic unit consists of a variety of sediments formed in continental and marine settings. Continental facies are characterised by fluvial channel-filled conglomerates and alluvial-plain sands and silts. Marine sediments are represented by silty marls with foraminifers. A river-dominated delta developed in the transitional zone at the NW edge of the Gafares area. Localised fan-delta deposits coming from the ESE also occur in the southeastern part of the study area. Microbial carbonates locally colonised the fan-delta conglomerates. During the deposition of the lower half of the post-evaporitic unit, sedimentation took place in a sheltered embayment, with restricted water circulation and relatively isolated from the Mediterranean Sea by an E-W-trending sill located at the south of the study area. In this palaeogeographic context, freshwater influx from the delta exerted a certain influence on the distribution of microorganisms. Thus, brackish settings developed close to the river outflows that were occupied by caspibrackish ostracod assemblages. The presence of gastropods of the family Cerithiidae as well as fishes attributable to the genus Aphanius, organisms that

  6. Late Jurassic plutonism in the southwest U.S. Cordillera

    USGS Publications Warehouse

    Barth, A.P.; Wooden, J.L.; Howard, K.A.; Richards, J.L.

    2008-01-01

    Although plate reconstructions suggest that subduction was an approximately steady-state process from the mid-Mesozoic through the early Tertiary, recent precise geochronologic studies suggest highly episodic emplacement of voluminous continental-margin batholiths in the U.S. Cordillera. In central and southern California and western Arizona, major episodes of batholithic magmatism are known to have occurred in Permian-Triassic, Middle Jurassic, and late Early to Late Cretaceous time. However, recent studies of forearc-basin and continental-interior sediments suggest that Late Jurassic time was probably also a period of significant magmatism, although few dated plutons of this age have been recognized. We describe a belt of Late Jurassic plutonic and hypabyssal rocks at least 200 km in length that extends from the northwestern Mojave Desert through the Transverse Ranges. The belt lies outboard of both the voluminous Middle Jurassic arc and the ca. 148 Ma Independence dike swarm at these latitudes. The plutons include two intrusive suites emplaced between 157 and 149 Ma: a calc-alkaline suite compositionally unlike Permian-Triassic and Middle Jurassic mon-zonitic suites but similar to Late Cretaceous arc plutons emplaced across this region, and a contemporaneous but not comagmatic alkaline suite. The Late Jurassic was thus a time of both tectonic and magmatic transitions in the southern Cordillera. ?? 2008 The Geological Society of America.

  7. Constraining the deformation and exhumation history of the Ronda Massif, Southern Spain

    NASA Astrophysics Data System (ADS)

    Myall, Jack; Donaldson, Colin

    2016-04-01

    The Ronda peridotite, southern Spain is comprised of four peridotite units hosted within metasedimentary units of the Betic Cordillera, Western Alps. These four areas of differing mineral facies are termed: the Garnet Mylonite , the Foliated Spinel Peridotite, the Granular Spinel Peridotite and the Foliated Plagioclase Peridotite. Whilst two of these units show a strong NE-SW foliation, the granular unit has no foliation and the Plagioclase facies shows a NW-SE foliation. The massif is separated from the metasedimentary host through a mylonite shear zone to the NW and thrust faults to the SE. The Garnets contain rims of Kelyphite which when combined with the rims of Spinel on the Plagioclase crystals illustrate the complicated exhumation of this massif. The Kelyphite shows the breakdown of garnet back to spinel and pyroxene showing the deeper high pressure high temperature mineral is under shallowing conditions whereas in contrast to this the low pressure low temperature plagioclase crystals have spinel rims showing that they have been moved into deeper conditions. The P-T-t pathway of the massif suggests slow exhumation to allow for partial recrystallisation of not only the garnets and plagioclases but of a 100m band of peridotite between the Foliated Spinel Peridotite and the Granular Spinel Peridotite facies. The tectonic model for the Ronda Peridotite that best describes the field data and subsequent lab work of this study is Mantle Core complex and slab roll back models. These models support mantle uprising during an extensional event that whereby slab roll back of the subducting lithosphere provides uplift into a void and emplacement into the crust. Further extension and final exhumation causes rotation of a mantle wedge into its present day position.

  8. Slab flattening, dynamic topography and normal faulting in the Cordillera Blanca region (northern Peru)

    NASA Astrophysics Data System (ADS)

    Margirier, A.; Robert, X.; Laurence, A.; Gautheron, C.; Bernet, M.; Simon-Labric, T.; Hall, S. R.

    2015-12-01

    Processes driving surface uplift in the Andes are still debated and the role of subduction processes as slab flattening on surface uplift and relief building in the Andes is not well understood. Some of the highest Andean summits, the Cordillera Blanca (6768 m) and the Cordillera Negra (5187 m), are located above a present flat subduction zone (3-15°S), in northern Peru. In this area, both the geometry and timing of the flattening of the slab are well constrained (Gutscher et al., 1999; Rosenbaum et al., 2005). This region is thus a perfect target to explore the effect of slab flattening on the Andean topography and uplift. We obtained new apatite (U-Th)/He and fission-track ages from three vertical profiles located in the Cordillera Blanca and the Cordillera Negra. Time-temperature paths obtained from inverse modeling of the thermochronological data indicates a Middle Miocene cooling for both Cordillera Negra profiles. We interpret it as regional exhumation in the Cordillera Occidental starting in Middle Miocene, synchronous with the onset of the subduction of the Nazca ridge (Rosenbaum et al., 2005). We propose that the Nazca ridge subduction at 15 Ma and onset of slab flattening in northern Peru drove regional positive dynamic topography and thus enhanced exhumation in the Cordillera Occidental. This study provides new evidence of the impact subduction processes and associated dynamic topography on paleogeography and surface uplift in the Andes.

  9. Time and mode of exhumation of the Cordillera Blanca batholith (Peruvian Andes)

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Audin, Laurence; Robert, Xavier; Herman, Frédéric; Ganne, Jérôme; Schwartz, Stéphane

    2016-08-01

    The Cordillera Blanca batholith (12-5 Myr) forms the highest Peruvian summits and builds the footwall of the Cordillera Blanca normal fault (CBNF). Even if several models have been proposed, the processes driving both the exhumation of the Cordillera Blanca and extensional deformation along the CBNF are still debated. Here we quantify the emplacement depth and exhumation of the batholith of the northern Peru arc from the late Miocene to present. Based on a compilation of crystallization ages and new thermobarometry data in the Cordillera Blanca batholith, we propose that the batholith was emplaced at a depth of ~3 km in successive sills from 14 to 5 Ma. By contrast, the younger rocks exposed at the surface were emplaced the deepest (i.e., ~6 km) and are located close to the CBNF, suggesting post 5 Ma tilting. Furthermore, a formal inversion of the thermochronologic data indicates an increase of the exhumation rates in the Cordillera Blanca during the Quaternary. The higher predicted exhumation rates correlate with areas of high relief, both in the northern and central part of the Cordillera Blanca, suggesting that Quaternary valley carving by glaciations have a significant impact on the latest stage of the Cordillera Blanca exhumation (2-0 Ma).

  10. Geology of the El Recodo Cu-Mo prospect, SE. Cordille-ra central, Dominican Republic

    SciTech Connect

    Dominguez, H.S.; Lewis, J.F.

    1985-01-01

    The main intrusive phase in the El Recodo area is a small stock of leucocractic quartz diorite which intrudes an unmetamorphosed Upper Cretaceous sequence of andesites, tuffs, agglomerates, breccias and minor interbedded limestones. At least three other intrusive phases might be related to the emplacement of the main quartz diorite stock: 1) porphyritic andesites, 2) a series of gabbros and hornblende gabbros and 3) late stage aplite, porphyritic dacite and mineralized quartz-epidote veins. Emplacement of this last phase was accompanied by extensive brecciation and hydrothermal alteration.Three distinct stages of hydrothermal alteration are recognized in the andesites an associated basic to intermediate intrusives: 1) pyroxene-hornblende alteration to chlorite +/- epidote-magnetite, 2) incipient plagioclase alteration to kaolinite-quartz and 3) advanced plagioclase alteration to sericite-quartz +/- chamosite. In altered quartz diorite and dacite porphyries the association K-feldspar-biotite indicates the highest grade of hydrothermal alteration. Mineralization is ubiquitous. Pyrite, chalcopyrite and bornite occur as thin stringers, disseminations and replacements of original mafic minerals. Throughout the area mineralized outcrops are thoroughly stained with a mixture of secondary limonite-hematite and minor chalcocite-malachite. The strongest mineralized areas correspond with significant soil, rock and stream sediment Cu and Mo Anomalies.

  11. Emeralds in the Eastern Cordillera of Colombia: Two tectonic settings for one mineralization

    NASA Astrophysics Data System (ADS)

    Branquet, Yannick; Laumonier, Bernard; Cheilletz, Alain; Giuliani, Gaston

    1999-07-01

    Colombian emeralds are formed through a hydrothermal-sedimentary process. On the western side of the Eastern Cordillera, the deposits are linked by tear faults and associated thrusts developed during a compressive tectonic phase that occurred at the time of the Eocene-Oligocene boundary, prior to the major uplift of the Cordillera during the Andean phase (middle Miocene). On the eastern side of the Cordillera, emerald mineralization occurred earlier, at the time of the Cretaceous-Tertiary boundary, during a thin-skinned extensional tectonic event linked to evaporite dissolution. This event predates the Andean phase, during which this part of the chain was folded and thrust over the Llanos foreland.

  12. Proglacial Groundwater Flux and Storage in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Chavez, D.; McKenzie, J. M.; Baraer, M.; Mark, B. G.

    2012-12-01

    As tropical glaciers continue to rapidly retreat in the Cordillera Blanca, Peru, dry-season water resources are becoming more dependent on groundwater baseflow. Therefore, understanding the flux and storage of proglacial groundwater is necessary to forecast how groundwater storage can offset decreasing water resources. Recent studies of the Rio Santa Watershed, which drains the western slopes of the Cordillera Blanca, have identified that groundwater is the largest contributor to outflow from many watersheds during the dry season and that the flux of groundwater is temporarily available (< 4years). These groundwater estimates are based on chemical mass balance models that use hydrochemical and isotopic results primarily from surface water samples and stream discharge measurements. Although effective, this approach is limited by the absence of data from proglacial aquifers. In July, 2012, we installed six groundwater monitoring wells to a maximum depth of 6 m in two proglacial valleys in the Cordillera Blanca. For each well, water samples were collected for hydrochemical and isotopic analysis, slug-tests were conducted to measure hydraulic conductivity, and water levels were continuously monitored using pressure transducers. In both valleys we observed an upper layer of clay to silt sized glaciolacustrine material at each drill site. This layer was typically less than 5 m in thickness and had a low hydraulic conductivity (< 10-7 m/s). Underlying the clay layer were water bearing units of course material (either well-sorted sand/gravel or talus deposits) with an average hydraulic conductivity of 10-5 m/s. Additionally numerous discontinuous sand lenses and localized glaciofluvial gravel deposits were observed within the clay layer. The glaciolacustrine deposits behave as confining units that were capable of generating localized artesian conditions in the coarse grain units. The occurrence of the clay units adjacent to the main stream channels suggests that the

  13. Tectonics of the North American Cordillera near the Fortieth Parallel

    USGS Publications Warehouse

    King, P.B.

    1978-01-01

    The North American Cordillera near the Fortieth Parallel consists of the following tectonic units: 1. (A) To the east is a reactivated cratonic area, in the Southern Rocky Mountains and Colorado Plateau, in which the supracrustal rocks (Cambrian to Cretaceous) were broadly deformed during the late Cretaceous-Paleocene Laramide orogeny, and the Precambrian basement was raised in folds of wide amplitude. 2. (B) West of it is a miogeosynclinal belt, in the eastern Great Basin, in which a thick sequence of Paleozoic carbonates and related deposits was thrust eastward along low-angle faults during the middle to late Cretaceous Sevier orogeny. The miogeosyncline is the downwarped western margin of the original North American continent, and its rocks accumulated on Precambrian basement. 3. (C) Beyond is a eugeosynclinal belt, in the western Great Basin, in which Paleozoic graywackes, cherts, and volcanics were thrust easteastward along low-angle faults during several Paleozoic orogenies - the mid-Paleozoic Antler orogeny which produced the Roberts thrust on the east, and the end-Paleozoic Sonoma orogeny which produced the Golconda thrust farther west. The Paleozoic eugeosynclinal rocks accumulated on oceanic basement. They are overlapped from the west by Triassic and Jurassic shelf deposits, which pass westward into eugeosynclinal deposits. 4. (D) A volcanic island-arc belt existed on the sites of the Sierra Nevada in Paleozoic and early Mesozoic time, which produced thick bodies of sediments and volcanics. During the mid-Mesozoic Nevadan orogeny these were steeply deformed and thrust westward over subduction zones, and were intruded by granitic rocks that rose from the upper mantle to form great batholiths. 5. (E) West of the Sierra Nevada, in the Great Valley, is a great sedimentary embankment of later Mesozoic flysch or turbidite, largely younger than the supracrustal rocks of the Sierra Nevada and the Nevadan orogeny. It was formed of the erosional products of the

  14. Large Scale Deformation of the Western U.S. Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2002-01-01

    Over the past couple of years, with support from NASA, we used a large collection of data from GPS, VLBI, SLR, and DORIS networks which span the Western U.S. Cordillera (WUSC) to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work was roughly divided into an analysis of these space geodetic observations to infer the deformation field across and within the entire plate boundary zone, and an investigation of the implications of this deformation field regarding plate boundary dynamics. Following the determination of the first generation WUSC velocity solution, we placed high priority on the dissemination of the velocity estimates. With in-kind support from the Smithsonian Astrophysical Observatory, we constructed a web-site which allows anyone to access the data, and to determine their own velocity reference frame.

  15. Large Scale Deformation of the Western U.S. Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2002-01-01

    Over the past couple of years, with support from NASA, we used a large collection of data from GPS, VLBI, SLR, and DORIS networks which span the Westem U.S. Cordillera (WUSC) to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work was roughly divided into an analysis of these space geodetic observations to infer the deformation field across and within the entire plate boundary zone, and an investigation of the implications of this deformation field regarding plate boundary dynamics. Following the determination of the first generation WUSC velocity solution, we placed high priority on the dissemination of the velocity estimates. With in-kind support from the Smithsonian Astrophysical Observatory, we constructed a web-site which allows anyone to access the data, and to determine their own velocity reference frame.

  16. Large Scale Deformation of the Western US Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2001-01-01

    Destructive earthquakes occur throughout the western US Cordillera (WUSC), not just within the San Andreas fault zone. But because we do not understand the present-day large-scale deformations of the crust throughout the WUSC, our ability to assess the potential for seismic hazards in this region remains severely limited. To address this problem, we are using a large collection of Global Positioning System (GPS) networks which spans the WUSC to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work can roughly be divided into an analysis of the GPS observations to infer the deformation field across and within the entire plate boundary zone and an investigation of the implications of this deformation field regarding plate boundary dynamics.

  17. Pericollisional strike-slip basins in western Cordillera, Canada

    SciTech Connect

    Eisbacher, G.H.

    1984-04-01

    The late Mesozoic-Paleogene evolution of the Canadian Cordillera was dominated by accretion of elongate crustal blocks against the North American craton. Geologic and paleomagnetic evidence suggest that these exotic terranes dispersed from volcanic arcs and oceanic platforms and approached North America along anastomosing right-lateral faults with great cumulative displacement. Obduction of oceanic allochthons was followed by transpressive thickening and regional metamorphism of the cratonic margin in the mid-Jurassic. Strike-slip motion and emplacement of plutonic rocks continued near relict sutures and reactivated deep faults. Sedimentary basins related to strike-slip faults formed by elongation of accreted terranes (''Stikinia'' and ''Wrangellia'') and by shear within the deformed cratonic margin zone (''Rocky Mountain Trench''). Subsidence is reflected by northwest-southeast stretching along pull-apart structures, and by massive influx of turbidites from incipient collision zones and relict are relief. It was interrupted and outlived by rotation of blocks, folding of basin sediments, and vigorous progradation of deltaic-fluvial clastics from rising collision belts. Transition from predominant transtension to prevailing transpression is diachronous from basin to basin. Near the Stikine-Wrangellia collision zone (Bowser basin), it occurred in the Late Jurassic; along the Stikine-Wrangellia border it occurred in the mid to Late Cretaceous. Only small nonmarine basins developed in the Rocky Mountain Trench system, which, in its southern-most part, was closed completely during Paleogene thrust faulting. The strike-slip basins of the western Canadian Cordillera were subject to high regional heat flow and also suffered from widespread intrusion of paleogene granitoids. Therefore, they are generally poor oil and gas prospects.

  18. The Cretaceous stratigraphy of the Western Cordillera Oriental, Columbia

    SciTech Connect

    Allen, R.B.; Alfonso, C.A.; Ressetar, R.; Salazar, A. ); Ballesteros, I.; Cardozo, E.; Laverde, F.; Ramirez, C. ); Moreno, J.M. ); Rubiano, J.; Sarmiento, L. )

    1993-02-01

    During 1987 and 1988, a major field project sponsored by Tenneco was undertaken along the west flank of the Cordillera Oriental of Colombia between Alpujarra (between the Neiva and Girardot Sub-Basins) and the Middle Magdalena Basin (Cimitarra area). An important result of this study was the documentation of pronounced regional variation in the age, thickness, and facies of the Cretaceous section. The maximum thickness estimated was 7 km for the Bogota-Villeta section, with ages as old as Berriasian. This section can be divided into 4 or 5 depositional sequences. A clastic source to the west or southwest is indicated for the lower sequence 1 (and 2 ), an eastern source dominated sequences 3 and 4, and eastern and western sources supplied the upper sequence. Toward the north the section thins to an estimated 3-5 km but still ranges in age throughout the Cretaceous. Southward, on the other hand, the Cretaceous thins to about 2 km and is restricted to Aptian-Albian and younger ages. The variations in ages, facies, and thickness are consistent with recent models of the evolution of the Cretaceous basin. During the Neocomian, the Bogata area formed the main depocenter of the basin and was characterized by restricted facies and turbidites, suggesting steep, possibly faulted basin margins. Facies to the north, near the Middle Magdalena Basin, indicate shallower water, possibly a platform. By the end of the Early Cretaceous, expansion of the marine basin out of the central Cordillera Oriental and regionally more constant facies indicate the onset of dominantly thermal subsidence. The end of the Cretaceous was marked by regression and asymmetric clastic input from east and west of the basin.

  19. The Cordillera Blanca normal fault and its contribution to the Andean topographic evolution (northern Peru)

    NASA Astrophysics Data System (ADS)

    Margirier, Audrey; Robert, Xavier; Schwartz, Stéphane; Audin, Laurence

    2015-04-01

    Nature and localization of Quaternary tectonics remains largely unconstrained in Peruvian Andes as well as the mechanism driving rock uplift. The Cordillera Blanca normal fault accommodates extension in a convergent context. The fault system trends parallel to the subduction zone, just above the Peruvian flat-slab, and separate the Cordilleras Blanca and Negra. The Cordillera Blanca batholith (8-5 Ma) is an elongated pluton, emplaced at ~6 km depth in the Jurassic sedimentary country rocks. The Cordillera Blanca range (6768 m) that comprises the highest Peruvian peak built the footwall of the fault. The ~200 km-long fault has showed ~4500 m of vertical displacement since 5 Ma. This normal fault is described as active despite the lack of historical seismicity and constitutes a striking singularity within the prevailing compressional setting of the Andean orogeny. This region is a perfect target to explore the contribution of large normal fault in relief building. Our goals are to determine if the fault was pre-existing before the Cordillera Blanca batholith emplacement, when it has been reactivated and how does it interact with the batholith exhumation. For that purpose, we focus on brittle deformation analysis from a regional scale (faults trends) to outcrop scale (fault planes, striaes and kinematics). We present here new structural data and focal mechanisms indicating a senestral transtensive component on the Cordillera Blanca normal fault and a regional extensional regime in the Cordillera Negra area. We compare the paleotensors obtained from the inversion of the microstructural data and focal mechanisms with the exhumation history deduced from the thermochronological data to constrain the role of the normal fault in relation with relief building. We propose that the Cordillera Blanca normal fault is an inherited tectonic feature reactivated in transtension after the slab flattening at ~8 Ma. The differential exhumation of the Cordillera Blanca with respect to

  20. Preserved record of initial rifting stages in the Betic collisional orogen (Spain). Palaeogeographic implications for the western Neo-Tethyan domain

    NASA Astrophysics Data System (ADS)

    Martin-Rojas, I.; Somma, R.; Delgado, F.; Estévez, A.; Iannace, A.; Perrone, V.; Zamparelli, V.

    2009-04-01

    The rifting process that lead to continental break-up of the Pangea continent has been well characterised in the Jurassic successions, as the main extension occurred during this time span. However, data from the initial Triassic rifting phases are scarce and based on indirect evidence. Here, we report on a wide range of features preserved in the Internal Zones of the Betic Cordillera collisional orogen (SE Spain): syn-sedimentary normal faults overstepped by younger strata, angular unconformities, slumps, intraformational breccias, pronounced thickness variations of lithological units, mafic igneous intrusions and Mississippi Valley-type ore deposits. Our biostratigraphical data (mainly based on foraminifers, algae and bivalves) allowed us to attribute most of the above-said features to the Ladinian-Carnian transition. We interpret these features as a direct record of the initial Triassic phase of continental rifting, preserved in the stratigraphic record because they were not reactivated during the Alpine orogeny. From a tectonic standpoint the features recorded in the study area appear to point to an active extension context for the Western Mediterranean sector during the Ladinian, as opposed to a sinistral transform proposed in some palaeotectonic models. This extensional area could connect the intracontinental rifts of eastern North America with the western Neo-Tethyan marine domain.

  1. New glaciological research projects in the Cordillera Vilcanota - Cusco - Peru

    NASA Astrophysics Data System (ADS)

    Montoya, Nilton; Molina, Edwin; Schauwecker, Simone; Haeberli, Wilfried; Giraldez, Claudia; Drenkhan, Fabian; Huggel, Christian

    2015-04-01

    Tropical glaciers are highly sensitive to alterations in climate and therefore good indicators for global climate change. Glaciers located in Peru represent 71% of all tropical glaciers in the world, and have shown a significant area reduction of about 43% within the last 40 years mainly due to the increase in surface temperature. Tropical glaciers play a particular role as freshwater reservoirs and buffers to river discharge variability and water scarcity within a pronounced wet and dry season. Their monitoring is extraordinarily important but few studies exist on mass balance. The Cordillera Vilcanota, at the origin of the Rio Vilcanota-Urubamba, contains about 25% of all glaciers in Peru. In recent decades, glacier shrinkage has accelerated in this mountain range. Between 1988 and 2010, glacier area was reduced at an annual rate of about 4 km2 (1.1 %) from some 360 km2 to about 270 km2 (25%). A total volume loss of 40-45% (from 17-20 km3 to 9.2-12.4 km3) can be estimated for the period 1962-2006, with an accelerated rate since the 1980s. In 2010/11, first point net mass balance measurements were carried out on Suyuparina glacier and the adjacent Quisoquipina glacier. In 2013, mass balance measurements were reinitiated in the frame of a long-term monitoring campaign. The first year of direct mass balance measurements (stakes and pits) show that ablation is highly influenced by the complex microtopography of the glacier, mainly characterized by the existence of ice cliffs, causing a spatially heterogeneous ablation pattern. There is a large scatter in point mass balance in function of elevation, which makes it difficult to estimate accurately the equilibrium line altitude (ELA) and the annual total glacier mass balance from these point measurements. For the hydrological year 2013/14, stake measurements for sites on the lower part of the glacier varied between +0.2 and -4 m w.e. (water equivalent), while accumulation in the uppermost part of the glacier showed

  2. Metallogeny of epithermal gold deposits in the western US Cordillera

    SciTech Connect

    Duke, N.A.

    1985-01-01

    The mid-Tertiary sediment-, volcanic-, and detachment fault-hosted epithermal gold deposits (EGDs) of the western US Cordillera favor the outboard side of the tectonically thickened miogeoanticlines. Post Mesozoic accretion, this cratonic shelf-oceanic basin transition zone underwent a period of extensional uplift that thinned the brittle upper crust through listric-normal and detachment faulting, and the decoupled metamorphic infrastructure by ductile necking. The EDGs formed in the upper crust peripheral to tectonically exposed metamorphic core complexes synchronously with active extension. They demonstrate close space/time relationships to the centers of ash flow tuff eruptions that characterized this period. In general the metal concentrated in EDGs had a common source and transport mechanism. The fact that major EGDs occur along obducted oceanic thrust plates indicates that the gold was originally scavaged from oceanic successions during dewatering along the thrust structures. The metal was again mobilized in meteoric dominated hot spring systems operating within volcani-tectonic sinks occurring at ignimbrite eruptive centers. As a result, the siting of both sediment- and volcanic-hosted EGDs is controlled largely by proximity to the mid-Tertiary paleosurface. Specific controls for the precipitation of gold varies with deposit type but critical behavior of the ore-bearing fluid and/or redox reactions between migrating fluids and reduced lithology crosscut by permeable structures are primary.

  3. Paleogene depositional patterns in the Magdalena Valley and Cordillera Oriental: Implications for deformational phases

    SciTech Connect

    Ressetar, R.; Allen, R.B.; Alfonso, C.A. ); Sarmiento, L. ); Ramirez, C.; Laverde, F. )

    1993-02-01

    The Paleogene rocks of the Magdalena Valley and the Cordillera Oriental of Colombia represent the synorogenic sedimentary fill of the ancestral Andean foreland basin. Although detailed correlation of the Paleogene is hampered by poor biostratigraphic control, recent field studies document variations between the Upper and Middle Magdalena Valleys in vertical facies succession and paleocurrent direction, suggesting independent depositional systems separated by the Girardot fold belt. In the northern Upper Magdalena Valley, the Paleogene Gualanday Group lies unconformably to paraconformably on marine Upper Cretaceous and Paleocene rocks. Lower and upperconglomeratic units in the Gualanday Group grade eastward into finer grained fluvial sandstones in the western Cordillera Oriental. North of the Girardot belt, conglomerates occur only in the lower part of the Paleogene and grade northeastward into fluvial sandstones. These unconformably overlie rocks as old as Neocomian in a series of en echelon structures on the west flank of the Cordillera Oriental. The structural trends and thickness of the Cretaceous here suggest inversion of the marine depocenter prior to Paleogene deposition. Previous reports of early Paleogene uplift of the Quetame Massif south of Bogota indicate that similar processes acted elsewhere in the Cordillera Oriental. These studies show that the Cordillera Oriental underwent at least one phase of uplift prior to the main inversion in the Neogene.

  4. Mantle plume influence on the Neogene uplift and extension of the US western Cordillera?

    USGS Publications Warehouse

    Parsons, T.; Thompson, G.A.; Sleep, N.H.

    1994-01-01

    Despite its highly extended and thinned crust, much of the western Cordillera in the United States is elevated more than 1km above sea level. Therefore, this region cannot be thought of as thick crust floating isostatically in a uniform mantle; rather, the lithospheric mantle and/or the upper asthenosphere must vary in thickness or density across the region. Utilizing crustal thickness and density constraints, the residual mass defcicit that must occur in the mantle lithosphere and asthenosphere beneath the western Cordillera was modelled. A major hot spot broke out during a complex series of Cenozoic tectonic events that included lithospheric thickening, back-arc extension, and transition from subduction to a transform plate boundary. It is suggested that many of the characteristics that make the western Cordillera unique among extensional provinces can be attributed to the mantle plume that created the Yellowstone hot spot. -Authors

  5. Structural evolution of the Llanos foothills, Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Martinez, Jaime A.

    2006-09-01

    The Llanos foothills are located in the frontal thrust zone of the Eastern Cordillera in Colombia in a complex environment that BP has been exploring actively since 1988. This exploration has resulted in the discovery of several fields with a variety of hydrocarbon fluids (gas condensate and volatile oil) in very tight quartz-arenites. The structural style and complexity of this fold-and-thrust belt changes along the trend from single frontal structures to an imbricate of up to five thrust sheets in a triangle zone. In highly complex environments, the seismic image quality is poor, and interpretation becomes very challenging. The structural models of the area have evolved as more data have been acquired. The initial structural model required inversion of the basin at the end of the Andean orogeny. The structural style changed to an in-sequence imbricate thrust stack with very long, trailing back limbs that return to regional elevation and finalize in a tighter structures with short back limbs. The concept of early deformation and multiple phases has been introduced. Three main phases have been distinguished: (1) an early event during the deposition of the Lower Carbonera (39-29 Ma), with incipient structures formed to create syntectonic deposition; (2) a phase of steady subsidence that increased notably at the end of the period (29-7 Ma); and (3) the latest phase (7-0 Ma), when most deformation and uplifting occurred. The migration of hydrocarbons happened simultaneously with the deformation, and its final distribution, amount, and variation in composition is related to the structural evolution of the area.

  6. Investigation of a measles outbreak in Cordillera, Northern Philippines, 2013

    PubMed Central

    Zapanta, Ma Justina; de los Reyes, Vikki Carr; Tayag, Enrique; Magpantay, Rio

    2016-01-01

    Introduction Measles is a highly infectious viral illness that remains one of the leading causes of death among children worldwide. In the Philippines, decreasing routine vaccination coverage from 2007 to 2011 led to local measles outbreaks. A team investigated a measles outbreak reported in Cordillera of the Philippines in May 2013. Methods Measles case data with symptom onset from 2 February to 27 May 2013 were obtained from official sources and verified on site. Data included age, sex, residential address, signs and symptoms and vaccination status. Active case-findings were also conducted for contacts of these cases. The living environments of the cases were investigated. A survey was conducted with the cases and caregivers to understand their knowledge and attitudes about measles. Results There were 50 measles cases identified with an age range from six months to 32 years (median: 16 years). Thirty-two were male (64%). Twenty (40%) were hospitalized with one death. Thirty-two (64%) cases were laboratory confirmed, and 36 (72%) received a single dose of measles vaccine. Overcrowded living environments were observed among many cases. The majority of respondents (46/48, 96%) knew about measles, but there were misconceptions about the cause of measles and how it can be prevented and managed. Conclusion This measles outbreak occurred in an area with low immunization coverage. Achieving 95% measles immunization coverage and strengthening routine immunization strategies to address high-risk populations are recommended. Also, we recommend health education campaigns to include components that address misconceptions about measles. PMID:27766180

  7. Coupled measurements of δ18O and δD of hydration water and salinity of fluid inclusions in gypsum from the Messinian Yesares Member, Sorbas Basin (SE Spain)

    NASA Astrophysics Data System (ADS)

    Evans, Nicholas P.; Turchyn, Alexandra V.; Gázquez, Fernando; Bontognali, Tomaso R. R.; Chapman, Hazel J.; Hodell, David A.

    2015-11-01

    We studied one cycle (Cycle 6) of gypsum-marl deposition from the Messinian Yesares Member in Sorbas Basin, Spain. The objective was to reconstruct the changing environment of deposition and its relation to astronomically-forced climate change. The δ18O and δD of gypsum hydration water (CaSO4 • 2H2O) and salinity of fluid inclusions were measured in the same samples to test if they record the composition of the mother fluid from which gypsum was precipitated. Water isotopes are highly correlated with fluid inclusion salinity suggesting the hydration water has not exchanged after formation. The relatively low water isotope values and fluid inclusion salinities indicate a significant influence of meteoric water, whereas δ34S, δ18OSO4 and 87Sr/86Sr support a dominant marine origin for the gypsum deposits. The discrepancy between water and elemental isotope signatures can be reconciled if meteoric water dissolved previously deposited marine sulfates supplying calcium and sulfate ions to the basin which maintained gypsum saturation. This recycling process accounts for the marine δ34S, δ18OSO4 and 87Sr/86Sr signatures, whereas the low δ18O and δD values of gypsum hydration water and fluid inclusion salinities reflect the influence of freshwater. The cyclic deposition of gypsum and marl in the Yesares Member has previously been interpreted to reflect changing climate related to Earth's precession cycle. We demonstrate that the δ18O, δD and salinity of the parent brine increased from low values at the base of the cycle to a maximum in the massive gypsum palisade, and decreased again to lower values in the supercones at the top of the cycle. This pattern, together with changes in mineralogy (calcite-dolomite-gypsum), is consistent with a precession-driven change in climate with wettest conditions (summer insolation maxima) associated with the base of the calcium carbonate marls and driest conditions (summer insolation minima) during formation of the gypsum

  8. Karst evolution in the Cordillera de la Sal (Atacama, Chili)

    NASA Astrophysics Data System (ADS)

    de Waele, J.; Forti, P.; Picotti, V.; Zini, L.; Cucchi, F.; Brook, G.

    2009-04-01

    Rock salt composed of halite is at least three orders of magnitude more soluble than limestone. Because of this very high solubility rock salt rarely crops out extensively at the surface and is readily dissolved leaving insoluble residue (mainly clays and marls). Rock salt can only survive at the surface where climate is extremely arid and normally displays a large set of typical solution morphologies similar to those developed on limestone. Solution of rock salt also leads to the formation of underground caves several km long. Close to the village of San Pedro de Atacama, North of the Salar de Atacama basin, there is an important NNE-SSW trending elongated anticlinal ridge composed of Oligo-Miocene evaporitic rocks known under the name Cordillera de la Sal. The thick salt beds of this ridge, even in this hyperarid climate (mean annual rainfall is below 20 mm/y and there may be no rain for several years), have been karstified by occasional rains and have a well developed surface karst geomorphology with extremely sharp rillenkarren often isolating salt pinnacles of up to 15 m in height. During the past 10 years interesting salt caves have been discovered in these halite beds and a detailed morphological study has been carried out both at the surface and in the most important caves with the aim of understanding the mechanisms responsible for their formation and evolution. Sixteen wood and bone fragments from the ceilings of caves and from diamictons in passages have been AMS radiocarbon dated, allowing us to determine when the cave systems formed and when the major sediment units were emplaced. In fact, cave formation appears to have been very rapid, with development of huge cave passages in salt (more than 10 m wide and 30 m high) in less than 2,000 years. Moreover, detailed surveys of cave morphology (e.g. meanders, erosion benches) and sediments (diamictons) suggest that the caves were formed by short-lived flash floods, probably produced by single extreme

  9. Evaporite deposits of Bogota area, Cordillera Oriental, Colombia

    USGS Publications Warehouse

    McLaughlin, Donald H.

    1972-01-01

    Four evaporite-bearing stratigraphic zones are known in Cretaceous strata of the Cordillera Oriental of Colombia north and east of Bogota. The easternmost and oldest zone is probably of Berriasian to Valanginian age. The next oldest is probably late Barremian to early Aptian in age. The third appears to be Aptian. The westernmost and best known sequence in the Sabana de Bogota is Turonian to early Coniacian in age. This youngest sequence contains the thickest salt deposits known in Colombia and is probably the most widespread geographically. Most of the rock salt exposed in the three accessible mines (at Zipaquira, Nemocon, and Upin) has a characteristic lamination of alternating slightly argillaceous and highly argillaceous salt layers of varied but moderate thickness. Black, calcareous claystone, commonly very pyritic, is interbedded conformably with the laminated salt in many places throughout the deposits. Fragments of black claystone derived from the thinner interbeds are ubiquitous in all deposits, both as concordant breccia zones and as isolated clasts. Anhydrite is scarce at Zipaquira and apparently even rarer at Nemocon and Upin. Gypsum is produced at three small deposits in the oldest evaporite zone where it probably was concentrated by leaching of salt initially associated with it. The two intervening evaporite zones are not exposed, but their existence and distribution are indicated by brine springs and locally by "rute," a distinctive black, calcareous mud formed by the leaching of salt beds. Fossils show that the youngest salt-claystone zone, in the Sabana de Bogota, is contemporary with associated hematitic sandstone and siltstone, and with carbonaceous and locally coaly claystone. Although evidence is poor, this same facies relation probably exists within the other three evaporite zones. All salt deposits in this study probably are associated with anticlines, a relation best exemplified by the deposits on the Sabana de Bogota. Within these

  10. GPS velocities and the construction of the Eastern Cordillera of the Colombian Andes

    NASA Astrophysics Data System (ADS)

    Mora-Páez, Héctor; Mencin, David J.; Molnar, Peter; Diederix, Hans; Cardona-Piedrahita, Leonardo; Peláez-Gaviria, Juan-Ramón; Corchuelo-Cuervo, Yuli

    2016-08-01

    GPS velocities across the northeast trending Eastern Cordillera of Colombia show oblique convergence at 8.8 ± 1.7 mm/yr, consisting of 8.0 ± 1.7 mm/yr of right-lateral strike-slip shear along the mountain range and 3.7 ± 0.3 mm/yr of northwest southeast shortening. Faster convergence occurs only at the northeast end of the Cordillera, where its eastern edge trends northwest and the highest mountains lie. The strike-slip shear corroborates geologic work suggesting such movement southwest and northeast of the range. Given the ~200 km width of the Eastern Cordillera, the ~100-150 km of crustal shortening inferred from balanced cross sections and implied by recent estimates of crustal thickness would require ~25-40 Myr of shortening at ~4 mm/yr. The present-day GPS measurements, therefore, are inconsistent with the inference, based on paleobotanical observations that the entire Eastern Cordillera rose 1500-2500 m since 3-6 Ma and called for a different interpretation of those data.

  11. Gravity sliding, thrusting, and petroleum traps in the Magdalena Basins and Cordillera Orientale, Colombia

    SciTech Connect

    Jones, P.B. )

    1993-02-01

    Major gravity slides on flanks of mountain belts can be misinterpreted as tectonic thrusts. They occur as synclines ([open quotes]fauteuils glisses[close quotes]) striking sub-parallel to dip slopes of major uplifts, overlie low-angle listric thrusts which pass upslope into listric or bedding-parallel normal faults, and may be associated with gravity-driven buried thrust fronts. The Nuevo Mondo syncline, underlain by the La Salinas thrust, and similar synclines along the east side of the Magdalena valley are interpreted as [open quotes]fauteuils glisses[close quotes], whose occurrence at the edge of the Cordillera Orientale creates an illusion of westward thrusting. Minor faults, formerly interpreted as east-dipping reverse faults along the west edge of the Cordillera Orientale are too small to have uplifted the Cordillera or to be correlatable with the major thrusts beneath synclines. They are reinterpreted as major west-dipping parallel faults, pass downslope westward beneath the synclines and/or into blind imbricate thrust structures. The Magdalena basins contain attractive east-verging tectonic thrust traps for hydrocarbons, and less attractive post-tectonic west-verging thrust traps formed by sliding down the east flank of the basin. Interpretation of these structures as post-deformational features allows modeling of the Cordillera Orientale as an overthrust sheet about 10 km thick that moved over 160 km southeastward. Its ramp underlies the east flank of the Magdalena basins. Its buried thrust front marks the edge of the Llanos basin.

  12. Population Declines of Mountain Coqui (Eleutherodactylus portoricensis) in the Cordillera Central of Puerto Rico

    PubMed Central

    Barker, Brittany S.; Ríos-Franceschi, Alejandro

    2014-01-01

    The Mountain Coqui (Eleutherodactylus portoricensis) is a frog endemic to montane rainforests in the Cordillera Central and Luquillo Mountains of Puerto Rico. Classified as endangered by the IUCN Red List and as vulnerable by the Department of Natural and Environmental Resources of Puerto Rico, this species has undergone considerable decline in the Luquillo Mountains. To evaluate the population status of E. portoricensis across its entire range, we conducted ~87 hours of surveys at 18 historical localities and 25 additional localities that we considered suitable for this species. We generated occupancy models to estimate the probability of occurrence at surveyed sites and to identify geographic and climatic factors affecting site occupancy. We also constructed a suitability map to visualize population status in relation to the presence of land cover at elevations where the species has been documented, and determined the dates when populations were last detected at historical localities. Eleutherodactylus portoricensis was detected at 14 of 43 localities, including 10 of 18 historical localities, but it was not detected at any localities west of Aibonito (western Cordillera Central). Occupancy models estimated the probability of occurrence for localities in the western Cordillera Central as zero. Site occupancy was positively associated with montane cloud forest, and negatively associated with the western Cordillera Central, maximum temperature, and precipitation seasonality. The suitability map suggests that declines have occurred despite the presence of suitable habitat. We suggest upgrading the extinction risk of E. portoricensis and potentially developing a captive breeding program for this species. PMID:25685250

  13. Tertiary Basins of Spain

    NASA Astrophysics Data System (ADS)

    Friend, Peter F.; Dabrio, Cristino J.

    1996-01-01

    During the Tertiary, Spain suffered compressional collision between France and Africa, and its Atlantic and Mediterranean coasts have been further modified by extensional rifting. Because it includes sectors of two separate foreland basins, and an intervening craton with basins that have been influenced by extensional and strikeSHslip deformation, Spain provides excellent material for the development and testing of theories on the study of sedimentary basin formation and filling. This book is one of the few studies available in English of the important Tertiary geology of Spain.

  14. Using nanogranite and glassy inclusions to unravel anatexis in the crustal footwall of the Ronda peridotites (Betic Cordillera, S Spain)

    NASA Astrophysics Data System (ADS)

    Bartoli, Omar; Acosta-Vigil, Antonio; Cesare, Bernardo; Remusat, Laurent; Tajčmanová, Lucie; Wälle, Markus; Heinrich, Christoph; Poli, Stefano; Bodnar, Robert J.

    2015-04-01

    The application of melt inclusion (MI) studies to migmatites and granulites is a recent, small-scale approach to a better understanding of melting in the continental crust [1]. Being trapped by growing peritectic phases at suprasolidus conditions, these MI represent a window into the pre-peak anatectic history of partially melted terranes, and may provide a wealth of microstructural and compositional information on crustal anatexis [2, 3, 4]. The crustal footwall of the Ronda peridotites consists of an inverted metamorphic sequence with migmatites and mylonites at the top. Mylonites represent strongly deformed former diatexites. To shed light on the nature and mechanisms of melting in the migmatites of the Ojén traverse, a detailed microstructural and geochemical study has been conducted on primary 2-10 µm MI hosted in peritectic garnet of i) metatexites at the bottom of the migmatitic sequence and ii) mylonitic former diatexites close to the contact with the mantle rocks. Both metatexites and mylonites have compositions corresponding to peraluminous greywackes. Phase equilibria modeling shows P-T conditions of equilibration of 4.5-5 kbar and 660-700 °C, and of 820-830 °C and 5.5-6.0 kbar for metatexites and mylonites, respectively. Clusters of MI in the metatexites are rounded and preferentially located at the core of small garnet crystals, whereas these clusters may have a sigmoidal to spiral-like shape in garnets of mylonites. MI show a variable degree of crystallization ranging from totally glassy to fully crystallized (i.e., nanogranites), consisting of Qtz+Pl+Kfs+Bt+Ms aggregates (often modal Kfs > Pl in mylonites). Piston cylinder remelting experiments led to the complete rehomogenization of nanogranites in metatexites at the conditions inferred for anatexis: 700 °C and 5 kbar. Rehomogenized nanogranites in metatexites and glassy MI in mylonites are all leucogranitic, although generally plot away from minimum melt compositions. Systematic compositional variations have been observed between MI in metatexites and mylonites. MI in metatexites show higher amounts of H2O and Na2O/K2O ratios, lower FeO content, and higher concentrations of those trace elements controlled by feldspars: Sr, Ba. MI in mylonites have higher concentrations of trace elements controlled by Bt (Cs, Rb and FRTE e.g. Zn, Sc) and accessory minerals (HFSE e.g. Zr, U, Th, and LREE). The compositions of MI in metatexites and mylonites are interpreted to record the composition of the anatectic melts produced from a peraluminous greywacke 1) on, and immediately after crossing, the fluid-saturated solidus of this metasedimentary rock, and 2) during syn-kinematic anatexis via biotite dehydration melting at increasing temperature, respectively. [1] Cesare et al. (2009) Geology, 37, 627-630. [2] Bartoli et al. (2013) Geology, 41, 115-118. [3] Bartoli et al. (2014) EPSL, 395, 281-290. [4] Acosta-Vigil et al. (2010) JPetrol 51, 785-821.

  15. Regional Analysis of the Hazard Level of Glacial Lakes in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Chisolm, Rachel E.; Jhon Sanchez Leon, Walter; McKinney, Daene C.; Cochachin Rapre, Alejo

    2016-04-01

    The Cordillera Blanca mountain range is the highest in Peru and contains many of the world's tropical glaciers. This region is severely impacted by climate change causing accelerated glacier retreat. Secondary impacts of climate change on glacier retreat include stress on water resources and the risk of glacial lake outburst floods (GLOFs) from the many lakes that are forming and growing at the base of glaciers. A number of GLOFs originating from lakes in the Cordillera Blanca have occurred over the last century, several of which have had catastrophic impacts on cities and communities downstream. Glaciologists and engineers in Peru have been studying the lakes of the Cordillera Blanca for many years and have identified several lakes that are considered dangerous. However, a systematic analysis of all the lakes in the Cordillera Blanca has never before been attempted. Some methodologies for this type of systematic analysis have been proposed (eg. Emmer and Vilimek 2014; Wang, et al. 2011), but as yet they have only been applied to a few select lakes in the Cordillera Blanca. This study uses remotely sensed data to study all of the lakes of the Glacial Lake Inventory published by the Glaciology and Water Resources Unit of Peru's National Water Authority (UGRH 2011). The objective of this study is to assign a level of potential hazard to each glacial lake in the Cordillera Blanca and to ascertain if any of the lakes beyond those that have already been studied might pose a danger to nearby populations. A number of parameters of analysis, both quantitative and qualitative, have been selected to assess the hazard level of each glacial lake in the Cordillera Blanca using digital elevation models, satellite imagery, and glacier outlines. These parameters are then combined to come up with a preliminary assessment of the hazard level of each lake; the equation weighting each parameter draws on previously published methodologies but is tailored to the regional characteristics

  16. Summary terrane, mineral deposit, and metallogenic belt maps of the Russian Far East, Alaska, and the Canadian Cordillera

    USGS Publications Warehouse

    Nokleberg, Warren J.; West, Timothy D.; Dawson, Kenneth M.; Shpikerman, Vladimir I.; Bundtzen, Thomas K.; Parfenov, Leonid M.; Monger, James W.; Ratkin, Vladimir V.; Baranov, Boris V.; Byalobzhesky, Stanislauv G.; Diggles, Michael F.; Eremin, Roman A.; Fujita, Kazuya; Gordey, Steven P.; Gorodinskiy, Mary E.; Goryachev, Nikolai A.; Feeney, Tracey D.; Frolov, Yuri F.; Grantz, Arthur; Khanchuk, Alexander I.; Koch, Richard D.; Natal'in, Boris A.; Natapov, Lev M.; Norton, Ian O.; Patton, William W.; Plafker, George; Pozdeev, Anany I.; Rozenblum, Ilya S.; Scholl, David W.; Sokolov, Sergei D.; Sosunov, Gleb M.; Stone, David B.; Tabor, Rowland W.; Tsukanov, Nickolai V.; Vallier, Tracy L.

    1998-01-01

    This report is part of a project on the major mineral deposits, metallogenesis, and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. The project is to provide critical information for collaborators and customers on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for the Russian Far East, Alaska, and the Canadian Cordillera.

  17. Timing of hydrocarbon maturation and trap formation in the Cordillera Oriental and adjacent petroleum provinces of Colombia

    SciTech Connect

    Schamel, S.; Richardson, A.; Carlos, A.A.P.

    1996-08-01

    The timing of hydrocarbon generation relative to the closure of migration pathways and trap formation is key to characterization of the petroleum systems of the Cordillera Oriental and the prolific petroleum provinces of the Llanos and Magdalena. The exceptionally thick and organic rich Cretaceous source rock successions of the Cordillera Oriental had the potential to have generated vast quantities of liquid hydrocarbons. Yet due to unfavorable timing of hydrocarbon maturation vs. regional deformation, only a small portion of this oil may have migrated into traps beyond the limits of the Cordillera Oriental. Maturation modeling based on detailed stratigraphic and structural data for sites in the Cordillera Oriental, Llanos, and the Middle and Upper Magdalena basins reveal the essential temporal features of the petroleum system. Virtually all of the Cretaceous source rock succession was generating liquid hydrocarbons in the Late Cretaceous and Paleocene, long before the development of the main structural traps within and along the foothills belts marginal to the Cordillera Oriental. Only in the northeast quarter and extreme south of the Cordillera Oriental and in the deeper parts of the flanking basins was oil being generated simultaneous with trap formation. The maturation modeling serves as a basis for understanding the known distribution of oil pools and a guide to future discoveries.

  18. Basin development and tectonic history of the Llanos Basin, Eastern Cordillera, and Middle Magdalena Valley, Colombia

    SciTech Connect

    Cooper, M.A.; Addison, F.T.; Alvarez, R.

    1995-10-01

    The Middle Magdalena Valley, Eastern Cordillera, and Llanos basin constituted a major regional sedimentary basin from the Triassic to the middle Miocene. Basin development began during the Triassic to the earliest Cretaceous with a synrift megasequence related to the separation of North and South America in the proto-Caribbean. The synrift megasequence began with deposition in a continental environment that became paralic and shallow marine in the Early Cretaceous. Basin development continued into the Cretaceous in a back-arc setting east of the Andean subduction zone. The back-arc megasequence was dominated by shallow-marine sedimentation and produced an excellent regional source rock during the Turonian-Coniacian. Marine deposition was abruptly terminated during the early Maastrichtian due to the final accretion of the Western Cordillera.

  19. Origins and movement of fluids during deformation and metamorphism in the canadian cordillera.

    PubMed

    Nesbitt, B E; Muehlenbachs, K

    1989-08-18

    Stable isotope data from quartz veins in the Canadian Cordillera indicate that crustal fluids were heterogeneous in terms of sources and flow paths during Mesozoic-Cenozoic metamorphism and deformation. In regions of strike-slip and extensional faulting, the fluid regime to depths of at least 15 kilometers was dominated by convected, chemically evolved meteoric water. In contrast, in thrust faulted regions, the fluid regime was dominated by fluids derived from metamorphic devolatilization reactions. Deep convection of meteoric water implies that fluid pressures are hydrostatic in such systems not lithostatic, as had been commonly assumed. The occurrence of significantly lower fluid pressures would necessitate reevaluation of the manner in which metamorphic phase equilibria and stress relations in the crust are modeled. In addition, this study indicates that mesothermal gold deposits in the Canadian Cordillera are a product of the meteoric water convection process.

  20. Spain to Join ESO

    NASA Astrophysics Data System (ADS)

    2006-02-01

    Today, during a ceremony in Madrid, an agreement was signed by the Spanish Minister of Education and Science, Mrs. María Jesús San Segundo, and the ESO Director General, Dr. Catherine Cesarsky, affirming their commitment to securing Spanish membership of ESO. ESO PR Photo 05a/06 ESO PR Photo 05a/06 Signature Event in Madrid Following approval by the Spanish Council of Ministers and the ratification by the Spanish Parliament of the ESO Convention and the associated protocols, Spain intends to become ESO's 12th member state on 1 July 2006. "Since long Spain was aware that entering ESO was a logical decision and it was even necessary for a country like Spain because Spain is ranked 8th in astrophysical research", said Mrs. María Jesús San Segundo. "The large scientific installations are not only necessary for research in different fields but are also partners and customers for hi-tech companies, helping to increase the funding of R&D." "Spanish Astronomy has made tremendous strides forward and we are delighted to welcome Spain as a new member of ESO. We very much look forward to working together with our excellent Spanish colleagues," said Dr. Cesarsky. "For ESO, the Spanish accession means that we can draw on the scientific and technological competences, some of them unique in Europe, that have been developed in Spain and, of course, for Europe the Spanish membership of ESO is an important milestone in the construction of the European Research Area." ESO PR Photo 05b/06 ESO PR Photo 05b/06 Signature Event in Madrid Indeed, Spain is an important member of the European astronomical community and has developed impressively over the last three decades, reaching maturity with major contributions in virtually all subjects of astronomy. In addition, Spain hosts, operates or owns a number of competitive facilities dedicated to foster astronomical research, among which the Observatorio del Roque de los Muchachos at La Palma, certainly the premier optical

  1. Lithospheric structure of the Yukon, northern Canadian Cordillera, obtained from magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Ledo, Juanjo; Jones, Alan G.; Ferguson, Ian J.; Wolynec, Lisa

    2004-04-01

    Two goals of Lithoprobe's geoscientific studies in the Phanerozoic accretionary cordillera of western North America were to define the subsurface geometries of the terranes and to infer the physical conditions of the crust. These questions were addressed in Canada's southern cordillera a decade ago and have more recently been addressed in the northern cordillera, of which one component of the new studies is magnetotelluric (MT) profiling from ancestral North American rocks to the coast. We present a resistivity cross section, and its interpretation, of the northern cordillera derived from modeling data from 42 MT sites along a 470-km-long NE-SW profile. Beneath the Coast Belt (southwestern end of the profile) a deep crustal low-resistivity layer dips inland; we interpret the crustal part of this conductor as being due to metasedimentary rocks emplaced and metamorphosed during Paleocene Kula plate subduction. A strong lateral transition in lithospheric mantle resistivity exists below the Intermontane Belt that is spatially coincident with changes in chemical and isotopic characteristics of Tertiary to recent alkaline lavas, suggesting that isotopically enriched lithosphere related to the Coast Belt basalts extends partly beneath the Intermontane Belt. The unusually high lower crustal resistivity in the Intermontane and Omineca Belts, similar in value to the resistivity found in the unextended part of central British Columbia, excludes the presence of fluids or conducting metasediments. Finally, our resistivity model displays strong lateral variation of the middle and lower crust between different terranes within the same belt, as a result of the complex structural evolution of the lithosphere.

  2. The basement of the Eastern Cordillera, Colombia: An allochthonous terrane in northwestern South America

    NASA Astrophysics Data System (ADS)

    Forero Suarez, A.

    The fault system of the Borde Llanero of Colombia represents the limit between two early Paleozoic geologic provinces: the Guiana Shield (Gondwana) to the east, and an allochthonous terrane — formerly a piece of the North American continent — to the west. The Baudó Range, the Western Cordillera, and the western flank of the Central Cordillera are the result of post-Jurassic accretion. In contrast the pre-Emsian metamorphic rocks of the eastern flank of the Central Cordillera, of the Eastern Cordillera of Colombia, and of the Mérida Andes correspond to an allochthonous terrane that was accreted to the north-western continental border of South America during the collision between North America and Gondwana in Silurian-Early Devonian times. Geochronologic and petrographic data indicate the presence of the Grenvillian granulite belt, represented by the Garzón-Sierra Nevada de Santa Marta belt. This belt is separated from the Guiana Shield by a magmatic tract which is parallel to the Borde Llanero of Venezuela and Colombia. The late Paleozoic regional metamorphism in the Northern Andes of Colombia occurred during Late Silurian-Early Devonian times. Since the late Emsian, a sedimentary cycle was initiated on this allochthonous basement. The faunal records of northwestern South America and the North American continent are indistinguishable for that time. This similarity clearly shows that both northwestern South America and the North American regions of the Appalachians and New Mexico belong to the same paleobiogeographic province. The faunal communication in this case supports the idea of the immediate neighborhood of the two continents.

  3. The Columbia Plateau Revealed; Low Temperature Thermochronology Across the Canadian Cordillera and Links to Lithospheric Delamination.

    NASA Astrophysics Data System (ADS)

    Guest, B.; Bacque, D.; Miles, N.; Stockli, D. F.

    2014-12-01

    Active deformation and mountain building in the Canadian Cordillera ceased in the Paleogene, a period during which this orogen was among the highest on earth. The present morphology, relief and altitude of the mountains and the foothills in the adjacent foreland belt are the result of a feedback relationship between erosion and isostatic compensation. Our low temperature thermochronology data (U-Th/He ages on zircon and apatite) were collected from 5 sample-transects spanning the Intermontane, Omineca, Foreland, and Foothills belts along a Jasper-Vancouver transect. The data show rapid cooling (>15℃/Ma) from >180℃ to <70℃ in the interior belts to the west of the Rocky Mountain Trench (RMT) during the Eocene (56 - 33 Ma). In the Foreland and Foothills belts to the east of the RMT the data show modest cooling (~4℃/Ma) during the latest Cretaceous to Early Eocene (~80Ma - 55 Ma) followed by rapid cooling (~15℃/Ma) between ~55 Ma and ~45 Ma transitioning to slower cooling (~1℃/Ma) after 45 Ma. This cooling pattern is consistent with rapid regional uplift and exhumation across the interior belts of the Cordillera during a regional transition from contraction to extension in the early to middle Eocene. At the same time in the Foreland and Foothills belts, during a period of accelerated cooling, contraction was continuing. The combination of rapid exhumation and extension in the interior belts and rapid exhumation and contraction in the Foreland and Foothills belts is similar to what is observed around the Altiplano and Tibetan plateaus. This suggests that the Canadian Cordillera is a fossil plateau (Columbia Plateau) that formed in the Eocene. The lack of a mantle lithosphere beneath the interior belts of the Canadian Cordillera (west of the RMT) and the regional extent of rapid exhumation suggests that the Columbia Plateau formed in response to a large-scale lithosphere removal event; possibly wholesale delamination.

  4. Source terrains and diagenetic imprints of Cretaceous marine rocks of the Cordillera Oriental, Colombia

    SciTech Connect

    Segall, M.P.; Allen, R.B. ); Rubiano, J.; Sarmiento, L. )

    1993-02-01

    Cretaceous marine rocks of the western Cordillera Oriental of Colombia are exposed in stratigraphic sections which reveal multiple source terrains and variable diagenetic histories that were imposed by later thrusting XRD and petrographic analyses indicate that earliest Cretaceous rocks were derived from a nearly plutonic source (Triassic-Jurassic Ibague Batholith of the Cordillera Central) which provided feldspathic lithic fragments and clay-sized illite. High smectite concentrations in the overlying Hauterivian-Barremian strata reflect contemporaneous volcanism, possibly in the Cordillera Central. This signal decreased upsection to the upper Aptian, where detrital clays (kaolinite, chlorite, feldspar, amphibole) indicate a shift to a cratonic source, probably the Guayana Shield. Cratonic detrital input continues into the Turonian-Coniacian and is accompanies by high concentrations of smectite representing another period of volcanic activity. Later tectonic activity divided the area into two regions, each with unique diagenetic signatures. Three primary clastic sources are inferred for the section east of the thrust belt, however, the mineral assemblage is masked by later diagenesis. Sediments within the thrust belt show greater variability in the relative abundance of mineral assemblages and more poorly crystallized illite than occurs to the east of the thrust section. The preservation of much of the original mineralogic components within the thrust section indicates that these sediments have experienced only limited diagenetic overprinting as a result of a relatively short burial history. These contrasting signatures have important implications for hydrocarbon maturation within Cretaceous source rocks in a structurally complex region.

  5. Age of anatexis in the crustal footwall of the Ronda peridotites, S Spain

    NASA Astrophysics Data System (ADS)

    Acosta-Vigil, Antonio; Rubatto, Daniela; Bartoli, Omar; Cesare, Bernardo; Meli, Sandro; Pedrera, Antonio; Azor, Antonio; Tajčmanová, Lucie

    2014-12-01

    This study investigates the age of anatexis of a crustal sequence constituting the footwall of the Ronda peridotite slab, in the hinterland of the Betic Cordillera (S Spain, region of Istán). These rocks represent a polymetamorphic basement involved in the Alpine orogeny and show an increase in the proportion of melt towards the peridotites. Metamorphic conditions in the migmatites vary between T ≈ 675-750 °C at P ≈ 0.30-0.35 GPa. The timing of metamorphism and deformation of the migmatites around the Ronda peridotites is controversial and has been previously ascribed to either the Alpine or Variscan orogenies. We present U-Pb SHRIMP dating of zircons from six samples collected across the migmatitic sequence that provide a tighter age constraint on the metamorphism. Zircon ages are related to conditions of metamorphism on the basis of the relationships between zircon microstructures and degree of melting recorded by the host rocks. Anatexis occurred during the late stages of the Variscan orogeny (≈ 280-290 Ma), as indicated by ages of euhedral, oscillatory-zoned domains or new crystals in metatexites and diatexites. Thin, U-rich zircon rims that are affected by radiation damage yield discordant scattered dates between ≈ 260 and 30 Ma, which are interpreted as reflecting a thermal and fluid overprint during the Alpine orogeny that produced recrystallization and Pb loss in Permian zircons. This study identifies a previously unknown Variscan domain within the Betic Cordillera, and indicates, in accordance with previous studies, that Variscan basements recycled during the Alpine orogeny that formed the Betic Cordillera preserve pre-Alpine mineral associations and tectonic fabrics.

  6. [El Laboratorio Foster de la Residencia de Señoritas. Las relaciones de la JAE con el International Institute for Girls in Spain, y la formación de las jóvenes científicas españolas].

    PubMed

    Portolés, Carmen Magallón

    2007-01-01

    In the first third of the twentieth century, relations among American and Spanish university women began; particularly the relationship between the JAE and the International Institute for Girls in Spain had a positive influence in the education of women scientists in Spain. An interchange of students and teachers came out from this relationship, and Spanish women received scholarships to stay in American universities. The history of the Foster Laboratory and some biographical notes of her founder are included in the paper. PMID:19845046

  7. [El Laboratorio Foster de la Residencia de Señoritas. Las relaciones de la JAE con el International Institute for Girls in Spain, y la formación de las jóvenes científicas españolas].

    PubMed

    Portolés, Carmen Magallón

    2007-01-01

    In the first third of the twentieth century, relations among American and Spanish university women began; particularly the relationship between the JAE and the International Institute for Girls in Spain had a positive influence in the education of women scientists in Spain. An interchange of students and teachers came out from this relationship, and Spanish women received scholarships to stay in American universities. The history of the Foster Laboratory and some biographical notes of her founder are included in the paper.

  8. Test Reviewing in Spain

    ERIC Educational Resources Information Center

    Muniz, Jose; Fernandez-Hermida, Jose R.; Fonseca-Pedrero, Eduardo; Campillo-Alvarez, Angela; Pena-Suarez, Elsa

    2012-01-01

    The proper use of psychological tests requires that the measurement instruments have adequate psychometric properties, such as reliability and validity, and that the professionals who use the instruments have the necessary expertise. In this article, we present the first review of tests published in Spain, carried out with an assessment model…

  9. Supported Employment in Spain.

    ERIC Educational Resources Information Center

    Verdugo, Miguel Angel; Borja, F.; de Urries, Jordan; Bellver, Fernando; Martinez, Salvador

    1998-01-01

    Supported employment is growing in Spain, assisted by models from other countries and national legislation. The Spanish Association of Supported Employment is providing a framework for program development. The field must deal with the lack of systematic evaluation and with funding problems. (SK)

  10. Career Development in Spain.

    ERIC Educational Resources Information Center

    Talavera, Elvira Repetto; Moreno, Luisa Rodriguez; Romeo, Javier; Malik, Beatriz

    In Spain, the term "career development" refers to vocational or career guidance services. The 1983 Law on University Reform conferred on universities the freedom of teaching, endowing them with legal status and administrative powers. Thus, there are no regulations regarding guidance at this educational level. Guidance departments in secondary…

  11. [Fertility decline in Spain].

    PubMed

    Arango, J

    1987-01-01

    The historical processes of secular fertility decline in Spain and Portugal are not well understood. Very few microdemographic studies of small geographic regions or particular social strata have been done. A contribution by David Reher to the First Spanish-Portuguese-Italian Historical Demography Conference on the fertility decline in the interior province of Cuenca, Spain, uses the own-children method to analyze changes in marital fertility in the 19th and 20th centuries. Reher discovered a slight fertility decline of perhaps 15% which occurred between the end of the 18th century and 1860-75. The fertility decline did not resume until after the Spanish Civil War, and then it was a very gradual and continuous process. When instead of the total female population, women aged 35-39 were studied, unequivocal signs of fertility control appeared. Conscious fertility control thus appears to have begun among older women limiting rather than spacing births. Reher's analysis by social groups demonstrates that fertility declined first and more rapidly in the nonagricultural and urban populations and among the higher income groups. The fertility decline in Cuenca was certainly not identical to that in most of Spain, but may have been fairly typical of a large part of the interior. Another contribution to the Historical Demography Conference, by Anna Cabre and Isabel Pujadas, analyzes fertility trends and cyclical fluctuations in 20th century Cataluna, arguing that they must be placed in historical perspective if recent changes are to be understood and plausible projections made. Their work demonstrates the value of selecting a relatively homogeneous geographic unit for analysis. The contribution of Margarita Delgado to the conference analyzed interregional fertility differences in contemporary Spain. The high legitimate fertility of the south of Spain is accentuated by high nuptiality rates. In central Spain, the combination of high legitimate fertility rates and low

  12. Alternative models for Late Jurassic and Early Cretaceous paleogeography of the western Cordillera, California to SE Alaska

    SciTech Connect

    Cowan, D.S. . Geological Sciences)

    1993-04-01

    The Franciscan-Great Valley-Sierran triad is indisputable evidence for late Mesozoic, west-facing subduction along the California sector of the N. American margin. In the northwestern sector (N of 48[degree]N), however, neither the configuration of plate boundaries, nor the paleogeographic disposition of the Insular and Intermontane superterranes, is confidently established. Models divide into two groups. One set, based entirely on geologic evidence such as the age and nature of deformational events, or putative stratigraphic links among terranes, places the two superterranes exclusively to the north of the Franciscan-Sierran system from 150 to 90 Ma. These hypotheses, which ignore or reject paleomagnetic data from mid-Cretaceous rocks, yield a paleogeography not too different from today's, but they are incompatible with the Franciscan and Great Valley rocks caught between the superterranes in the mid-Cretaceous San Juan-Cascade thrust system. An alternative model fully respecting paleomagnetic data from mid-Cretaceous rocks with paleohorizontal control restores most of the Intermontane superterrane [approximately]1,200 km south of its expected (i.e. present) latitudinal position with respect to North America, and the Insular superterrane [approximately]2,900 km south, at 95--105 Ma. The mid-Cretaceous thrust system along the eastern margin of the Insular superterrane records the collision of Wrangellia et al. with the southern continuation of the Franciscan subduction zone. The thrust system, a silver of hanging wall, and the Insular superterrane were all subsequently translated > 2,500 km northward by post-80, pre-60 Ma coast-parallel dextral slip, accommodated on the proto-Pasayten and proto-Yalakom faults, and along or near the Coast Range shear zone.

  13. El uso periodistico de las formas -ra y -se del imperfecto de subjunctivo. (The Use and Frequency of the -ra and -se Forms of the Imperfect Subjunctive.)

    ERIC Educational Resources Information Center

    Rodriguez-Ford, Pilar; Georgalas, Sotiri

    1983-01-01

    Results of a statistical study of the two imperfect subjunctive endings in Spanish and Latin American journalism show the use of "-se" to be decreasing, although usage is slightly higher in Spain. Use of the imperfect subjuntive with an indicative meaning is also slightly more common in Spain. (MSE)

  14. The asymmetric evolution of the Colombian Eastern Cordillera. Tectonic inheritance or climatic forcing? New evidence from thermochronology and sedimentology

    NASA Astrophysics Data System (ADS)

    Ramirez-Arias, Juan Carlos; Mora, Andrés; Rubiano, Jorge; Duddy, Ian; Parra, Mauricio; Moreno, Nestor; Stockli, Daniel; Casallas, Wilson

    2012-11-01

    New thermochronological data, facies, paleocurrents and provenance allow us to refine the chronology of deformation in the central segment of the Colombian Eastern Cordillera. Based on a new extensive AFT dataset, we document the spatial evolution of active deformation, from the axial zone of the Eastern Cordillera at about 50 Ma in to active growth of the frontal thin skinned structures in Late Miocene time. Paleocurrents allow us to push backwards into the Middle to Early Late-Miocene the emergence of the easternmost frontal thrust; whereas careful assessment of exposure gates tied to AFT data enable to refine the unroofing history for Eocene to Miocene times. Based on that, we produced a kinematically restored cross section with higher resolution than previous assessments. Using these datasets, we compare the evolution of the central segment of the Eastern Cordillera in this region with the evolution of adjacent areas in the context of climatic forcing of orogenic evolution. We find that in this region and, in the Eastern Cordillera in general, tectonic inheritance and transpression exert an initial dominant control on the initial orogen asymmetry, which is later enhanced due to an orographically-focused erosion. We therefore suggest that it is not climate alone the factor controlling orogenic asymmetry in the Eastern Cordillera of Colombia.

  15. Occupational cancer in Spain.

    PubMed Central

    González, C A; Agudo, A

    1999-01-01

    The knowledge of specific problems of occupational cancer in Spain is scarce. The environment of the workplace has improved over the last few years after a long period distinguished by bad working conditions, incomplete legislation, and insufficient safety measures and control. It has been estimated that 3,083,479 workers (25.4% of employees) were exposed to carcinogens. The most common occupational exposures to carcinogenic agents were solar radiation, environmental tobacco smoke, silica, and wood dust. The highest number of employees were exposed to silica crystalline (404,729), diesel engine exhaust (274,321), rubber products (99,804), benzene (89,932), ethylene dibromide (81,336), agents used in furniture and cabinet making (72,068), and formaldehyde (71,189). The percentage of total cancer deaths attributed to occupational exposure was 4% (6% in men, 0.9% in women). Compared with other European countries, the incidence of lung cancer and leukemia in Spain are one of the lowest, but it is rapidly increasing. The incidence of urinary bladder and larynx cancer, on the contrary, are one of the highest. Few studies on occupational cancer have been conducted in Spain. The main problems are the availability of death certificates and the quality of the information on occupation in mortality of statistics. It is necessary to improve methods of assessment of exposures using expert hygienists and biologic markers of exposure and diseases. Reduction of cancer by limiting or avoiding exposure to known occupational carcinogens is still necessary. PMID:10350510

  16. Resolving the tectonic transition between ancestral North America and the northern Cordillera

    NASA Astrophysics Data System (ADS)

    Schaeffer, A. J.; Audet, P.; Lebedev, S.

    2015-12-01

    The northern Cordillera, situated in the Canadian northwest, is one of the most actively deforming regions in Canada and host to the highest earthquake activity in the country. Furthermore, it presents a largely contiguous snapshot through almost 4 Gyr of Earth's history across a zone <2000 km in linear extent. Deformation is thought to be driven by tectonic forces transferred from the Alaska-Pacific plate collision eastwards to the Cordilleran Deformation Front (CDF), where the westward edge of the Canadian Shield acts as a rigid backstop. Past studies in the southern Yukon indicate a sharp transition into the craton underlying the CDF and evidence of craton growth through shallow subduction. Further north the proximity of the craton edge to the CDF remains largely unresolved; based on studies of the southern Cordillera and Alaska, significant variations in lithospheric architecture are expected. Additionally, significant seismicity is observed further north off the Beaufort Shelf; however, its relationship to the regional stress fields and associated tectonic forcing is unclear. Despite the high seismicity levels across, detailed study of this region has been limited by insufficient coverage of seismological infrastructure, hindering resolution in past models. With the deployment of the USArray Transportable Array in Alaska over the last several years, combined with regional arrays such as the Yukon-Northwest Seismic Network (YNSN), Banks Island Seismic Network (BISN) and Mackenzie Mountains Experiment, new studies will leverage these datasets enabling more detailed imaging of the structure and seismicity across the region. Here we present a new high-resolution, vertically polarized shear speed and azimuthal model of northwestern Canada and Alaska, constrained by vertical component seismogram fits computed using the Automated Multimode Inversion of Surface, S, and multiple-S waveforms. With this new model, we aim to address key questions relating to the dynamics

  17. Lithofacies control in detrital zircon provenance studies: Insights from the Cretaceous Methow basin, southern Canadian Cordillera

    USGS Publications Warehouse

    DeGraaff-Surpless, K.; Mahoney, J.B.; Wooden, J.L.; McWilliams, M.O.

    2003-01-01

    High-frequency sampling for detrital zircon analysis can provide a detailed record of fine-scale basin evolution by revealing the temporal and spatial variability of detrital zircon ages within clastic sedimentary successions. This investigation employed detailed sampling of two sedimentary successions in the Methow/Methow-Tyaughton basin of the southern Canadian Cordillera to characterize the heterogeneity of detrital zircon signatures within single lithofacies and assess the applicability of detrital zircon analysis in distinguishing fine-scale provenance changes not apparent in lithologic analysis of the strata. The Methow/Methow-Tyaughton basin contains two distinct stratigraphic sequences of middle Albian to Santonian clastic sedimentary rocks: submarine-fan deposits of the Harts Pass Formation/Jackass Mountain Group and fluvial deposits of the Winthrop Formation. Although both stratigraphic sequences displayed consistent ranges in detrital zircon ages on a broad scale, detailed sampling within each succession revealed heterogeneity in the detrital zircon age distributions that was systematic and predictable in the turbidite succession but unpredictable in the fluvial succession. These results suggest that a high-density sampling approach permits interpretation of finescale changes within a lithologically uniform turbiditic sedimentary succession, but heterogeneity within fluvial systems may be too large and unpredictable to permit accurate fine-scale characterization of the evolution of source regions. The robust composite detrital zircon age signature developed for these two successions permits comparison of the Methow/Methow-Tyaughton basin age signature with known plutonic source-rock ages from major plutonic belts throughout the Cretaceous North American margin. The Methow/Methow-Tyaughton basin detrital zircon age signature matches best with source regions in the southern Canadian Cordillera, requiring that the basin developed in close proximity to the

  18. Isotopic evolution of the idaho batholith and Challis intrusive province, Northern US Cordillera

    USGS Publications Warehouse

    Gaschnig, R.M.; Vervoort, J.D.; Lewis, R.S.; Tikoff, B.

    2011-01-01

    The Idaho batholith and spatially overlapping Challis intrusive province in the North American Cordillera have a history of magmatism spanning some 55 Myr. New isotopic data from the ???98 Ma to 54 Ma Idaho batholith and ???51 Ma to 43 Ma Challis intrusions, coupled with recent geochronological work, provide insights into the evolution of magmatism in the Idaho segment of the Cordillera. Nd and Hf isotopes show clear shifts towards more evolved compositions through the batholith's history and Pb isotopes define distinct fields correlative with the different age and compositionally defined suites of the batholith, whereas the Sr isotopic compositions of the various suites largely overlap. The subsequent Challis magmatism shows the full range of isotopic compositions seen in the batholith. These data suggest that the early suites of metaluminous magmatism (98-87 Ma) represent crust-mantle hybrids. Subsequent voluminous Atlanta peraluminous suite magmatism (83-67 Ma) results primarily from melting of different crustal components. This can be attributed to crustal thickening, resulting from either subduction processes or an outboard terrane collision. A later, smaller crustal melting episode, in the northern Idaho batholith, resulted in the Bitterroot peraluminous suite (66-54 Ma) and tapped different crustal sources. Subsequent Challis magmatism was derived from both crust and mantle sources and corresponds to extensional collapse of the over-thickened crust. ?? The Author 2011. Published by Oxford University Press. All rights reserved.

  19. Centennial-scale dynamics of glacier changes and stream flow in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Huh, K.; Mark, B. G.; Baraer, M.; Fernandez, A.; Ahn, Y.

    2013-12-01

    Evaluating the historical contribution of the volume loss of ice to stream flow based on reconstructed volume changes back to the Little Ice Age (LIA) can be directly connected to the understanding of glacier-hydrology in current epoch of rapid glacier loss as a water resource in the Cordillera Blanca in the Peruvian Andes. Modeling LIA paleoglaciers, with the most extensive recent period of mountain glacier expansion, in different catchments of the Cordillera Blanca allows us to evaluate likely combinations of climatic control variables as well as variation by aspect and slope. We compute the rate and magnitude of centennial-scale glacier volume changes for glacier surfaces between LIA and modern defined by 2008 Light Detection and Range (LiDAR) data. Also, we employ a recently demonstrated approach (Baraer et al., 2012) to calculate glacier contribution to meltwater runoff as a function of glacier loss rate in the selected catchments, and effectively reconstruct long-term glacier significance to stream flow.

  20. Neoglaciation and climate change recorded in sediments from Lake Lutacocha in the Cordillera Raura, Peru

    NASA Astrophysics Data System (ADS)

    Stansell, N.; Abbott, M.; Rodbell, D. T.

    2009-12-01

    Radiocarbon dated lake sediments were used to identify neoglacial advances in the Cordillera Raura (10°S) of Peru. Sediments were measured using scanning X-ray fluorescence for bulk sediment geochemistry, and coulometry for organic carbon and calcium carbonate content. Terrigenous sediments were fingerprinted by comparing the geochemistry of bulk sediment with that of bedrock and till samples collected within the watershed. Higher terrigenous input is interpreted as coinciding with a change in sediment source and increased ice cover relative to modern from ~3100 to 2400, 1700 to 1100 and 800 to 150 cal yr BP. The long-term, Holocene pattern of glaciations in the Cordillera Raura was probably driven by changes in moisture availability, and the short-term ice advances that punctuate the record were likely enhanced by cooling events. The peak neoglacial advance in the Lutacocha watershed occurred at ~ 300 cal yr BP, during the Little Ice Age (LIA), when equilibrium-line altitudes (ELAs) were 190 m lower, conditions were wetter and temperature was ~1.1 ±0.2°C colder than modern.

  1. Normal faulting origin for the Cordillera and Outer Rook Rings of Orientale Basin, the Moon

    NASA Astrophysics Data System (ADS)

    Nahm, Amanda L.; Öhman, Teemu; Kring, David A.

    2013-02-01

    Orientale Basin is the youngest and best-preserved large impact basin on the Moon with at least four topographic rings contained within the topographic rim marked by the Cordillera Ring (diameter = 930 km). Its well-exposed interior makes this basin a prime location to study basin formation processes. Forward mechanical modeling of basin ring topography shows that the outermost rings, the Cordillera Ring (CR) and Outer Rook Ring (ORR) are large-scale normal faults with displacements (D) of 0.8 to 5.2 km, fault dip angles (δ) of 54° to 80°, and vertical depth of faulting (T) between 19 and 37 km with most faults having T = 30 ± 5 km. These faults and the distribution of maria inside the basin suggest that the transient crater, important for determining many impact-related characteristics such as projectile size, was contained entirely within the ORR and likely had a diameter between 500 and 550 km. The difference in crustal thickness between the western and eastern sides of the basin is not a result of the basin-forming event, which indicates the formation of the hemispheric crustal thickness asymmetry was likely before the formation of Orientale Basin 3.68 to 3.85 Ga.

  2. New isotopic ages and the timing of orogenic events in the Cordillera Darwin, southernmost Chilean Andes

    NASA Astrophysics Data System (ADS)

    Hervé, F.; Nelson, E.; Kawashita, K.; Suárez, M.

    1981-10-01

    The Cordillera Darwin, a structural culmination in the Andes of Tierra del Fuego, exposes an orogenic core zone that has undergone polyphase deformation and metamorphism. Some of the classic problems of orogenic zones have remained unanswered in the Cordillera Darwin: the age of deformed plutonic rocks, the distinction of structurally reactivated basement and metamorphosed cover rocks, and the timing of orogenic events. This study addresses and partially answers these questions. A well-constrained Rb-Sr isochron age of157±8m.y. and an initial 87Sr/ 86Sr ratio of 0.7087 obtained from a pre-tectonic granitic suite suggest a genetic relation between this suite and Upper Jurassic silicic volcanic rocks in the cover sequence (Tobifera Formation), and also suggest involvement of continental crust in formation of these magmas. A poorly constrained Rb-Sr isochron age of240±40m.y. obtained from supposed basement schists is consistent with field relations in the area which suggest a late Paleozoic/early Mesozoic metamorphism for these pre-Late Jurassic rocks. However, because of scatter in the data and the uncertainties involved in dating metasedimentary rocks, the significance of the isotopic age is dubious. Compilation of previously published ages in the area [9] with new mineral ages reported here indicate that "early Andean" orogenic events occurred between 100 and 84 m.y. ago, and that subduction-related magmatism has contributed, probably discontinuously, to the crustal evolution of the region throughout the Mesozoic.

  3. Subduction system and flat slab beneath the Eastern Cordillera of Colombia

    NASA Astrophysics Data System (ADS)

    Chiarabba, Claudio; De Gori, Pasquale; Faccenna, Claudio; Speranza, Fabio; Seccia, Danilo; Dionicio, Viviana; Prieto, Germán. A.

    2016-01-01

    Seismicity at the northern terminus of the Nazca subduction is diffused over a wide area containing the puzzling seismic feature known as the Bucaramanga nest. We relocate about 5000 earthquakes recorded by the Colombian national seismic network and produce the first 3-D velocity model of the area to define the geometry of the lithosphere subducting below the Colombian Andes. We found lateral velocity heterogeneities and an abrupt offset of the Wadati-Benioff zone at 5°N indicating that the Nazca plate is segmented by an E-W slab tear, that separates a steeper Nazca segment to the south from a flat subduction to the north. The flat Nazca slab extends eastward for about 400 km, before dip increases to ˜50° beneath the Eastern Cordillera, where it yields the Bucaramanga nest. We explain this puzzling locus of intermediate-depth seismicity located beneath the Eastern Cordillera of Colombia as due to a massive dehydration and eclogitization of a thickened oceanic crust. We relate the flat subducting geometry to the entrance at the trench at ca. 10 Ma of a thick - buoyant oceanic crust, likely a volcanic ridge, producing a high coupling with the overriding plate. Sub-horizontal plate subduction is consistent with the abrupt disappearance of volcanism in the Andes of South America at latitudes > 5°N.

  4. Liver transplantation in Spain.

    PubMed

    de la Rosa, Gloria; Fondevila, Constantino; Navasa, Miquel

    2016-09-01

    Liver transplantation (LT) activity started in Spain in 1984 and has exceeded 23,700 interventions, with more than 1000 transplants performed yearly. Every hospital needs official authorization to perform a LT, which implies the obligation to register all patients on the national waiting list. The Spanish National Transplant Organization (ONT) provides essential support for organ procurement, allocation, and management of the waiting list at a national level. Liver allocation is center-oriented as all available organs are referred to the ONT for the whole country. The allocation rules for LT are made according to disease severity after consensus among professionals from every transplant center and ratified by representatives of the regional health authorities. Authorization and location/distribution of transplant centers are regulated by the country (Spain) and by the different regions according to the Real Decreto 1723/2012. For a total population of 47,850,795 inhabitants, there are 24 centers for LT for adults (1 team/2 million people) and 5 for LT for children (1 team/9.5 million people). Nonbiliary cirrhosis, particularly alcohol- and hepatitis C virus-related cirrhosis (60%), and tumors, mainly hepatocellular carcinoma (19%), are the most common indications for LT in Spain. Unusual causes of LT include metabolic diseases like Wilson's disease, familial amyloid polyneuropathy and hyperoxaluria type I, polycystic kidney and liver disease, and some tumors (epithelioid hemangioendothelioma and neuroendocrine tumors). Important efforts are now being undertaken to improve the quality and transplantability of extended criteria livers, in particular those arising from DCD, which represent the greatest opportunity to expand the donor pool. These efforts have to be addressed to adapt the organ preservation procedures, be it through the application of regional perfusion in situ or the use of machine perfusion preservation ex situ. Liver Transplantation 22 1259-1264 2016

  5. Mesozoic transtensional basin history of the Eastern Cordillera, Colombian Andes: Inferences from tectonic models

    NASA Astrophysics Data System (ADS)

    Sarmiento-Rojas, L. F.; Van Wess, J. D.; Cloetingh, S.

    2006-09-01

    Backstripping analysis and forward modeling of 162 stratigraphic columns and wells of the Eastern Cordillera (EC), Llanos, and Magdalena Valley shows the Mesozoic Colombian Basin is marked by five lithosphere stretching pulses. Three stretching events are suggested during the Triassic-Jurassic, but additional biostratigraphical data are needed to identify them precisely. The spatial distribution of lithosphere stretching values suggests that small, narrow (<150 km), asymmetric graben basins were located on opposite sides of the paleo-Magdalena-La Salina fault system, which probably was active as a master transtensional or strike-slip fault system. Paleomagnetic data suggesting a significant (at least 10°) northward translation of terranes west of the Bucaramanga fault during the Early Jurassic, and the similarity between the early Mesozoic stratigraphy and tectonic setting of the Payandé terrane with the Late Permian transtensional rift of the Eastern Cordillera of Peru and Bolivia indicate that the areas were adjacent in early Mesozoic times. New geochronological, petrological, stratigraphic, and structural research is necessary to test this hypothesis, including additional paleomagnetic investigations to determine the paleolatitudinal position of the Central Cordillera and adjacent tectonic terranes during the Triassic-Jurassic. Two stretching events are suggested for the Cretaceous: Berriasian-Hauterivian (144-127 Ma) and Aptian-Albian (121-102 Ma). During the Early Cretaceous, marine facies accumulated on an extensional basin system. Shallow-marine sedimentation ended at the end of the Cretaceous due to the accretion of oceanic terranes of the Western Cordillera. In Berriasian-Hauterivian subsidence curves, isopach maps and paleomagnetic data imply a (>180 km) wide, asymmetrical, transtensional half-rift basin existed, divided by the Santander Floresta horst or high. The location of small mafic intrusions coincides with areas of thin crust (crustal stretching

  6. SHRIMP U-Pb dating of the Antucoya porphyry copper deposit: new evidence for an Early Cretaceous porphyry-related metallogenic epoch in the Coastal Cordillera of northern Chile

    NASA Astrophysics Data System (ADS)

    Maksaev, Victor; Munizaga, Francisco; Fanning, Mark; Palacios, Carlos; Tapia, José

    2006-10-01

    The Antucoya porphyry copper deposit (300 Mt at 0.45% total Cu) is one of the largest deposits of a poorly known Early Cretaceous porphyry belt in the Coastal Cordillera of northern Chile. It is related to a succession of granodioritic and tonalitic porphyritic stocks and dikes that were emplaced within Jurassic andesitic rocks of the La Negra Formation immediately west of the N-S trending sinistral strike-slip Atacama Fault Zone. New zircon SHRIMP U-Pb data indicate that the porphyries of Antucoya crystallized within the time span from 142.7 ± 1.6 to 140.6 ± 1.5 Ma (±2 σ), and late, unmineralized, NW-SE trending dacite dikes with potassic alteration and internal deformation crystallized at 141.9 ± 1.4 Ma. The Antucoya porphyry copper system appears to be formed after a change of stress conditions along the magmatic arc from extensional in the Late Jurassic to transpressive during the Early Cretaceous and provides support for an Early Cretaceous metallogenic episode of porphyry-type mineralization along the Coastal Cordillera of northern Chile.

  7. Early Childhood Inclusion in Spain

    ERIC Educational Resources Information Center

    Giné, Climent; Balcells-Balcells, Anna; Cañadas, Margarita; Paniagua, Gema

    2016-01-01

    This article describes early childhood inclusion in educational settings in Spain. First, we address the legislative framework of preschool education in Spain and offer a brief analysis of some relevant issues, including the current situation of early childhood education and inclusion at this stage. Second, current policies and practices relating…

  8. Pavlov in Spain.

    PubMed

    Bandrés, Javier; Llavona, Rafael

    2003-11-01

    Reflexology has been present throughout Spanish science since the last third of the nineteenth century and its importance can be seen in the works of authors such as Martín Salazar, Ramón y Cajal, Gómez Ocaña, Simarro and Turró. The most important research in Reflexology in Spain takes place a) at the Schools of Neurophysiology and Psychology in Barcelona and Madrid, b) with a group of authors specializing in pathological medicine and c) in the Military's Health Department, Pavlov's work was received in Spain with special interest. Fernández-España, who could be considered the "first Spanish Pavlovian," emphasized Pavlov's work in a series dedicated to the study of objective psychology which was published between 1914 and 1924. Planelles was the first investigator to develop a program in pavlovian experimentation, presenting his results in 1935. The Civil War (1936-1939) ended these and many other Spanish projects in psychology. After the war, interest in Reflexology and Pavlov's theories slowly rose again, first through psychosomatic medicine and then in the 60's because of the works of such authors as Monserrat-Esteve, Rof Carballo and Colodrón. The progressive inclusion of psychology in the Schools of Philosophy and Arts after 1968 marked the beginning of a new era.

  9. DNA Barcoding Survey of Anurans across the Eastern Cordillera of Colombia and the Impact of the Andes on Cryptic Diversity.

    PubMed

    Guarnizo, Carlos E; Paz, Andrea; Muñoz-Ortiz, Astrid; Flechas, Sandra V; Méndez-Narváez, Javier; Crawford, Andrew J

    2015-01-01

    Colombia hosts the second highest amphibian species diversity on Earth, yet its fauna remains poorly studied, especially using molecular genetic techniques. We present the results of the first wide-scale DNA barcoding survey of anurans of Colombia, focusing on a transect across the Eastern Cordillera. We surveyed 10 sites between the Magdalena Valley to the west and the eastern foothills of the Eastern Cordillera, sequencing portions of the mitochondrial 16S ribosomal RNA and cytochrome oxidase subunit 1 (CO1) genes for 235 individuals from 52 nominal species. We applied two barcode algorithms, Automatic Barcode Gap Discovery and Refined Single Linkage Analysis, to estimate the number of clusters or "unconfirmed candidate species" supported by DNA barcode data. Our survey included ~7% of the anuran species known from Colombia. While barcoding algorithms differed slightly in the number of clusters identified, between three and ten nominal species may be obscuring candidate species (in some cases, more than one cryptic species per nominal species). Our data suggest that the high elevations of the Eastern Cordillera and the low elevations of the Chicamocha canyon acted as geographic barriers in at least seven nominal species, promoting strong genetic divergences between populations associated with the Eastern Cordillera.

  10. Drainage reorganization during mountain building in the river system of the Eastern Cordillera of the Colombian Andes

    NASA Astrophysics Data System (ADS)

    Struth, Lucía; Babault, Julien; Teixell, Antonio

    2015-12-01

    The Eastern Cordillera of Colombia is a thick-skinned thrust-fold belt that is characterized by two topographic domains: (1) the axial zone, a high altitude plateau (the Sabana de Bogotá, 2500 masl) with low local relief and dominated by longitudinal rivers, and (2) the Cordillera flanks, where local relief exceeds 1000 m and transverse rivers dominate. On the basis of an analysis of digital topography and river parameters combined with a review of paleodrainage data, we show that the accumulation of shortening and crustal thickening during the Andean orogeny triggered a process of fluvial reorganization in the Cordillera. Owing to a progressive increase of the regional slope, the drainage network evolves from longitudinal to transverse-dominated, a process that is still active at present. This study provides the idea of progressive divide migration toward the inner part of the mountain belt, by which the area of the Sabana de Bogotá plateau is decreasing, the flanks increase in area, and ultimately transverse rivers will probably dominate the drainage of the Cordillera.

  11. DNA Barcoding Survey of Anurans across the Eastern Cordillera of Colombia and the Impact of the Andes on Cryptic Diversity

    PubMed Central

    Guarnizo, Carlos E.; Paz, Andrea; Muñoz-Ortiz, Astrid; Flechas, Sandra V.; Méndez-Narváez, Javier; Crawford, Andrew J.

    2015-01-01

    Colombia hosts the second highest amphibian species diversity on Earth, yet its fauna remains poorly studied, especially using molecular genetic techniques. We present the results of the first wide-scale DNA barcoding survey of anurans of Colombia, focusing on a transect across the Eastern Cordillera. We surveyed 10 sites between the Magdalena Valley to the west and the eastern foothills of the Eastern Cordillera, sequencing portions of the mitochondrial 16S ribosomal RNA and cytochrome oxidase subunit 1 (CO1) genes for 235 individuals from 52 nominal species. We applied two barcode algorithms, Automatic Barcode Gap Discovery and Refined Single Linkage Analysis, to estimate the number of clusters or “unconfirmed candidate species” supported by DNA barcode data. Our survey included ~7% of the anuran species known from Colombia. While barcoding algorithms differed slightly in the number of clusters identified, between three and ten nominal species may be obscuring candidate species (in some cases, more than one cryptic species per nominal species). Our data suggest that the high elevations of the Eastern Cordillera and the low elevations of the Chicamocha canyon acted as geographic barriers in at least seven nominal species, promoting strong genetic divergences between populations associated with the Eastern Cordillera. PMID:26000447

  12. Structural and thermochronological evidence for Paleogene basement-involved shortening in the axial Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Saylor, Joel E.; Horton, Brian K.; Stockli, Daniel F.; Mora, Andrés; Corredor, Jaime

    2012-11-01

    Although most recent studies regard the northern Andes primarily as a low-shortening inversion orogen, new mapping and thermochronology along the paired basement-involved Floresta massif and Floresta basin in the axial Eastern Cordillera of Colombia suggest major Paleogene shortening in a ramp-flat fold-thrust belt. Field mapping indicates that the hanging wall of the east-directed Soápaga fault system contains a series of upright thrust sheets with flat-on-flat cutoff relationships and a deformed footwall characterized by a complex triangle zone. These geometries necessitate roughly east-west shortening exceeding that of a previously mapped overturned hanging wall anticline and disharmonic footwall folds. Zircon (U-Th)/He (ZHe) ages indicate exhumation-induced cooling of the Soápaga hanging wall through the ˜180 °C closure temperature at 31-25 Ma. This cooling postdated documented shortening to the west and predated shortening to the east, suggesting an eastward progression of Paleogene deformation. Synorogenic Oligocene footwall strata of the Floresta basin contain distal fine-grained sediments and lack growth strata or Oligocene detrital ZHe ages, suggesting relatively high heave along the Soápaga fault system. These results are consistent with a rapidly eastward-propagating, basement-involved fold-thrust belt with ramp-flat structures that accommodated tens of km of shortening. Long-term stasis of the deformation front on the eastern and western flanks of the Eastern Cordillera due to localization of Neogene shortening along Mesozoic rift-bounding normal faults indicates a shift in deformational style in late Oligocene-early Miocene time. This geometric and temporal framework implies: 1) a total shortening in the northern Andes exceeding most current estimates; 2) Paleogene deformation in the Eastern Cordillera marked by rapid advances of the deformation front along a ramp-flat thrust system; and 3) focused Neogene reactivation (inversion) of master rift

  13. Lichenometric Dating of Little Ice Age Moraines in the Cordillera Vilcabamba, Southern Peruvian Andes

    NASA Astrophysics Data System (ADS)

    Taggart, J. R.; Licciardi, J. M.

    2008-12-01

    Lateral and end moraines deposited by two valley glaciers were mapped on the south side of Nevado Tucarhuay (5910 m asl) and on the east side of Nevado Salcantay (6271 m asl) in the Cordillera Vilcabamba in the southern Peruvian Andes (~13°S latitude). The geomorphic expression of outer and inner moraine sequences in these two drainages mimics that of a previously studied pair of moraines in the upper Rio Blanco valley on the south side of Nevado Salcantay. Cosmogenic 10Be surface exposure dating has yielded ages of 9.0 ± 0.3 ka and 195 ± 24 years, respectively, for these outer and inner Rio Blanco moraines. In all three valleys, prominent outer moraines occur ~3-5 km from headwalls and inner moraine ridges are found ~2.5-3 km from headwalls. Recessional moraines found exclusively on the east side of Salcantay indicate multiple early- to late-Holocene glacier pauses, rather than continuous retreat, prior to the latest Holocene glacier readvance. Diameters of the lichen Rhizocarpon subgenus Rhizocarpon were measured on moraine boulders from the inner moraines in all three valleys. Lichen diameters on the two undated inner moraines are consistent with diameters on the inner 10Be-dated Rio Blanco moraine, which signifies similar lichenometric ages and supports synchronous glacier culminations in all three drainages during the Little Ice Age. The new lichen measurements and age estimates provide a critical link between previous lichen studies in the Cordillera Blanca to the north and in the Cordillera Real to the south, thereby increasing spatial coverage of terrestrial paleoclimate information. Moreover, the extensive lichen measurements gathered on the inner 10Be-dated Rio Blanco moraine define a new control point for the Rhizocarpon subgenus Rhizocarpon growth curve in the tropical Peruvian- Bolivian Andes, which will increase the accuracy of lichenometric age estimates in this region. 10Be exposure dating of the inner moraines in adjacent valleys is underway

  14. Air temperature, radiation budget and area changes of Quisoquipina glacier in the Cordillera Vilcanota (Peru)

    NASA Astrophysics Data System (ADS)

    Suarez, Wilson; Macedo, Nicolás; Montoya, Nilton; Arias, Sandro; Schauwecker, Simone; Huggel, Christian; Rohrer, Mario; Condom, Thomas

    2015-04-01

    The Peruvian Andes host about 71% of all tropical glaciers. Although several studies have focused on glaciers of the largest glaciered mountain range (Cordillera Blanca), other regions have received little attention to date. In 2011, a new program has been initiated with the aim of monitoring glaciers in the centre and south of Peru. The monitoring program is managed by the Servicio Nacional de Meteorología e Hidrología del Perú (SENAMHI) and it is a joint project together with the Universidad San Antonio Abad de Cusco (UNSAAC) and the Autoridad Nacional del Agua (ANA). In Southern Peru, the Quisoquipina glacier has been selected due to its representativeness for glaciers in the Cordillera Vilcanota considering area, length and orientation. The Cordillera Vilcanota is the second largest mountain range in Peru with a glaciated area of approximately 279 km2 in 2009. Melt water from glaciers in this region is partly used for hydropower in the dry season and for animal breeding during the entire year. Using Landsat 5 images, we could estimate that the area of Quisoquipina glacier has decreased by approximately 11% from 3.66 km2 in 1990 to 3.26 km2 in 2010. This strong decrease is comparable to observations of other tropical glaciers. In 2011, a meteorological station has been installed on the glacier at 5180 m asl., measuring air temperature, wind speed, relative humidity, net short and longwave radiation and atmospheric pressure. Here, we present a first analysis of air temperature and the radiation budget at the Quisoquipina glacier for the first three years of measurements. Additionally, we compare the results from Quisoquipina glacier to results obtained by the Institut de recherche pour le développement (IRD) for Zongo glacier (Bolivia) and Antizana glacier (Ecuador). For both, Quisoquipina and Zongo glacier, net shortwave radiation may be the most important energy source, thus indicating the important role of albedo in the energy balance of the glacier

  15. Geochronology, geochemistry and tectonic evolution of the Western and Central cordilleras of Colombia

    NASA Astrophysics Data System (ADS)

    Villagómez, Diego; Spikings, Richard; Magna, Tomas; Kammer, Andreas; Winkler, Wilfried; Beltrán, Alejandro

    2011-08-01

    Autochthonous rocks of the pre-Cretaceous continental margin of NW South America (the Tahami Terrane) are juxtaposed against a series of para-autochthonous rock units that assembled during the Early Cretaceous. Allochthonous, oceanic crust of the Caribbean Large Igneous Province collided with and accreted onto the margin during the Late Cretaceous. We present the first regional-scale dataset of zircon U-Pb LA-ICP-MS ages for intrusive and metamorphic rocks of the autochthonous Tahami Terrane, Early Cretaceous igneous para-autochthonous rocks and accreted oceanic crust. The U-Pb zircon data are complemented by multiphase 40Ar/ 39Ar crystallization and cooling ages. The geochronological data are combined with whole rock major oxide, trace element and REE data acquired from the same units to constrain the tectonic origin of the rock units and terranes exposed in the Western Cordillera, Cauca-Patía Valley and the Central Cordillera of Colombia. The Tahami Terrane includes lower Paleozoic orthogneisses (~ 440 Ma) that may have erupted during the active margin stage of the Rheic Ocean. Basement gneisses were intruded by Permian, continental arc granites during the final assembly of Pangea. Triassic sedimentary rocks were subsequently deposited in rift basins and partially melted during high-T metamorphism associated with rifting of western Pangea during 240-220 Ma. Continental arc magmatism during 180-145 Ma is preserved along the whole length of the Central Cordillera and was followed by an Early Cretaceous out-board step of the arc axis and the inception of the Quebradagrande Arc that fringed the continental margin. Back-stepping of the arc axis may have been caused by the collision of buoyant seamounts, which were coeval with plateau rocks exposed in the Nicoya Peninsular of Costa Rica. Rapid westward drift of South America closed the Quebradagrande basin in the late Aptian and caused medium-high P-T metamorphic rocks of the Arquía Complex to exhume and obduct onto

  16. A new species of Psychrophrynella (Anura: Craugastoridae) from the Cordillera Real, Department La Paz, Bolivia.

    PubMed

    De La Riva, Ignacio; Burrowes, Patricia A

    2014-11-26

    We describe a new species of Psychrophrynella from a single locality in the Cordillera Real, in the Andes of Department of La Paz, Bolivia. Psychrophrynella teqta sp. nov. is highly variable in color pattern and differs from the species geographically closer mostly by presenting yellow or red blotches, usually absent in other species. In addition, the new species differs from all species in the genus because the males have a pulsed call. Males of this species show parental care, and the high number of eggs per nest suggest that perhaps more than one clutch might be attended by a single male. As other species in the genus, the new species is infected by Batrachochytrium dendrobatidis, and thus, a conservation threat is already present upon its discovery.

  17. Paleoseismicity and neotectonics of the Cordillera Blanca fault zone, Northern Peruvian Andes.

    USGS Publications Warehouse

    Schwartz, D.P.

    1988-01-01

    The Cordillera Blanca fault zone is a major W dipping normal fault that bounds the W side of a 120- 170-km wide zone of active extension along the crest of the N Peruvian Andes. The fault is approximately 210 km long and exhibits continuous geomorphic evidence of repeated late Pleistocene and Holocene displacements but has not been the source of historical or teleseismically recorded earthquakes. Trenching and mapping of fault scarps provide new information on earthquake recurrence, slip rate, timing of the most recent events and Andean neotectonics. At Quebrada Queroccocha, 55 km from valley fill lacustrine and fluvial deposits are displaced 7.5-8 m. Scarp profiles, tectonic terraces, and trench exposures indicate 5 to 7 scarp-forming earthquakes of 2-3 m per event during the past 11 000-14 000 yrs at this location.-from Author

  18. Miocene non-marine diatoms from the western Cordillera basins of northern Peru

    USGS Publications Warehouse

    Fourtanier, E.; Gasse, F.; Bellier, O.; Bonhomme, M.G.; Robles, I.

    1993-01-01

    Diatom assemblages are documented from diatomite layers of two Miocene fluvio-lacustrine units from the basins of the western Cordillera of northern Peru: the Namora Formation and the Cajabamba Formation. Emphasis is given to taxa of particular stratigraphic interest. The diatom assemblages indicate for the Namora Formation the occurrence of swampy conditions with very dilute, low alkalinity water. The diatom assemblages of the Cajabamba Formation reflect the occurrence of fresh, slightly alkaline, eutrophic lakes with deep water in some samples, and swampy conditions with relatively high salt content in other samples. The Namora formation is late Miocene in age based on the diatom assemblages and radiometric analyses. The diatom layers of the Cajabamba Formation are dated as late middle to early late Miocene. -from Authors

  19. Precambrian crust beneath the Mesozoic northern Canadian Cordillera discovered by Lithoprobe seismic reflection profiling

    NASA Astrophysics Data System (ADS)

    Cook, Frederick A.; Clowes, Ronald M.; Snyder, David B.; van der Velden, Arie J.; Hall, Kevin W.; Erdmer, Philippe; Evenchick, Carol A.

    2004-04-01

    The Cordillera in northern Canada is underlain by westward tapering layers that can be followed from outcrops of Proterozoic strata in the Foreland belt to the lowermost crust of the orogenic interior, a distance of as much as 500 km across strike. They are interpreted as stratified Proterozoic rocks, including ˜1.8-0.7 Ga supracrustal rocks and their basement. The layering was discovered on two new deep seismic reflection profiles in the Yukon (Line 3; ˜650 km) and northern British Columbia (Line 2; ˜1245 km in two segments) that were acquired as part of the Lithoprobe Slave-Northern Cordillera Lithospheric Evolution (SNORCLE) transect. In the Mackenzie Mountains of the eastern Yukon, the layering in Line 3 is visible between 5.0 and 12.0 s (˜15 to 36 km depth). It is followed southwestward for nearly 650 km (˜500 km across strike) and thins to less than 1.0 s (˜3.0-3.5 km thickness) near the Moho at the Yukon-Alaska international boundary. In the northern Rocky Mountains of British Columbia, the upper part of the layering on Line 2 correlates with outcrops of Proterozoic (1.76-1.0 Ga) strata in the Muskwa anticlinorium. At this location, the layering is at least 15 km thick and is followed westward then southward into the middle and lower crust for ˜700 km (˜300 km across strike). It disappears as a thin taper at the base of the crust ˜150 km east of the coast of the Alaskan panhandle. The only significant disruption in the layering occurs at the Tintina fault zone, a late to postorogenic strike-slip fault with up to 800 km of displacement, which appears as a vertical zone of little reflectivity that disrupts the continuity of the deep layering on both profiles (˜300 km apart). The base of the layered reflection zone coincides with the Moho, which exhibits variable character and undulates in a series of broad arches with widths of ˜150 km. In general, the mantle appears to have few reflections. However, at the southwest end of Line 3 near the Alaska

  20. Remains of early Ordovician mantle-derived magmatism in the Santander Massif (Colombian Eastern Cordillera)

    NASA Astrophysics Data System (ADS)

    Mantilla Figueroa, Luis C.; Bissig, Thomas; Cottle, John M.; Hart, Craig J. R.

    2012-10-01

    An Early Ordovician magmatic event has been documented in the Santander Massif (north-Eastern Cordillera, Colombia). Three U/Pb laser ablation ages of 477 ± 2 Ma (Arenig), were obtained from metamorphosed and foliated calc-alkaline diorites. The 176Hf/177Hf values in zircons from these meta-diorites, yielded epsilon Hf values (ɛHft) > 0 (Mean = 2 ± 1, at 477 Ma). These data allow interpretation of the origin of these zircons from a radiogenic initial Hf isotope source, which is characteristic of the Earth's mantle. This, together with the fact that the rocks have been affected subsequently by tectonometamorphic processes, suggests that the early Ordovician diorites have been emplaced in a supra-subduction tectonic setting, related to onset of the Iapetus Ocean closure.

  1. Holocene Paleoglacier History of Glaciar Dalla Vedova, Cordillera DARWIN, Tierra del Fuego, Chile

    NASA Astrophysics Data System (ADS)

    Reynhout, S.

    2015-12-01

    Southernmost South America is unique in its position immediately north of the present-day Antarctic Convergence, making it ideally suited for the evaluation of Antarctic influences on terrestrial paleoclimate. Here we present a glacial geomorphic interpretation of the paleoglacial history of Glaciar Dalla Vedova in Bahía Blanca, Cordillera Darwin, Chile (53°S). This interpretation is further constrained by radiocarbon dating, cosmogenic dating, dendrochronology, and historical photogrammetry. Preliminary field work suggests that Holocene glacier fluctuations have been constrained to within 3 km of the present glacier boundary, punctuated by rapid recent glacier retreat over the past century. By comparing the observed chronology with the record contained further north in Patagonia, we will evaluate possible mechanisms of regional climate variability over the Holocene across southernmost South America.

  2. Ethno-botanical survey of edible wild fruits in Benguet, Cordillera administrative region, the Philippines

    PubMed Central

    Chua-Barcelo, Racquel Tan

    2014-01-01

    Objective To conduct a survey on the common name/s, traditional uses and cultural importance of the edible wild fruits in different municipalities of Benguet, Cordillera administrative region. Methods Interviews using questionnaires with barangay leaders and indigenous people were conducted with 176 key informants from June 2011 to July 2013. Results A total of 36 fruit species were found in different municipalities of Benguet. These fruit species belong to 27 genera and 20 families. Among the 13 municipalities of Benguet, Kibungan has the highest number of species. There are many uses of wild fruits which ranged from food (snack/dessert/table food), forage (especially for birds, monkeys and wild animals such as cloud rat and grass eaters), offertory, processed/preserved (as jam, jellies, candies, juice and wine), condiment or ingredient (for cooking), source of dye or ink, decoration (to garnish food) and as medicine to common ailments or health problems. Based on the inventory and calculated cultural importance index, Garcinia binucao (balokok) belonging to Clusiaceae is the most abundant fruit, hence it is the commonly used fruit for various purposes such as food, forage, processing/preservation and condiment/ingredient; Vaccinium myrtoides (ayusip) for offerings and as source of dye/ink; Saurauia elegans (uyok) for decoration, and, Antidesma bunius (bugnay) for medicine. Conclusions Benguet province in the Cordillera region provides a diversity of edible wild fruits. The data gathered from the study signifies that collection, processing and utilization of edible wild fruits are still part of the daily activities of the people in Benguet. PMID:25183144

  3. Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2015-02-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light-absorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, 240 snow samples were collected from 15 mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the 3 years and some mountains were sampled multiple times during the same year. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particles on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective black carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light-absorbing particles in the more polluted regions were likely BC. The 3 years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  4. Measurements of light absorbing particulates on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2014-10-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in air temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light absorbing particulates sampled from glaciers during three surveys in the Cordillera Blanca in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, two hundred and forty snow samples were collected from fifteen mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the three expeditions and some mountains were sampled multiple times during the same expedition. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particulates on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective Black Carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the filter analysis and the SP2 refractory Black Carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light absorbing particulates in the more polluted areas were likely BC. The three years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  5. Cenozoic sedimentary and deformational history of hispaniola, 1: southeastern Cordillera Central

    SciTech Connect

    Heubeck, C.; Mann, P.

    1988-01-01

    The Cordillera Central approximates an elongate (220 km), elevated (>3 km), thrust-bounded anticline cored by Cretaceous-Paleogene arc rocks and uplifted during Miocene to recent time by convergent strike-slip movements between the North American and Caribbean plates. The southeastern termination of the anticline plunges beneath a thick (>6 km), well-exposed marine clastic sedimentary sequence. Because uplift-related faulting is minimal in this hinge region of the Cordillera Central anticline, the authors have carried out detailed mapping of the area to determine (1) relation of Cretaceous-Paleogene arc basement to overlying Cenozoic sedimentary cover, and (2) Cenozoic deformational history of arc and basin sequences. Mapping has clearly distinguished three superimposed Cenozoic basins lying on arc basement. The lowest basin (basin 1) is Paleocene-Eocene in age and consists of alternations of arc-derived turbidies with interbedded pelagic limestone and red mudstone. In apparent conformity above this basin is an approximately 4-km thick marine clastic sequence of medial Eocene through early Miocene age (basin 2). These sediments consist of fining-upward turbiditic sequence derived from the northwest and northeast. Arc basement and overlying basins 1 and 2 were shortened approximately 25% in a short-lived, northwest-southeast-directed compressional event that resulted in the formation of large open synclines and tightly folded and faulted anticlines with fold amplitudes of 1-6 km. Underformed, medial Miocene sediments of a mixed clastic and carbonate shelf facies (basin 3) unconformably overlie the folded latest Oligocene-early Miocene rocks of basin 2 and thus constrain the age of folding as early to middle Miocene.

  6. Sources and pathways of stream generation in tropical proglacial valleys of the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Gordon, Ryan P.; Lautz, Laura K.; McKenzie, Jeffrey M.; Mark, Bryan G.; Chavez, Daniel; Baraer, Michel

    2015-03-01

    Tropical glaciers supply approximately half of dry-season stream discharge in glacierized valleys of the Cordillera Blanca, Peru. The remainder of streamflow originates as groundwater stored in alpine meadows and other proglacial geomorphic features. A better understanding of the hydrogeology of alpine groundwater, including sources, storage zones, and the locations and magnitudes of contributions to streamflow, is important for making accurate estimates of glacial inputs to the hydrologic budget, and for our ability to make predictions about future water resources as glaciers retreat. This field study focuses on two high-elevation meadows in valleys of the Cordillera Blanca, in headwaters and mid-valley locations. Tracer measurements of stream and spring discharge and groundwater-surface water exchange were combined with synoptic sampling of water isotopic and geochemical composition in order to characterize and quantify contributions to streamflow from different groundwater reservoirs. At the headwaters site, groundwater supplied approximately half of stream discharge from a small meadow, with most originating in an alluvial fan adjacent to the meadow and little (6%) from the meadow itself; however, at the mid-valley site, where meadows are extensive, local groundwater has a large impact on streamflow and chemistry through large net contributions to discharge and turnover of surface water due to gross exchanges with groundwater. At the mid-valley site, stream discharge increased by 200 L s-1 (18% of average discharge) over 1.2 km as it descended a moraine between two meadows. Such valley-crossing moraines, which create significant steps in the down-valley slope, are likely locations of substantial groundwater contribution to streams.

  7. Isotopic characteristics of mantle sources for Quaternary continental alkaline magmas in the northern Canadian Cordillera

    NASA Astrophysics Data System (ADS)

    Carignan, Jean; Ludden, John; Francis, Don

    1994-12-01

    Three mantle compositions are identified as potential source end members for Quaternary to recent alkaline volcanic rocks from Fort Selkirk, Llangorse-Hirschfeld, Alligator Lake and Mt. Edziza in the northern Canadian Cordillera. These are: (1) an amphibole-rich source, characterized by unradiogenic Sr, Nd and Pb, from which the olivine nephelinite lavas formed, (2) the continental lithospheric mantle which is characterised by high Pb-207/Pb-204 and appears to be involved in the formation of the alkali olivine basalts of Fort Selkirk, and (3) a mantle with radiogenic Pb and unradiogenic Sr (HIMU-type) represented by lavas from Mt. Edziza. The Mt. Edziza volcano is the largest of the volcanic centres in the region, and is considered to reflect melting of sublithospheric mantle of HIMU composition below central British Columbia. Incipient melting of amphibole-veined subcontinental mantle lithosphere resulted from plume upwelling and/or transtensional pressure release and produced the small nephelinite to olivine basalt centres of the northern Cordilleran Province. The source of the nephelinite magmas is slightly more radiogenic than present-day Pacific Mid-Ocean ridge basalts (MORB), and is best represented by the most depleted component of the Aleutian magmas. This suggests enrichment of the subcontinental lithosphere in the northern Cordillera by melts of this isotopic composition during Cretaceous subduction. The Alligator Lake complex is anomalous and charaterized by the most radiogenic lavas. Despite the presence of crustal xenoliths there is no clear geochemical signature for crustal contamination and, in contrast to the other volcanic centers which were erupted through the Intermontain Belt, the lavas of this center may have been derived from a highly radiogenic lithospheric mantle beneath the Coast Plutonic complex.

  8. Climate in the Western Cordillera of the Central Andes over the last 4300 years

    NASA Astrophysics Data System (ADS)

    Engel, Zbyněk; Skrzypek, Grzegorz; Chuman, Tomáš; Šefrna, Luděk; Mihaljevič, Martin

    2014-09-01

    The Distichia peat core obtained in the Carhuasanta valley near Nevado Mismi, Cordillera Chila, provides information on climatic and environmental conditions over the last ˜4300 years. The relative changes in the stable carbon isotope composition of plant remains preserved in the core reflect major temperature fluctuations in the Western Cordillera of the southern Peruvian Andes. These temperature variations can be additionally linked with the changes in precipitation patterns by analysing C% and C/N ratio in the core. Relatively warm and moist conditions prevailed from 4280 to 3040 cal. yrs BP (BC 2330-1090) with a short colder dry episode around 3850 cal. yrs BP (BC 1900). The most prominent climate changes recorded in the peat occurred between 3040 and 2750 cal. yrs BP (BC 1090-800) when the initial warming turned to a rapid cooling to temperatures at least 2 °C lower than the mean for the Late Holocene. Initially drier conditions within this event turned to a short wet phase after 2780 cal. yrs BP (BC 830) when the temperature increased again. This event coincides with significant changes in peat and ice core records in the Central Andes matching the timing of the global climate event around 2.8 cal. ka BP. Climatic conditions in the study area became relatively dry and stable after the event for about 800 years. Highly variable temperatures and humidity prevailed during the last 2000 years when an extended warm and relatively humid period occurred between 640 and 155 cal. yrs BP (AD 1310-1795) followed by predominantly colder and drier conditions. The established δ13C peat record represents the first continuous proxy for the temperature in the southern Peruvian Andes dated by the AMS 14C. Distichia peat is wide spread in the Andes and the proposed approach can be applied elsewhere in high altitudes, where no other traditional climate proxies are available.

  9. Growth and gravitational collapse of a mountain front of the Eastern Cordillera of Colombia

    NASA Astrophysics Data System (ADS)

    Kammer, Andreas; Montana, Jorge; Piraquive, Alejandro

    2016-04-01

    The Eastern Cordillera of Colombia is bracketed between the moderately east-dipping flank of the Central Cordillera on its western and the gently bent Guayana shield on its eastern side. It evolved as a response to a considerable displacement transfer from the Nazca to the Southamerican plate since the Oligocene break-up of the Farallon plate. One of its distinctive traits refers to its significant shortening by penetrative strain at lower and folding at higher structural levels, approximating a wholesale pure-shear in analogy to a vice model or a crustal welt sandwiched between rigid buttresses. This contrasting behavior may be explained by the spatial coincidence between Neogene mountain belt and a forebulge that shaped the foreland trough during a Cretaceous subduction cycle and was very effective in localizing a weakening of the backarc region comprised between two basin margin faults. In this paper we examine a two-phase evolution of the Eastern mountain front. Up to the late Miocene deformation was restrained by the inherited eastern basin margin fault and as the cordilleran crust extruded, a deformation front with an amplitude similar the present structural relief of up to 10.000 m may have built up. In the Pliocene convergence changed from a roughly strike-perpendicular to an oblique E-W direction and caused N-S trending faults to branch off from the deformation front. This shortening was partly driven by a gravitational collapse of the Miocene deformation front, that became fragmented by normal faults and extruded E on newly formed Pliocene thrust faults. Normal faults display displacements of up to 3000 m and channelized hydrothermal fluids, leading to the formation of widely distributed fault breccias and giving rise to a prolific Emerald mineralization. In terms of wedge dynamics, the Pliocene breaching of the early formed deformation front helped to establish a critical taper.

  10. Guerrero terrane of Mexico: Its role in the Southern, Cordillera from new geochemical data

    NASA Astrophysics Data System (ADS)

    Centeno-García, Elena; Ruíz, Joaquín; Coney, Peter J.; Patchett, P. Jonathan; Ortega-Gutiérrez, Fernando

    1993-05-01

    The Guerrero terrane makes up most of the western part of Mexico, is one of the largest terranes of the North American Cordillera, and is characterized by an Upper Jurassic-Lower Cretaceous volcanic-sedimentary sequence of are affinity. Metamorphic rocks that crop out in the western area of the terrane (Arteaga complex) may represent its basement. They are mostly composed of terrigenous sediments (Varales Formation) with minor basaltic pillow lavas, chert, tuff, and limestone. Initial ɛNd values (+13) and rare earth element (REE) values for pillow lavas of the Arteaga complex are characteristic of mid-ocean ridge basalts (MORB). In contrast, the Varales Formation sedimentary rocks from the Arteaga complex have negative initial ɛNd (-6.2 and -7.2) and are enriched in light REEs. These data indicate that the sediments of the Varales Formation were supplied from an evolved continental crust. The overlying Jurassic(?)-Cretaceous arc-related rocks have initial ɛNd (+7.9 to +3.9) and REE patterns similar to those of evolved intraoceanic island arcs. These data show that the evolution of the Guerrero terrane had an early pre-Cretaceous(?) stage, which consisted of an oceanic crust receiving sediments from a continental source, and a Cretaceous stage, which was the development of an island arc.The oceanic-continental isotopic signature of the Arteaga complex is different from other western North American Cordilleran terranes (e.g., Alexander, Wrangelfia) that are more completely "oceanic" in affinity. Nevertheless, the extensive Jurassic(?).Cretaceous arc represents additions of juvenile material to the western North American Cordillera.

  11. The magmatic history of the Vetas-California mining district, Santander Massif, Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Mantilla Figueroa, Luis C.; Bissig, Thomas; Valencia, Víctor; Hart, Craig J. R.

    2013-08-01

    The Vetas-California Mining District (VCMD), located in the central part of the Santander Massif (Colombian Eastern Cordillera), based on U-Pb dating of zircons, records the following principal tectono-magmatic events: (1) the Grenville Orogenic event and high grade metamorphism and migmatitization between ˜1240 and 957 Ma; (2) early Ordovician calc-alkalic magmatism, which was synchronous with the Caparonensis-Famatinian Orogeny (˜477 Ma); (3) middle to late Ordovician post-collisional calc-alkalic magmatism (˜466-436 Ma); (4) late Triassic to early Jurassic magmatism between ˜204 and 196 Ma, characterized by both S- and I-type calc-alkalic intrusions and; (5) a late Miocene shallowly emplaced intermediate calc-alkaline intrusions (10.9 ± 0.2 and 8.4 ± 0.2 Ma). The presence of even younger igneous rocks is possible, given the widespread magmatic-hydrothermal alteration affecting all rock units in the area. The igneous rocks from the late Triassic-early Jurassic magmatic episodes are the volumetrically most important igneous rocks in the study area and in the Colombian Eastern Cordillera. They can be divided into three groups based on their field relationships, whole rock geochemistry and geochronology. These are early leucogranites herein termed Alaskites-I (204-199 Ma), Intermediate rocks (199-198 Ma), and late leucogranites, herein referred to as Alaskites-II (198-196 Ma). This Mesozoic magmatism is reflecting subtle changes in the crustal stress in a setting above an oblique subduction of the Panthalassa plate beneath Pangea. The lower Cretaceous siliciclastic Tambor Formation has detrital zircons of the same age populations as the metamorphic and igneous rocks present in the study area, suggesting that the provenance is related to the erosion of these local rocks during the late Jurassic or early Cretaceous, implying a local supply of sediments to the local depositional basins.

  12. Timing and Style of Deformation in the Floresta Massif, Axial Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Saylor, J.; Stockli, D. F.; Mora, A.

    2009-12-01

    The Floresta Massif is one of the largest exposures of Paleozoic and Pre-Cambrian rocks in the Eastern Cordillera. Estimates for the age of onset of shortening-related deformation in the Eastern Cordillera range from late Cretaceous to late Miocene (e.g., Hoorn et al., 1995; Bayona et al., 2008; Parra et al., 2009). The massif is typically interpreted as being exhumed along a high-angle reverse fault (the Soapaga fault) that reactivated Mesozoic extensional structures (e.g., Kammer and Sanchez, 2006). We examined these dual linked issued with new zircon U/Th-He (ZHe) data, new geological mapping and previously published apatite fission track (AFT) data from the Floresta Massif and the associated footwall strata. Previously, an overturned Paleozoic - Cretaceous sequence was mapped emplaced on Tertiary strata along the Soapaga fault. However, new geologic mapping identifies two previously unrecognized thrusts which place, from west to east, Paleozoic strata on Jurassic strata (Fault 3), Jurassic strata on Cretaceous strata (Fault 2) and Cretaceous strata on Tertiary strata (along the previously identified Fault 1). These results are confirmed by AFT and ZHe data. ZHe ages show no resetting in the Tertiary footwall strata, but show partial resetting in the Cretaceous strata and full resetting in the Jurassic and Paleozoic strata. Similarly, AFT data show older ages in the Cretaceous strata than in the Jurassic or Paleozoic strata. Fully reset ZHe ages from Jurassic strata show that exhumation of the Floresta Massif was ongoing by at least the early Oligocene (~ 30 Ma). However, this deformation post-dates an older episode of deformation associated with partially reset ZHe ages in the Cretaceous strata. Based on a decrease in lag time in detrital ZHe data, we infer that the earlier episode of deformation occurred in the mid - late Eocene (45 - 35 Ma).

  13. Human Gongylonema infection in Spain.

    PubMed

    Illescas-Gómez, M P; Rodriguez Osorio, M; Gómez Garcia, V; Gómez Morales, M A

    1988-03-01

    A case of gongylonemiasis in a 31-year-old woman of Granada, Spain, is reported. The worm, clearly belonging to Gongylonema genus, could not be identified definitively as Gongylonema pulchrum, the species usually described in humans.

  14. Late Cenozoic tectonics of the Coastal Cordillera of N Chile and implications for paleoclimate and interplate processes

    NASA Astrophysics Data System (ADS)

    Allmendinger, R. W.; González, G.; Yu, J.; Isacks, B.; Hoke, G.

    2003-12-01

    The Coastal Cordillera of northern Chile is located in the hyperarid Atacama Desert and is situated over the interplate seismic zone of the Nazca-South America convergent plate boundary. The Coastal Cordillera is bounded to the west by a 1000 m high escarpment that plunges directly to the sea north of Iquique but to the south has a 1-5 km wide Pleistocene abrasion platform at its base. We use a 20 m InSAR digital elevation model (DEM) combined with fieldwork to investigate the relations between the late Cenozoic tectonics and drainage development in the Cordillera between the Río Loa (21.6S) and the Quebrada de Camarones (19S). Late Cenozoic structures in this region consist of ~EW striking reverse faults and ~NS striking normal faults. The primary development of the reverse faults occurred in the Miocene and early Pliocene, though warped Pleistocene marine terraces indicate some later reactivation. These structures produce about 1% shortening parallel to, and appear to be related to the seaward concave curvature of, the plate boundary. Late Miocene to Recent normal faults throughout the Coastal Cordillera parallel the plate boundary and dip both towards and away from the trench. At several places in the study area, paleodrainages were incised across the uplifting ~EW reverse fault blocks prior to being dammed, producing internally drained evaporite basins in the footwalls of the structures. These relations indicate that there was considerably more water in the Coastal Cordillera in the latest Miocene and early Pliocene than is available at present, in agreement with the prior suggestion that the onset of hyperaridity in the region post-dates ~5 Ma. The Río Loa, the only river to reach the sea along more than 500 km of coastline, truncates on of these paleodrainages indicating that the Loa was incised at its current location after the middle Miocene. The incision of the R¡o Loa could be due either to uplift of the Coastal Cordillera, or due to lateral (W to E

  15. Neogene to Quaternary ash deposits in the Coastal Cordillera in northern Chile: Distal ashes from supereruptions in the Central Andes

    NASA Astrophysics Data System (ADS)

    Breitkreuz, Christoph; de Silva, Shanaka L.; Wilke, Hans G.; Pfänder, Jörg A.; Renno, Axel D.

    2014-01-01

    Silicic volcanic ash deposits investigated at 14 localities between 22° and 25°S in the Chilean Coastal Cordillera are found to be the distal ash fall from supereruptions in the Central Andean cordillera several hundreds of kilometers to the east. Depositional textures, modal composition and granulometry of the ashes and tuffs (the latter lithified by halite and gypsum under ultra-arid conditions) allow for a distinction between primary fallout/aeolian deposits (mean 4-5 Φ, sorting 1.5-2 Φ) and secondary deposits that formed by down wash from hill slopes during local rain fall. Primary volcanic components comprise two types of glass shards (with small stretched vesicles and coarse-walled with rounded to elliptic vesicles), and biotite.

  16. Transgressive stratigraphy, anoxia, and regional correlations within the late Precambrian Windermere grit of the southern Canadian Cordillera

    SciTech Connect

    Ross, G.M.; Murphy, D.C.

    1988-02-01

    The Windermere grit system in the southern Canadian Cordillera comprises the depositional record of a late Precambrian continental basin of uncertain tectonic affinity. Attempts to analyze the basin by means of these largely nonfossiliferous turbiditic rocks have been frustrated by a lack of chronostratigraphic marker units, a problem common in Precambrian sedimentary sequences. Stratigraphic analysis and regional mapping in the Cariboo Mountains (southeastern Canadian Cordillera) suggest that comparison of Precambrian sequences with Phanerozoic analogues holds promise for constructing chronologically significant sea-level lithostratigraphy. In the Cariboo and western Rocky mountains, a distinctive upward-thinning, dominantly pelitic succession (120 m thick) of rhythmic marble-silty pelite that is capped by a 20-m-thick carbonaceous sulfidic pelite represents a dramatic departure from sandy turbidite deposition and is interpreted as the depositional response of the turbidite system to eustatic sea-level rise. This marker unit appears to persist throughout Windermere grits in the southern Canadian Cordillera and, by analogy with well-constrained Phanerozoic examples of black shale deposition, is inferred to represent a synchronous basinwide highstand event. When analyzed within the context of black-shale depositional models, facies variations within the marker unit provide important constraints on basin shape, possibly water depth, and the magnitude of transcurrent fault movement in the southern Rocky Mountain trench.

  17. Diversity and abundance of forest frogs (Anura: Leptodactylidae) before and after Hurricane Georges in the Cordillera Central of Puerto Rico

    USGS Publications Warehouse

    Vilella, F.J.; Fogarty, J.H.

    2005-01-01

    Caribbean hurricanes often impact terrestrial vertebrates in forested environments. On 21 September 1998, Hurricane Georges impacted Puerto Rico with sustained winds in excess of 166 km/hr, causing damage to forests of the island's principal mountain range; the Cordillera Central. We estimated forest frog abundance and diversity from call counts conducted along marked transects before and after Hurricane Georges in two forests reserves of the Cordillera Central (Maricao and Guilarte). We used distance sampling to estimate density of Eleutherodactylus coqui and recorded counts of other species. After the hurricane, the abundance of E. coqui increased in both reserves compared to prehurricane levels while abundance of other frog species decreased. In Maricao, relative abundance of E. richmondi (P = 0.013) and E. brittoni (P = 0.034) were significantly lower after the hurricane. Moreover, species richness and evenness of the Maricao and Guilarte frog assemblages declined after the hurricane. Our results on abundance patterns of the forest frog assemblages of Maricao and Guilarte Forests were similar to those reported from the Luquillo Experimental Forest after Hurricane Hugo in September 1989. Long-term demographic patterns of the forest frog assemblages in the Cordillera Central may be associated with changes due to the ecological succession in post-hurricane forests. Copyright 2005 College of Arts and Sciences.

  18. New insights on the crustal thickness and its lateral variations beneath the Rif Cordillera

    NASA Astrophysics Data System (ADS)

    Gil de la Iglesia, A.; Diaz Cusi, J.; Gallart, J.; Carbonell, R.; Harnafi, M.; Levander, A.

    2014-12-01

    The Rif cordillera forms, together with the Betic ranges, one of the tightest orogenic arcs on Earth. This continental boundary zone is dominated now by the slow convergence between Nubia and Eurasia, but with clear evidences of extensional tectonics. One of the missing elements to constrain the complex geodynamics of the Gibraltar Arc System is the knowledge on crustal structure beneath northern Morocco. In the last decade a major effort has been done in this sense, from active and passive seismics. We compile here the recent results available from the Rif domains. Two 330 km long wide angle DSS profiles were recorded end of 2011 across the Rif in NS and EW transects within the Rifsis project, complemented by onshore recordings of the Gassis-WestMed marine profiles. At the same period, BB seismic arrays were deployed in the area within Topo-Iberia and Picasso projects, allowing receiver function analyses of crustal depths. The ray-tracing modeling of the Rifsis profiles reveal a large Moho step and an area of crustal thickening both in EW and NS directions, grossly coincident with the Bouguer gravity anomalies. The deployment logistics allowed that all the stations recorded all the shots, thus providing useful offline data. We will use here all available in-line and offline data to provide a map of the crustal thickness in northern Morocco. We combined two approaches: i) a hyperbolic time reduction applied to the seismic data, resulting in low-fold stacks in which the reflections from the Moho should appear as subhorizontal lines; ii) the arrival times of the observed PmP phases allow, assuming a mean crustal velocity, to assign a midpoint crustal thickness to each lecture. Although some uncertainties may be inherent to those approaches, a large crustal root, reaching more than 50 km, is well documented in the central part of the Rif Cordillera, close to the zone where the Alboran slab may still be attached to the lithosphere. We also compared these results with

  19. Active faulting in the frontal Rif Cordillera (Fes region, Morocco): Constraints from GPS data

    NASA Astrophysics Data System (ADS)

    Chalouan, Ahmed; Gil, Antonio J.; Galindo-Zaldívar, Jesús; Ahmamou, M.'Fedal; Ruano, Patricia; de Lacy, Maria Clara; Ruiz-Armenteros, Antonio Miguel; Benmakhlouf, Mohamed; Riguzzi, Federica

    2014-07-01

    The southern Rif cordillera front, between Fes and Meknes, is formed by the Prerif Ridges, which constitute a thrust and fold belt, in contact with the Saïss foreland basin. Geological evidence and regional GPS network data support recent and active tectonics of this Alpine cordillera, with a top-to-the-S-SW motion with respect to stable Africa. A local non-permanent GPS network was installed in 2007 around Fes to constrain the present-day activity of the mountain front. Six GPS sites are located in the Prerif mountain front (jbel Thratt and jbel Zalarh), the Saïss basin and the foreland constituted by the tabular Middle Atlas. Measurements of the GPS network in 2007, 2009 and 2012, over a five year span, seem to indicate that this region is tectonically active and is subjected to significant horizontal motions: (i) a regional displacement toward the SW with respect to stable Africa, showing an average rate of 2 mm/yr; (ii) a southwestward convergent motion between the jbel Thratt with respect to the Saïss basin and the eastern Zalarh ridge, with an average rate of about 4 mm/yr; and (iii) moderate NNE-SSW divergent dextral motion between the Saïss basin and the northern front of the tabular Middle Atlas with an average rate of about 1-2 mm/yr. The regional southwestward motion is related to the activity of the NE-SW sinistral North Middle Atlas-Kert fault zone, which follows the Moroccan Hot Line. Convergence between the Prerif ridges, located at the southern edge of the Rif, and the Saïss basin is accommodated by ENE-WSW striking northward dipping reverse sinistral faults and south vergent folds. In addition, increasing deformation toward the western ridges is in agreement with the stepped mountain front and the development of the arched structures of the Prerif ridges. Normal faults located south of the Saïss basin are responsible for local extension. Whereas the most active deformation occurs in the southern front of the jbel Thratt near Fes, the Sa

  20. Constraining the crustal root geometry beneath the Rif Cordillera (North Morocco)

    NASA Astrophysics Data System (ADS)

    Diaz, Jordi; Gil, Alba; Carbonell, Ramon; Gallart, Josep; Harnafi, Mimoun

    2016-04-01

    The analyses of wide-angle reflections of controlled source experiments and receiver functions calculated from teleseismic events provide consistent constraints of an over-thickened crust beneath the Rif Cordillera (North Morocco). Regarding active source data, we investigate now offline arrivals of Moho-reflected phases recorded in RIFSIS project to get new estimations of 3D crustal thickness variations beneath North Morocco. Additional constrains on the onshore-offshore transition are derived from onland recording of marine airgun shots from the coeval Gassis-Topomed profiles. A regional crustal thickness map is computed from all these results. In parallel, we use natural seismicity data collected throughout TopoIberia and PICASSO experiments, and from a new RIFSIS deployment, to obtain teleseismic receiver functions and explore the crustal thickness variations with a H-κ grid-search approach. The use of a larger dataset including new stations covering the complex areas beneath the Rif Cordillera allow us to improve the resolution of previous contributions, revealing abrupt crustal changes beneath the region. A gridded surface is built up by interpolating the Moho depths inferred for each seismic station, then compared with the map from controlled source experiments. A remarkably consistent image is observed in both maps, derived from completely independent data and methods. Both approaches document a large modest root, exceeding 50 km depth in the central part of the Rif, in contrast with the rather small topographic elevations. This large crustal thickness, consistent with the available Bouguer anomaly data, favor models proposing that the high velocity slab imaged by seismic tomography beneath the Alboran Sea is still attached to the lithosphere beneath the Rif, hence pulling down the lithosphere and thickening the crust. The thickened area corresponds to a quiet seismic zone located between the western Morocco arcuate seismic zone, the deep seismicity area

  1. Historical and future hydrologic response to glacier recession in the Cordillera Real, Bolivia

    NASA Astrophysics Data System (ADS)

    Frans, C. D.; Istanbulluoglu, E.; Naz, B.; Lettenmaier, D. P.; Condom, T.; Clarke, G. K.; Burns, P. J.; Nolin, A. W.

    2013-12-01

    In many partially glaciated watersheds climate-forced glacier recession has altered and will continue to alter seasonal water availability, leading to profound implications for water supply systems. The tropical glaciers of the Cordillera Real, Bolivia, whose melt water significantly contributes to water supply and energy production for the densely populated La Paz area, have retreated at unprecedented rates since the 1970's. This glacier recession will continue with ongoing increasing temperatures projected for the subtropical Andes. We use a recently developed glacio-hydrological model to evaluate the contribution of glacier melt to watershed discharge, and track this contribution in time with changing glacier area. A glacier model, solving time-evolving and spatially-distributed balance equations for glacier mass and momentum, is integrated within the Distributed Hydrology Soil Vegetation Model (DHSVM). The glacio-hydrologic behavior of Cordillera Real watersheds is simulated during the historical period of 1987-2010. This model application is validated through comparisons with satellite derived glacier extent estimates and in-situ mass balance, surface energy flux, and stream discharge measurements. The retrospective analysis indicates that glacier melt contributed, on average, 31% (63%) of total annual (dry season-JJA) watershed discharge. Further, the modeling approach is used to predict the transitioning contribution of glacier melt and watershed hydrology through the 21st century. Multiple realizations of the 21st century meteorological data, used to force the glacier-hydrological model, are produced using a stochastic statistical downscaling technique. In this technique a weather generator (Advanced Weather Generator, AWE-GEN) is employed with statistical parameters of the future climate obtained from predictions of 11 CMIP5 general circulation models (GCMs). Future simulations indicate a 17% (23%) decrease in annual (JJA) runoff by the end of the 21st

  2. New tools for integrative thermochronology, and their application to the Colombian Eastern Cordillera

    NASA Astrophysics Data System (ADS)

    Ketcham, R. A.; Mora, A.; Almendral, A.; Parra-Amezquita, M.; Casallas, W.; Robles, W.

    2013-12-01

    We present two new tools for interpreting thermochronometric data that facilitate the joint use of multiple samples to better constrain thermal history, and demonstrate their utilization in the Colombian Eastern Cordillera. The first, Fetkin, is a finite element solver that takes as input a series of detailed balanced cross sections created using dedicated software such as (2D)Move, and solves the heat flow equation in 2D along with predicted thermochronometric ages which can be compared against measured data. It also performs an independent analysis of the cross sections and flags aspects that are structurally out of balance. It is distinguished from similar tools in 2D and 3D principally by providing a level of detail that allows for investigation of samples in very specific and complex structural contexts, and a workflow that allows the interpreter to engage in successive refinements of the structural model using the inferences provided by thermochronometric data. The second tool is a new set of functionality in HeFTy for inverse modeling of thermochronometric data that allows for simultaneous modeling of samples down a well or borehole. This extension forces attention on issues that have previously been relatively neglected in such modeling, in particular that of multiple provenance. It is axiomatic that mineral grains in different strata may have come from different regions and have different inherited thermal histories. Interpreting such data in a realistic geological context thus requires allowing for different inherited populations within and between samples. The rewards in doing so include more robust modeling and interpretation and, in some cases, insights concerning the unroofing histories of the source rocks that contributed to a given sedimentary unit. Similarly, the mutual constraints imposed by modeling multiple samples with known or constrained depositional and structural context considerably amplifies the resolving power of thermochronometric data

  3. Downscaling reanalysis data to high-resolution variables above a glacier surface (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Hofer, Marlis; Mölg, Thomas; Marzeion, Ben; Kaser, Georg

    2010-05-01

    Recently initiated observation networks in the Cordillera Blanca provide temporally high-resolution, yet short-term atmospheric data. The aim of this study is to extend the existing time series into the past. We present an empirical-statistical downscaling (ESD) model that links 6-hourly NCEP/NCAR reanalysis data to the local target variables, measured at the tropical glacier Artesonraju (Northern Cordillera Blanca). The approach is particular in the context of ESD for two reasons. First, the observational time series for model calibration are short (only about two years). Second, unlike most ESD studies in climate research, we focus on variables at a high temporal resolution (i.e., six-hourly values). Our target variables are two important drivers in the surface energy balance of tropical glaciers; air temperature and specific humidity. The selection of predictor fields from the reanalysis data is based on regression analyses and climatologic considerations. The ESD modelling procedure includes combined empirical orthogonal function and multiple regression analyses. Principal component screening is based on cross-validation using the Akaike Information Criterion as model selection criterion. Double cross-validation is applied for model evaluation. Potential autocorrelation in the time series is considered by defining the block length in the resampling procedure. Apart from the selection of predictor fields, the modelling procedure is automated and does not include subjective choices. We assess the ESD model sensitivity to the predictor choice by using both single- and mixed-field predictors of the variables air temperature (1000 hPa), specific humidity (1000 hPa), and zonal wind speed (500 hPa). The chosen downscaling domain ranges from 80 to 50 degrees west and from 0 to 20 degrees south. Statistical transfer functions are derived individually for different months and times of day (month/hour-models). The forecast skill of the month/hour-models largely depends on

  4. Petrographic and Geochemical Characterization of the Cambumbia STOCK in Andean Central Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Rojas Lequerica, S.; Jaramillo Mejía, J.; Concha Perdomo, A.

    2012-12-01

    The Cambumbia Stock is located on the western flank of the Central Cordillera of the northern Andes. The goals of this study were to petrographic and geochemically characterize the Cambumbia igneous body and to establish its petrogenetic history. 41 samples were collected, 28 for petrographic analysis and 14 for elementary chemical determination by ICP-MS. Petrographically the samples were classified as hornblende and pyroxene-gabbros varying to diorites, gabbronorites and tonalites, the rock texture varies from medium to coarse granular grain, with local microporfiritic texture. It was concluded from the major elements analysis that the samples correspond to the sub-alkaline series with low K content, mainly in the calc-alkaline series, within the gabbros and diorites fields. By using the SiO2 vs TiO2 (Jaramillo, 1980), Th/Yb vs Ta/Yb (Pearce, 1984) (Fig. 1) and Zr/117-Th-Nb/16 (Wood, 1979) diagrams it was determined that these rocks were generated in two geotectonic environments: one type MOR (extension) and other island arc (subduction, compression). Petrographic and geochemical comparisons between the rocks of Cambumbia Stock and Diorite and Gabbro El Pueblito (Giraldo, 2009) (located about 25 km to the north-west) may postulate a possible genetic link between them. Recently, a U/Pb age was obtained by the Universidad de Caldas in zircon in 2009 (not published data), yielded an age of 233.41 ± 3.4 Ma (Middle Triassic). This age is consistent with the global event of the extension and fragmentation of Pangea supercontinent. In addition, the mantle nature of the source and the petrogenetic evolution of the magmatic system were established. References GIRALDO, M.I., (2009): Esquema geodinámica de la parte noroccidental de la cordillera Central de Colombia. (Thesis). p.56-68. Universidad Nacional de Colombia, Medellín. JARAMILLO, J.M. (1980): Petrology and geochemistry of the Nevado del Ruiz Volcano northern Andes, Colombia (Thesis). 167 p. University of Houston

  5. [Nuclear medicine in Spain: high technology 2013].

    PubMed

    Soriano Castrejón, A M; Prats Rivera, E; Alonso Farto, J C; Vallejo Casas, J A; Rodriguez Gasen, A; Setoain Perego, J; Arbizu Lostao, J

    2014-01-01

    This article details the high technology equipment in Spain obtained through a survey sent to the three main provider companies of equipment installed in Spain. The geographical distribution of high technology by Autonomous Communities and its antiquity have been analyzed.

  6. Light pollution in Spain 2010

    NASA Astrophysics Data System (ADS)

    Sánchez de Miguel, A.; Zamorano, J.; Pila-Díez, B.; Rubio, J.; Ruiz, R.; Rodríguez-Herranz, I.; González-Pérez, A.

    2011-11-01

    The most recent data on electricity consumption for public lighting inSpain is presented and compared with light pollution measurements asderived from night satellite imagery. NOAA-MSP images (low-resolution)and higher resolution images obtained with conventional DSLR cameras on board the International Space Station (ISS) have been used.We show that the data can be related to night sky brightness maps with a study conducted within the Comunidad Autónoma de Madrid. Weintend to extend our work to the rest of Spain through tight collaborationwith amateur astronomers.

  7. Impact of the Hapagea surpercontinental aggregation on American Cordilleras and the seafloor age distribution

    NASA Astrophysics Data System (ADS)

    Husson, L.; Conrad, C. P.

    2009-12-01

    The ongoing aggregation of Africa, Arabia, India and Australia onto Eurasia is forming a supercontinent that we refer to as Hapagea. Although not as large as the older Pangea and Rodinia, Hapageais nevertheless large enough to profoundly modify Cenozoic plate kinematics as it gradually becomes a hub apart from which American continents spread. The continuation of Atlantic spreading is carried out at the expense of the Pacific Ocean, forcing the Farallon / Nazca plates down into eastern Pacific subduction zones, despite the fact that this seafloor is theoretically too young and too buoyant to subduct efficiently. This process occurred later for South America, where the subduction of the Tethys buffered the impact of the Atlantic expansion, and earlier for North America where this configuration was never met. The implications of the current plate tectonics are multiple and include (i) increased compression on the western coasts of the Americas, leading to Cordillera formation in North America (Sevier and Laramide) and later in South America (Andean), (ii) the transition from a rectangular distribution of seafloor ages to a triangular distribution as westward progress of the Americas engulfs young Farallon/Nazca seafloor, and (iii) a decrease in the convective efficiency of mantle flow that results in decreased rates of lithospheric productionat ridges, a situation that is cyclically met during the Wilson cycle and diminishes both mantle heat flow and sea level. These results imply that mantle drag causes the Atlantic spread and dominates the force balance of the Earth’s lithospheric shell.

  8. Recent evolution and degradation of the bent Jatunraju glacier (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Emmer, Adam; Loarte, Edwin C.; Klimeš, Jan; Vilímek, Vít

    2015-01-01

    This article brings new insight into the recent evolution and degradation of the bent Jatunraju glacier in the northern part of the Cordillera Blanca, Peru. Analysis of topographical maps, aerial photos and satellite images covering a period of 66 years and a field survey performed in June 2013 and May 2014 helped to describe the geomorphological setting and ongoing processes. Recent evolution and degradation processes are also deduced from surface movements. Historical geodetic measurements (1967-1968; 1977-1984) and current LANDSAT images (2001-2013) were used to estimate surface velocities and changes in surface velocities over time. Our investigation showed that the most significant changes happened at an altitude of between 4300 and 4450 m asl. A significant decrease in surface velocities and increase in debris thickness indicate that this part of Jatunraju turned from a debris-covered glacier into an ice-cored rock glacier during the analyzed period. Particular parts of the article describe the cycle of formation and extinction of supraglacial lakes and the melting of buried (debris-covered) ice. A scenario of future evolution is outlined and discussed as well. We assume that ice degradation within the debris-covered glacier will continue and that the altitude of its presence will increase hand-in-hand with the changing environment.

  9. Spatial Patterns of Preinstrumental Moisture Variability in the Southern Canadian Cordillera.

    NASA Astrophysics Data System (ADS)

    Watson, Emma; Luckman, Brian H.

    2005-08-01

    Extreme wet and dry intervals of the last 350 yr in the Canadian Cordillera and adjacent United States are examined using a network of 25 tree-ring-based precipitation and Palmer Drought Severity Index (PDSI) reconstructions. Reconstructed twentieth-century-mapped patterns compare well with patterns based on the instrumental records at both annual and decadal scales. During the most extreme events, dry conditions occurred over the entire area. The longest widespread drought in the last 350 yr occurred from 1917 to 1941. Shorter intervals of more severely dry conditions occurred in the early 1720s, 1750s, 1790s, 1860s-70s, and the 1890s. Many of the driest individual years and most extreme dry periods of <7 yr are reconstructed for the eighteenth century. The longest, wettest periods identified by these reconstructions occurred in the early twentieth century. In agreement with published studies that explore links between instrumental precipitation records from the region and conditions in the Pacific Ocean, the reconstructed records show that drier (wetter)-than-normal conditions are associated with El Niño (La Niña) events and the positive (negative) phase of the Pacific decadal oscillation (PDO).

  10. The unusual nature of recent snowpack declines in the North American cordillera

    USGS Publications Warehouse

    Pederson, Gregory T.; Gray, Stephen T.; Woodhouse, C.A.; Betancourt, Julio L.; Fagre, Daniel B.; Littell, Jeremy S.; Watson, Emma; Luckman, B.H.; Graumlich, Lisa J.

    2015-01-01

    In western North America, snowpack has declined in recent decades, and further losses are projected through the 21st century. Here, we evaluate the uniqueness of recent declines using snowpackreconstructions from 66 tree-ring chronologies in key runoff-generating areas of the Colorado, Columbia, and Missouri River drainages. Over the past millennium, late 20th century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains and in their north-south synchrony acrossthe cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming that is due to positive reinforcement of the anthropogenic warming by decadal variability. The increasing roleof warming on large-scale snowpack variability and trends foreshadows fundamental impacts on streamflow and water supplies across the western United States.

  11. Lake sediment record of neo-glacial advances in the southwestern Cordillera Raura, Peruvian Andes

    NASA Astrophysics Data System (ADS)

    Stansell, N. D.; Abbott, M. B.

    2006-12-01

    Radiocarbon dated lake sediments are used to identify the timing of middle and late Holocene glacial advances in the southwestern Cordillera Raura of central Peru. Elemental iron, titanium and calcium data, obtained using scanning X-Ray Fluorescence (XRF), record relative changes in the rate of deposition of titanium/iron-rich versus calcium-rich sediments. Magnetic susceptibility, coulometry and digital color analyses of high- resolution core-scan images complement the XRF data. Combined, the data indicate that glacial advances in the watershed took place from 3320 to 2490 cal. yr BP, 2400 to 2190 cal. yr BP, 1780 to 1385 cal. yr BP and 790 to 270 cal. yr BP. Independent ice core data and lake level records suggest that the advances from 3320 to 2490 and from 2400 to 2190 cal. yr BP took place during colder and drier periods. The advance from 1780 to 1385 cal. yr BP was initially during a cold and drier period from 1780 to 1615 cal. yr BP, followed by a warmer and wetter period from 1615 to 1385 cal. yr BP. Likewise, the advance from 790 to 270 cal. yr BP initially took place during a cold and drier period followed by a cold and wetter period from 620 to 270 cal. yr BP.

  12. Results of land cover change detection analysis in and around Cordillera Azul National Park, Peru

    USGS Publications Warehouse

    Sleeter, Benjamin M.; Halsing, David L.

    2005-01-01

    The first product of the Optimizing Design and Management of Protected Areas for Conservation Project is a land cover change detection analysis based on Landsat thematic mapper (TM) and enhanced thematic mapper plus (ETM+) imagery collected at intervals between 1989 and 2002. The goal of this analysis was to quantify and analyze patterns of forest clearing, land conversion, and other disturbances in and around the Cordillera Azul National Park in Peru. After removing clouds and cloud shadows from the imagery using a series of automatic and manual processes, a Tasseled Cap Transformation was used to detect pixels of high reflectance, which were classified as bare ground and areas of likely forest clearing. Results showed a slow but steady increase in cleared ground prior to 1999 and a rapid and increasing conversion rate after that time. The highest concentrations of clearings have spread upward from the western border of the study area on the Huallaga River. To date, most disturbances have taken place in the buffer zone around the park, not within it, but the data show dense clearings occurring closer to the park border each year.

  13. Varve deposition and the sediment yield record at three small lakes of the southern Canadian Cordillera

    SciTech Connect

    Desloges, J.R. )

    1994-05-01

    Lacustrine sediments deposited in three small glacier-fed lakes of the southern Canadian Cordillera are derived primarily from subglacial erosion and delivered via short proglacial streams or by direct melting and calving of cirque glaciers. Sediment transport and deposition during early summer is controlled by runoff-generated bottom currents and in the late summer through winter by settling from suspension. This forms distinct rhythmic laminations of silt and clay in distal lake areas. Cesium-137 content in all three lakes indicates that these are varve sediments. Time series of varve thickness covering the interval 1863 to present show distinct declines in sediment yield from 310 to less than 150 t km[sup [minus]2] a[sup [minus]1]. The decline is related to sediment exhaustion following glacier retreat from Little Ice Age maxima and the opening of intervening sediment storage sites. Annual varve thickness is significantly related to fluctuations in summer or late summer temperature highlighting the importance of ice ablation, melt-water runoff, and subglacial sediment sources in controlling deposition rates. Singular climate events, such as autumn storms provide distinctive sedimentary signatures in the varve record. Reconstructed sediment yield for the Little Ice Age is as much as 100% greater than the average Holocene rate. 39 refs., 8 figs., 2 tabs.

  14. Mid-tertiary volcano-tectonic development of the Southwestern Cordillera of North America

    NASA Technical Reports Server (NTRS)

    Nelson, Kerri L.

    1987-01-01

    In the Southwestern Cordillera (SC) of North America, volcanic style changed from dominantly calcalkaline stratovolcanoes to caldera-related magmatism during the mid-Tertiary. The dominant tectonic process affecting the region during this time was convergence of the Farallon and North American Plates. The change in style of volcanism indicates a change in the operative stress regime: compressional for the earlier calcalkaline volcanism and tensional for development of the calderas. The development of the centers were compared to evaluate the volcano-tectonic relationship of caldera development within and between centers and determine the relationships between the earlier calcalkaline and later caldera-style volcanisms. The calderas exhibit three distinct stages of development that are closely associated with the East Pacific Rise/trench collision. The spatial and temporal association of the calcalkaline and caldera-related volcanism argues for the SC representing a region of continued arc magnetism in which the style of volcanism varied in response to differences in regional stresses.

  15. In Spain, Inbreeding Threatens Academe

    ERIC Educational Resources Information Center

    Rocca, Francis X.

    2007-01-01

    With 25 years of teaching experience at Spain's top-ranked veterinary school, 58 articles in prestigious international journals, and numerous patents to her name, Victoria Lopez Rodas would be a strong candidate for any academic job in her field. So when she took a national qualifying examination for a full professorship in animal science last…

  16. Novel Lyssavirus in Bat, Spain

    PubMed Central

    Morón, Sonia Vázquez; Berciano, José M.; Nicolás, Olga; López, Carolina Aznar; Juste, Javier; Nevado, Cristina Rodríguez; Setién, Álvaro Aguilar; Echevarría, Juan E.

    2013-01-01

    A new tentative lyssavirus, Lleida bat lyssavirus, was found in a bent-winged bat (Miniopterus schreibersii) in Spain. It does not belong to phylogroups I or II, and it seems to be more closely related to the West Causasian bat virus, and especially to the Ikoma lyssavirus. PMID:23648051

  17. Slope deformations in high-mountain regions as observed by InSAR: Examples from the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Frey, Holger; Strozzi, Tazio; Caduff, Rafael; Huggel, Christian; Klimeš, Jan; Vilímek, Vít; Wiesmann, Andreas; Kääb, Andreas; Cochachin, Alejo; Plummer, Stephen

    2016-04-01

    Steep topography, the world's highest concentration of tropical glaciers, numerous glacial lakes and strong seismic activity combined with a densely populated valley bottom in the Rio Santa basin characterize the Cordillera Blanca in Peru. Besides glacier-related processes, a variety of landslide types and processes is present outside the glaciated areas, favoured by the steep terrain, geological conditions, sparse vegetation, intense precipitation, and strong seismicity. This combination of high hazard potentials and vulnerabilities results in a long list of natural disasters. Information on surface displacements is very valuable for early detection of emerging hazard potentials and their assessment. Interferometric processing of SAR data (InSAR) provides the possibility to remotely detect different types of surface displacement processes, also in remote locations where no other monitoring data are available. This contribution, developed under the ESA-funded S:GLA:MO project (sglamo.gamma-rs.ch), shows the potential of InSAR products for hazard assessments and glaciological investigations in high-mountain regions. We present a selection of different surface displacements as observed in the Cordillera Blanca based on InSAR data: a landslide zone near the Rampac Grande village, where in 2009 a landslide caused casualties and property loss; a landslide at the entry of the Santa Cruz Valley, northern Cordillera Blanca, where the displacement history could be reconstructed over five years; surface displacements at the interior moraine slopes surrounding Laguna Palcacocha, a major glacier lake above the city of Huaraz, which are compared to and complemented by geophysical investigations in the field; surface displacements at the moraine damming Laguna Safuna Alta, a glacier lake in the northern part of the Cordillera Blanca; glacier velocities across the entire Cordillera Blanca, revealing ice flow velocities of more than 200 m yr-1 at certain locations at the end of

  18. Ophiolites and Continental Margins of the Mesozoic Western U.S. Cordillera

    NASA Astrophysics Data System (ADS)

    Dilek, Y.

    2001-12-01

    The Mesozoic tectonic history of the western U.S. Cordillera records evidence for multiple episodes of accretionary and collisional orogenic events and orogen-parallel strike-slip faulting. Paleozoic-Jurassic volcanic arc complexes and subduction zone assemblages extending from Mexico to Canada represent an East-Pacific magmatic arc system and an accretionary-type orogen evolved along the North American continental margin. Discontinuous exposures of Paleozoic upper mantle rocks and ophiolitic units structurally beneath this magmatic arc system are remnants of the Panthalassan oceanic lithosphere, which was consumed beneath the North American continent. Pieces of this subducted Panthalassan oceanic lithosphere that underwent high-P metamorphism are locally exposed in the Sierra Nevada foothills (e.g. Feather River Peridotite) indicating that they were subsequently (during the Jurassic) educted in an oblique convergent zone along the continental margin. This west-facing continental margin arc evolved in a broad graben system during much of the Jurassic as a result of extension in the upper plate, keeping pace with slab rollback of the east-dipping subduction zone. Lower to Middle Jurassic volcanoplutonic complexes underlain by an Upper Paleozoic-Lower Mesozoic polygenetic ophiolitic basement currently extend from Baja California-western Mexico through the Sierra-Klamath terranes to Stikinia-Intermontane Superterranes in Canada and represent an archipelago of an east-facing ensimatic arc terrane that developed west and outboard of the North American continental margin arc. The Smartville, Great Valley, and Coast Range ophiolites (S-GV-CR) in northern California are part of this ensimatic terrane and represent the island arc, arc basement, and back-arc tectonic settings, respectively. The oceanic Josephine-Rogue-Chetco-Rattlesnake-Hayfork tectonostratigraphic units in the Klamath Mountains constitute a west-facing island arc system in this ensimatic terrane as a

  19. Une faune très diversifiée du Pléistocène inférieur de la Sierra de Quibas (province de Murcia, Espagne)A very diverse Lower Pleistocene faunistic assemblage from Sierra de Quibas (province of Murcia, Spain)

    NASA Astrophysics Data System (ADS)

    Montoya, Plinio; Alberdi, María. Teresa; Barbadillo, Luis Javier; van der Made, Jan; Morales, Jorge; Murelaga, Xabier; Peñalver, Enrique; Robles, Fernando; Ruiz Bustos, Antonio; Sánchez, Antonio; Sanchiz, Borja; Soria, Dolores; Szyndlar, Zbigniew

    2001-03-01

    The Quaternary karstic site of Sierra de Quibas (Abanilla, province of Murcia, Spain) has provided a wide faunal list with more than 60 species. The assemblage of the taxa Arvicola deucalion, Castillomys rivas rivas, Eliomys intermedius, Equus altidens, Capra sp. aff. C. alba and cf. Praeovibos allows the correlation with other Spanish Lower Pleistocene sites in the Betic Cordillera, as Plines 1, Orce 3 and Venta Micena. Therefore Quibas can be located between 1.3 and 1.0 Ma. The palaeoenvironmental features of the area around the karstic cavity and the palaeoclimatic regime are inferred.

  20. Infrared Imaging and Modeling of Proglacial Stream Temperature in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Baker, E. A.; Lautz, L.; McKenzie, J. M.; Aubry-Wake, C.; Somers, L. D.; Wigmore, O.; Glose, A.; Glas, R. L.; Mark, B. G.

    2015-12-01

    In the tropical Andes, glacial meltwater is an important water resource for downstream communities, especially during the dry season. Due to climate change, glacial retreat is accelerating and straining already limited water resources in the region. It is hypothesized that groundwater storage and discharge will play a critical role in sustaining future river flows. To improve our understanding of the hydrologic fluxes in proglacial valleys of the tropical Andes, we monitored a ~1.2 km reach of the Quilcayhuanca River, in the Cordillera Blanca, Peru, using a high resolution infrared (IR) camera and in-stream temperature sensors. We positioned the IR camera on the southern valley wall, 96 m above the valley floor, and collected >700 IR images at 10 minute intervals over 5 days. We deployed 40 temperature sensors along the stream at ~25 m intervals and 10 sensors at additional control points throughout the surrounding valley, recording temperature at 10 minute intervals. Groundwater temperature was recorded in 6 wells in the study area. The reach had diurnal temperature fluctuations from ~4 to 13°C, but did not exhibit large longitudinal temperature differences. Stream temperature profiles within the water column show stream water is well mixed, improving the ability of the IR camera to accurately observe the stream temperature at this research site. Temperature sensors in 4 reach tributaries recorded warmer temperatures than the main channel. The daily temperatures of one tributary fluctuated within the range of the groundwater temperature (~9 to 11°C), while another tributary exhibited a range of ~18°C. A weather station in the study area recorded climate data (air temperature, humidity, wind speed, solar radiation) at 10 minute intervals. We used this field data as input for a spatial and temporal energy balance model of the reach. Our model demonstrates the utility of IR imagery to monitor stream temperatures and improves our understanding of energy fluxes in

  1. New measurements of particulates in glacial snow and ice in the Cordillera Blanca mountains of Peru

    NASA Astrophysics Data System (ADS)

    All, J.; Schmitt, C.; Celestian, A. J.; Rucks, M.; Arnott, W. P.; Cole, R.

    2012-12-01

    During the local dry season (June/July) of 2011 and 2012, the American Climber Science Program (organized with the assistance of the American Alpine Club) conducted scientific expeditions in Huascaran National Park in Peru. The Park is located in the Cordillera Blanca mountain range and contains the world's largest collection of tropical mountain glaciers. One component of the environmental research program was sampling particulates on glacier surfaces by means of snow collection and filtration. Over 150 samples were collected during the two expeditions by volunteer climbers working with scientists in the field. Glacier snows were collected on over fifteen peaks throughout the range at altitudes from 4800 to nearly 6800 meters. Snow samples were kept frozen until the climber-scientists returned to basecamp - at which point they were rapidly melted and then immediately filtered through 0.7 micron PallFlex tissuequartz filters. The particulates captured on the filters have been analyzed for their bulk heat absorption properties as well as to determine the properties of individual particles through X-ray diffraction for bulk mineral identification, and Raman microscopy for chemical mapping of minerals. Preliminary results indicate that snow age, altitude, as well as geographic location (with respect to urban areas, mines, and predominant wind direction) all play significant roles in the amount and types of contaminants. Multiple locations were sampled during both expeditions as well as at different times during the same climbing season. Results include the relative heating capacity of the samples at various wavelengths as well as mineral composition information across the range. Local weather patterns and geographic observations will be used to identify potential sources of contaminants. Sampling will continue under the American Climber Science Program in 2013 and beyond.

  2. Paleontologic and stratigraphic relations of phosphate beds in Upper Cretaceous rocks of the Cordillera Oriental, Colombia

    USGS Publications Warehouse

    Maughan, Edwin K.; Zambrano O., Francisco; Mojica G., Pedro; Abozaglo M., Jacob; Pachon P., Fernando; Duran R., Raul

    1979-01-01

    Phosphorite crops out in the Cordillera Oriental of the Colombian Andes in rocks of Late Cretaceous age as strata composed mostly of pelletal carbonate fluorapatite. One stratum of Santonian age near the base of the Galembo Member of the La Luna Formation crops out at many places in the Departments of Santander and Norte de Santander and may be of commercial grade. This stratum is more than one meter thick at several places near Lebrija and near Sardinata, farther south it is locally one meter thick or more near the base of the Guadalupe Formation in the Department of Boyaca. Other phosphorite beds are found at higher stratigraphic levels in the Galembo Member and the Guadalupe Formation, and at some places these may be commercial also. A stratigraphically lower phosphorite occurs below the Galembo Member in the Capacho Formation (Cenomanian age) in at least one area near the town of San Andres, Santander. A phosphorite or pebbly phosphate conglomerate derived from erosion of the Galembo Member forms the base of the Umir Shale and the equivalent Colon Shale at many places. Deposition of the apatite took place upon the continental shelf in marine water of presumed moderate depth between the Andean geosyncline and near-shore detrital deposits adjacent to the Guayana shield. Preliminary calculations indicate phosphorite reserves of approximately 315 million metric tons in 9 areas, determined from measurements of thickness, length of the outcrop, and by projecting the reserves to a maximum of 1,000 meters down the dip of the strata into the subsurface. Two mines were producing phosphate rock in 1969; one near Turmeque, Boyaca, and the other near Tesalia, Huila.

  3. Mesozoic igneous activity in the southern Cordillera of North America: Implications for tectonics and magma genesis

    SciTech Connect

    Asmerom, Y.

    1988-01-01

    A representative section in Santa Rita Mountains is dated using the zircon U-Th-Pb isotopic method. The oldest unit, the lower member of the Mt. Wrightson Formation, is concordantly dated at 210 {plus minus} 3 Ma. Initial basaltic andesite to andesite volcanism was followed by deposition of red beds and associated volcanic rocks that are dated at 200 Ma. Felsic volcanism and eolian sand deposition may have spanned from 190 to 170 Ma. The Piper Gulch Granodiorite, representing the earliest Mesozoic intrusive equivalent, gives concordant dates of 188 {plus minus}2 Ma. A second cycle of andesite and rhyolitic volcanism and sedimentation is dated at 151 {plus minus} 5 Ma using the whole-rock Rb-Sr isotopic method. The Hovatter Volcanics in the Little Harquahala Mountains, southwestern Arizona is dated at 165 Ma. Whole-rock Rb-Sr isotopic method on the same rocks gives a coherent reset isochron of 70 {plus minus} 3 Ma. A new stratigraphic correlation is proposed based on the dating data. This part of the Cordillera was an uplifted arc terrane during the Early Mesozoic and may have provided volcanic detritus to the Late Triassic Chinle Formation in the Colorado Plateau. The second part deals with magma evolution and crust modification during arc magmatism. Rocks in southeastern Arizona have {sub Nd} values of {minus}3.4 to {minus}6.4, while rocks to the west have {sub Nd} values ranging from {minus}8.5 to {minus}9.2. Combined REE and isotopic data indicate that assimilation of lower crust by mantle melts followed by fractional crystallization took place.

  4. Water Resources and Groundwater in a Glaciated Andean Watershed (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Gordon, R.; Baraer, M.; Lautz, L.; Mark, B. G.; Wigmore, O.; Chavez, D.; Aubry-Wake, C.

    2014-12-01

    It is estimated that almost 400 million people live in watersheds where glaciers provide at least 10% of the runoff, yet many questions remain regarding the impact of climate change and glacier recession on water resources derived from these high mountain watersheds. We present research from the Cordillera Blanca, Peru, an area with the highest density of glaciers in the tropics. While glacier meltwater buffers stream discharge throughout the range, groundwater is a major component of dry season runoff, contributing up to 50-70% of outflow in some tributaries. In order to predict future changes to water resources it is critical to understand how groundwater can offset future hydrologic stress by maintaining stream baseflow, including recharge mechanisms, subsurface pathways, storage, and net fluxes to rivers. We present a synthesis of results based on hydrologic modeling, drilling/piezometers, geophysics, and artificial and natural hydrologic tracers. Our findings show that 'pampas', low-relief mountain valleys, are critical for baseflow generation by storing groundwater on interannual timescales. Pampas have a total area of ~65 km2 and are comprised of unconsolidated glacial, talus, lacustrine and wetland (bofedales) deposits. The valleys commonly have buried talus aquifers that are overlain by low permeability, glaciolacustrine deposits. Glaciofluvial outwash deposits and small wetlands also act as unconfined aquifers. These groundwater systems appear to be primarily recharged by wet season precipitation, and at higher elevations also by glacial meltwater. Additionally a ubiquitous feature in the valleys are springs, often located at the base of talus deposits, which generate a large hydrologic flux within the hydrologic systems. While glaciers are the most visible and vulnerable component of the Andean waterscape, we argue that it is crucial to understand the complete mountain hydrologic cycle, including groundwater, in order to understand the ongoing

  5. Documenting and describing the redox evolution of the Neoproterozoic ocean: lessons from the Canadian Cordillera (Invited)

    NASA Astrophysics Data System (ADS)

    Johnston, D. T.; Poulton, S. W.; Langmuir, C. H.; MacDonald, F. A.; Chen, Z.; Knoll, A.

    2009-12-01

    The geological record of the Neoproterozoic preserves evidence for large-scale perturbations in Earth’s climate and changes in tectonic configuration. During the terminal Proterozoic, and within the context of these changes, Earth’s fluid envelope achieved a level of oxygenation that allowed for the evolution and subsequent radiation of complex multi-cellular life. As such, better constraining the geochemical evolution of the oceans and atmosphere throughout the entire Neoproterozoic will allow for a more mechanistic understanding of the links between changing environmental chemistry and biological innovation. Further, it will provide information on the relative timing of these changes and, where robust dates are available, estimates on the absolute rates of change (both chemical and biological). To this end, our ongoing work has focused on constructing high stratigraphic resolution geochemical records through mixed lithological packages of sedimentary rocks from eastern Alaska and the Canadian Cordillera. Here, we present detailed chemostratigraphic reconstructions of redox sensitive proxies, including Fe-speciation and trace element budgets, that provide an integrated window into Neoproterozoic marine oxidant budgets. These oxidant budgets then allow for the modeling of the relative influence of different aerobic and anaerobic microbial processes on the overall carbon cycle. Taken together, it is this cascade of microbial processes that drives remineralization reactions, the sum of which serves to counter-act organic carbon export, which is ultimately responsible for the buildup of O2. This simple framework serves as the foundation for our interpretation of Neoproterozoic biogeochemistry and informs our view of late Precambrian marine ecosystems. This approach can be further applied to more specific, and perhaps even more anomalous intervals of Neoproterozoic Earth history, including the Cryogenian Bitter Springs event and the Ediacaran Shuram anomaly; both

  6. Wealth of P-T-t information in medium-high grade metapelites: Example from the Jubrique Unit of the Betic Cordillera, S Spain

    NASA Astrophysics Data System (ADS)

    Massonne, Hans-Joachim

    2014-11-01

    It is demonstrated here that medium-high grade metapsammopelites contain a wealth of information to derive a well-constrained P-T-t path relevant for the understanding of the geodynamics resulting in a collisional orogen. The presented example is related to three samples from the Migmatite gneiss zone of the Jubrique Unit, being part of the Alpujárride Complex half way between Malaga and Cadiz. The rocks were studied to determine their pressure (P)-temperature (T) evolution mainly on the basis of the zonation of mm-sized garnet and contoured P-T pseudosections calculated with PERPLE_X. In addition, monazite was dated with the electron microprobe. Ca-poor garnet cores yielded granulite-facies P-T conditions around 0.7 GPa and 800 °C. This metamorphic event occurred in late Hercynian times [287 ± 9 (2σ) Ma] according to monazite enclosed in such garnet cores. The cores are surrounded by a Ca-richer garnet zone, which points to a high-pressure (HP) event close to 1.3 GPa and temperatures above 650 °C. At this stage, melting occurred as indicated by abundant melt inclusions in the Ca-rich garnet zone. Subsequently, the rocks were exhumed and heated to peak temperatures of 740 °C. The final metamorphic stage is characterised by late sillimanite and an outermost garnet rim which is poor in Ca. The melting event is late Alpine confirmed by age dating on monazite in the rock matrix. Similar conditions of a late Alpine HP event were also reported from other areas of the Alpujárride Complex. As the studied rocks never reached P-T conditions of the diamond stability field, it is concluded that the previously reported nanodiamonds in these rocks either grew metastably or were artificially introduced into rock thin-sections.

  7. Cretaceous exhumation history of Cordillera Darwin, southern Patagonia, from patchily recrystallized garnet and U-Th-Pb monazite dating

    NASA Astrophysics Data System (ADS)

    Maloney, K. T.; Clarke, G. L.; Klepeis, K. A.; Fanning, C. M.; Wang, W.

    2010-12-01

    Garnet in amphibolite facies pelitic schists from Bahía Pia of Cordillera Darwin displays patchy textures whereby a single grain may have regions of turbid garnet with comparatively large inclusions of biotite, muscovite, plagioclase and quartz, juxtaposed against a region of clear, “ordinary” garnet. Clear areas with S1 inclusion trails are grossular rich, whereas post-S1 turbid areas are comparatively spessartine-pyrope rich. Raman spectroscopy identified the presence of an aqueous solution in turbid regions of garnet, lacking from clear areas. Turbid patches are associated with the growth of S2 kyanite and staurolite. Pseudosection modelling in Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3 (NCKFMASHTO) is consistent with garnet mode decreasing from c. 5% to less than 1% during exhumation of Cordillera Darwin, coinciding with the growth of S2 kyanite and staurolite at P≈9 kbar and T≈625°C. Turbid garnet in patchy and atoll-style textures is inferred to reflect recrystallization facilitated by fluid ingress whereby garnet cores, formed at higher P-T conditions than the rims, were preferentially recrystallised along grain cracks and boundaries. P-T paths inferred from the modelling indicate higher metamorphic conditions than previously documented, P conditions declining from 12 to 9 kbar over T= 610 to 630°C. U-Th-Pb dating of S2 monazite indicates that rapid exhumation was underway before 72.61±1.13 Ma, reflecting a tectonic shift from burial to uplift of Cordillera Darwin between c. 86 and c. 73 Ma. Sillimanite-bearing assemblages are restricted to contact aureoles associated with the intrusion of the Late Cretaceous Beagle Suite at shallower crustal conditions.

  8. Constraining Subsurface Structure and Composition Using Seismic Refraction Surveys of Proglacial Valleys in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Glas, R. L.; Lautz, L.; McKenzie, J. M.; Mark, B. G.; Baker, E. A.; Aubry-Wake, C.; Somers, L. D.; Wigmore, O.

    2015-12-01

    As tropical glaciers rapidly recede in response to climate change, the storage and discharge of groundwater will play an increasing role in regulating river baseflow, particularly during the dry season, when stream flow is currently sustained predominantly by glacial melt. Little is understood regarding the hydrogeologic processes controlling base flow characteristics of low-gradient proglacial valleys of the Cordillera Blanca in Northwestern Peru, which has the world's highest density of tropical glaciers. To better understand the processes of groundwater storage and discharge in proglacial meadows, we completed seismic refraction surveys in three representative valleys of the Cordillera Blanca range: the Quilcayhuanca, Yanamarey, and Pachacoto valleys. The locations of survey transects were chosen based on locations of previous sediment core sampling, GPR lines, and quantification of groundwater-surface water interaction derived from dye and temperature tracing experiments. The seismic surveys consisted of 48 vertical component geophones with 2.5 m spacing. Across the three representative valleys a total of 15 surveys were conducted, covering a distance of 1800 m in cross, down, and oblique-valley directions. Preliminary interpretation of the seismic refraction data indicates a maximum imaging depth of 16 m below land surface, and a transition from glacio-lacustrine sediments to buried saturated talus at a depth of 6 m in the Quilcayhuanca valley. The organic-rich glacio-lacustrine sediments in the Yanamarey valley have seismic velocities ranging from 300 to 800 m/s and are >16 m in thickness at mid- valley. Weathered metasedimentary bedrock in the Pachacoto valley was imaged at ~5 m below the valley surface, exhibiting a p-wave velocity of 3400 m/s. The knowledge of hydrogeologic structure derived from seismic refraction surveys will provide crucial boundary conditions for future groundwater models of the valleys of the Cordillera Blanca.

  9. Late Quaternary geomorphic history of a glacial landscape - new sedimentary and chronological data from the Cordillera de Cochabamba (Bolivia)

    NASA Astrophysics Data System (ADS)

    May, J.-H.; Preusser, F.; Zech, R.; Ilgner, J.; Veit, H.

    2009-04-01

    Throughout the Central Andes, glacial landscapes have long been used for the reconstruction of Late Quaternary glaciations and landscape evolution. Much work has focused on the Andes in Peru, Chile and the Bolivian Altiplano, whereas relatively little data has been published on glaciation history in the eastern Andean ranges and slopes. Even less is known with regard to the postglacial evolution of these glacial landscapes. In the Cordillera de Cochabamba (Bolivia), local maximum advances probably peaked around 20-25 ka BP and were followed by significant readvances between ~12-16 ka BP. This generally points to temperature controlled maximum glacial advances along the humid eastern slopes of the Central Andes, which is supported by glacier-climate-modelling studies. However, most studies include only marginal information with regard to the complex geomorphic and sedimentary situation in the Cordillera de Cochabamba. Furthermore, the chronological results are afflicted with several methodological uncertainties inherent to surface exposure dating and call for application of alternative, independent age dating methods. Therefore this study aims at i) documenting and interpreting the complex glacial geomorphology of the Huara Loma valley in the Cordillera de Cochabamba (Bolivia), ii) analyzing the involved units of glacial sediments, and iii) improving the chronological framework by applying optically stimulated luminescence (OSL) and radiocarbon dating (14C). For this purpose, geomorphic mapping was combined with field documentation of sedimentary profiles. The involved sediments were subject to geochemical and mineralogical analysis in order to deduce information on their erosional and weathering histories. In addition, the interpretation of OSL ages from glacial and proglacial sediments integrated several methodological procedures with regard to sample preparation and statistical analysis of the measurements in order to increase the degree of confidence. These

  10. A distinctive new subspecies of Scytalopusgriseicollis (Aves, Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela.

    PubMed

    Avendaño, Jorge Enrique; Donegan, Thomas M

    2015-01-01

    We describe a new subspecies of Pale-bellied Tapaculo Scytalopusgriseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopusgriseicollisgriseicollis and Scytalopusgriseicollisgilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy. PMID:26085800

  11. A distinctive new subspecies of Scytalopus griseicollis (Aves, Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela

    PubMed Central

    Avendaño, Jorge Enrique; Donegan, Thomas M.

    2015-01-01

    Abstract We describe a new subspecies of Pale-bellied Tapaculo Scytalopus griseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopus griseicollis griseicollis and Scytalopus griseicollis gilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy. PMID:26085800

  12. Mapping Glacier Dynamics and Proglacial Wetlands with a Multispectral UAV at 5000m in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Wigmore, O.; Mark, B. G.

    2015-12-01

    The glaciers of the Cordillera Blanca, Peru are rapidly retreating as a result of rising temperatures, transforming the hydrology and impacting the socio-economic and environmental systems of the Rio Santa basin. Documenting the heterogeneous spatial patterns of these changes to understand processes of water storage and flow is hindered by technologic and logistic challenges. Highly complex topography, cloud cover and coarse spatial resolution limit the application of satellite data while airborne data collection remains costly and potentially dangerous. However, recent developments have made Unmanned Aerial Vehicle (UAV) technology a viable and potentially transformative method for studying glacier dynamics and proglacial hydrology. The extreme altitudes (4000-6700m) of the Cordillera Blanca limit the use of 'off the shelf' UAVs. Therefore we developed a low cost multispectral (visible, near-infrared and thermal infrared) multirotor UAV capable of conducting fully autonomous aerial surveys at elevations over 5000m within the glacial valleys of the Cordillera Blanca. Using this platform we have completed repeat aerial surveys (in 2014 and 2015) of the debris covered Llaca Glacier, generating highly accurate 10-20cm DEM's and 5cm orthomosaics using a structure from motion workflow. Analysis of these data reveals a highly dynamic system with some areas of the glacier losing as much as 16m of vertical elevation, while other areas have gained up to 5m of elevation over one year. The magnitude and direction of these changes appears to be associated with the presence of debris free ice faces and meltwater ponds. Additionally, we have mapped proglacial meadow and wetland systems. Thermal mosaics at 10-20cm resolution are providing novel insights into the hydrologic pathways of glacier meltwater including mapping the distribution of artesian springs that feed these wetland systems. The high spatial resolution of these UAV datasets facilitates a better understanding of the

  13. An enigmatic frog of the genus Atelopus (Family Bufonidae) from Parque Nacional Chirripó, Cordillera de Talamanca, Costa Rica.

    PubMed

    Savage, Jay M; Bolaños, Federico

    2009-01-01

    A distinctive new species of Atelopus is described from Parque Nacional Chirrip6 Grande, Cordillera de Talamanca (3,400-3,500 m). It closely resembles populations of the Atelopus ignescens complex from the Andes of northern Ecuador and southern Colombia. It differs most significantly from these frogs in the pattern of spiculae and coni development on the throat, chest, hands and feet. The Costa Rican species appears to be an outlier of the complex inexplicably separated geographically from its nearest allies by an over land distance of about 1,600 km. PMID:19637715

  14. 7 CFR 319.56-34 - Clementines from Spain.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Clementines from Spain. 319.56-34 Section 319.56-34... Clementines from Spain. Clementines (Citrus reticulata) from Spain may only be imported into the United States... agreement. Clementines from Spain may be imported only if the Government of Spain or its...

  15. [History of microscopy in Spain].

    PubMed

    Fernández-Galiano, D

    1994-12-01

    Nowadays, many Spanish research centers have excellent electronic microscopy services. The current situation, however, should not allow us to forget that the initial steps of microscopy in Spain were very difficult. The construction of excellent optical microscopies in the late XIX century, and their almost immediate introduction in Spain, coincides with a period of thriving scientific activity in our country. Both micrography and histology saw the highlights of their development in Spain, with scientists such as Ramón y Cajal, Río Hortega, Ferrán, Simarro, among others, all of them widely known at present. This article evokes briefly the vicissitudes of Spanish microscopy, from its very beginning in 1843, when the Allgemeine Anatomie by Jacob Henle was translated into Spanish, to present. Scientific historical facts in this article are often accompanied with anecdotes, which show the human aspect of those great scientists. The persevering task carried out by researchers whose names have been recorded in the history of Spanish science and technology, have established the grounds in which our current development is based.

  16. Structure of the Cordillera de la Costa Belt, North-Central Venezuela: Implications for plate tectronic models

    SciTech Connect

    Ave Lallemant, H.G.; Sisson, V.B.; Wright, J.E. )

    1993-02-01

    Preliminary results of an on-going study of the Cordillera de la Costa belt between Puerto Cabello and Choroni, north-central Venezuela, indicate that the deformational history is far more complicated than expected from simple plate-tectonic models. The Cordillera de la Costa belt consists of oceanic rocks (e.g., serpentinites, amphibilites, with lenses of eclogite and blueschist) intimately intermixed with metamorphosed continental margin deposits (e.g., mica and graphite schist, quartzite, marble). Locally, large granitic (basement ) complexes of Lower Paleozoic age are included as well. In late Cretaceous time, the entire belt was involved in four synmetamorphic deformations phases (D[sub 1a] to D[sub 1d]); the first (D[sub 1a]) occurred at depths of at 35-40 km and the later ones at successively shallower depths. This deformation occurred in a subduction zone, related to right-oblique convergence of the Farallon and Atlantic plates. The most penetrative structures resulted from (all in present coordinates) north-south contraction and east-west dextral simple shear (D[sub 1b]). During an Early Tertiary ( ) event (D[sub 2]), the belt was emplaced southward onto the South American continental margin. Subsequent deformational structures (D[sub 3]) resulted in cross folds and faults (with small pull-apart basins) which are consistent with the eastward passage of the Caribbean past the South American plate.

  17. Volcanism subprogram: Volcanological interpretation of the northern part of the Occidental Cordillera of Bolivia, utilizing ERTS imagery

    NASA Technical Reports Server (NTRS)

    Brockmann, C. E. (Principal Investigator); Kussmaul, S.

    1973-01-01

    The author has identified the following significant results. In the present study, 6 ERTS-1 images have been interpreted on a 1:1 million scale (black and white) with the respective field reconnaissance. The area studied is located in the region bordering with Chile and includes the western part of the Bolivian Altiplano, the volcano Cordillera (western cordillera) and the northern part of Chile to the Pacific Coast. The greater part of this region is formed by Pliocene/Pleistocene volcani rock, which is discordant with the Tertiary sediments with intercalations of calcareous tuff. The ERTS-1 imagery permits the tracing of regional boundaries of the great volcanic formations and the alinements of the volcanic bodies along the fault zones. They also permit a clear examination of the volcanic apparatus, including their secondary forms, such as lava flows, parasitic cones, and lava domes. Because of the great scale, it is not possible to identify either the small structures or those of low relief. On the basis of the interpretation of the images, it is possible to give an idea of the relative age of the volcanoes.

  18. Magmatic evolution of the Andean Eastern Cordillera of Colombia during the Cretaceous: Influence of previous tectonic processes

    NASA Astrophysics Data System (ADS)

    Vásquez, Mónica; Altenberger, Uwe; Romer, Rolf L.; Sudo, Masafumi; Moreno-Murillo, Juan Manuel

    2010-03-01

    The Eastern Cordillera of the Colombian Andes represents an inverted Cretaceous basin where Cretaceous magmatism is characterized by rare mafic dykes and sills. We use 40Ar/ 39Ar, Sr-Nd-Pb isotopes, as well as major and trace elements analyses of Cretaceous intrusions from both flanks of the Eastern Cordillera in combination with structural data to document the complex evolution of the basin. Magmatism, which is diachronous and geochemically diverse, seems to be related to mantle melting beneath the most subsiding segments of each sub-basin during enhanced extensional tectonics. The mafic intrusions display two different compositional series: an alkaline one with OIB-like pattern and a tholeiitic one with MORB-like features. This indicates at least two diverse mantle sources. Trace-element patterns suggest that the intrusions were emplaced in an extensional setting. 40Ar/ 39Ar dating on primary plagioclase and hornblende provides plateau ages between ˜136 and ˜74 Ma. The geochemical and temporal diversities show that the emplacement of the magmas was tectonically controlled, each sub-basin reflecting an individual subsidence event.

  19. Role of plate kinematics and plate-slip-vector partitioning in continental magmatic arcs: Evidence from the Cordillera Blanca, Peru

    SciTech Connect

    McNulty, B.A.; Farber, D.L.; Wallace, G.S.; Lopez, R.; Palacios, O.

    1998-09-01

    New structural and geochronological data from the Cordillera Blanca batholith in the Peruvian Andes, coupled with Nazca-South American plate-slip-vector data, indicate that oblique convergence and associated strike-slip partitioning strongly influenced continental magmatic arc evolution. Both the strain field and mode of magmatism (plutonism vs. volcanism) in the late Miocene Peruvian Andes were controlled by the degree to which the arc-parallel component of the plate slip vector was partitioned into the arc. Strong strike-slip partitioning at ca. 8 Ma produced arc-parallel sinistral shear, strike-slip intercordilleran basins and east-west-oriented tension fractures that facilitated emplacement of the Cordillera Blanca batholith (ca. 8.2 {+-} 0.2 Ma). Periods during which the strike-slip component was not partitioned into the arc (ca. 10 and ca. 7 Ma) were associated with roughly arc-normal contraction and ignimbrite volcanism. The data thus support the contention that contraction within continental magmatic arcs favors volcanism, whereas transcurrent shear favors plutonism. The tie between oblique convergence and batholith emplacement in late Miocene Peruvian Andes provides a modern analogue for batholiths emplaced as the result of transcurrent shear in ancient arcs.

  20. Recent trends in annual snowline variations in the northern wet outer tropics: case studies from southern Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Veettil, Bijeesh Kozhikkodan; Wang, Shanshan; Bremer, Ulisses Franz; de Souza, Sergio Florêncio; Simões, Jefferson Cardia

    2016-03-01

    This paper describes the changes in the annual maximum snowlines of a selected set of mountain glaciers at the southern end of the Cordillera Blanca between 1984 and 2015 using satellite images. Furthermore, we analysed the existing glacier records in the Cordillera Blanca since the last glacial maximum to understand the evolution of glaciers in this region over a few centuries. There was a rise in the snowline altitude of glaciers in this region since the late 1990s with a few small glacier advances. Historical to the present El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) records were also analysed to understand whether there was a teleconnection between the glacier fluctuations in the region and the phase changes of ENSO and PDO. We also assessed the variations in three important climatic parameters that influence the glacier retreat—temperature, precipitation, and relative humidity—over a few decades. We calculated the anomalies as well as the seasonal changes in these variables since the mid-twentieth century. There was an increase in temperature during this period, and the decrease in precipitation was not so prominent compared with the temperature rise. There was an exceptionally higher increase in relative humidity since the early 2000s, which is relatively higher than that expected due to the observed rate of warming, and this increase in humidity is believed to be the reason behind the unprecedented rise in the snowline altitudes since the beginning of the twenty-first century.

  1. Tectonic and unroofing history of Neogene Manantiales foreland basin deposits, Cordillera Frontal (32°30'S), San Juan Province, Argentina

    NASA Astrophysics Data System (ADS)

    Pérez, Daniel J.

    2001-12-01

    The Miocene Manantiales foreland basin is located in Cordillera Frontal of San Juan, between 32°30' and 33°S. The unroofing study of the synorogenic Miocene deposits provides information about the structural evolution of Cordón de La Ramada fold-and-thrust belt. These Tertiary deposits are represented by the Chinches Formation and comprise seven members (Tc0-Tc6). They are the result of the uplift of Mesozoic sequences that crop out in La Ramada fold-and-thrust belt of the Cordillera Principal. Quaternary deposits unconformably overlying the Chinches Formation are composed of granitic and rhyolitic blocks, and represent the final uplift of the Cordón del Espinacito and a series of out-of-sequence thrusts. The unroofing studies also provide sufficient information to establish the out-of-sequence timing of the deformation at this latitude. Initial deposition of the Tertiary deposits can be dated at about 20 Ma, or early Miocene. Andesitic lavas dated in 9.2±0.3, 10.7±0.7, and 12.7±0.7 Ma unconformably overlie the structure of La Ramada fold-and-thrust belt. These facts constrain the uplift of the High Andes between 20 and 10 Ma at this latitude. The unconformity between Tertiary and Quaternary deposits suggests final uplift during Pliocene-Pleistocene times.

  2. Fault-Assisted Vertical Pluton Growth: Coastal Cordillera, North Chilean Andes

    NASA Astrophysics Data System (ADS)

    Grocott, J.; Arevalo, C.; Welkner, D.; Cruden, A.

    2004-12-01

    Immense volumes of plutonic rocks exposed in magmatic arcs challenge our ability to understand fundamental interactions between deformation and magma emplacement at convergent margins. Although close temporal and spatial relationships between fault activity and emplacement of arc plutons have been inferred, the hypothesis that there is always a direct link between faults and plutons in magmatic arcs remains controversial. It is also remarkable that there is no consensus on how individual arc plutonic complexes were constructed. The current assumption is that large granitic plutons formed from large magma bodies but this is rejected here because it fails to account for the sheet-like form and composite nature of many arc plutons. We show that composite arc plutons in the Chilean Coastal Cordillera were constructed incrementally, unit-by-unit, and that dip-slip on reactivated, steeply-dipping faults was instrumental to this process. Extension to oblique-extension of the overriding plate at the Andean subduction boundary in Triassic to Palaeocene time was accommodated by displacement on margin-parallel fault systems that were initially extensional but were reactivated as strike-slip and later still, as contractional fault systems. As the retreating subduction boundary evolved, large volumes of mainly granitic magmas were emplaced into the upper plate. In the Vallenar district (29ºS), elongate plutons with an asymmetrical, wedge-shaped cross section have one steeply-dipping side marked by synplutonic ductile fabrics that reworked a steeply-dipping fault. Partial-coupling across the fault during subsidence of the pluton floor caused a large-scale monocline to form in the host rocks, so that layering is characteristically deflected down towards the steep pluton margin. The vertical limb of these monoclines contains a high-temperature ductile shear zone with a down-dip stretching fabric and pluton-down shear sense. All of these features are expressions of fault

  3. Timing and paleoclimatic significance of Holocene glacier fluctuations in the Cordillera Vilcabamba of southern Peru

    NASA Astrophysics Data System (ADS)

    Licciardi, J. M.; Taggart, J. R.; Schaefer, J. M.; Lund, D. C.

    2009-12-01

    Past fluctuations in climatically sensitive tropical glaciers provide important insight into regional paleoclimatic trends and forcings, but well-dated chronologies are scarce, particularly during the Holocene. We have established precise cosmogenic 10Be surface exposure ages of moraine sequences in the Cordillera Vilcabamba (13°20’S latitude), located in the outer tropics of southern Peru. Results indicate the dominance of two major glacial culminations and associated climatic shifts in the Vilcabamba, including an early Holocene glacial interval and a somewhat less extensive glaciation late in the ‘Little Ice Age’ (LIA) period. Lichenometric measurements on the youngest moraines support the 10Be ages, but uncertainties in the lichen ages arise from the lack of a local lichen growth curve. The Peruvian glacier chronologies differ from a recently-developed New Zealand record but are broadly correlative with well-dated glacial records in Europe, suggesting climate linkages between the tropics and the North Atlantic region. For the latest Holocene, our leading hypothesis is that climate forcings involving southward migration of the Atlantic Intertropical Convergence Zone can explain concurrent glaciations in tropical South America and northern high latitudes, but the influence of other climate drivers such as the El Niño/Southern Oscillation may have also played a role. Estimated differences between equilibrium-line altitudes (ELAs) on modern glaciers and those inferred for expanded latest Holocene glaciers reveal an ELA rise of 165-200 m since the LIA, suggesting that temperatures 1.1-1.3°C cooler than present could have sustained glaciers at their LIA maximum positions if temperature was the only control, and thus providing an upper bound on temperature depression during the LIA. However, further work is required to constrain the likely role of precipitation changes. These new Peruvian glacier chronologies and ELA reconstructions complement ice core and

  4. Transverse Zones in the Eastern Cordillera (Colombia): An example in the Zipaquira Anticline

    NASA Astrophysics Data System (ADS)

    Garcia Delgado, H. S.; Jimenez, G.

    2014-12-01

    model for the Eastern Cordillera. Our goal is related the ZA and the transverse zones using Anisotropy of Magnetic Susceptibility (AMS) and paleomagnetism to unraveal the kinematic evolution of the anticline and the temporal relationship between the transverse zones and the ZA.

  5. SE-FIT

    NASA Technical Reports Server (NTRS)

    Chen, Yongkang; Weislogel, Mark; Schaeffer, Ben; Semerjian, Ben; Yang, Lihong; Zimmerli, Gregory

    2012-01-01

    The mathematical theory of capillary surfaces has developed steadily over the centuries, but it was not until the last few decades that new technologies have put a more urgent demand on a substantially more qualitative and quantitative understanding of phenomena relating to capillarity in general. So far, the new theory development successfully predicts the behavior of capillary surfaces for special cases. However, an efficient quantitative mathematical prediction of capillary phenomena related to the shape and stability of geometrically complex equilibrium capillary surfaces remains a significant challenge. As one of many numerical tools, the open-source Surface Evolver (SE) algorithm has played an important role over the last two decades. The current effort was undertaken to provide a front-end to enhance the accessibility of SE for the purposes of design and analysis. Like SE, the new code is open-source and will remain under development for the foreseeable future. The ultimate goal of the current Surface Evolver Fluid Interface Tool (SEFIT) development is to build a fully integrated front-end with a set of graphical user interface (GUI) elements. Such a front-end enables the access to functionalities that are developed along with the GUIs to deal with pre-processing, convergence computation operation, and post-processing. In other words, SE-FIT is not just a GUI front-end, but an integrated environment that can perform sophisticated computational tasks, e.g. importing industry standard file formats and employing parameter sweep functions, which are both lacking in SE, and require minimal interaction by the user. These functions are created using a mixture of Visual Basic and the SE script language. These form the foundation for a high-performance front-end that substantially simplifies use without sacrificing the proven capabilities of SE. The real power of SE-FIT lies in its automated pre-processing, pre-defined geometries, convergence computation operation

  6. Teaching Gender and Geography in Spain

    ERIC Educational Resources Information Center

    Garcia-Ramon, Maria-Dolors

    2011-01-01

    Since the introduction of gender themes into university teaching in geography in Spain in 1989, significant gains have been made but challenges remain in relation to placing gender into undergraduate curricula and developing teaching resources in local languages. Geographers in Spain have to meet those challenges in the near future in order to…

  7. The Dance of Spain: Classical Folkloric Flamenco.

    ERIC Educational Resources Information Center

    Gallant, Clifford J.

    A text on the classical and folk dance of Spain includes a pretest, provided in both English and Spanish; text about the dance in general and the dance of Spain, both classical and folkloric; tests on the text, in both English and Spanish; more specific readings about the traditions of flamenco, castanets, and "el jaleo"; a glossary of flamenco…

  8. Digital Economy and Management in Spain.

    ERIC Educational Resources Information Center

    del Aguila, Ana R.; Padilla, Antonio; Serarols, Christian; Veciana, Jose M.

    2003-01-01

    Explains the digital economy and its impact on the firm. Highlights include subsectors of the digital economy, including infrastructure; analysis of the digital economy in Spain; analysis of the ICT (information and communication technology) sector in Spain; and electronic commerce through the Internet. (LRW)

  9. Cretaceous tectonism, mineralization & hydrocarbon trap formation in the northern Canadian Cordillera: results of zircon (U-Th)/He thermochronology

    NASA Astrophysics Data System (ADS)

    Schneider, David; Powell, Jeremy; Ryan, Jim

    2013-04-01

    The northern Intermontane terranes of the Canadian Cordillera are dissected by a series of diachronous dextral strike-slip faults, including the Cretaceous Teslin fault possessing moderate displacement (~100 km) and the major Tertiary Tintina fault with >400 km displacement. The Teslin can be traced down to 7-8 seconds (~20 km) in seismic profiles and likely originated as a SW-directed thrust fault during the Jurassic which has been reactivated as a strike-slip fault in the Cretaceous. Jurassic cooling and exhumation of the middle crust now exposed across the central Yukon Cordillera has been slowly coming to light. We suggest unroofing is likely more widespread and long-lived then previously documented. Thirty Paleozoic and Mesozoic granitoids from the northern termination of the Teslin fault were selected for (U-Th)/He zircon thermochronology and only samples that exhibited typical igneous zoning and lack metamorphic overgrowths were analyzed. Analyses yield robust and reliable ages for each sample, which can be divided into three fault-parallel corridors: 215-130 Ma, 115-90 Ma, and 70-55 Ma. No clear pattern emerges when comparing age versus elevation, grain size, or mineral chemistry. The Klondike Plateau and rocks directly west of the Tintina fault record Jurassic cooling. The youngest domainal ages are proximal to voluminous Early to Mid-Cretaceous plutons and fault splays of the Teslin system, where structures with overall small displacement are associated with gold and copper-gold deposits. The remaining structural-age corridor can be resolved into a SW-directed extrusion wedge geometry, exhuming a large portion of the Yukon-Tanana terrane during Albian-Cenomanian tectonism. In the Cordilleran foreland front range of the Northwest Territories, 500 km to the northeast, detrital ZHe ages from ten Neoproterozoic units record contemporaneous cooling during the Late Cretaceous. Moreover, a subset of these samples serves to resolve the timing of movement on the

  10. [Epidemiology of acromegaly in Spain].

    PubMed

    Sesmilo, Gemma

    2013-10-01

    Epidemiology of acromegaly in Spain does not differ from that reported in other published series. Prevalence rate is approximately 60 cases per million, peak incidence occurs in middle age, more women are affected (61%), and there is a substantial delay between occurrence of the first symptoms and diagnosis. Studies REA (Spanish Acromegaly Registry) and OASIS analyzed the epidemiology, clinical characteristics, and management of the disease in Spain. Surgery, performed in more than 80% of patients, has been (and continues to be) the main treatment for the past four decades. In the past decade, however, more patients have received somatostatin analogs (SSAs) as first-line treatment. Use of radiation therapy has significantly decreased in recent decades. Somatostatin analogs (SSAs) are the most commonly used drugs, administered to 85% of patients; however, only 12%-15% continue on drug treatment alone. The surgical remission rate was 38.4% in the last decade, with a significant improvement over decades. Preoperative treatment with SSAs has no influence on surgical cure rates. Second-line therapies used after surgical failure in the past decade included SSAs in 49% of patients, repeat surgery in 27%, radiotherapy in 11%, pegvisomant in 15%, and dopamine agonists in 5%. Mean cost of acromegaly treatment was 9.668€ (data estimated in 2009 and adjusted in 2010), of which 71% was due to the cost of SSAs. Patients treated with pegvisomant have a more aggressive form of the disease and higher comorbidity rates.

  11. On the use of SEM techniques to determine clockwise or counterclockwise P-T paths: insights from metapelites (Yunquera Unit, Betic Cordilleras)

    NASA Astrophysics Data System (ADS)

    Esteban, J. J.; Tubía, J. M.; Cuevas, J.; Gil Ibarguchi, J. I.

    2012-04-01

    Garnet porphyroblast textures and compositions, coupled to those of accompanying phases, are one of the most useful tools to determine the change of P-T conditions during metamorphism. This is currently done quantitatively through the use of conventional thermobarometry and pseudosection analysis, whose validity is conditioned by assumptions on the chemical mineral equilibrium (e.g. Spear, 1993). In the case of metapelites, the classic approach involves the use of core to rim compositions in zoned garnets and coexisting phases by electron microprobe analysis. Nonetheless, it is a high time consuming technique. As an alternative, we test the use of back-scattered electron (BSE) images and semi-quantitative energy-dispersive X-ray spectroscopy profiles obtained by scanning eletron microscope (SEM-EDX) to distinguish between clockwise and counterclockwise P-T paths. We applied these SEM techniques in samples of micaschist from the Yunquera Unit (Internal Zone, Betic Cordilleras, Spain) (Dürr, 1969). BSE images were obtained on selected areas covering the texturally and mineralogically most significant garnet-bearing portions, whereas semiquantitative profiles for Ca, Fe, Mg and Mn were obtained by means of EDX counting. Different types of chemical profiles were observed: (a) normal (growth) continuous zoning, (b) discontinuous, and (c) reverse continuous zoning. The patterns of chemical profiles are in agreement with changes in internal microstructures and density of inclusion. Two types of continuous growth zoning were identified in subspherical garnets bearing internal foliations. XMn and XFe ratios show the classical bell-shaped geometry while XCa increases in some cases and decreases in others towards rims. Discontinuous garnet profiles are typical of multistage garnet growth, which is outlined by the occurrence of alternating low- and high-inclusion density areas. Garnets with low-inclusion density cores show homogeneous core composition with an abrupt change

  12. Metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera

    USGS Publications Warehouse

    Nokleberg, Warren J.; Bundtzen, Thomas K.; Eremin, Roman A.; Ratkin, Vladimir V.; Dawson, Kenneth M.; Shpikerman, Vladimir I.; Goryachev, Nikolai A.; Byalobzhesky, Stanislav G.; Frolov, Yuri F.; Khanchuk, Alexander I.; Koch, Richard D.; Monger, James W.H.; Pozdeev, Anany I.; Rozenblum, Ilya S.; Rodionov, Sergey M.; Parfenov, Leonid M.; Scotese, Christopher R.; Sidorov, Anatoly A.

    2005-01-01

    The Proterozoic and Phanerozoic metallogenic and tectonic evolution of the Russian Far East, Alaska, and the Canadian Cordillera is recorded in the cratons, craton margins, and orogenic collages of the Circum-North Pacific mountain belts that separate the North Pacific from the eastern North Asian and western North American Cratons. The collages consist of tectonostratigraphic terranes and contained metallogenic belts, which are composed of fragments of igneous arcs, accretionary-wedge and subduction-zone complexes, passive continental margins, and cratons. The terranes are overlapped by continental-margin-arc and sedimentary-basin assemblages and contained metallogenic belts. The metallogenic and geologic history of terranes, overlap assemblages, cratons, and craton margins has been complicated by postaccretion dismemberment and translation during strike-slip faulting that occurred subparallel to continental margins. Seven processes overlapping in time were responsible for most of metallogenic and geologic complexities of the region (1) In the Early and Middle Proterozoic, marine sedimentary basins developed on major cratons and were the loci for ironstone (Superior Fe) deposits and sediment-hosted Cu deposits that occur along both the North Asia Craton and North American Craton Margin. (2) In the Late Proterozoic, Late Devonian, and Early Carboniferous, major periods of rifting occurred along the ancestral margins of present-day Northeast Asia and northwestern North America. The rifting resulted in fragmentation of each continent, and formation of cratonal and passive continental-margin terranes that eventually migrated and accreted to other sites along the evolving margins of the original or adjacent continents. The rifting also resulted in formation of various massive-sulfide metallogenic belts. (3) From about the late Paleozoic through the mid-Cretaceous, a succession of island arcs and contained igneous-arc-related metallogenic belts and tectonically paired

  13. Geochemistry, paleoenvironment and timing of Lower Aptian organic rich beds of Paja Formation (Eastern Cordillera, Colombia)

    NASA Astrophysics Data System (ADS)

    Gaona Narvaez, T.; Maurrasse, F. J.; Etayo Serna, F.

    2011-12-01

    High-resolution analyses were carried out on two sections of the Colombian Eastern Cordillera to determine the stratigraphic and geochemical relationship between some Aptian-age organic-rich levels within the Paja Fm and the Oceanic Anoxic Event 1a. These analyses included: petrography, total inorganic carbon (TIC, wt% CaCO3), total organic carbon (TOC, wt% C), stable carbon isotopes in the organic matter (δ13Corg), and ammonite biostratigraphy. In a global context, the Lower Aptian organic-rich marine sediments are believed to include an episode of anoxia referred as the "Oceanic Anoxic Event 1a" (OAE-1a), which correlates with δ13C stages C3 to C6, and had a duration of about 1.0 to 1.3 MA [1,2]. At the Villa de Leiva section (Tunja-Villa de Leiva road), a 115 m succession of the Paja Fm Arcillolitas Abigarradas Member was studied. At this locality the unit has a prominent 4m-thick interval of black shale, ten meters below the base of the lowest Upper Aptian (Gargasian) Dufrenoyia sanctorum-Stoyanowiceras treffryanus ammonite assemblage zone [3]. Similarly, at Curiti Quarry (San Gil-Curiti road), a 12 m section includes an 8 m-thick organic-rich shale at the basal interval of the Paja Fm. At this locality the succession overlies the Barremian-age carbonate ramp deposits of the Rosablanca Fm; and the base of the Paja Fm yielded a reworked and phosphatized assemblage of middle Barremian to lowest Aptian ammonites of the genera Pulchellia, Gerhardtia, Toxancycloceras, Karsteniceras and Prodeshayesites. At Villa de Leiva, the 4 m-thick interval of TOC-rich clay-shale and marlstones (191.6 m to 195.5 m), shows horizontal laminae associated with gypsum, absence of bioturbation and benthic fossils, and presence of pyritic concretions. At this locality the studied interval has TOC values between 1.17% and 5.33%; and the Fm Paja is interpreted as have been deposited under anoxic conditions in a subtidal, hypersaline environment. Carbon isotope data below the base of the

  14. Emerging Glacial Lakes in the Cordillera Blanca, Peru: A Case Study at Arteson Glacier

    NASA Astrophysics Data System (ADS)

    Chisolm, R. E.; Mckinney, D. C.; Gomez, J.; Voss, K.

    2012-12-01

    Tropical glaciers are an essential component of the water resources systems in the mountainous regions where they are located, and a warming climate has resulted in the accelerated retreat of Andean glaciers in recent decades. The shrinkage of Andean glaciers influences the flood risk for communities living downstream as new glacial lakes have begun to form at the termini of some glaciers. As these lakes continue to grow in area and volume, they pose an increasing risk of glacial lake outburst floods (GLOFs). Ice thickness measurements have been a key missing link in studying the tropical glaciers in Peru and how climate change is likely to impact glacial melt and the growth of glacial lakes. Ground penetrating radar (GPR) has rarely been applied to glaciers in Peru to measure ice thickness, and these measurements can tell us a lot about how a warming climate will affect glacier mass balance. This study presents GPR data taken in July 2012 at the Arteson glacier in the Cordillera Blanca, Peru. A new lake has begun to form at the terminus of the Arteson glacier, and this lake has key features, including overhanging ice and loose rock likely to create landslides, that could trigger a catastrophic GLOF if the lake continues to grow. This new lake is part of a series of three lakes that have formed below the Arteson glacier. The two lower lakes, Artesonraju and Paron, are much larger so that if there were an avalanche or landslide into the new lake below Arteson glacier, the impact could potentially be more catastrophic than a GLOF from one single lake. Estimates of how the lake mass balance is likely to evolve due to the retreating glacier are key to assessing the flood risk from this dynamic three-lake system. Because the glacier mass balance and lake mass balance are closely linked, the ice thickness measurements and measurements of the bed slope of the Arteson glacier and underlying bedrock give us a clue to how the lake is likely to evolve. GPR measurements of

  15. Early Cretaceous continental sedimentation in the Coastal Cordillera (Atajaña Formation), Northern Chile

    NASA Astrophysics Data System (ADS)

    Fuentes, G.; Garcia, M.; Sepulveda, F.; Vasquez, P.

    2013-12-01

    Early Cretaceous continental sedimentation development at the Coastal Cordillera of northern Chile has been described in a broad sense. The Atajaña Formation represents this continental sedimentation, south of Arica (18°30S), where it exposes mostly as an elongated swath oriented N70°E, forming a 20 km long and 8 km wide area of outcrop. Northward, these deposits occur as isolated outcrops at the bottom of Chiza, Camarones, Vitor and Azapa valleys. The Atajaña succession was deposited in apparent angular unconformity over Cuya Formation (Middle-Late Jurassic) and Chiza Formation (Bajocian-Oxfordian). The Atajaña Formation is overlain, conformable and transitional, by the Blanco Formation (Aptian-Albian) and overlain in erosion unconformity by the Suca Formation (upper Early Cretaceous). Angular unconformity contact between Atajaña Formation and Cenozoic units (Azapa Formation and alluvial deposits) is exposed at previously named valleys. In the Camarones valley, the Atajaña Formation unconformably overlies Middle to Late Jurassic intrusive rocks. In this work, the Atajaña Formation is divided in three facies associations, exposed close to Atajaña hill and Chiza valley (Kia1, Kia2 y Kia2a). Reddish conglomerates and sedimentary breccias facies (Kia1) consists of an up to 850 m thick. These rocks are massive, polymictic and poorly-sorted, and form laterally extensive beds. Clasts are mostly composed by diorites, monzodiorites, grayish fine sandstones, fine calcareous sandstones, limestones, volcarenites and porphyric andesites. Facies Kia1 includes interbedded red calcareous sandstones and siltstones, some of them displaying low-angle cross bedding. Facies Kia2 consists of an up to 570 m thick of red sandstone and siltstone, interbedded with conglomerates. This well stratified succession, parallel bedded and minor cross bedded, form continuous beds with subrounded and well-sorted clasts. Previous authors described dessication cracks in the red siltstones

  16. The Meaning of High K2O Volcanism In the U.S. Cordillera

    NASA Astrophysics Data System (ADS)

    Putirka, K. D.; Busby, C.

    2010-12-01

    K2O contents provide a highly effective discriminant between volcanic rocks erupted in the Cascades and Basin-and Range-provinces, with Cascades volcanics having lower K2O contents at a given SiO2. To differentiate these suites, we use a K-index, where K-index = K2Oobserved - 0.12[SiO2] + 5.1 (oxides in wt. %). In the Sierra Nevada, regional K2O contents are not controlled by wall-rock assimilation. In addition, none are candidates for K-metasomatism, and none are likely to be derived by partial melting of a K-metasomatized source. As to the latter issue, even volcanic rocks with the highest K2O in the Sierra Nevada have K2O/Na2O <5, and most such ratios are <3. In contrast, K-metasomatized rocks have K2O/Na2O >5, and as high as 30-40 (Brooks and Snee (1996). Also, Sierra-wide K2O variations are not connected to indices of subduction-related mantle enrichments (such as La/Nb, Ba/Nb or Sr/P2O5), and so K2O is unconnected to regional variations in source composition. K2O contents are instead controlled by the degree of partial melting (F) in the mantle source and fractional crystallization. Putirka and Busby (2007) show that maximum K2O in the Sierra increases with increasing crust thickness, and this relationship also holds across the U.S. the Cordillera (at 39oN latitude). This relationship implies that low F magmas more easily transit thick, low-density upper crust (Putirka and Busby, 2007), which is a consequence of the fact that low F melts are enriched not just in K2O, but also in H2O, which greatly lowers magma density (Ochs and Lange, 1999). This model can explain the contrast in Cascade and Basin-and-Range K2O contents: the modern Cascades are built on the thinner crust of accreted terranes, while typical Basin-and-Range volcanics are erupted on older, and thicker, cratonized crust. Mean crust density, however, cannot be the only explanation of high K2O. In the central Sierra Nevada, the Colorado River Extensional Corridor, and at the Lunar Crater

  17. Miocene latitudinal climatic and topographic variability within the central North American Cordillera

    NASA Astrophysics Data System (ADS)

    Gébelin, Aude; Mulch, Andreas; Teyssier, Christian; Heizler, Matthew

    2010-05-01

    The long-term climatic evolution and atmospheric circulation patterns of the Earth are influenced by the topography of large mountain chains whose topography is in turn controlled by links and feedbacks of surface processes and those acting within the Earth's interior. Stable isotopes in precipitation change systematically with elevation in many modern mountain ranges and have become an increasingly important tool in reconstructing the long-term topographic and climatic evolution of the world's largest mountain ranges. Here, we present stable isotope data from meteoric fluids trapped in orogen-scale deformation zones and associated fault-bounded basin sediments that record paleoelevation and also link the geodynamics of orogens with the overall long-term landscape and climate histories. To reconstruct the Cenozoic paleoelevation history of the central part of the North American Cordillera, we focus on the metamorphic core complexes of the Snake Range (Nevada) and Buckskin Mountains (Arizona). The Snake Range and Buckskin Mountains represent both classic examples of normal fault-bounded metamorphic core complexes that developed as a consequence of Oligocene Miocene extension of the Basin and Range Province. Synkinematic muscovites collected systematically over the top-300 m of section within the Snake Range detachment reveal a pattern of increasingly younger 40Ar/39Ar ages (26.9 Ma to 21.3 Ma) from the top to the bottom of the detachment. Across the same section dD muscovite values as low as -150 per mil occur at the top of the detachment zone and attain progressively higher values of up to -72 per mil towards the bottom of the section. This hydrogen stable isotope trend suggests that meteoric fluids percolated 10s to 100s of meters into the ductile segment of the detachment over the time scale of mylonitic deformation (ca. 27 to 23 Ma). In contrast, dDmuscovite values of similarly aged mylonitic quartzites from the Buckskin Mountains are much higher and range

  18. A new colorful species of Pristimantis (Anura: Craugastoridae) from the eastern flank of the Cordillera Central in Colombia .

    PubMed

    Rivera-Prieto, Diego A; Rivera-Correa, Mauricio; Daza, Juan M

    2014-01-01

    We describe a new species of Pristimantis from the humid forests on the eastern flank of the northern Cordillera Central in Colombia (6º 23' 19.3554" N, 75º 1' 24.0594" W; ca. 1150 m.a.s.l.). Pristimantis jaguensis sp. nov. is characterized by an extraordinary variation in color and is readily distinguished from congeneric species by lacking nuptial pads, discoidal fold and conical calcar tubercles; flanks and belly white to cream without blotches as well as iris yellow ocher to copper with thick brown reticulation and cream sclera. Molecular phylogenetic analyses recovered the new species in a clade with species mostly distributed in Ecuador. Our finding suggests that new taxa can still be discovered in the Middle Magdalena River valley of Colombia despite the extensive sampling this region has received during the last decades.  PMID:25543734

  19. A new golden frog species of the genus Diasporus (Amphibia, Eleutherodactylidae) from the Cordillera Central, western Panama

    PubMed Central

    Hertz, Andreas; Hauenschild, Frank; Lotzkat, Sebastian; Köhler, Gunther

    2012-01-01

    Abstract We describe the frog species Diasporus citrinobapheus sp. n. from the Cordillera Central of western Panama. The new species differs from all other species in its genus in coloration, disk cover and disk pad shape, skin texture, advertisement call, and size. It is most similar to Diasporus tigrillo, from which it differs in dorsal skin texture, relative tibia length, number of vomerine teeth, ventral coloration, dorsal markings, and relative tympanum size, and to Diasporus gularis, from which it can be distinguished by the lack of membranes between the toes, adult size, posterior thigh coloration, and position of the choanae. We provide data on morpho- logy, vocalization, and distribution of the new species, as well as brief information on its natural history. PMID:22679389

  20. Recalibration of the yellow Rhizocarpon growth curve in the Cordillera Blanca (Peru) and implications for LIA chronology

    NASA Astrophysics Data System (ADS)

    Jomelli, V.; Grancher, D.; Brunstein, D.; Solomina, O.

    2008-01-01

    A new lichen dating method and new moraine observations enabled us to improve the chronology of glacier advances in the Cordillera Blanca (Peru) during the Little Ice Age (LIA). Our results reveal that an early LIA glacial advance occurred around AD 1330 ± 29. However, a second major glacial advance at the beginning of the 17th century overlapped the earlier stage for most glaciers. Hence, this second glacial stage, dated from AD 1630 ± 27, is considered as the LIA maximum glacial advance in the Cordillera Blanca. During the 17th-18th centuries, at least three glacial advances were recorded synchronously for the different glaciers (AD 1670 ± 24, 1730 ± 21, and 1760 ± 19). The moraines corresponding to the two first stages are close to the one in 1630 suggesting a slow recession of about 18% in the total length of the glacier. From the LIA maximum extent to the beginning of the 20th century, the 24 glaciers have retreated a distance of about 1000 m, corresponding to a reduction of 30% in their length. This rate is comparable to that observed during the 20th century. Estimates of palaeo-Equilibrium Line Altitudes show an increase in altitude of about 100 m from the LIA maximum glacial extension at the beginning of the 17th century to the beginning of the 20th century. Because long time series are not available for precipitation and temperature, this glacial retreat is difficult to explain by past climate changes. However, there is a fair correspondence between changes in glacier length and the δ18O recorded in the Quelccaya ice core at a century timescale. Our current knowledge of tropical glaciers and isotope variations leads us to suggest that this common tropical signal reflects a change from a wet LIA to the drier conditions of today. Finally, a remarkable synchronicity is observed with glacial variations in Bolivia, suggesting a common regional climatic pattern during the LIA.

  1. Characterization of Quartz and Feldspar Deformation in the Mid-crust: Insights from the Cordillera Blanca Shear Zone, Peru

    NASA Astrophysics Data System (ADS)

    Hughes, C. A.; Jessup, M. J.; Shaw, C. A.

    2014-12-01

    Deformation mechanisms within shear zones from various crustal levels must be characterized to develop accurate models of lithospheric rheology. The Cordillera Blanca Shear Zone (CBSZ) in the central Peruvian Andes records changes in temperature, microstructures, and deformation mechanisms that occurred during exhumation through the brittle-ductile-transition during normal-sense slip over the last ~5 m.y. The 100-500-m-thick mylonitic shear zone occupies the footwall of a 200-km-long normal detachment fault, marking the western boundary of the 8 Ma, leucogranodiorite Cordillera Blanca Batholith. Though local variations do occur, including recrystallized quartz veins and local, decimeter- to meter- scale shear zones, the CBSZ follows a general trend of increasing strain towards the detachment. Structurally lowest positions are weakly deformed and transition to protomylonite, mylonite, and ultramylonite at higher positions, truncating at a cataclasite nearest the detachment. We characterize strain using EBSD analyses of quartz lattice preferred orientations and deformation temperatures using quartz and feldspar textures and two-feldspar thermometry of asymmetric strain-induced myrmekite. At the deepest structural positions, feldspar grains record a complex history characterized by bulging recrystallization, myrmekite formation, and brittle fracture, while quartz exhibits dominant grain-boundary migration recrystallization (T> 500 °C) and prism slip. Intermediate samples exhibit more prevalent strain-induced myrmekite, brittle fracture in feldspar, and reaction-associated recrystallization of K-feldspar to mica; quartz records mainly subgrain-rotation recrystallization (400-500 °C) and dominant prism slip with a rhomb component. Shallower positions preserve fewer, smaller, and more rounded feldspar porphyroclasts with no myrmekite, and dominant bulging recrystallization (280-400 °C) in quartz that records prism , rhomb , and some basal slip.

  2. Investigating Glacier Surface Conditions using High-Definition Ground Based Infrared Imagery: Insight from the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Aubry-Wake, C.; Baraer, M.; McKenzie, J. M.; Mark, B. G.; Wigmore, O.; Hellstrom, R.

    2014-12-01

    The Cordillera Blanca, Peru, has the highest concentration of glaciers in the tropics. These glaciers, which in some valleys provide up to 70% of the dry season runoff, are rapidly retreating, with potential impacts on water resources. To predict the future changes in water resource in the region, it is important to better understand the processes driving tropical glacier ablation at the headwater of these systems. However, due to the glaciers' high altitude and the remote location, new techniques are needed to investigate these processes. Here we use high-definition ground-based infrared thermal imagery, paired with traditional weather monitoring instruments located on and adjacent to the glacier, to obtain high temporal and spatial resolution temperature maps of the surface of the Cuchillacocha glacier in the Cordillera Blanca. For four consecutive dry seasons (July 2011-2014), 24 to 48 hours of time-lapse imagery (5-30 minute spacing) of the glacier surface and surrounding area were acquired in conjunction with climate data. We compare the spatial and temporal variability of the surface temperature with numerous factors, including the surface conditions (e.g. ice, firn, debris cover, etc.), the thermal gradient at the edge of the glacier and with night time radiative cooling under different atmospheric conditions. The results show that sub-daily fluctuations in runoff from the glacier can be explained in large part by the incoming solar radiation and that the heating not only of the ice surface, but the surround bedrock, are important controls on the rate of meltwater generation. This study shows the potential utility for collecting and analyzing ground based infrared imagery for glacier studies, with implications for hydrologic and water resource applications.

  3. From the Cordillera Blanca to the Pacific Ocean: hydrological changes and consequences across the Rio Santa watershed

    NASA Astrophysics Data System (ADS)

    Baraer, M.; Mark, B. G.; Wigmore, O.; Fernandez-Rivera, A.; McKenzie, J. M.; Walsh, E.

    2012-12-01

    The Rio Santa, Peru, drains the western slopes of the glacierized Cordillera Blanca and provides water resources for intense and diversified purposes. The Rio Santa basin sustains one of the most important hydropower plants in Peru, several middle-sized cities, high-elevation slope agriculture and mining industries. Glaciers in the Cordillera Blanca are rapidly retreating, modifying the hydrology of the upper Rio Santa watershed. Previous results show that the upper Rio Santa watershed has passed peak-water, the moment of maximum water availability, and now exhibit decreasing dry season discharge as a consequence of glacial retreat. We present results from data collected in July of 2011 and 2012, including discharge measurements using acoustic Doppler current profiling and major dissolved ion concentrations and stable isotopes of water. The hydrochemical data were analysed using the Hydrochemical Basin Characterization Method and the results are used to map the dry-season specific discharge variations across the entire Rio Santa watershed. Measurements from 2011 suggest that around 80% of current lower Rio Santa dry-season flows are diverted to supply water to major cities, intensive agriculture and hydro-electricity projects situated in the dry coastal area. Glacier retreat simulations are used to localize future hydrological changes and evaluate the downstream repercussions. Results show that glacierized catchments have higher specific discharge compared to non-glacierized catchments but the contribution of the glaciers during the dry season represent less than 30% of the Rio Santa discharge. As the glaciers further retreat, the Rio Santa dry-season outflows are going to progressively decrease to a level below the actual freshwater demand. These changes will adversely impact the socioeconomic vulnerability to water scarcity in the entire watershed while deepening the upstream/downstream disparity in water availability.

  4. Finite Frequency Traveltime Tomography of Lithospheric and Upper Mantle Structures beneath the Cordillera-Craton Transition in Southwestern Canada

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Gu, Y. J.; Hung, S. H.

    2014-12-01

    Based on finite-frequency theory and cross-correlation teleseismic relative traveltime data from the USArray, Canadian National Seismograph Network (CNSN) and Canadian Rockies and Alberta Network (CRANE), we present a new tomographic model of P-wave velocity perturbations for the lithosphere and upper mantle beneath the Cordillera-cration transition region in southwestern Canada. The inversion procedure properly accounts for the finite-volume sensitivities of measured travel time residuals, and the resulting model shows a greater resolution of upper mantle velocity heterogeneity beneath the study area than earlier approaches based on the classical ray-theoretical approach. Our model reveals a lateral change of P velocities from -0.5% to 0.5% down to ~200-km depth in a 50-km wide zone between the Alberta Basin and the foothills of the Rocky Mountains, which suggests a sharp structural gradient along the Cordillera deformation front. The stable cratonic lithosphere, delineated by positive P-velocity perturbations of 0.5% and greater, extends down to a maximum depth of ~180 km beneath the Archean Loverna Block (LB). In comparison, the mantle beneath the controversial Medicine Hat Block (MHB) exhibits significantly higher velocities in the uppermost mantle and a shallower (130-150 km depth) root, generally consistent with the average depth of the lithosphere-asthenosphere boundary beneath Southwest Western Canada Sedimentary Basin (WCSB). The complex shape of the lithospheric velocities under the MHB may be evidence of extensive erosion or a partial detachment of the Precambrian lithospheric root. Furthermore, distinct high velocity anomalies in LB and MHB, which are separated by 'normal' mantle block beneath the Vulcan structure (VS), suggest different Archean assembly and collision histories between these two tectonic blocks.

  5. Coarse Grain Progradation in a Foreland basin: Application of Detrital Zircon Double Dating to Cenozoic Stratigraphy, Eastern Cordillera, Colombia.

    NASA Astrophysics Data System (ADS)

    Odoh, S.; Saylor, J. E.; Higuera-Diaz, C.; Lapen, T. J.; Copeland, P.

    2015-12-01

    Progradation of coarse clastic material into distal foreland basins has been attributed to both 1) enhanced sediment production during rapid tectonic exhumation and 2) sediment reworking during tectonic quiescence. The Floresta and Medina basins in the Eastern Cordillera record deposition of alternating coarse- and fine-grained clastic strata in medial and distal (respectively) Cenozoic foreland basins. The Medina Basin records the continued eastward progradation of the deformation front in the Neogene. We use detrital zircon U-Pb (ZPb) and (U-Th)/He (ZHe) analyses from the Paleogene Floresta Basin and the entire Cenozoic Medina Basin record to evaluate the effects of episodic thrust-belt exhumation and wide-spread deposition of coarse-grained sediments in the adjacent foreland basin. Both ZPb and ZHe systems are applied to individual grains (double dating) to constrain source area and up-section variations in exhumation rates. Changes in exhumation rate or introduction of new sediment sources are recorded as changes in lag time (ZHe age - depositional age). Analysis of 6 samples from the Floresta Basin shows a decrease in lag time during deposition of the coarse-grained middle Eocene Picacho Formation and upper Paleocene Socha Sandstone suggesting that Paleogene deposition of coarse-grained intervals in this medial location corresponds to an increase in exhumation rate. However, initial results from the Medina basin are less clear as there is evidence for Paleocene volcanic input but no clear evidence for thrust-belt related sediment until the Oligocene-early Miocene. We interpret the evidence for different sediment sources for Eocene strata in the axial Eastern Cordillera (Floresta) versus the Eastern foothills (Medina) as indicative of separation of these two regions by an emergent forebulge. Exhumation rate and granularity appear to be inversely correlated in post-Oligocene strata, though confirmation of initial interpretations awaits larger samples sizes

  6. Seismic investigations of the Earth's lithosphere and asthenosphere in two unique convergent margin settings: The Carpathians, Romania, and U.S. Cordillera, Idaho-Oregon

    NASA Astrophysics Data System (ADS)

    Stanciu, Adrian Christian

    Proposed mechanisms for the unusual seismicity ~100 km southeast of the contact between the Transylvanian Basin and the Eastern Carpathians in Romania have included tearing and rollback of a subducted slab of oceanic lithosphere and gravitational instability and delamination of continental lithosphere. We examined the upper mantle fabrics using shear wave splitting of SK(K)S phases recorded at four broadband seismic stations in the Transylvanian Basin. Our results indicate a regional NW-SE splitting trend, with measurements that reflect an abrupt change from this regional flow field in the vicinity of the Vrancea body to a NE-SW trend that is consistent with redirection of mantle flow. Crustal thickness measurements show 28-30 km in the western part of the Transylvanian Basin, 34-39 km at the contact with the Eastern Carpathians, and 40-45 km further east. These results, along with previous estimates, constrain the locus of the inferred Miocene suture between the southeastern-most portion of the Tisza-Dacia terrane and the East European Platform. The second convergent margin system represented here is in the North American Cordillera in Idaho and Oregon, where subduction and accretion of exotic terranes have modified the western margin of North America. We used teleseismic receiver functions from 85 broadband stations to analyze the geometry of the Salmon River suture zone, the western Idaho shear zone, and the Grouse Creek-Farmington zone boundary. Results show a clear break in crustal thickness from ~28 km beneath the accreted terranes to 36 km east of the surface expression of the WISZ. A strong mid-crustal converter at ~20 km depth is consistent with tectonic wedging during accretion of the Blue Mountains terranes. An eastern Moho offset of ~6 km is consistent with the Archean Grouse Creek-Farmington zone boundary. We used deep converted phases generated beneath the study area to image the mantle transition zone. We observe a continuous high amplitude P410s

  7. 7 CFR 319.56-31 - Peppers from Spain.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Peppers from Spain. 319.56-31 Section 319.56-31... from Spain. Peppers (fruit) (Capsicum spp.) may be imported into the United States from Spain only... subpart: (a) The peppers must be grown in the Alicante or Almeria Province of Spain in...

  8. Clinical biochemistry education in Spain.

    PubMed

    Queraltó, J M

    1994-12-31

    Clinical biochemistry in Spain was first established in 1978 as an independent specialty. It is one of several clinical laboratory sciences specialties, together with haematology, microbiology, immunology and general laboratory (Clinical analysis, análisis clinicos). Graduates in Medicine, Pharmacy, Chemistry and Biological Sciences can enter post-graduate training in Clinical Chemistry after a nation-wide examination. Training in an accredited Clinical Chemistry department is 4 years. A national committee for medical and pharmacist specialties advises the government on the number of trainees, program and educational units accreditation criteria. Technical staff includes nurses and specifically trained technologists. Accreditation of laboratories is developed at different regional levels. The Spanish Society for Clinical Biochemistry and Molecular Pathology (SECQ), the national representative in the IFCC, has 1600 members, currently publishes a scientific journal (Química Clinica) and a newsletter. It organizes a continuous education program, a quality control program and an annual Congress.

  9. [Viper bite treatment in Spain].

    PubMed

    Estefanía Díez, M; Alonso Peña, D; García Cano, P; López Gamo, A

    2016-01-01

    Viper snake bite is, by far, the most common ophidian accident in Spain. It is responsible for between 100 and 150 hospitalizations per year in this country, although it is difficult to determine the frequency of emergency admissions due to this cause. The cornerstone to their approach rests on the correct evaluation of the possible effects derived from envenomation and the use of anti-venoms. In spite of all the controversies surrounding the use of anti-venoms, they have become a powerful therapeutic weapon ever since the serum has been highly purified and the great decrease of related anaphylactic reactions. The aim of this article is to update the emergency room procedures when viper bites are suspected, and to clarify the main therapeutic recommendations. PMID:25440968

  10. Petrological characteristics of Plio-Quaternary 'Sencca' Ignimbrites, Western Cordillera of the Central Andes in Peru

    NASA Astrophysics Data System (ADS)

    Çubukçu, H. E.; Gerbe, M.-C.; Thouret, J.-C.; de la Rupelle, A.; Boivin, P.

    2012-04-01

    Large-volume ignimbrite deposits have been emplaced between 24.6 and 1.37 Ma in the western Andean Cordillera of Southern Peru. The ignimbrites older than 9 Ma (Nazca, Alpabamba, Huaylillas and Caraveli ignimbrites) have formed plateaus, whereas the deep valleys incised in plateaus have been filled by younger Lower-Upper Sencca (~5- 2 Ma) and Las Lomas ignimbrites. Among the younger valley-filling units, Lower and Upper Sencca ignimbrites, with intercalated Upper Barroso lavas, have probably originated from a source beneath the Nevado Coropuna volcano. The unwelded-to-loose, crystal-poor pumice flows of Las Lomas unit (c.1.56-1.37 Ma) can be readily distinguished in the field from the rhyolitic Sencca ignimbrites. In contrast, discriminating Lower Sencca from Upper Sencca deposits in the field is difficult due to comparable lithofacies characteristics. Such a distinction is, however, essential in order to determine temporal constraints on valley incision. The Lower Sencca compound ignimbrite sheet is more widespread (~800 km2) than the Upper Sencca ignimbrite sheet (~600 km2). The Lower Sencca ignimbrites usually form terraces hanging on valley sides but Upper Sencca form deposits crop out near the present valley bottoms or in shallow valleys on high plateaus around Barroso volcanoes. The Lower Sencca ignimbrite is composed of multiple cooling units with a crystal- and fiamme-rich vitrophyric base, overlain by strongly welded, eutaxitic subunits towards the top. Uppermost subunits exhibit an indurated ash and pumice rich vapour-phase facies. The Upper Sencca ignimbrite sheet comprises two subunits only: (1) the basal, black vitrophyre, overlain by a fiamme- and crystal-rich, strongly welded, eutaxitic subunit; 2) the upper subunit with an indurated or slightly welded, crystal-poor, pumice-rich vapour phase facies The dominant mineralogy of Lower Sencca compound ignimbrites includes plagioclase (An13-68) + alkali feldspar (Or38-65) + biotite (XMg: Mg/Mg+Fe= 0

  11. Zircon U-Pb age of the Paramo Rico tonalite-granodiorite, Santander Massif (Cordillera Oriental, Colombia) and its geotectonic significance

    NASA Astrophysics Data System (ADS)

    Dörr, W.; Grösser, J. R.; Rodriguez, G. I.; Kramm, U.

    1995-04-01

    We present the first U-Pb data, which document the existence of early Mesozoic magmatism in the Santander Massif, within the Cordillera Oriental of Colombia. Zircon fractions separated from a tonalite and a granodiorite of the Paramo Rico intrusion yield crystallization ages of 205-210 Ma. Biotite K-Ar ages of other intrusions in this region range from 177 to 210 Ma, overlapping these data, but are reinterpreted as cooling ages after the solidification of the magmatic melts. The Late Triassic/Early Jurassic magmatic activity documented here indicates that the geotectonic position of the Cordillera Oriental was similar to the present-day position of the South American plate to the Nazca plate, (i.e., subduction related).

  12. Absorption and optical conduction in InSe/ZnSe/InSe thin film transistors

    NASA Astrophysics Data System (ADS)

    Al Garni, S. E.; Qasrawi, A. F.

    2016-01-01

    In this work, (n)InSe/(p)ZnSe and (n)InSe/(p)ZnSe/(n)InSe heterojunction thin film transistor (TFT) devices are produced by the thermal evaporation technique. They are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy and optical spectroscopy techniques. While the InSe films are found to be amorphous, the ZnSe and InSe/ZnSe films exhibited polycrystalline nature of crystallization. The optical analysis has shown that these devices exhibit a conduction band offsets of 0.47 and valence band offsets of 0.67 and 0.74eV, respectively. In addition, while the dielectric spectra of the InSe and ZnSe displayed resonance peaks at 416 and 528THz, the dielectric spectra of InSe/ZnSe and InSe/ZnSe/InSe layers indicated two additional peaks at 305 and 350THz, respectively. On the other hand, the optical conductivity analysis and modeling in the light of free carrier absorption theory reflected low values of drift mobilities associated with incident alternating electric fields at terahertz frequencies. The drift mobility of the charge carrier particles at femtoseconds scattering times increased as a result of the ZnSe sandwiching between two InSe layers. The valence band offsets, the dielectric resonance at 305 and 350THz and the optical conductivity values nominate TFT devices for use in optoelectronics.

  13. A cosmogenic 10Be chronology for the local last glacial maximum and termination in the Cordillera Oriental, southern Peruvian Andes: Implications for the tropical role in global climate

    NASA Astrophysics Data System (ADS)

    Bromley, Gordon R. M.; Schaefer, Joerg M.; Hall, Brenda L.; Rademaker, Kurt M.; Putnam, Aaron E.; Todd, Claire E.; Hegland, Matthew; Winckler, Gisela; Jackson, Margaret S.; Strand, Peter D.

    2016-09-01

    Resolving patterns of tropical climate variability during and since the last glacial maximum (LGM) is fundamental to assessing the role of the tropics in global change, both on ice-age and sub-millennial timescales. Here, we present a10Be moraine chronology from the Cordillera Carabaya (14.3°S), a sub-range of the Cordillera Oriental in southern Peru, covering the LGM and the first half of the last glacial termination. Additionally, we recalculate existing 10Be ages using a new tropical high-altitude production rate in order to put our record into broader spatial context. Our results indicate that glaciers deposited a series of moraines during marine isotope stage 2, broadly synchronous with global glacier maxima, but that maximum glacier extent may have occurred prior to stage 2. Thereafter, atmospheric warming drove widespread deglaciation of the Cordillera Carabaya. A subsequent glacier resurgence culminated at ∼16,100 yrs, followed by a second period of glacier recession. Together, the observed deglaciation corresponds to Heinrich Stadial 1 (HS1: ∼18,000-14,600 yrs), during which pluvial lakes on the adjacent Peruvian-Bolivian altiplano rose to their highest levels of the late Pleistocene as a consequence of southward displacement of the inter-tropical convergence zone and intensification of the South American summer monsoon. Deglaciation in the Cordillera Carabaya also coincided with the retreat of higher-latitude mountain glaciers in the Southern Hemisphere. Our findings suggest that HS1 was characterised by atmospheric warming and indicate that deglaciation of the southern Peruvian Andes was driven by rising temperatures, despite increased precipitation. Recalculated 10Be data from other tropical Andean sites support this model. Finally, we suggest that the broadly uniform response during the LGM and termination of the glaciers examined here involved equatorial Pacific sea-surface temperature anomalies and propose a framework for testing the viability

  14. Evaluating glacier volume changes since the Little Ice Age maximum and consequences for stream flow by integrating models of glacier flow and hydrology in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Huh, K. I.; Mark, B. G.; Baraer, M.; Ahn, Y.

    2014-12-01

    Assessing the historical contribution of glacier ice volume loss to stream flow based on reconstructed volume changes through Little Ice Age (LIA) can be directly related to the understanding of glacier-hydrology in the current epoch of rapid glacier ice loss that has disquieting implications for water resources in the Cordillera Blanca of the Peruvian Andes. However, the accurate prediction of the future glacial meltwater availability for the increasing regional Andean society needs more extensive quantitative estimation from long-term glacial meltwater of reconstructed glacial volume. Modeling LIA paleoglaciers using a cellular automata glacier flow model in different catchments of the Cordillera Blanca allows us to reconstruct glacier volume and its change from likely combinations of climatic control variables and time. We compute the rate and magnitude of glacier volume changes for Yanamarey and Queshque glaciers between the LIA and modern defined by 2011 Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model Version 2 (GDEM V2) from the Cordillera Blanca. Also, we employ a recently demonstrated hydrological stream model (Baraer et al., 2012) for integrating the reconstructed glacier volume and its change to calculate glacier contribution to meltwater runoff as a function of glacier loss rate in the Yanamarey and the Queshque catchments, and reconstruct long-term glacier significance to stream flow.

  15. Characterization of organic matter from a restricted/evaporative sedimentary environment: Late Miocene of Lorca Basin, Southeastern Spain

    SciTech Connect

    Benali, S.; Helman, M.L.; Schreiber, B.C. |

    1995-06-01

    The Lorca basin, located within the tectonically evolving Betic Cordillera of southeastern Spain, developed as a rapidly subsiding basin in an open-marine setting during much of the late Miocene. The basin underwent sporadic phases of circulatory restriction with marked production and preservation of organic matter, culminating in evaporative sedimentation (latest Miocene). An organic geochemical study using biomarker analyses clarifies the degree of mixing between inflowing water sources (both marine and nonmarine), gives clues to the complex and variable circulation within the water, and helps determine the extent of basinal hypersalinity. As the water in this basin evolved toward evaporative conditions, a number of organic-rich depositional phases (>25 wt.% TOC), here termed {open_quotes}pre-evaporative,{close_quotes} took place. During the early parts of these phases, the upper water is interpreted as nutrient rich and comparatively normal, and the bottom water as anoxic. This was followed by rising salinities and short phases of evaporate formation. Such a sedimentary history may serve as a model for understanding of evaporite-related source rocks and related hydrocarbons in other areas of the world.

  16. Doctorate nursing degree in Spain

    PubMed Central

    López-Montesinos, Mª José; Maciá-Soler, Loreto

    2015-01-01

    Analytical and descriptive study of the process of change being experienced in the Spanish university system over the last decade (2005-2014). OBJECTIVE: To describe the structural changes occurring in Nursing Education in Spain, reaching access to doctoral studies from the European Convergence Process and the subsequent legislative development. METHODOLOGY: Bibliographical review of royal decrees and reference literature on the subject of study and descriptive analysis of the situation. RESULTS: Carries various changes suffered in the curricula of nursing education in the last decade, the legislation of the European Higher Education sets the guidelines for current studies of Masters and Doctorates. CONCLUSIONS: The implementation of the Master and Doctorate stages after a basic degree, which is now possible with the new legislation. A formal beginning made of scientific nursing in order to generate their own lines of research led by Doctors of nursing who can integrate in research groups under the same condition as other researcher, yet now, from the nursing discipline itself. PMID:26312628

  17. [Reform of psychiatry in Spain].

    PubMed

    Pedrosa Gil, F; Luderer, H J

    2000-11-01

    Since the 1980's psychiatric care in Spain changed considerably (Reforma psiquiátrica española). In the course of this reform, many positive results were achieved. An extensive community network of mental health centres was build up which resulted in the majority of psychiatric patients being integrated in the Spanish general health care system and making a better organized mental health care structure possible. New legislation also improved the care and civil rights of patients. An analysis of the experiences of the Spanish psychiatric reform shows that the tendency to retain the old mental hospitals, alongside the other institutions still exists. The process of deinstitutionalization and the original aims of the psychiatric reform cannot only be satisfied by the closure of large psychiatric hospitals as during the reform new aspects and problems as well the great complexity of the task have become apparent. This article together with the details of the Spanish sources gives the German public a good overview of the developments in Spanish psychiatry.

  18. Crustal root beneath the Rif Cordillera as imaged from both active seismic data and teleseismic receiver functions.

    NASA Astrophysics Data System (ADS)

    Diaz, Jordi; Gil, Alba; Gallart, Josep; Carbonell, Ramon; Harnafi, Mimoun; Levander, Alan

    2015-04-01

    The Rif cordillera forms, together with the Betic ranges, one of the tightest orogenic arcs on Earth. This continental boundary zone is dominated now by the slow convergence between Nubia and Eurasia, but with clear evidences of extensional tectonics. One of the missing elements to constrain the complex geodynamics of the Gibraltar Arc System is the knowledge of the crustal architecture beneath northern Morocco. In the last decade a major effort has been done in this sense, from active and passive seismics. We compile here the recent results available from the Rif domains. Two 330 km long wide angle DSS profiles were recorded end of 2011 across the Rif in NS and EW transects within the Rifsis project, complemented by onshore recordings of the Gassis-WestMed marine profiles. At the same period, BB seismic arrays were deployed in the area within Topo-Iberia and Picasso projects, allowing receiver function analyses of crustal depths. The ray-tracing modeling of the Rifsis profiles reveal a large Moho step and an area of crustal thickening both in EW and NS directions, grossly coincident with the Bouguer gravity anomalies. The deployment logistics allowed that all the stations recorded all the shots, thus providing useful offline data. We will use here all available in-line and offline data to provide a map of the crustal thickness in northern Morocco. We combined two approaches: i) a hyperbolic time reduction applied to the seismic data, resulting in low-fold stacks in which the reflections from the Moho should appear as subhorizontal lines; ii) the arrival times of the observed PmP phases allow, assuming a mean crustal velocity, to assign a midpoint crustal thickness to each lecture. Although some uncertainties may be inherent to those approaches, a large crustal root, reaching more than 50 km, is well documented in the central part of the Rif Cordillera, close to the zone where the Alboran slab may still be attached to the lithosphere. We also compared these results

  19. Hydrogen Isotope Evidence for Giant Meteoric-Hydrothermal Systems Associated with Extension and Magmatism in the Southern Canadian Cordillera

    NASA Astrophysics Data System (ADS)

    Holk, G. J.; McCarthy, A.

    2014-12-01

    Over 400 published mineral and fluid inclusion δD values from the southern Canadian Cordillera and our new data from the Eocene Penticton Group Volcanics and Coryell Intrusive Suite of the Southern Omineca Belt and the Western Metamorphic Belt of the Central Coast Orogen are compiled using GIS. δDH2O is estimated using published D/H fractionation factors at 400°C; the error is ±20‰, small enough to distinguish deep magmatic/metamorphic fluids from meteoric-hydrothermal fluids. Histogram plots of δDH2O values estimated from minerals reveal peaks at δD = -60‰ (deep fluid) and ­-110‰ (Early Cenozoic meteoric-hydrothermal fluid); this provides a clear distinction between the two kinds of fluid. Our analysis reveals that syn-extensional meteoric-hydrothermal systems (δDH2O < -80‰) affected the eastern margin of the Coast Ranges Batholith between latitude 49° and 55° and the Omineca Belt between latitude 49° and 52°45'; both regions were affected by detachment faulting during late stages of magmatism in the Early Cenozoic (e.g., Parrish et al., 1988; Crawford et al., 2009). Zones that escaped the effects of meteoric-hydrothermal systems, preserving the D/H signature of deep fluids (δD > -80‰), include the Western Metamorphic Belt, the Western and Central Coast Ranges Batholith, the belt of Jurassic metamorphism that extends from the Cariboo Mountains to the Purcell Mountains, and the deepest structural levels of the Shuswap Metamorphic Core Complex; most of these samples have quartz-feldspar 18O/16O fractionations indicative of magmatic temperatures. High δDH2O values (> -50‰) suggest seawater alteration of the plutons of Vancouver Island (Magaritz and Taylor, 1986). Histogram plots of vein quartz fluid inclusion δD values (Nesbitt and Muehlenbachs, 1995) reveal three peaks that include the two produced by the mineral δD values, but these data are dominated by a large peak at δD = -150, a value similar to modern meteoric waters in the region

  20. Late Mesozoic-Cenozoic Evolution of the North American Cordillera: Lithospheric Response to Plume-Slab Interaction

    NASA Astrophysics Data System (ADS)

    Ihinger, P. D.; Watkins, J. M.; Bernhardt, J. E.; Johnson, B. R.

    2003-12-01

    Throughout the late Mesozoic and Cenozoic eras, western North America experienced widespread deformation and volcanism. The nature and extent of this activity does not fit conveniently into the plate tectonic framework for crustal evolution. To date, there is no satisfying explanation that integrates the Laramide Orogeny, Basin and Range extensional activity, and the rise of the Colorado Plateau with the voluminous Tertiary volcanism including Eocene high-K magmatism, the mid-Tertiary ignimbrite `flare-up' in and around the Great Basin, and the more recent out-pouring of the Columbia River flood basalts (CRB). In fact, the unusual spatial and temporal relationship between the CRB and the on-going time-progressive basaltic and rhyolitic volcanism associated with the Yellowstone hot-spot track has led some researchers to question whether upwelling plumes do, indeed, exist. We note that magmas produced in western North America throughout the Cenozoic were derived from two compositionally distinct source regions: the sub-continental lithosphere (representing >95% of the magmatism) and the OIB source region (<5%). The two magma types occur at the same place and time throughout the province. We propose that the impingement of the positively buoyant plume head of the Yellowstone hot spot with the underside of the negatively buoyant, subducting Farallon plate at 80 My is responsible for the widespread Tertiary deformation and magmatic activity in the North American Cordillera. The dynamics of mantle flow required to accommodate the mutual passing of the two bodies led to a crisis in the normal mantle flow regime. Upwelling of the plume head was accommodated by shallowing both the Farallon slab and the overlying mantle wedge. This activity drove the subsequent tectonics of the over-riding continental lithosphere for nearly 80 My. We argue that this model is consistent with existing geological, geochemical and geophysical observations of the Cordillera; it provides a new

  1. Mantle to Surface Fluid Transfer Above a Flat Slab Subduction Zone: Isotopic Evidence from Hot Springs in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Newell, D. L.; Jessup, M. J.; Hilton, D. R.; Shaw, C. A.; Hughes, C. A.

    2015-12-01

    Thermal springs in the Cordillera Blanca, Peru, provide geochemical evidence for deeply circulated hydrothermal fluids that carry significant mantle-derived helium. The Cordillera Blanca is a ~200 km-long NNW-SSE trending mountain range in the Peruvian Andes located above an amagmatic flat-slab subduction segment. The west side of the range is bounded by the Cordillera Blanca detachment that preserves a progression of top to the west ductile shear to brittle normal faulting since ~5 Ma. We report aqueous and stable isotope geochemical results from fluid and gas samples collected in 2013 and 2015 from 13 hot springs emanating from the Cordillera Blanca detachment and associated hanging wall faults. Most springs are vigorously bubbling (degassing), and range in temperature, pH, and conductivity from 17-89 °C, 5.95-8.87, and 0.17-21.5 mS, respectively. The hottest springs issue directly from the northern segment of the detachment. Geochemically, springs are CO2-rich, alkaline-chloride to alkaline-carbonate waters, with elevated trace metal contents including Fe, Cu, As, Zn, Sb, and Tl. Notably, As contents are ≤11 ppm, indicating that thermal waters may be adversely impacting local water quality. Water δ18O and δD, trends in elemental chemistry, and cation geothermometry collectively demonstrate mixing of hot (200-260 °C) saline fluid with cold meteoric recharge along the fault. Helium isotope ratios (3He/4He) for dissolved gases in the hot springs range from 0.62 to 1.98 RC/RA, indicating the presence of ~25% mantle-derived helium, assuming mixing of an asthenospheric end-member with the crustal helium reservoir. CO2/3He and carbon stable isotope ratios indicate a carbon source derived from mixing of crustal sources with minor mantle carbon. Overall, the volatile signature overlaps with orogen-wide datasets where crustal overprinting has modified mantle contributions at active arc volcanoes. Given the long duration since active magmatism in the Cordillera

  2. Mesozoic fault systems, deformation and fault block rotation in the Andean forearc: a crustal scale strike-slip duplex in the Coastal Cordillera of northern Chile

    NASA Astrophysics Data System (ADS)

    Taylor, G. K.; Grocott, J.; Pope, A.; Randall, D. E.

    1998-12-01

    In this paper we discuss the evolution and tectonic significance of the Mesozoic trench-parallel fault systems which affected the Coastal Cordillera and their relation to magmatism and crustal rotation. The oldest, extensional, fault system separates basement from rift-related Late Triassic and younger sedimentary units. This system [I] subsequently developed into a wider extensional fault system which acted as the locus of magma ascent and emplacement of the Coastal Batholith during much of the Jurassic to earliest Cretaceous period. This extensional fault system defined the forearc sliver during this period and was the consequence of a retreating subduction boundary. During the Early Cretaceous (c. 132-125 Ma) the kinematics of this fault system changed to transtension [II] and accommodated a major component of left-lateral strike-slip motion, the principal fault being the Atacama Fault Zone along which plutons continued to be emplaced. The final phase of pluton emplacement within the Coastal Cordillera appears to be c. 106 Ma, after which this magmatic arc and fault system was abandoned. An Late Cretaceous arc and fault system [III] developed some 20 Ma later and located some 50 km to the east in what is now the Central Valley of northern Chile. This paper seeks to show that the Coastal Cordillera was deformed as a whole by this Late Cretaceous fault system [III] which formed a crustal-scale left-lateral transpressional duplex. During this deformation the thermally weakened crust was dissected into a series of large-scale blocks bounded by NW-trending left-lateral strike-slip faults which merge into a NNE-SSW fault zone which forms the eastern boundary to the duplex. We term this eastern boundary zone the Central Valley Fault Zone (CVFZ) and this together with the NW-trending faults defines the duplex system which we refer to as a whole as the Coastal Cordillera Fault System (CCFS) [III]. We have traced the CCFS duplex between 25°S and 29°S and suspect that it

  3. Properties of Se/InSe Thin-Film Interface

    NASA Astrophysics Data System (ADS)

    Qasrawi, A. F.; Kayed, T. S.; Elsayed, Khaled A.

    2016-06-01

    Se, InSe, and Se/InSe thin films have been prepared by the physical vapor deposition technique at pressure of ˜10-5 torr. The structural, optical, and electrical properties of the films and Se/InSe interface were investigated by means of x-ray diffraction (XRD) analysis, ultraviolet-visible spectroscopy, and current-voltage ( I- V) characteristics. XRD analysis indicated that the prepared InSe films were amorphous while the Se films were polycrystalline having hexagonal structure with unit cell parameters of a = 4.3544 Å and c = 4.9494 Å. Spectral reflectance and transmittance analysis showed that both Se and InSe films exhibited indirect allowed transitions with energy bandgaps of 1.92 eV and 1.34 eV, respectively. The Se/InSe interface exhibited two energy bandgaps of 0.98 eV and 1.73 eV above and below 2.2 eV, respectively. Dielectric constant values were also calculated from reflectance spectra for the three layers in the frequency range of 500 THz to 272 THz. The dielectric constant exhibited a promising feature suggesting use of the Se/InSe interface as an optical resonator. Moreover, the Au/Se/InSe/Ag heterojunction showed some rectifying properties that could be used in standard optoelectronic devices. The ideality factor and height of the energy barrier to charge carrier motion in this device were found to be 1.72 and 0.66 eV, respectively.

  4. Heavy metal pollution in soils of abandoned mining areas (SE, Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, M. J.; Pérez-Sirvent, C.; Molina, J.; Tudela, M. L.; Navarro, M. C.; García-Lorenzo, M. L.

    2009-04-01

    Elevated levels of heavy metals can be found in and around disused metalliferous mines due to discharge and dispersion of mine wastes into nearby agricultural soils, food crops and stream systems. Heavy metals contained in the residues from mining and metallurgical operations are often dispersed by wind and/or water after their disposal. These areas have severe erosion problems caused by wind and water runoff in which soil and mine spoil texture, landscape topography and regional and microclimate play an important role. The present study was carried out in the Cabezo Rajao (La Uni

  5. Geochemical study of stream waters affected by mining activities in the SE Spain

    NASA Astrophysics Data System (ADS)

    Garcia-Lorenzo, Maria Luz; Perez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Bech, Jaime

    2015-04-01

    Water pollution by dissolved metals in mining areas has mainly been associated with the oxidation of sulphide-bearing minerals exposed to weathering conditions, resulting in low quality effluents of acidic pH and containing a high level of dissolved metals. According to transport process, three types of pollution could be established: a) Primary contamination, formed by residues placed close to the contamination sources; b) Secondary contamination, produced as a result of transport out of its production areas; c) Tertiary contamination. The aim of this work was to study trace element in water samples affected by mining activities and to apply the MINTEQ model for calculating aqueous geochemical equilibria. The studied area constituted an important mining centre for more than 2500 years, ceasing activity in 1991. The ore deposits of this zone have iron, lead and zinc as the main metal components. As a result, a lot of contaminations sources, formed by mining steriles, waste piles and foundry residues are present. For this study, 36 surficial water samples were collected after a rain episode in 4 different areas. In these samples, the trace element content was determined by by flame atomic absorption spectrometry (Fe and Zn), electrothermal atomization atomic absorption spectrometry (Pb and Cd), atomic fluorescence spectrometry (As) and ICP-MS for Al. MINTEQA2 is a geochemical equilibrium speciation model capable of computing equilibria among the dissolved, adsorbed, solid, and gas phases in an environmental setting and was applied to collected waters. Zone A: A5 is strongly influenced by tailing dumps and showed high trace element content. In addition, is influenced by the sea water and then showed high bromide, chloride, sodium and magnesium content, together with a basic pH. The MINTEQ model application suggested that Zn and Cd could precipitate as carbonate (hidrocincite, smithsonite and otavite). A9 also showed acid pH and high trace element content; is influenced by tailing dumps and also by waters from gully watercourses, transporting materials from Sierra Minera. The MINTEQ simulation showed that Pb and Ca could precipitate as sulphates (anglesite and gypsum). Waters affected by secondary contamination have been mixed with carbonate materials, present in the zone increasing the pH. Some elements have precipitated, such as Cu and Pb, while Cd, Zn and As are soluble. The MINTEQ model results showed that in A10 and A14, Al could precipitate as diaspore but also carbonates could be formed, particularly dolomite. These model in A12 sample showed that soluble Zn could precipitate as carbonate and Al as oxyhydroxide, similarly than in A13. A2 and A6 waters are affected by tertiary contamination and showed basic pH, soluble carbonates and lower trace element content. Only Zn, Cd and Al are present. The speciation model showed that in A2, Cd and Zn could precipitate as carbonates while Al as oxihydroxide. In A6, the model suggested that soluble Pb could precipitate as carbonate (hidrocerusite and cerusite) or as hydroxide; Al as diaspore, Ca as calcite and Fe as hematite. Zone B: All waters are strongly affected by mining activities and showed acid pH, high trace element content and high content of soluble sulphates. The MINTEQ results showed that in B8, Fe could precipitate as hydroxychloride and in B12 could form alunite. In B9, B10, B13 y B14, the model estimates the precipitation of anglesite, gypsum and Fe hydroxichloride (B9 and B10), diaspore in B13 and B14, and gypsum and Fe hydroxychloride in B13. All the sampling points collected in Zone C are affected by primary contamination, because there are a lot of tailing dumps. C1 showed high trace element content because is a reception point of a lot of tailing dumps. Water samples from C3 to C8 also had acid pH and high trace element content, particularly As, Zn and Cd. In addition, they showed high soluble sulphates. C2 water showed neutral pH, soluble carbonate and low trace element content because is influenced by a stabilised tailing dump. In all samples, except C2, the MINTEQ model showed that a lot of efflorescences could be formed, mainly sulphates. Zone D: All waters collected in this zone showed acid pH and high trace element content, mainly Zn, Cd and As. MINTEQ model results showed that elements could precipitate as jarosite but also anglesite in D8 and gypsum in D9, D11 and D12. D1 is affected by secondary contamination, which showed higher pH (still acid) and lower content in soluble salts and trace elements. The MINTEQ model suggested that Al could precipitate as diaspore, gibbsite and alunite. The applied model is an appropriate tool for the analysis of waters affected by mining activities. The obtained simulations confirm natural attenuation processes.

  6. Highly ordered antigorite from Cerro del Almirez HP-HT serpentinites, SE Spain

    NASA Astrophysics Data System (ADS)

    Padrón-Navarta, J. A.; López Sánchez-Vizcaíno, V.; Garrido, C. J.; Gómez-Pugnaire, M. T.; Jabaloy, A.; Capitani, G. C.; Mellini, M.

    2008-11-01

    The Cerro del Almirez ultramafic massif offers an example of high pressure and high temperature antigorite serpentinites. A sharp antigorite-out isograd separates them from Chl-harzburgites, consisting of olivine + enstatite + chlorite. Antigorite is characterized by aluminium contents as high as 4 wt.% Al2O3. The microstructural study shows that, prior to the transformation, antigorite is exceptionally ordered and consists of the polysome m = 17. No polysomatic defect occurs in antigorite forming most of the Cerro del Almirez serpentinites. Close to the antigorite-out isograd, limited disorder features may occur, mainly as (001) twins, reaction rims and reduction of m down to 14-15. Here, local recrystallization phenomena lead to sporadic growth of large antigorite and chlorite crystals.

  7. Significance of organic matter in Eocene turbidite sediments (SE Pyrenees, Spain)

    NASA Astrophysics Data System (ADS)

    Caja, M. A.; Permanyer, A.

    2008-11-01

    Although turbidite deposits are classically considered to be good reservoir rocks for oil and gas, there are no reports concerning their source rock potential in the literature. The sediments from the Vallfogona Formation in the South-Eastern Pyrenees present numerous organic matter-rich levels interbedded in sandstones and coarse turbidite deposits. Two types of organic matter deposits were differentiated on the basis of organic geochemistry and petrography: type A and type B. Type A was deposited in a carbonate marine environment under hypersaline conditions as indicated mainly by even/odd n-alkane predominance, pristane and phytane ratio (Pr/Ph) < 1, presence of gammacerane, and trisnorneohopane over trisnorhopane ratio (Ts/Tm) > 1. Type B was deposited in a more mud-rich marine environment evidenced by the predominance of odd n-alkane, Pr/Ph ≥ 1, Ts/Tm < 1, the absence of gammacerane, similar concentrations of the C27 and C29 regular steranes, and the greater abundance of C27 diasteranes. Turbidite facies can be regarded as an environment where organic matter sedimentation is heterogeneous in type and amount. This study suggests that turbidite deposits with interbedded organic matter-rich levels may act as a combined source reservoir system.

  8. Significance of organic matter in Eocene turbidite sediments (SE Pyrenees, Spain).

    PubMed

    Caja, M A; Permanyer, A

    2008-11-01

    Although turbidite deposits are classically considered to be good reservoir rocks for oil and gas, there are no reports concerning their source rock potential in the literature. The sediments from the Vallfogona Formation in the South-Eastern Pyrenees present numerous organic matter-rich levels interbedded in sandstones and coarse turbidite deposits. Two types of organic matter deposits were differentiated on the basis of organic geochemistry and petrography: type A and type B. Type A was deposited in a carbonate marine environment under hypersaline conditions as indicated mainly by even/odd n-alkane predominance, pristane and phytane ratio (Pr/Ph) < 1, presence of gammacerane, and trisnorneohopane over trisnorhopane ratio (Ts/Tm) > 1. Type B was deposited in a more mud-rich marine environment evidenced by the predominance of odd n-alkane, Pr/Ph > or = 1, Ts/Tm < 1, the absence of gammacerane, similar concentrations of the C(27) and C(29) regular steranes, and the greater abundance of C(27) diasteranes. Turbidite facies can be regarded as an environment where organic matter sedimentation is heterogeneous in type and amount. This study suggests that turbidite deposits with interbedded organic matter-rich levels may act as a combined source-reservoir system.

  9. Influence of Pig Slurry on Microbial and Biochemical Characteristics of Soil in Albacete Region, SE Spain

    NASA Astrophysics Data System (ADS)

    Halil Yanardaǧ, Ibrahim

    2013-04-01

    Soil quality is very important in terms of agricultural sustainability, ecosystem and terrestrial carbon (C) cycle. In turn, soil microbial and biochemical characteristics are indicative of nutrient cycling and soil organic matter dynamics. We investigated the effects of the pig slurries (raw pig slurry (RPS) and treated pig slurry (TPS) from liquid and solid feeding diets) on microbial and biochemical characteristics of soil under barley cropping system. Application doses of slurries are identified with legal doses of Castilla La Mancha Region, which is 210 kg N ha-1 year-1. Microbial biomass C, soluble C, black C and three soil enzymes (β-Glucosidase, β-galactosidase and Arylesterase enzymes) are studied to determine effect slurry on soil biochemical characteristics, which are very important in terms of C cycle in soil. Black carbon content and β-Glucosidase enzyme activities are increased with all pig slurry applications from liquid and traditional feeding diet, as well as microbial biomass and organic carbon content and β-galactosidase enzyme activities are increased with slurry from liquid feeding diet doses. However, pig slurry application from liquid feeding diet doses have increased yield, quality, length and total biomass content of barley. Bioavailable metal contents are increased with all slurry application and with using high doses of slurry can be caused soil pollution. Pig slurries from liquid feeding diet had positive impacts on microbial and biochemical characteristics in terms of soil quality in comparison to the different feeding diets. PS addition to soil had a very significant stimulating effect on the enzyme activities, microbial biomass, soluble and black C compared with different kind of PS and control plots on Mediterranean soil in barley monoculture. This effect may originate from the organic C, N, P and S compounds added with PS. The highest enzyme activity and microbial biomass were observed on the soil samples from the RPS treatment, whereas, black and soluble C was decreased with PS addition. There may have been a transient positive effect of the RPS treatments on the soil biochemical parameters. However, the effect could not be detected because of less labile C content during the experiment. The beneficial effects of the PS additions were less pronounced in the 0-30 cm. soil layer. In this monoculture barley production system and under these Mediterranean climate conditions, applications of TPS should be avoided, so they were associated with a decline in microbial counts and a leveling of almost all the enzymatic activities and microbial biomass C. Keywords: Pig slurry, Microbial biomass C, soluble C, black C, β-Glucosidase, β-galactosidase and Arylesterase enzyme activities.

  10. Isotope geochemistry of waters affected by acid mine drainage in old labour sites (SE, Spain).

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Agudo, Ines; Hernandez-Cordoba, Manuel; Recio, Clemente

    2015-04-01

    The ore deposits of this zone have iron, lead and zinc as the main metal components. Iron is present in oxides, hydroxides, sulfides, sulfates, carbonates, and silicates; lead and zinc occur in sulfides (galena and sphalerite, respectively), carbonates, sulfates, and lead or zinc-bearing (manganese, iron) oxides. Mining started with the Romans and activity peaked in the second half of the 19th century and throughout the 20th century until the 1980's. From 1940 to 1957, mineral concentration was made by froth flotation and, prior to this, by gravimetric techniques. The mining wastes, or tailings, with a very fine particle size were deposited inland (tailings dams) and, since 1957, huge releases were made in directly the sea coast. The objective of this work was to evaluate processes affecting waters from abandoned mine sites by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. Several common chemical and physical processes, such as evaporation, water-rock interaction and mixing could alter water isotopic composition. Evaporation, which causes an enrichment in δD and δ18O in the residual water, is an important process in semiarid areas. The results obtained indicate that, for sites near the coast, waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe3+ was predominant in the surface, and controlled by A. ferrooxidans, while at depth, sulfate reduction occurred.

  11. Seismic hazard assessment of the Province of Murcia (SE Spain): analysis of source contribution to hazard

    NASA Astrophysics Data System (ADS)

    García-Mayordomo, J.; Gaspar-Escribano, J. M.; Benito, B.

    2007-10-01

    A probabilistic seismic hazard assessment of the Province of Murcia in terms of peak ground acceleration (PGA) and spectral accelerations [SA( T)] is presented in this paper. In contrast to most of the previous studies in the region, which were performed for PGA making use of intensity-to-PGA relationships, hazard is here calculated in terms of magnitude and using European spectral ground-motion models. Moreover, we have considered the most important faults in the region as specific seismic sources, and also comprehensively reviewed the earthquake catalogue. Hazard calculations are performed following the Probabilistic Seismic Hazard Assessment (PSHA) methodology using a logic tree, which accounts for three different seismic source zonings and three different ground-motion models. Hazard maps in terms of PGA and SA(0.1, 0.2, 0.5, 1.0 and 2.0 s) and coefficient of variation (COV) for the 475-year return period are shown. Subsequent analysis is focused on three sites of the province, namely, the cities of Murcia, Lorca and Cartagena, which are important industrial and tourism centres. Results at these sites have been analysed to evaluate the influence of the different input options. The most important factor affecting the results is the choice of the attenuation relationship, whereas the influence of the selected seismic source zonings appears strongly site dependant. Finally, we have performed an analysis of source contribution to hazard at each of these cities to provide preliminary guidance in devising specific risk scenarios. We have found that local source zones control the hazard for PGA and SA( T ≤ 1.0 s), although contribution from specific fault sources and long-distance north Algerian sources becomes significant from SA(0.5 s) onwards.

  12. Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

    NASA Astrophysics Data System (ADS)

    Pozo, M.; Calvo, J. P.; Scopelliti, G.; González-Acebrón, L.

    2016-04-01

    A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is present as both microcrystalline to fibro-radial quartz and opal, the latter occurring mainly as cement whereas the former replace the carbonate and infill voids. Yet one of the carbonate mounds shows distinctive petrography and geochemical features thus suggesting a distinctive growth pattern. The carbon isotope compositions of calcite from the mound samples range from - 11.56 to - 5.15 δ‰ whilst dolomite is depleted in 13C, with values of - 12.38 to 3.02 δ‰. Oxygen isotopic compositions vary from - 9.42 to - 4.64 δ‰ for calcite and between - 6.68 and 8.19 δ‰ for dolomite. Carbonate in the mounds shows significant enrichment in Co, Cr, Ni and Pb content, especially in the strongly deformed (F-2-2 lithofacies) and brecciated carbonate (F-4). The carbonate deposits show depletion in REE and Y in contrast to that determined in lutite. The formation of the carbonate mounds was related to local artesian seepage thermal water flows of moderate to relative high temperatures. Pressure differences between the low permeability host rock and the circulating fluids accounted for dilational fracturing and brecciation of the host sediment packages, which combined with precipitation of new carbonate and silica mineral phases. Locally, some carbonate mounds developed where groundwater intersected the lake floor, this resulting in bedded carbonate deposits composed of organic constituents.

  13. Late Quaternary Glacial Chronology in the Cordillera de Talamanca, Costa Rica, Investigated Using Cosmogenic Cl-36 Surface Exposure Dating

    NASA Astrophysics Data System (ADS)

    Li, Y.; Potter, R.; Horn, S.; Orvis, K. H.

    2015-12-01

    The role of the tropics in past and future climate change has garnered significant attention in recent decades, but debate still exists over climate linkages between the tropics and the middle and high latitudes. Glaciers in tropical mountains are highly sensitive indicators of climate, and glacial landforms left behind by past glacier fluctuations provide key evidence of paleoclimate trends and their forcing mechanisms. We investigated late Quaternary glacial chronology from two glaciated valleys on the Chirripó massif in the Cordillera de Talamanca, Costa Rica. Previous studies in this highland have constrained the most recent deglaciation to 12.4-9.7 ka cal BP based on radiocarbon dates on basal sediments of glacial lakes within the cirque at the head of the Morrenas Valley. However, no studies have been conducted to constrain the ages of the moraines located down valley. We dated the formation ages of these moraines in the Morrenas and Talari valleys using cosmogenic Cl-36 surface exposure dating. Our results indicate a major glacial event ~21-18 ka, broadly synchronous with the global Last Glacial Maximum (LGM). Glaciers during this period advanced 3.2-3.4 km down valley on both sides of the Chirripó massif. Our ages also suggest periods of glacial retreat or standstills ~18-10 ka before complete deglaciation of this highland ~10 ka. These results provide insight into the timing and extent of glacial events in this tropical highland that is of critical importance for reconstructing regional and global climate patterns.

  14. Oxygen isotope evidence of Little Ice Age aridity on the Caribbean slope of the Cordillera Central, Dominican Republic

    NASA Astrophysics Data System (ADS)

    Lane, Chad S.; Horn, Sally P.; Orvis, Kenneth H.; Thomason, John M.

    2011-05-01

    Climate change during the so-called Little Ice Age (LIA) of the 15th to 19th centuries was once thought to be limited to the high northern latitudes, but increasing evidence reflects significant climate change in the tropics. One of the hypothesized features of LIA climate in the low latitudes is a more southerly mean annual position of the Intertropical Convergence Zone (ITCZ), which produced more arid conditions through much of the northern tropics. High-resolution stable oxygen isotope data and other sedimentary evidence from Laguna de Felipe, located on the Caribbean slope of the Cordillera Central of the Dominican Republic, support the hypothesis that the mean annual position of the ITCZ was displaced significantly southward during much of the LIA. Placed within the context of regional paleoclimate and paleoceanographic records, and reconstructions of global LIA climate, this shift in mean annual ITCZ position appears to have been induced by lower solar insolation and internal dynamical responses of the global climate system. Our results from Hispaniola further emphasize the global nature of LIA climate change and the sensitivity of circum-Caribbean climate conditions to what are hypothesized to be relatively small variations in global energy budgets.

  15. An Integrated approach for in situ stress prediction - Fault Block Scale Case Study for the northern Central Cordillera of Colombia

    NASA Astrophysics Data System (ADS)

    Whitehill, C. S.; Cobos, D.; Vargas, C. A.; Martinez, M.

    2013-05-01

    This study develops an integrated, geological approach for evaluation of in situ stress, and presents a case study of the Central Cordillera of Colombia. The case study considers the effect of the complex tectonic interplay between Nazca-South American subduction, Panamanian indention, continental volcanism and crustal deformation. Regional stress fields and the related potential geo-hazards for this region are constrained by the limited structural control at depth on the primary deterministic features, sparse paleoseismology and active strain measurements on fault slip. In the absence of data needed for the traditional approach to this kind of problem; we model the system from a geo-mechanical perspective that allows us to vary parameters controlling in-situ stress fields at both the fault block scale and the discrete fracture network scale. The approach presented in this paper focuses on in situ stress estimation at the fault block scale. Using available fault geometry, earthquake focal mechanism, subsurface, stratigraphic, GIS, GPS, topographic and paleoseismology data, we utilize FracMan® technology to model variations on stress field analyses along strike on the dominant structures. We interpret relative intensities and the probability for seismic release along several key faults such as the Romeral Norte, Cauca, Ibagué, Fallas de Magdalena, Murindo, Armenia and Palestina faults each with significant (Mw > 6) displays of historic seismicity.

  16. Paleomagnetic isochrons, unsteadiness, and uniformity of sedimentation in Miocene intermontane basin sediments at Salla, eastern Andean cordillera, Bolivia

    SciTech Connect

    McRae, L.E. )

    1990-07-01

    Fine-scaled stratigraphic data are combined with chronologic information provided by paleomagnetic stratigraphy to document and analyze chronostratigraphic variability of the Salla Beds, a sequence of distal floodplain and lacustrine intermontane basin sediments within the eastern Andean cordillera of Bolivia. Unsteadiness in sediment accumulation is identified using a conceptual model of episodic accumulation in which simulated accumulation histories are constructed using estimated rates for various fluvial facies and taking into account gaps in deposition and possible effects of erosion. Variability in the Salla Beds is compared to that in sequence of Miocene fluvial sediments in northern Pakistan to evaluate controls on spatial and temporal stratigraphic variability. Sedimentation in the Salla sequence was generally steady over short time scales, but over longer intervals infrequent carbonates, associated with unusually long hiatuses, served to reduce the net sediment accumulation rate. In the Chinji sequence of Pakistan, unsteady accumulation evolved into a pattern of steadier sediment accumulation as recurring cycles of unsteadiness were superimposed on the overall sequence. The controls on sediment accumulation over time in these two sequences may be similarly related to the presence and extent of atypical and infrequent events of deposition, non-deposition, or erosion that exert a significant effect on net sediment accumulation. The discrepancy of short-term episodic and long-term net stratigraphic accumulation rates in both these sequences suggests that the decrease in net sediment accumulation rate with increasing time reflects the superimposed effects of different levels of local geomorphic and extrabasinal controls.

  17. Stratigraphic and isotopic link between the northern Stikine terrane and an ancient continental margin assemblage, Canadian Cordillera

    SciTech Connect

    Jackson, J.L.; Gehrels, G.E.; Patchett, P.J. ); Mihalynuk, M.G. )

    1991-12-01

    Geologic and isotopic data strongly imply a Late Triassic depositional link between a juvenile volcanic arc (northern Stikine terrane) and an outboard ancient continental margin assemblage (Nisling terrane) in the Canadian Cordillera. Two sandstone samples and a schist clast from a conglomerate layer at the base of the Upper Triassic Stuhini Group (northern Stikine terrane) have Nd-depleted mantle model ages of 1400-1430 and 1600 Ma, respectively; other Stuhini Group rocks have model ages of 390,660 and 690 Ma. Three samples of Nisling terrane schist and gneiss yield Nd model ages of 910, 1770, and 2450 Ma and highly radiogenic {sup 87}Sr/{sup 86}Sr ratios. These isotopic data corroborate stratigraphic evidence that detritus at the base of northern Stikine was shed from the Nisling terrane and strengthen interpretations that these terranes became linked by Late Triassic time. Thus, Upper Triassic strata of the northern Stikine terrane may have accumulated on top of or adjacent to an exotic continental fragment, a rifted fragment of the North American margin, or the in situ North American margin.

  18. On the lag time between internal strain and basement involved thrust induced exhumation: The case of the Colombian Eastern Cordillera

    NASA Astrophysics Data System (ADS)

    Mora, Andrès; Blanco, Vladimir; Naranjo, Julian; Sanchez, Nelson; Ketcham, Richard A.; Rubiano, Jorge; Stockli, Daniel F.; Quintero, Isaid; Nemčok, Michal; Horton, Brian K.; Davila, Hamblet

    2013-07-01

    Thrust sheets accumulate internal strain before they start moving along discrete fault planes. However, there are no previous studies evaluating the time difference between initiation of strain and fault displacement. In this paper we use observations from the Eastern Cordillera of Colombia to evaluate this interval. We utilize multiple thermochronometers and paleothermometers to refine the timing of deformation. Based on these new data we build time-temperature path estimates that together with geometric outcrop-based structural analysis and fluid inclusions allow us to assign relative timing to features associated with strain, such as cleavage, veins and certain types of fractures, and compare that with the timing of thrusting. We find that cleavage was only formed close to maximum paleotemperatures, almost coeval with the onset of thrust-induced denudation by the Late Oligocene. The corresponding structural level of fold-related veins suggest that they were formed later but still when the country rocks were at temperatures higher than 160 °C, mostly during the Early Miocene and still coexisted with the latest stages of cleavage formation. Our data show that the main period of strain hardening was short (probably a few million years) and occurred before first-order basement thrusting was dominant, but was associated with second-order folding.

  19. Uses of plasma in Spain.

    PubMed

    Algora, M; Barbolla, L

    2007-12-01

    In Spain, fresh frozen plasma (FFP) currently recovered either by whole blood centrifugation or by apheresis is mainly considered as a source of plasma derivates rather than a product to be transfused. Upon this consideration, the amount of plasma transfused in the last two decades has remained stable, while the production of FFP has grown steadily during all these years. Thus, much more plasma has been derived to industry for manufacturing. Although, since 1993 a consensus conference established the clinical situation where plasma has demonstrated its efficacy, the true situation is that many indications seem not to be supported on a scientific evidence basis. Only a few studies have been performed in the last years to assess the appropriateness of these indications. We present the initial result of an ongoing survey addressed by the Madrid Blood Transfusion Centre. Based on the criteria of total amount of RBC transfused per year, large hospitals (more than 10,000 units of RBC) transfused an average of 23.87% of FFP, while medium hospitals (5000-10,000 units of RBC) used 19.5% and small ones (less than 5000) about 12.5%. It is important to point out that inside each group there were some important differences in ratio values for similar hospitals. This could indicate that much more is necessary to cope with indications. Although national figures of uses of FFP, whether in ratio or absolute terms, show a moderate consumption in comparison with published figures of other European countries, there can be no doubt that plasma overuses still seem to be present. PMID:18417402

  20. Uses of plasma in Spain.

    PubMed

    Algora, M; Barbolla, L

    2007-12-01

    In Spain, fresh frozen plasma (FFP) currently recovered either by whole blood centrifugation or by apheresis is mainly considered as a source of plasma derivates rather than a product to be transfused. Upon this consideration, the amount of plasma transfused in the last two decades has remained stable, while the production of FFP has grown steadily during all these years. Thus, much more plasma has been derived to industry for manufacturing. Although, since 1993 a consensus conference established the clinical situation where plasma has demonstrated its efficacy, the true situation is that many indications seem not to be supported on a scientific evidence basis. Only a few studies have been performed in the last years to assess the appropriateness of these indications. We present the initial result of an ongoing survey addressed by the Madrid Blood Transfusion Centre. Based on the criteria of total amount of RBC transfused per year, large hospitals (more than 10,000 units of RBC) transfused an average of 23.87% of FFP, while medium hospitals (5000-10,000 units of RBC) used 19.5% and small ones (less than 5000) about 12.5%. It is important to point out that inside each group there were some important differences in ratio values for similar hospitals. This could indicate that much more is necessary to cope with indications. Although national figures of uses of FFP, whether in ratio or absolute terms, show a moderate consumption in comparison with published figures of other European countries, there can be no doubt that plasma overuses still seem to be present.

  1. Nursing Education in Spain--Past, Present and Future.

    ERIC Educational Resources Information Center

    Yarnoz, Adelaida Zabalegui

    2002-01-01

    In Spain, the nursing diploma is inadequate for current health care needs. To meet the demand, Spain is developing baccalaureate, master's, and doctoral programs using European Union guidelines to ensure the preparation of a professional nursing work force. (SK)

  2. Mathematics education and learning disabilities in Spain.

    PubMed

    Casas, Ana Miranda; Castellar, Rosa García

    2004-01-01

    In the first part of this article, we describe the basic objectives of the math curriculum in Spain as well as the basic contents, teacher resources, and obstacles perceived in mathematics instruction. Second, we briefly describe the concept of learning disabilities (LD) as they are currently defined in Spain. As stated in the recent educational reform, a student with LD is any student with special educational needs. The emphasis is placed on the educational resources that these students need in order to achieve the curricular objectives that correspond to their age group or grade. Third, we comment specifically on the educational services model and the evaluation and instructional procedures for students with math learning disabilities. Finally, we describe some lines of research that have appeared in the last few years in Spain that have led to the development of new evaluation and intervention procedures for students with LD in computation and problem solving. PMID:15493468

  3. 48 CFR 252.229-7005 - Tax exemptions (Spain).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Tax exemptions (Spain... of Provisions And Clauses 252.229-7005 Tax exemptions (Spain). As prescribed in 229.402-70(e)(1), use the following clause: Tax Exemptions (Spain) (MAR 2012) (a) As the Contractor represented in its...

  4. Trauma care systems in Spain.

    PubMed

    Queipo de Llano, E; Mantero Ruiz, A; Sanchez Vicioso, P; Bosca Crespo, A; Carpintero Avellaneda, J L; de la Torre Prado, M V

    2003-09-01

    Trauma care systems in Spain are provided by the Nacional Health Service in a decentralized way by the seventeen autonomous communities whose process of decentralization was completed in January 2002. Its organisation is similar in all of them. Public sector companies of sanitary emergencies look after the health of citizens in relation to medical and trauma emergencies with a wide range of up to date resources both technical and human. In the following piece there is a description of the emergency response teams divided into ground and air that are responsible for the on site care of the patients in coordination with other public services. They also elaborate the prehospital clinical history that is going to be a valuable piece of information for the teams that receive the patient in the Emergency Hospital Unit (EHU). From 1980 to 1996 the mortality rate per 10.000 vehicles and the deaths per 1.000 accidents dropped significantly: in 1980 6.4 and 96.19% and in 1996, 2.8 and 64.06% respectively. In the intrahospital organisation there are two differentiated areas to receive trauma patients the casualty department and the EHU. In the EHU the severe and multiple injured patients are treated by the emergency hospital doctors; first in the triage or resuscitation areas and after when stabilised they are passed too the observation area or to the Intensive Care Unit (ICU) and from there the EHU or ICU doctors call the appropriate specialists. There is a close collaboration and coordination between the orthopaedic surgeon the EHU doctors and the other specialists surgeons in order to comply with treatment prioritization protocols. Once the patient has been transferred an entire process of assistance continuity is developed based on interdisciplinary teams formed in the hospital from the services areas involved in trauma assistance and usually coordinated by the ICU doctors. There is also mentioned the assistance registry of trauma patients, the ICU professional training

  5. Tarasca: ritual monster of Spain.

    PubMed

    Gilmore, David D

    2008-09-01

    Let us now revisit our original assumptions. First, we note that for the participants in Hacinas Carnival the Tarasca is a figure of fun and joy, but it also exudes a strain of aggressive misogyny that many female residents, not to mention tourists, find somewhat unsettling. In the spirit of feminist currents in Spain, a group of young women protested in 1992 to town officials and, when rebuffed, sought to build their own female monster, which they intended to use to attack boys and men. While their plan was never carried out, and indeed met with stiff opposition from officialdom and, especially, from older women, some of the younger, more modern girls find the Tarasca appalling, and they told me so without compunction. Accordingly, today the festival tends to polarize the sexes as well as the generations. Also, many children are frightened by the gigantic mock-up with its snapping teeth and foul breath, and many of them burst into tears at the roaring of the demons. But despite these negatives--or perhaps because of them--the Tarasca breaks down boundaries between things normally kept separate in the mind: humor and terror, man and beast, order and disorder, old and young, life and death, and so on. In so collapsing opposites, the Tarasca causes people to pause and to think about and question everyday reality in the non-Carnival universe. All these observations of course support the structural arguments of our four theorists above and in particular seem to corroborate Bloch's concept (1992) of the regenerative power of "rebounding violence." However, there are three specific features here that need psychological amplification beyond simply confirming the work of previous theorists. We must first note that like most grotesque fantasies, the Hacinas monster combines disparate organic "realities" into a bizarre and monstrous image that by its very oddness and the resulting "cognitive mismatch" captures people's attention and sparks the imagination, especially that of

  6. Tarasca: ritual monster of Spain.

    PubMed

    Gilmore, David D

    2008-09-01

    Let us now revisit our original assumptions. First, we note that for the participants in Hacinas Carnival the Tarasca is a figure of fun and joy, but it also exudes a strain of aggressive misogyny that many female residents, not to mention tourists, find somewhat unsettling. In the spirit of feminist currents in Spain, a group of young women protested in 1992 to town officials and, when rebuffed, sought to build their own female monster, which they intended to use to attack boys and men. While their plan was never carried out, and indeed met with stiff opposition from officialdom and, especially, from older women, some of the younger, more modern girls find the Tarasca appalling, and they told me so without compunction. Accordingly, today the festival tends to polarize the sexes as well as the generations. Also, many children are frightened by the gigantic mock-up with its snapping teeth and foul breath, and many of them burst into tears at the roaring of the demons. But despite these negatives--or perhaps because of them--the Tarasca breaks down boundaries between things normally kept separate in the mind: humor and terror, man and beast, order and disorder, old and young, life and death, and so on. In so collapsing opposites, the Tarasca causes people to pause and to think about and question everyday reality in the non-Carnival universe. All these observations of course support the structural arguments of our four theorists above and in particular seem to corroborate Bloch's concept (1992) of the regenerative power of "rebounding violence." However, there are three specific features here that need psychological amplification beyond simply confirming the work of previous theorists. We must first note that like most grotesque fantasies, the Hacinas monster combines disparate organic "realities" into a bizarre and monstrous image that by its very oddness and the resulting "cognitive mismatch" captures people's attention and sparks the imagination, especially that of

  7. Time-lapse and UAV Thermal Imaging of Glacial and Periglacial Environments in the Peruvian Andes (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    McKenzie, J. M.; Wigmore, O.; Aubry-Wake, C.; Mark, B. G.; Hellstrom, R. A.; Lautz, L.

    2015-12-01

    In the tropics, the acquisition of high-resolution geospatial data of high-mountain glacial and periglacial systems presents unique challenges due to remote site access and very high elevations. For glaciers and hydrologic systems, a key variable of interest is surface temperature as it constrains glacier melt rates, traces hydrologic processes, and is needed for the calibration of energy budget models. We present results from two studies that acquired high resolution temperature data from the Cuchillacocha Glacier, Peru (9.24°S, 77.21°W). The glacier resides on the western drainage of the Cordillera Blanca with an elevation range of 4700 to 6096 m. In the first study we use high resolution time-lapse infrared imagery (5-10 minute interval over 3 days; 0.6 m2 pixel size) to observe diel changes in the surface energy budget of the glacier and to demonstrate how radiation from bare rock adjacent to the glacier may affect melt rates. In the second study we use a newly developed, inexpensive unmanned aerial vehicle (UAV) for high resolution multispectral mapping of the glacier (2 cm resolution orthomosaic and 5 cm resolution DEM). We present results showing how the time-lapse and the high-resolution UAV imagery can be combined to further strengthen our understanding of the Cuchillacocha Glacier's energy budget and possible insights about turbulent heat fluxes. While the new instruments provide unprecedented data acquisition capabilities, there is an outstanding need for proper data correction. Spatial/thermal control points and post-processing algorithms are needed to produce quantifiable datasets. For example, our post-processed time-lapse imagery has an r2 > 0.9 after emissivity, transmissivity and offset corrections.

  8. The Quebradagrande Complex: A Lower Cretaceous ensialic marginal basin in the Central Cordillera of the Colombian Andes

    NASA Astrophysics Data System (ADS)

    Nivia, Alvaro; Marriner, Giselle F.; Kerr, Andrew C.; Tarney, John

    2006-09-01

    The Quebradagrande Complex of Western Colombia consists of volcanic and Albian-Aptian sedimentary rocks of oceanic affinity and outcrops in a highly deformed zone where spatial relationships are difficult to unravel. Berriasian-Aptian sediments that display continental to shallow marine sedimentary facies and mafic and ultramafic plutonic rocks are associated with the Quebradagrande Complex. Geochemically, the basalts and andesites of the Quebradagrande Complex mostly display calc-alkaline affinities, are enriched in large-ion lithophile elements relative to high field strength elements, and thus are typical of volcanic rocks generated in supra-subduction zone mantle wedges. The Quebradagrande Complex parallels the western margin of the Colombian Andes' Central Cordillera, forming a narrow, discontinuous strip fault-bounded on both sides by metamorphic rocks. The age of the metamorphic rocks east of the Quebradagrande Complex is well established as Neoproterozoic. However, the age of the metamorphics to the west - the Arquía Complex - is poorly constrained; they may have formed during either the Neoproterozoic or Lower Cretaceous. A Neoproterozoic age for the Arquía Complex is favored by both its close proximity to sedimentary rocks mapped as Paleozoic and its intrusion by Triassic plutons. Thus, the Quebradagrande Complex could represent an intracratonic marginal basin produced by spreading-subsidence, where the progressive thinning of the lithosphere generated gradually deeper sedimentary environments, eventually resulting in the generation of oceanic crust. This phenomenon was common in the Peruvian and Chilean Andes during the Uppermost Jurassic and Lower Cretaceous. The marginal basin was trapped during the collision of the Caribbean-Colombian Cretaceous oceanic plateau, which accreted west of the Arquía Complex in the Early Eocene. Differences in the geochemical characteristics of basalts of the oceanic plateau and those of the Quebradagrande Complex

  9. The timing of Jurassic orogenesis in the continental arc terrane of the western US Cordillera: Jackston Mountains, northwestern Nevada

    SciTech Connect

    Quinn, M.J.; Wright, J.E. . Dept. of Geology and Geophysics)

    1993-04-01

    Pre-Nevadan, Jurassic orogenesis appears to be characteristic of many Mesozoic arc assemblages of the western US Cordillera. In most places this deformation is Middle Jurassic ([approximately]170--160 Ma). The authors recent work in the Black Rock Desert (BRD) documents an episode of Early Jurassic metamorphism and tectonism in the Jackson Mountains (JM). Here, an extensive arc section, including the Norian to Middle ( ) Jurassic Happy Creek Volcanics and Early to Middle Jurassic plutons, indicate vigorous arc magmatism in the arly Mesozoic. Among the southwest flank of the range the lower Mesozoic section is overridden by an east vergent thrust sheet carrying upper Paleozoic rocks of the McGill Canyon Unit. Another thrust package is located on the same side of the range, but further to the north, and contains variably metamorphosed clastic rocks, carbonate, and mafic volcanics. There is also an abrupt drop in metamorphic grade across the main thrust fault where greenschist facies rocks are in contact with virtually unmetamorphosed Happy Creek Volcanics. Two plutons with U/Pb zircon age of 188 [+-] 2 Ma and 193 [+-] 3 Ma crosscut the northern thrust fault. These relations suggest than an episode of regional metamorphism followed by E-W compressional tectonism was completed during the Early Jurassic in this portion of the arc terrane. These results differ significantly from previous studies that have interpreted all compressive deformation in the JM to have taken place between the Middle Jurassic and Cretaceous. The authors new data indicate that pre-Nevada Jurassic deformation is somewhat older in the BRD than that documented in other parts of the Mesozoic arc. Because voluminous Jurassic magmatism also began at an earlier time (Early Jurassic) in the BRD than elsewhere, they suggest that deformation and metamorphis within the arc may be facilitated and localized during periods of high heat flux related to magmatic input.

  10. Crustal structure beneath the Rif Cordillera, North Morocco, from the RIFSIS wide-angle reflection seismic experiment

    NASA Astrophysics Data System (ADS)

    Gil, Alba; Gallart, Josep; Diaz, Jordi; Carbonell, Ramon; Torne, Montserrat; Levander, Alan; Harnafi, Mimoun

    2014-12-01

    different geodynamic models proposed since the late 1990s to account for the complex evolution of the Gibraltar Arc System lack definite constraints on the crustal structure of the Rif orogen. Here we present the first well-resolved P-wave velocity crustal models of the Rif Cordillera and its southern continuation toward the Atlas made using controlled-source seismic data. Two 300+ km-long wide-angle reflection profiles crossed the Rif along NS and EW trends. The profiles recorded simultaneously five land explosions of 1Tn each using ˜850 high frequency seismometers. The crustal structure revealed from 2-D forward modeling delineates a complex, laterally varying crustal structure below the Rif domains. The most surprising feature, seen on both profiles, is a ˜50 km deep crustal root localized beneath the External Rif. To the east, the crust thins rapidly by 20 km across the Nekkor fault, indicating that the fault is a crustal scale feature. On the NS profile the crust thins more gradually to 40 km thickness beneath Middle Atlas and 42 km beneath the Betics. These new seismic results are in overall agreement with regional trends of Bouguer gravity and are consistent with recent receiver function estimates of crustal thickness. The complex crustal structure of the Rif orogen in the Gibraltar Arc is a consequence of the Miocene collision between the Iberian and African plates. Both the abrupt change in crustal thickness at the Nekkor fault and the unexpectedly deep Rif crustal root can be attributed to interaction of the subducting Alboran slab with the North African passive margin at late Oligocene-early Miocene times.

  11. Investigating potential precipitation changes with impacts on small-scale farming in mountain villages, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, Wolfgang; Hofer, Marlis; Juen, Irmgard; Schauwecker, Simone; Singer, Katrin; Neuburger, Martina; Kaser, Georg

    2015-04-01

    Small subsistence farmers on the slopes above the city of Huaraz in the Peruvian Cordillera Blanca assign recent challenges in agricultural production - beyond other factors - to decreasing precipitation during the early crop cultivation period in August and September. In general, local climate is characterized by low annual variation in air temperature but a strong seasonality in precipitation. While driest conditions prevail in June and July, precipitation increases gradually towards the October to April wet season with strong topographically induced gradients. Because seeding occurs soon after the core dry months, cultivation is highly vulnerable to potential alterations in the transition period from dry to wet conditions. Within this study we try to find "data-based" evidence for changes in precipitation patterns, even though the availability of meteorological information for proving precipitation trends is generally poor for this region. We currently investigate the respective potential of connecting approx. 10 years (2003-2013) of ground measurements (weekly resolution with some gaps) with ERA-interim total precipitation output (0.75 deg. resolution) by (1) selecting those adjacent model grid points that explain measured precipitation variability best and by (2) fitting the data from the selected grid points to the measurements with quantile mapping. Uncertainties arising from the transfer functions are assessed with a cross validation approach. Our preliminary results suggest that (1) ground measurements are fairly explained by ERA interim data (despite the very complex topography), that (2) no significant trends in precipitation at the end of the dry season (August, September) are detectable for the period 1979-2013, but relatively high year-to-year variability occurs and that (3) process based limited area modeling might be required to effectively assess specific requests of user groups related to local precipitation variability.

  12. Geology, K-Ar geochronology and paleomagnetism of parts of the coastal cordillera of central Chile, South America

    SciTech Connect

    Irwin, J.J.

    1986-01-01

    A complex composed of ultrabasic and basaltic lavas, chert-argillite, arkose and conglomerate was assembled in the coast of north central Chile prior to 220 Ma ago. Three major episodes of deformation and metamorphism have been observed in this area. The first episode of deformation and metamorphism (F/sub 1/) produced a compositional layering (S/sub 1/) and amphibolite facies metamorphism within the formations listed above. This episode of deformation and metamorphism occurred coevally with intrusion of a regionally extensive 220-200 Ma fine grained gabbro and granitic complex. The second episode of deformation and metamorphism locally formed tight, recumbent folds in S/sub 1/ and at least one low angle reverse fault. K-Ar and Rb-Sr ages on units in which F/sub 2/ folds are well developed range between 163 and 140 Ma. A third episode of deformation and low grade metamorphism (F/sub 3/) locally formed upright, open to tight folds with sharp hinges and axial planes that strike north and dip steeply east. Igneous intrusions that were affected by F/sub 3/ yield K-Ar ages between 140 Ma and 126 Ma. Undeformed cross cutting mafic dykes have been dated by K-Ar at 121 Ma. Paleomagnetic samples collected from 19 sites in radioisotopically dated (using the K-Ar and /sup 40/Ar-/sup 39/Ar techniques) Jurassic mafic dykes and plutons in the coastal cordillera of Chile yield mean paleomagnetic poles that are consistent with the average pole from coeval sequences within the South American craton. The paleomagnetic directions are consistent over the latitudinal range and variety of lithologies encompassed by this study. Paleomagnetic results presented here indicate that no major rotation or translation of crustal blocks has been taken place in this part of central Chile since middle Jurassic time.

  13. The isolation of the temperature effect on branched GDGT distribution in an elevation transect of the Eastern Cordillera, Colombia

    NASA Astrophysics Data System (ADS)

    Anderson, V. J.; Shanahan, T. M.; Saylor, J.; Horton, B. K.

    2012-12-01

    Recently, the distribution of branched GDGT's (glycerol dialkyl glycerol tetraethers) has been proposed as a proxy for temperature and pH in soils via the MBT/CBT index, and has been used to reconstruct past temperature variations in a number of settings ranging from marine sediments to loess deposits and paleosols. However, empirical calibrations of the MBT/CBT index against temperature show significant scatter, leading to uncertainties as large as ±2 degrees C . In this study we seek to add to and improve upon the existing soil calibration using a new set of samples spanning a large elevation (and temperature) gradient in the Eastern Cordillera of Colombia. At each site we buried temperature loggers to constrain the diurnal and seasonal temperature experienced by each soil sample. Located only 5 degrees north of the equator, our sites experience a very small seasonal temperature variation - most sites display an annual range of less than 4 degrees C. In addition, the pH of all of the soils is almost invariant across the transect, with the vast majority of samples having pH's between 4 and 5. This dataset represents a "best-case" scenario - small variations in seasonal temperature, pH, and well-constrained instrumental data - which allow us to examine the brGDGT-temperature relationship in the absence of major confounding factors such as seasonality and soil chemistry. Interestingly, the relationship between temperature and the MBT/CBT index is not improved using this dataset, suggesting that these factors are not the cause of the anomalous scatter in the calibration dataset. However, we find that using other parameterizations for the regression equation instead of the MBT and CBT indices, the errors in our temperature estimates are significantly reduced.

  14. Late Pleistocene and Holocene Hydroclimate Variability in the Tropical Andes from Alpine Lake Sediments, Cordillera de Mérida, Venezuela

    NASA Astrophysics Data System (ADS)

    Larsen, D. J.; Abbott, M. B.; Polissar, P. J.

    2014-12-01

    The tropics play a major role in the global hydrologic cycle and changes to tropical rainfall patterns have critical implications for water resources and ecosystem dynamics over large geographic scales. In tropical South America, late Pleistocene and Holocene precipitation variability has been documented in geologic records and associated with numerous external and internal variables, including changes in summer insolation, South American summer monsoon strength, Pacific Ocean sea surface temperatures, continental moisture recycling, and other climate processes. However, there are few records from the northern hemisphere tropical Americas, a key region for understanding interhemispheric linkages and the drivers of tropical hydroclimate variability. Here, we present a ~13 ka record of coupled hydroclimate and environmental changes from Laguna Brava, a small (~0.07 km2), hydrologically closed lake basin situated at 2400 m asl in the Cordillera de Mérida, Venezuela. Sediment cores collected from varying water depths and proximity to shore are placed in a chronologic framework using radiocarbon ages from terrestrial macrofossils, and analyzed for a suite of physical, bulk geochemical, and stable isotopic parameters. Compound specific hydrogen isotope (D/H) measurements of terrestrial plant waxes (long-chain n-alkanes) show a sharp increase in the late Pleistocene, followed by a long-term trend toward more negative values that suggest a ~20‰ decrease in the D/H ratios of South American tropical precipitation during the Holocene. This pattern is consistent in sign and magnitude to other South American precipitation reconstructions from both hemispheres, indicating interhemispheric similarities in tropical hydroclimate variability. Superimposed on this continent-scale trend are changes in moisture balance and environmental conditions in the Venezuelan Andes. We reconstruct these parameters at Laguna Brava at multidecadal and centennial resolution and evaluate this

  15. A geomorphological approach to determining the Neogene to Recent tectonic deformation in the Coastal Cordillera of northern Chile (Atacama)

    NASA Astrophysics Data System (ADS)

    Riquelme, R.; Martinod, J.; Hérail, G.; Darrozes, J.; Charrier, R.

    2003-01-01

    The large (≈10000 km 2) and local-scale (<400 km 2) geomorphologic, geomorphometric and field evidence indicates that, from the mid-Miocene onwards, the Atacama Fault System (AFS) accommodated the relative uplift of the western side of the Chilean Coastal Cordillera of the Chañaral region (southern Atacama Desert). The mean regional altitude systematically decreases eastwards crossing the AFS, independent of the lithological characteristics of the substratum cut by this system of faults. Topographic analysis reveals a more incised landscape west of the AFS that, at the local scale, is reported by the distribution of the altitudes (hypsometric curves and integrals) of tributary basins and by the presence of terraces. In the Middle and Upper Miocene, a thick (>300 m) sedimentary succession was deposited east of the AFS. The succession fills previously deep paleovalleys. And it consists of gravel, so-called "Atacama Gravels", which passes laterally into fine-grained playa related deposits near the AFS. We interpret the deposition of this succession as a result of a blocking closure of the valley flowing from the Precordillera due to the activity on AFS. A pedimentation episode followed sediment deposition and is locally strongly re-incised by the main modern-day river valleys draining the Precordillera. Incision may result from either regional uplift of the forearc, and/or from more localized activity on the AFS. Furthermore, Recent (Quaternary?) tectonic activity on the AFS has been observed which is consistent with a localized relative uplift of the crustal block west of the AFS.

  16. Unraveling Tropical Mountain Hydroclimatology by Coupling Autonomous Sensor Observations and Climate Modeling: Llanganuco Valley, Cordillera Blanca, Peru.

    NASA Astrophysics Data System (ADS)

    Hellstrom, R. A.; Fernandez, A.; Mark, B. G.; Covert, J. M.

    2015-12-01

    Northern Peru will face critical water resource issues in the near future as permanent ice retreats. Much of current global and regional climate research neglects the meteorological forcing of lapse rates and valley wind dynamics on critical components of the Peruvian Andes' water-cycle. In 2004 and 2005 we installed an autonomous sensor network (ASN) within the glacierized Llanganuco Valley, Cordillera Blanca (9°S), consisting of discrete, cost-effective, automatic temperature loggers located along the valley axis and anchored by two automatic weather stations. Comparisons of these embedded atmospheric measurements from the ASN and climate modeling (CM) by dynamical downscaling using the Weather Research and Forecasting (WRF) model elucidate distinct diurnal and seasonal characteristics of the mountain valley winds and lapse rates. Wind, temperature, humidity, and cloud simulations by WRF suggest that thermally driven valley winds converging with easterly flow aloft enhance late afternoon and evening cloud development which helps explain detected nocturnal precipitation maxima measured by the ASN. We attribute sustained evapotranspiration (ET), as estimated by the FAO-56 Penman-Monteith model, to an abundance of glacial melt-water during the dry season and strong pre-noon solar heating during the wet season. Furthermore, the extreme diurnal variability of along-valley-axis lapse rates and valley wind detected from ground observations and confirmed by dynamical downscaling demonstrate the importance of realistic scale parameterizations of the boundary layer to improve regional CM projections in mountainous regions. Our findings portray ET as an integral yet poorly represented process in Andean hydroclimatology. We show that coupling ASN and CM can improve understanding of multi-scale atmospheric and associated hydrological processes in mountain valleys.

  17. Does Education Affect Happiness? Evidence for Spain

    ERIC Educational Resources Information Center

    Cunado, Juncal; de Gracia, Fernando Perez

    2012-01-01

    In this paper we study the impact of education on happiness in Spain using individual-level data from the European Social Survey, by means of estimating Ordinal Logit Models. We find both direct and indirect effects of education on happiness. First, we find an indirect effect of education on happiness through income and labour status. That is, we…

  18. Border disease virus among chamois, Spain.

    PubMed

    Marco, Ignasi; Rosell, Rosa; Cabezón, Oscar; Mentaberre, Gregorio; Casas, Encarna; Velarde, Roser; Lavín, Santiago

    2009-03-01

    Approximately 3,000 Pyrenean chamois (Rupicapra pyrenaica pyrenaica) died in northeastern Spain during 2005-2007. Border disease virus infection was identified by reverse transcription-PCR and sequencing analysis. These results implicate this virus as the primary cause of death, similar to findings in the previous epizootic in 2001.

  19. Border Disease Virus among Chamois, Spain

    PubMed Central

    Rosell, Rosa; Cabezón, Oscar; Mentaberre, Gregorio; Casas, Encarna; Velarde, Roser; Lavín, Santiago

    2009-01-01

    Approximately 3,000 Pyrenean chamois (Rupicapra pyrenaica pyrenaica) died in northeastern Spain during 2005–2007. Border disease virus infection was identified by reverse transcription–PCR and sequencing analysis. These results implicate this virus as the primary cause of death, similar to findings in the previous epizootic in 2001. PMID:19239761

  20. Mesocriconema kirjanovae (Nematoda: Criconematidae) from Southeastern Spain

    PubMed Central

    Castillo, P.; Vovlas, N.

    1992-01-01

    An abundant female population of a criconematid species identified as Mesocriconema kirjanovae (Andr ssy, 1962) Loof &De Grisse, 1989 is reported from a natural habitat in southeastern Spain. Measurements and morpho-anatomy obtained with light microscopy and scanning electron microscopy are included and compared with previous data on this species. PMID:19283203

  1. Road accidents and business cycles in Spain.

    PubMed

    Rodríguez-López, Jesús; Marrero, Gustavo A; González, Rosa Marina; Leal-Linares, Teresa

    2016-11-01

    This paper explores the causes behind the downturn in road accidents in Spain across the last decade. Possible causes are grouped into three categories: Institutional factors (a Penalty Point System, PPS, dating from 2006), technological factors (active safety and passive safety of vehicles), and macroeconomic factors (the Great recession starting in 2008, and an increase in fuel prices during the spring of 2008). The PPS has been blessed by incumbent authorities as responsible for the decline of road fatalities in Spain. Using cointegration techniques, the GDP growth rate, the fuel price, the PPS, and technological items embedded in motor vehicles appear to be statistically significantly related with accidents. Importantly, PPS is found to be significant in reducing fatal accidents. However, PPS is not significant for non-fatal accidents. In view of these results, we conclude that road accidents in Spain are very sensitive to the business cycle, and that the PPS influenced the severity (fatality) rather than the quantity of accidents in Spain. Importantly, technological items help explain a sizable fraction in accidents downturn, their effects dating back from the end of the nineties.

  2. Educational Reform and Renewal in Contemporary Spain.

    ERIC Educational Resources Information Center

    Brickman, William W.

    This study is one of a series of Office of Education publications on educational developments in other countries. It describes and analyzes in social, economic, and historical context the educational changes mandated in Spain by the Education Reform Law of 1970, one of contemporary Europe's most far-reaching plans for educational reform and…

  3. Good Effective School Improvement Practices in Spain.

    ERIC Educational Resources Information Center

    Murillo, F. Javier

    2002-01-01

    Presents case studies of five effective school improvement (ESI) programs developed in Spain. Identified characteristics of the Spanish education system that affect the way ESI programs are carried out and developed descriptions of the five programs and lessons learned from them. (SLD)

  4. Kinematic evolution of Andean fold-thrust structures along the boundary between the Eastern Cordillera and Middle Magdalena Valley basin, Colombia

    NASA Astrophysics Data System (ADS)

    SáNchez, Javier; Horton, Brian K.; Tesón, Eliseo; Mora, AndréS.; Ketcham, Richard A.; Stockli, Daniel F.

    2012-06-01

    Surface and subsurface data support a kinematic reconstruction of Cenozoic fold-thrust deformation along the Eastern Cordillera-Magdalena Valley transition in Colombia. The La Salina fault (LSF) marks the boundary between west-vergent Eastern Cordillera structures and hinterland deposits of the Middle Magdalena Valley basin. Apatite fission track and (U-Th)/He thermochronological results for the west-directed LSF reveal initial hanging wall exhumation during middle Eocene-early Oligocene (45-30 Ma) shortening, renewed exhumation in the early middle Miocene (18-12 Ma), and accelerated late Miocene-Pliocene (12-3 Ma) exhumation. Vitrinite reflectance data suggest maximum burial of 4-6 km, helping constrain Cenozoic basin architecture. Mapping of the LSF reveals hanging wall Cretaceous-Eocene rocks in a broad anticline-syncline pair with limited faulting and footwall Eocene-Quaternary basin fill in a complex series of tight thrust-related folds. Limited displacement along the westernmost (frontal) thrust suggests that shortening is largely accommodated by east-directed thrusting within a broader triangle zone of a passive-roof duplex (and probable minor strike-slip deformation). In the preferred kinematic restoration, the most recent phase of shortening to transpressional deformation represents out-of-sequence reactivation of the LSF consistent with irregular crosscutting relationships among footwall structures. Earliest exhumation by 45-30 Ma in the Eastern Cordillera fold-thrust belt is correlated with increased sedimentary lithic fragments and high compositional maturity in sandstones of the adjacent Magdalena Valley basin. Exhumation since ˜15 Ma coincided with decreased compositional maturity and elevated accumulation rates for the Real Group. The compositional provenance shifts are attributed to westward advance of fold-thrust deformation into the proximal (eastern) segments of the Magdalena Valley basin.

  5. Provenance through the limit: integrated provenance from the Devonian sedimentary and basement rocks from the northern segment of the Eastern Cordillera of the Colombian Andes

    NASA Astrophysics Data System (ADS)

    Cardona, Agustin; Valencia, Victor; Lotero, Andrea; Villafañez, Yohana; Augustsson, Carita; Bayona, German; Ibañez, Mauricio

    2013-04-01

    The provenance record of sedimentary rocks is sometimes the only available archive of the geological evolution in continuously active continental margins where continuous exhumation, erosion and along strike fragmentation of continental margins destroy geological evidences. New integrated provenance constraints from segmented exposures of Devonian rocks of the northern segment of the Eastern Cordillera of Colombia are used to reconstruct overimposed Paleozoic, Mesozoic and Cenozoic paleogeographic scenarios of the northern Andes. Sandstones from deltaic to platform environments are characterized by very high quartz contents, stable to ultrastable heavy minerals and mostly angular fragments. U-Pb detrital zircon geochronology reveals prominent Silurian to Ordovician and Mesoproterozoic (Grenvillian) age populations with minor Devonian zircons. Tourmaline geochemistry and detrital quarz characterization suggest prominent low grade metamorphic sources. These provenance fingerprints can be related to the erosion of the older metasedimentary basement exposed in the same region and record the transition from a terrane collisional event to the formation of a new subduction zone before the final Late Paleozoic events that end in the agglutination of Pangea. The U-Pb detrital record of the Devonian and basement rocks of the Eastern Cordillera are also comparable with Early to Middle Paleozic Paleozoic rocks form the Northern segment of the eastern Peruvian Andes re-inforcing the view of along strike terrane thousand of kilometer transport along the Mesozoic proto-Andean margin. Petrographic and heavy mineral petrofacies and stratigraphic correlation between Devonian localities are also used as piercing points to document Cenozoic ten of kilometers strike slip displacements along the northern termination of the Eastern Cordillera.

  6. Assessing the variability of glacier lake bathymetries and potential peak discharge based on large-scale measurements in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Cochachin, Alejo; Huggel, Christian; Salazar, Cesar; Haeberli, Wilfried; Frey, Holger

    2015-04-01

    Over timescales of hundreds to thousands of years ice masses in mountains produced erosion in bedrock and subglacial sediment, including the formation of overdeepenings and large moraine dams that now serve as basins for glacial lakes. Satellite based studies found a total of 8355 glacial lakes in Peru, whereof 830 lakes were observed in the Cordillera Blanca. Some of them have caused major disasters due to glacial lake outburst floods in the past decades. On the other hand, in view of shrinking glaciers, changing water resources, and formation of new lakes, glacial lakes could have a function as water reservoirs in the future. Here we present unprecedented bathymetric studies of 124 glacial lakes in the Cordillera Blanca, Huallanca, Huayhuash and Raura in the regions of Ancash, Huanuco and Lima. Measurements were carried out using a boat equipped with GPS, a total station and an echo sounder to measure the depth of the lakes. Autocad Civil 3D Land and ArcGIS were used to process the data and generate digital topographies of the lake bathymetries, and analyze parameters such as lake area, length and width, and depth and volume. Based on that, we calculated empirical equations for mean depth as related to (1) area, (2) maximum length, and (3) maximum width. We then applied these three equations to all 830 glacial lakes of the Cordillera Blanca to estimate their volumes. Eventually we used three relations from the literature to assess the peak discharge of potential lake outburst floods, based on lake volumes, resulting in 3 x 3 peak discharge estimates. In terms of lake topography and geomorphology results indicate that the maximum depth is located in the center part for bedrock lakes, and in the back part for lakes in moraine material. Best correlations are found for mean depth and maximum width, however, all three empirical relations show a large spread, reflecting the wide range of natural lake bathymetries. Volumes of the 124 lakes with bathymetries amount to 0

  7. Ephemeral skin-flows on talus affected by permafrost degradation (Corral del Veleta, Spain)

    NASA Astrophysics Data System (ADS)

    Tanarro, L. M.; Palacios, D.; Zamorano, J. J.; Gómez, A.

    2009-04-01

    In mountain environments, talus formed at the foot of valley sides are frequently affected by hillslope processes, such as skin-flows. The main characteristic of this type of flow is that it only causes the movement of a thin layer of soil, regolith or debris over an inclined plane parallel to the topographical surface of the talus. Some examples of this movement have already been described (Rapp, 1960; Akerman; 1984; White, 1981, Benedict, 1970; Jahn, 1967; Söderman, 1980; Lewkowicz, 1988, Harris, 1987). The causes of the formation of these movements vary, but in general they have been linked primarily with rapid snow melt and/or with degraded permafrost levels (Jahn, 1967; Nyberg, 1991; Rapp and Nyberg, 1988; Strömquist, 1985; Hall, 1985; Thorn, 1988; McRoberts and Morgenstern, 1974, Caine, 1976). Within this context, the aims of this paper are: first, to present and describe the characteristics and temporal and geomorphological evolution of a series of skin-flows which have occurred on the talus which lies at the foot of the Corral del Veleta glacial cirque, and second, to analyze the factors that appear to have triggered them. The Pico del Veleta mountain (3398 m a.s.l.) is one of the main summits in the Sierra Nevada Massif, a group of mountains forming part of the Cordilleras Béticas, in SE Spain (37°03´N, 3°22´W). The Corral del Veleta is a glacial cirque on the northeastern face of the Pico del Veleta, c. 600 m long in a NW-SE direction, with a head is formed by a steep wall which falls more than 250 meters to meet with a wide and irregular talus. The cirque headwall is composed of metamorphic rocks (mainly micaschist), lined up in structural steps or shelves tilted towards the NNW. One of these shelves forms the base of the cirque, on which a series of moraine ridges, tardiglacial or from the Little Ice Age, which close off the cirque towards the North (Gómez et al., 2001). The talus is formed from abundant debris resulting from weathering

  8. New approach to date the extensional tectonics in the Betic Chain (Spain)

    NASA Astrophysics Data System (ADS)

    Julián Esteban, José; María Tubía, José; Cuevas, Julia; Seward, Diane; Larionov, Alexander; Sergeev, Sergey; Navarro-Vilá, Francisco

    2013-04-01

    The Betic Cordilleras, in southern Spain, represent a good example of a collisional orogen disaggregated by extensional collapse in a convergent setting during the Miocene. The Alpujarride and Malaguide Complexes, in the Internal Zone, are bounded by an extensional detachment, previously interpreted as a thrust-nappe. In the western Betics, the Malaguide Complex overlies the Los Reales nappe (one of the tectonic slices that conforms the Alpujarride Complex) and although their boundary is characterized as a brittle-ductile extensional detachment, little is known about its age of movement. In order to constraint the age of the detachment, two dolerite dykes cut by the boundary were dated by U-Pb SHRIMP on zircons along with nine samples, from the lowest to the upper structural levels of the Malaguide Complex, by zircon fission-track analysis (ZFT). Zircons separated from dolerite dykes display rounded or eroded edges bounded by light or dark luminescent rims. Zircons cores with igneous appearance (euhedral, oscillatory zoning, high Th/U content) yield 206Pb/238U ages between 1799 and 264 Ma, which cannot be correlated with dolerite dyke intrusion, as similar dykes appear within Middle-Upper Triassic pelites in other Alpujarride sections. Otherwise, the external rims yield ages between 1187 to 28 Ma. Four of the youngest analysed zircon rims show Th/U ratios consistent with a metamorphic origin. These zircons define a mixing line intersecting the Concordia at 20.9 ± 9 (2σ), that agrees with the age of the thermal Alpine metamorphism. Two of the youngest rims display high Th/U contents, common in igneous zircons. They give concordant ages of 33.1 ± 1.5 (2σ) and 39.0 ± 2.5 (2σ) Ma. However, the youngest is the only one that has geological meaning, as similar ages have been reported using different geochronological systems. Therefore, it could be considered as the age of dolerite dyke intrusion. The ZFT samples yield ages between 18.6 ± 1.8 (2σ) and 25.8 ± 3

  9. Pressure stabilized Se-Se dimer formation in PbSe 2

    NASA Astrophysics Data System (ADS)

    Bremholm, M.; Hor, Y. S.; Cava, R. J.

    2011-01-01

    The preparation of PbSe 2 through the reaction of PbSe with excess Se at 4.5 GPa and 650 °C is reported. The crystal structure, determined from X-ray powder diffraction data (CuAl 2 structure type, I4/mcm (#140), a = 6.42695(11) Å, c = 7.70254(13) Å, Z = 4), consists of layers of [Se 2] 2- dimers with Pb 2+ in square antiprismatic coordination with Se. This is a rare crystal structure for divalent metal chalcogenides, previously only identified for SrS 2 and BaTe 2. Undoped PbSe 2 as well as Bi 3+- and Ag +-doped samples (10% Pb substitution) show semi-metallic resistivity down to 0.4 K. Magnetic susceptibility measurement of PbSe 2 shows no magnetic ordering above 1.8 K. The Seebeck coefficients show nearly linear behavior from 35 to 400 K and the largest numerical values are found in the case of undoped PbSe 2, + 99 μVK -1, and Bi 3+-doped PbSe 2, - 146 μVK -1, at the highest temperature measured, 400 K.

  10. Niche shifts and range expansions along cordilleras drove diversification in a high-elevation endemic plant genus in the tropical Andes.

    PubMed

    Kolář, Filip; Dušková, Eva; Sklenář, Petr

    2016-09-01

    The tropical Andes represent one of the world's biodiversity hot spots, but the evolutionary drivers generating their striking species diversity still remain poorly understood. In the treeless high-elevation Andean environments, Pleistocene glacial oscillations and niche differentiation are frequently hypothesized diversification mechanisms; however, sufficiently densely sampled population genetic data supporting this are still lacking. Here, we reconstruct the evolutionary history of Loricaria (Asteraceae), a plant genus endemic to the Andean treeless alpine zone, based on comprehensive population-level sampling of 289 individuals from 67 populations across the entire distribution ranges of its northern Andean species. Partly incongruent AFLP and plastid DNA markers reveal that the distinct genetic structure was shaped by a complex interplay of biogeography (spread along and across the cordilleras), history (Pleistocene glacial oscillations) and local ecological conditions. While plastid variation documents an early split or colonization of the northern Andes by at least two lineages, one of which further diversified, a major split in the AFLP data correlate with altitudinal ecological differentiation. This suggests that niche shifts may be important drivers of Andean diversification not only in forest-alpine transitions, but also within the treeless alpine zone itself. The patterns of genetic differentiation at the intraspecific level reject the hypothesized separation in spatially isolated cordilleras and instead suggest extensive gene flow among populations from distinct mountain chains. Our study highlights that leveraging highly variable markers against extensive population-level sampling is a promising approach to address mechanisms of rapid species diversifications.

  11. Niche shifts and range expansions along cordilleras drove diversification in a high-elevation endemic plant genus in the tropical Andes.

    PubMed

    Kolář, Filip; Dušková, Eva; Sklenář, Petr

    2016-09-01

    The tropical Andes represent one of the world's biodiversity hot spots, but the evolutionary drivers generating their striking species diversity still remain poorly understood. In the treeless high-elevation Andean environments, Pleistocene glacial oscillations and niche differentiation are frequently hypothesized diversification mechanisms; however, sufficiently densely sampled population genetic data supporting this are still lacking. Here, we reconstruct the evolutionary history of Loricaria (Asteraceae), a plant genus endemic to the Andean treeless alpine zone, based on comprehensive population-level sampling of 289 individuals from 67 populations across the entire distribution ranges of its northern Andean species. Partly incongruent AFLP and plastid DNA markers reveal that the distinct genetic structure was shaped by a complex interplay of biogeography (spread along and across the cordilleras), history (Pleistocene glacial oscillations) and local ecological conditions. While plastid variation documents an early split or colonization of the northern Andes by at least two lineages, one of which further diversified, a major split in the AFLP data correlate with altitudinal ecological differentiation. This suggests that niche shifts may be important drivers of Andean diversification not only in forest-alpine transitions, but also within the treeless alpine zone itself. The patterns of genetic differentiation at the intraspecific level reject the hypothesized separation in spatially isolated cordilleras and instead suggest extensive gene flow among populations from distinct mountain chains. Our study highlights that leveraging highly variable markers against extensive population-level sampling is a promising approach to address mechanisms of rapid species diversifications. PMID:27482945

  12. Empirical-statistical downscaling of reanalysis data to high-resolution air temperature and specific humidity above a glacier surface (Cordillera Blanca, Peru)

    NASA Astrophysics Data System (ADS)

    Hofer, Marlis; MöLg, Thomas; Marzeion, Ben; Kaser, Georg

    2010-06-01

    Recently initiated observation networks in the Cordillera Blanca (Peru) provide temporally high-resolution, yet short-term, atmospheric data. The aim of this study is to extend the existing time series into the past. We present an empirical-statistical downscaling (ESD) model that links 6-hourly National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis data to air temperature and specific humidity, measured at the tropical glacier Artesonraju (northern Cordillera Blanca). The ESD modeling procedure includes combined empirical orthogonal function and multiple regression analyses and a double cross-validation scheme for model evaluation. Apart from the selection of predictor fields, the modeling procedure is automated and does not include subjective choices. We assess the ESD model sensitivity to the predictor choice using both single-field and mixed-field predictors. Statistical transfer functions are derived individually for different months and times of day. The forecast skill largely depends on month and time of day, ranging from 0 to 0.8. The mixed-field predictors perform better than the single-field predictors. The ESD model shows added value, at all time scales, against simpler reference models (e.g., the direct use of reanalysis grid point values). The ESD model forecast 1960-2008 clearly reflects interannual variability related to the El Niño/Southern Oscillation but is sensitive to the chosen predictor type.

  13. Interannual and Interseasonal Variability of Surface Energy and Mass Fluxes on Shallap Glacier, Cordillera Blanca, Retrieved from ERA-Interim Reanalysis Data

    NASA Astrophysics Data System (ADS)

    Maussion, F.; Gurgiser, W.; Marzeion, B.

    2014-12-01

    The glaciers of the Cordillera Blanca (Peru) mountain range are exposed to the strongest mode of interannual global variability: El Niño/Southern Oscillation (ENSO). Because of the sparse mas balance observations, the quantification of ENSO influence on tropical glaciers is difficult. The starting point of this study is a four-year long time series of distributed surface energy and mass balance (SEB/SMB) at Shallap Glacier, southern Cordillera Blanca, calculated using a process-based model driven by in-situ observations. We use these data to calibrate a fully automated regression-based statistical downscaling tool, developed especially to downscale the individual SEB/SMB fluxes from large-scale gridded atmospheric data on a monthly basis (in this study, ERA-Interim) and for regularly spaced altitude slices on the glacier. Albeit some limitations inherent to the mass balance model and to the statistical downscaling strategy, the skill of the model evaluated by leave-one-out cross-validation allows a robust evaluation of the ENSO influence on glacier SEB/SMB fluxes for the longer period 1980 - 2013. The presented downscaling tool can be applied easily to other glaciers and/or atmospheric datasets, providing a new way to extend observed SEB/SMB time series to much longer time scales.

  14. U-Th-Pb geochronology of meta-carbonatites and meta-alkaline rocks in the southern Canadian Cordillera: A geodynamic perspective

    NASA Astrophysics Data System (ADS)

    Millonig, Leo J.; Gerdes, Axel; Groat, Lee A.

    2012-11-01

    U-Pb and Th-Pb ages of zircons from seven meta-carbonatite and three meta-alkaline rock samples provide evidence for three distinct episodes of carbonatite and alkaline magmatism in the southern Canadian Cordillera spanning a period of ~ 460 Ma. The earliest, Neoproterozoic event occurred at ~ 800-700 Ma and coincides with the postulated initial break-up of Rodinia. The second, previously undocumented, event of carbonatitic magmatism is constrained to the Late Cambrian at ~ 500 Ma and corresponds to a period of extensional tectonics that affected the western continental margin of North America from the Canadian Cordillera to the southwestern United States. The youngest and most prevalent period of alkaline igneous activity occurred in Late Devonian to Early Carboniferous times at ~ 360-340 Ma and resulted from extensional tectonics, presumably caused by slab rollback. In addition, different episodes of amphibolite-facies metamorphism subsequently affected the igneous rocks between ~ 155 and 50 Ma. This dataset puts new constraints on the timing of carbonatite and alkaline igneous activity and the evolution of (ancestral) North America's western continental margin from Neoproterozoic to Carboniferous times.

  15. Surface-exposure Dating of Late Quaternary Glacial Advances in the Cordillera Blanca, Peruvian Andes (9°-10°S)

    NASA Astrophysics Data System (ADS)

    Smith, J. A.; Zehner, S. P., Jr.; Bowen, D. R.; Rodbell, D. T.

    2013-12-01

    New 10Be surface-exposure ages from boulders on lateral moraines bordering Querococha Valley (9°44.6' S, 77°21.6' W) in the southern Cordillera Blanca, Peru, indicate that late-glacial (˜16 ka) ice extended as much as 15 km downvalley from the headwall(s). With the glacier terminus at ˜3900 masl and the headwall at ˜5200 masl, THAR reconstruction (THAR=0.45) places the late-glacial equilibrium-line altitude (ELA) at ˜4485 masl, as compared to an estimated modern ELA of ˜5100 masl. The late-glacial Querococha advance was coeval with late-glacial advances at the Nevado Jeulla Rajo (NJR) massif at the southern end of the Cordillera Blanca (10°00'S, 77°16'W; peaks ˜5600 masl), ˜35 km to the south, where we have dated multiple moraines. Surface-exposure ages (10Be) indicate that the largest lateral moraines from Jeullesh Valley at NJR are compound features deposited during both the local last glacial maximum (˜30 ka) and a late-glacial readvance (˜15 ka). Late-glacial moraines are the largest lateral moraines in neighboring Quenua Ragra and Tuco valleys. The timing of the late-glacial advances in the Cordillera Blanca suggests a link to increased precipitation associated with Heinrich Event I (˜17 ka). Additional new 10Be surface-exposure ages from boulders on a moraine crossing a side valley in the upper reaches of Jeullesh Valley are early Holocene (˜9-11 ka), suggesting retreat of 3-4 km from the late-glacial terminal position in ˜4 kyr. Using the same THAR methodology, the late-glacial ELA in Jeullesh Valley was ˜4815 masl and the early Holocene ELA was ˜4995 masl. The active, west-dipping Cordillera Blanca Normal Fault (CBNF) vertically offsets the crests of 10Be-dated moraines in six valleys where we have profiled CBNF scarps: Jeullesh, Quenua Ragra, and Tuco valleys in the NJR massif; and Llaca, Cojup, and Querococha valleys in the south-central Cordillera Blanca (9°28'-45'S, 77°28'-21'W). In Jeullesh Valley, the CBNF scarp offsets both late

  16. [Intake of trans fats; situation in Spain].

    PubMed

    Riobó, Pilar; Breton, Irene

    2014-04-01

    Current nutritional recommendations include decreasing the intake of trans fatty acids (TFA), since there exists sufficient scientific evidence of its influence to cardiovascular disease. During the last decades, in many European countries the TFA intake has considerably decreased through the established legislation and changes in the technological processes developed by the food industry. In Spain, just 2.1 g/day, a 0.7% of the daily energy intake comes from TFA, a lower value than the recommended maximum (<1%), according to data from TRANSFAIR study. The TFA content of processed products such as margarines, factory-baked goods and etc, has declined over recent years and is less than 1% in more than 90% of all these products in Spain. However, it is necessary to develop and implement regulations, governing the TFA content in the products sold in our country, in which there should be the requirement to include this information in the label too.

  17. Young people's heroes in France and Spain.

    PubMed

    Gash, Hugh; Domínguez Rodríguez, Pilar

    2009-05-01

    Heroes play collectivist or individualist roles in imagination and self-development. Representations of heroic figures in questionnaires given to French (n = 241) and Spanish (n = 227) samples of 10 and 15-year-olds were examined to assess the extent that heroes originated in digital media, and whether they were proximal or distal personalities. There is strong evidence that heroes in this sample were largely learned about in digital media (France 45%, Spain 50%): family and community heroes were a minority (France 11%, Spain 9%). Male heroes were more important to Spanish participants compared to their French peers. The acquisition sequence for hero type reported in the pre-television era, proximal (family and community) to distal (beyond the neighbourhood), is reversed in this study. Generally, 10-year-olds preferred heroes with collectivist qualities and 15-year-olds with individualised qualities. Findings are discussed in terms of the emergence of social capital. PMID:19476237

  18. Patents, antibiotics, and autarky in Spain.

    PubMed

    Romero De Pablos, Ana

    2014-01-01

    Patents on antibiotics were introduced in Spain in 1949. Preliminary research reveals diversification in the types of antibiotics: patents relating to penicillin were followed by those relating to streptomycin, erythromycin and tetracycline. There was also diversification in the firms that applied for patents: while Merck & Co. Incorporated and Schenley Industries Inc. were the main partners with Spanish antibiotics manufacturers in the late 1940s, this industrial space also included many others, such as Eli Lilly & Company, Abbott Laboratories, Chas. Pfizer & Co. Incorporated, and American Cyanamid Company in the mid-1970s. The introduction of these drugs in Spain adds new elements to a re-evaluation of the autarkic politics of the early years of the Franco dictatorship.

  19. Patents, antibiotics, and autarky in Spain.

    PubMed

    Romero De Pablos, Ana

    2014-01-01

    Patents on antibiotics were introduced in Spain in 1949. Preliminary research reveals diversification in the types of antibiotics: patents relating to penicillin were followed by those relating to streptomycin, erythromycin and tetracycline. There was also diversification in the firms that applied for patents: while Merck & Co. Incorporated and Schenley Industries Inc. were the main partners with Spanish antibiotics manufacturers in the late 1940s, this industrial space also included many others, such as Eli Lilly & Company, Abbott Laboratories, Chas. Pfizer & Co. Incorporated, and American Cyanamid Company in the mid-1970s. The introduction of these drugs in Spain adds new elements to a re-evaluation of the autarkic politics of the early years of the Franco dictatorship. PMID:26054209

  20. Training in breast surgery in Spain.

    PubMed

    Miguelena, José M; Domínguez Cunchillos, Fernando

    2016-01-01

    Breast surgery is a key part of training and competency in general surgery in Spain and is a "frontier area" that can be efficiently managed by general surgeons and gynecologists. The main objective of the training process consists of the surgical treatment of breast cancer, including conservative surgery, oncoplastic and reconstructive techniques. This article analyses the current status of breast surgery training in Spain and schematically proposes potential targets of the different training programs, to improve access and training for surgeons and residents in this area, taking into account the RD 639/2014 and European regulation. The priority is to specify the level of training that should be achieved, in relation to the group of professionals involved, considering their area of competency: surgery resident, educational programs, and surgeons with special dedication to this area.

  1. Training in breast surgery in Spain.

    PubMed

    Miguelena, José M; Domínguez Cunchillos, Fernando

    2016-01-01

    Breast surgery is a key part of training and competency in general surgery in Spain and is a "frontier area" that can be efficiently managed by general surgeons and gynecologists. The main objective of the training process consists of the surgical treatment of breast cancer, including conservative surgery, oncoplastic and reconstructive techniques. This article analyses the current status of breast surgery training in Spain and schematically proposes potential targets of the different training programs, to improve access and training for surgeons and residents in this area, taking into account the RD 639/2014 and European regulation. The priority is to specify the level of training that should be achieved, in relation to the group of professionals involved, considering their area of competency: surgery resident, educational programs, and surgeons with special dedication to this area. PMID:27059252

  2. Entrepreneurship research in Spain: developments and distinctiveness.

    PubMed

    Sánchez, José C; Gutiérrez, Andrea

    2011-08-01

    This article presents a review of research on entrepreneurship in Spain, paying particular attention to its beginnings, nature and main focus of interest. We have developed a database based on the review of 471 works produced between 1977 and 2009, including articles published in national and international journals and dissertations (read in Spain) that allowed us to extract the following results. There is a preference for qualitative methods, conceptual contributions and the entrepreneurial process as the privileged research theme. There is also a strong focus of interest on micro and small enterprises. These characteristics of Spanish research in areas of entrepreneurship can make a distinctive contribution to international research. However, the dissemination of knowledge and inadequate strategies for international publication limit the diffusion of Spanish research in entrepreneurship. Lastly, we discuss the implications for future research.

  3. Young people's heroes in France and Spain.

    PubMed

    Gash, Hugh; Domínguez Rodríguez, Pilar

    2009-05-01

    Heroes play collectivist or individualist roles in imagination and self-development. Representations of heroic figures in questionnaires given to French (n = 241) and Spanish (n = 227) samples of 10 and 15-year-olds were examined to assess the extent that heroes originated in digital media, and whether they were proximal or distal personalities. There is strong evidence that heroes in this sample were largely learned about in digital media (France 45%, Spain 50%): family and community heroes were a minority (France 11%, Spain 9%). Male heroes were more important to Spanish participants compared to their French peers. The acquisition sequence for hero type reported in the pre-television era, proximal (family and community) to distal (beyond the neighbourhood), is reversed in this study. Generally, 10-year-olds preferred heroes with collectivist qualities and 15-year-olds with individualised qualities. Findings are discussed in terms of the emergence of social capital.

  4. Modelling cascading and erosional processes for glacial lake outburst floods in the Quillcay catchment, Huaraz, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Baer, Patrick; Huggel, Christian; Frey, Holger; Chisolm, Rachel; McKinney, Daene; McArdell, Brian; Portocarrero, Cesar; Cochachin, Alejo

    2016-04-01

    Huaraz as the largest city in Cordillera Blanca has faced a major disaster in 1941, when an outburst flood from Lake Palcacocha killed several thousand people and caused widespread destruction. Recent studies on glacial lake outburst flood (GLOF) modelling and early warning systems focussed on Lake Palcacocha which has regrown after the 1941 event, from a volume of half a million m3 in 1974 to a total volume of more than 17 million m3 today. However, little research has been conducted so far concerning the situation of other lakes in the Quillcay catchment, namely Lake Tullparaju (12 mill. m3) and Cuchillacocha (2.5 mill. m3), which both also pose a threat to the city of Huaraz. In this study, we modelled the cascading processes at Lake Tullparaju and Lake Cuchillacocha including rock/ice avalanches, flood wave propagation in the lake and the resulting outburst flood and debris flows. We used the 2D model RAMMS to simulate ice avalanches. Model output was used as input for analytical 2D and 3D calculations of impact waves in the lakes that allowed us to estimate dam overtopping wave height. Since the dimension of the hanging glaciers above all three lakes is comparable, the scenarios in this study have been defined similar to the previous study at Lake Palcacocha. The flow propagation model included sediment entrainment in the steeper parts of the catchment, adding up to 50% to the initial flow volume. The results for total travel time as well as for inundated areas and flow depth and velocity in the city of Huaraz are comparable to the previous studies at Lake Palcacocha. This underlines the importance of considering also these lakes within an integral hazard analysis for the city of Huaraz. A main challenge for modelling GLOFs in the Quillcay catchment using RAMMS is the long runout distance of over 22 km combined with the very low slope gradient of the river. Further studies could improve the process understanding and could focus on more detailed investigations

  5. Controls on the isotopic composition of surface water and precipitation in the Northern Andes, Colombian Eastern Cordillera

    NASA Astrophysics Data System (ADS)

    Saylor, Joel E.; Mora, Andrés; Horton, Brian K.; Nie, Junsheng

    2009-12-01

    Empirical datasets provide the constraints on the variability and causes of variability in stable isotope compositions (δD or δ 18O) of surface water and precipitation that are essential not only for models of modern and past climate but also for investigations of paleoelevation. This study presents stable isotope data for 76 samples from four elevation transects and three IAEA GNIP stations in the Eastern Cordillera of Colombia and the northern Andean foreland. These data are largely consistent with theories of stable isotope variability developed based on a global dataset. On a monthly basis, the precipitation-amount effect exerts the dominant control on δD p and δ 18O p values at the IAEA GNIP stations. At the Bogotá station (2547 m), the δD p and δ 18O p values vary seasonally, with isotopic minima correlating with maxima in precipitation-amount. Although surface water samples from Eastern Cordilleran streams and rivers fall on the Global Meteoric Water Line, samples from three of four lakes (2842-3459 m) have evaporatively elevated δD sw and δ 18O sw values. The IAEA GNIP station data averaged over multiple years, combined with stream and river water data, define vertical lapse rates of -1.8‰ km -1 for Δδ 18O and -14.6‰ km -1 for ΔδD, and are a close fit to a common thermodynamically based Rayleigh distillation model. Elevation uncertainties for these relationships are also evaluated. Comparison of this Colombian dataset with the elevation uncertainties generated by the thermodynamically based model shows that the model underestimates uncertainty at high Δδ 18O and ΔδD values while overestimating it for low Δδ 18O and ΔδD values. This study presents an independent, empirical assessment of stable isotope-based elevation uncertainties for the northern Andes based on a dataset of sufficient size to ensure statistical integrity. These vertical lapse rates and associated uncertainties form the basis for stable isotope paleoelevation studies

  6. Multiproxy records of Holocene climate and glacier variability from sediment cores in the Cordillera Vilcabamba of southern Peru

    NASA Astrophysics Data System (ADS)

    Schweinsberg, A. D.; Licciardi, J. M.; Rodbell, D. T.; Stansell, N.; Tapia, P. M.

    2012-12-01

    Sediments contained in glacier-fed lakes and bogs provide continuous high-resolution records of glacial activity, and preserve multiproxy evidence of Holocene climate change. Tropical glacier fluctuations offer critical insight on regional paleoclimatic trends and controls, however, continuous sediment records of past tropical climates are limited. Recent cosmogenic 10Be surface exposure ages of moraine sequences in the Cordillera Vilcabamba of southern Peru (13°20'S latitude) reveal a glacial culmination during the early Holocene and a less extensive glaciation coincident with the Little Ice Age of the Northern Hemisphere. Here we supplement the existing 10Be moraine chronology with the first continuous records of multiproxy climate data in this mountain range from sediment cores recovered from bogs in direct stratigraphic contact with 10Be-dated moraines. Radiocarbon-dated sedimentological changes in a 2-meter long bog core reveal that the Holocene is characterized by alternating inorganic and organic-rich laminae, suggesting high-frequency climatic variability. Carbon measurements, bulk density, and bulk sedimentation rates are used to derive a record of clastic sediment flux that serves as a proxy indicator of former glacier activity. Preliminary analyses of the bog core reveal approximately 70 diatom taxa that indicate both rheophilic and lentic environments. Initial results show a general decrease in magnetic susceptibility and clastic flux throughout the early to mid-Holocene, which suggests an interval of deglaciation. An episode of high clastic flux from 3.8 to 2.0 ka may reflect a late Holocene glacial readvance. Volcanic glass fragments and an anomalous peak in magnetic susceptibility may correspond to the historical 1600 AD eruption of Huaynaputina. Ten new bog and lake sediment cores were collected during the 2012 field expedition and analytical measurements are underway. Ongoing efforts are focused on analyzing diatom assemblage data, developing

  7. Evolution and hazard analysis of high-mountain lakes in the Cordillera Vilcabamba (Southern Peru) from 1991 to 2014

    NASA Astrophysics Data System (ADS)

    Guardamino, Lucía; Drenkhan, Fabian

    2015-04-01

    In recent decades, glaciers in high-mountain regions have experienced unprecedented glacier retreat since the Little Ice Age (LIA). This development triggers the formation and growth of glacier lakes, which in combination with changes in glacier parameters might produce more frequent conditions for the occurrence of disasters, such as Glacier Lake Outburst Floods (GLOF). Facing such a scenario, the analysis of changing lake characteristics and identification of new glacier lakes are imperative in order to identify and reduce potential hazards and mitigate or prevent future disasters for adjacent human settlements. In this study, we present a multi-temporal analysis with Landsat TM 5 and OLI 8 images between 1991 and 2014 in the Cordillera Vilcabamba region (Southern Peru), a remote area with difficult access and climate and glaciological in-situ data scarcity. A semi-automatic model was developed using the band ratios Normalized Difference Snow Index (NDSI) and Normalized Difference Water Index (NDWI) in order to identify glacier and lake area changes. Results corroborate a strong glacier area reduction of about 51% from 1991 (200.3 km²) to 2014 (98.4 km²). At the same time, the number of lakes (total lake surface) has increased at an accelerated rate, from 0.77% (0.48%) in 1991 to 2.31% (2.49%) in 2014. In a multiple criteria analysis to identify potential hazards, 90 out of a total of 329 lakes in 2014 have been selected for further monitoring. Additionally, 29 population centers have been identified as highly exposed to lake related hazards from which 25 indicate a distance less than 1 km to an upstream lake and four are situated in a channel of potential debris flow. In these areas human risks are particularly high in view of a low HDI below Peru's average and hence pronounced vulnerability. We suggest more future research on measurements and monitoring of glacier and lake characteristics in these remote high-mountain regions, which include comprehensive risk

  8. Origin of gem corundum in calcite marble: The Revelstoke occurrence in the Canadian Cordillera of British Columbia

    NASA Astrophysics Data System (ADS)

    Dzikowski, Tashia J.; Cempírek, Jan; Groat, Lee A.; Dipple, Gregory M.; Giuliani, Gaston

    2014-06-01

    The calcite marble-hosted gem corundum (ruby, sapphire) occurrence near Revelstoke, British Columbia, Canada, occurs in the Monashee Complex of the Omineca Belt of the Canadian Cordillera. Corundum occurs in thin, folded and stretched layers with green muscovite + Ba-bearing K-feldspar + anorthite (An0.85-1) ± phlogopite ± Na-poor scapolite. Other silicate layers within the marble are composed of: (1) diopside + tremolite ± quartz and (2) garnet (Alm0.7-0.5Grs0.2-0.4) + Na-rich scapolite + diopside + tremolite + Na,K-amphiboles. Non-silicate layers in the marble are either magnetite- or graphite-bearing. Predominantly pink (locally red or purple) opaque to transparent corundum crystals have elevated Cr2O3 (≤ 0.21 wt.%) and variable amounts of TiO2; rare blue rims on the corundum crystals contain higher amounts of TiO2 (≤ 0.53 wt.%) and Fe2O3 (≤ 0.07 wt.%). The associated micas have elevated Cr, V, Ti, and Ba contents. Petrography of the silicate layers show that corundum formed from muscovite at the peak of metamorphism (~ 650-700 °C at 8.5-9 kbar). Because the marble is almost pure calcite (dolomite is very rare), the corundum was preserved because it did not react with dolomite to spinel + calcite during decompression. The scapolite-bearing assemblages formed during or after decompression of the rock at ~ 650 °C and 4-6 kbar. Gem-quality corundum crystals formed especially on borders of the mica-feldspar layers in an assemblage with calcite. Whole rock geochemistry data show that the corundum-bearing silicate (mica-feldspar) layers formed by mechanical mixing of carbonate with the host gneiss protolith; the bulk composition of the silicate layers was modified by Si and Fe depletion during prograde metamorphism. High element mobility is supported by the homogenization of δ18O and δ13C values in carbonates and silicates for the marble and silicate layers. The silicate layers and the gneiss contain elevated contents of Cr and V due to the volcanoclastic

  9. Unraveling an antique subduction process from metamorphic basement around Medellín city, Central Cordillera of Colombian Andes

    NASA Astrophysics Data System (ADS)

    Bustamante, Andres; Juliani, Caetano

    2011-10-01

    varies between 400 and 555 °C at pressures of 5-6 kbar in the retrograde metamorphic path. The El Retiro rocks evidence strong decompression with narrow variation in temperature, showing pressure values between 8.7 and 2.7 kbar at temperatures of 740-633 °C. These metamorphic fragments of the basement in the Central Cordillera of the Colombian Andes could represent a close relationship with an antique subduction zone.

  10. Tectonics of the Jurassic-Early Cretaceous magmatic arc of the north Chilean Coastal Cordillera (22°-26°S): A story of crustal deformation along a convergent plate boundary

    NASA Astrophysics Data System (ADS)

    Scheuber, Ekkehard; Gonzalez, Gabriel

    1999-10-01

    The tectonic evolution of a continental magmatic arc that was active in the north Chilean Coastal Cordillera in Jurassic-Early Cretaceous times is described in order to show the relationship between arc deformation and plate convergence. During stage I (circa 195-155 Ma) a variety of structures formed at deep to shallow crustal levels, indicating sinistral arc-parallel strike-slip movements. From deep crustal levels a sequence of structures is described, starting with the formation of a broad belt of plutonic rocks which were sheared under granulite to amphibolite facies conditions (Bolfin Complex). The high-grade deformation was followed by the formation of two sets of conjugate greenschist facies shear zones showing strike-slip and thrust kinematics with a NW-SE directed maximum horizontal shortening, i.e., parallel to the probable Late Jurassic vector of plate convergence. A kinematic pattern compatible to this plate convergence is displayed by nonmetamorphic folds, thrusts, and high-angle normal faults which formed during the same time interval as the discrete shear zones. During stage II (160-150 Ma), strong arc-normal extension is revealed by brittle low-angle normal faults at shallow levels and some ductile normal faults and the intrusion of extended plutons at deeper levels. During stage III (155-147 Ma), two reversals in the stress regime took place indicated by two generations of dikes, an older one trending NE-SW and a younger one trending NW-SE. Sinistral strike-slip movements also prevailed during stage IV (until ˜125 Ma) when the Atacama Fault Zone originated as a sinistral trench-linked strike-slip fault. The tectonic evolution of the magmatic arc is interpreted in terms of coupling and decoupling between the downgoing and overriding plates. The structures of stages I and IV suggest that stress transmission due to seismic coupling between the plates was probably responsible for these deformations. However, decoupling of the plates occurred possibly

  11. Sociological Profile of Astronomers in Spain

    NASA Astrophysics Data System (ADS)

    Iglesias de Ussel, Julio; Trinidad, Antonio; Ruiz, Diego; Battaner, Eduardo; Delgado, Antonio J.; Rodriguez-Espinosa, José M.; Salvador-Solé, Eduard; Torrelles, José M.

    In this paper the main findings are presented of a recent study made by a team of sociologists from the University of Granada on the professional astronomers currently working in Spain. Despite the peculiarities of this group - its youth, twentyfold increase in size over the last 20 years, and extremely high rate of specialization abroad - in comparison with other Spanish professionals, this is the first time that the sociological characteristics of the group have been studied discretely. The most significant results of the study are presented in the following sections. Section 1 gives a brief historical background of the development of Astronomy in Spain. Section 2 analyzes the socio-demographic profile of Spanish Astronomy professionals (sex, age, marital status, etc.). Sections 3-5 are devoted to the college education and study programs followed by Spanish astronomers, focusing on the features and evaluations of the training received, and pre- and postdoctoral study trips made to research centers abroad. The results for the latter clearly show the importance that Spanish astronomers place on having experience abroad. Special attention is paid to scientific papers published as a result of joint research projects carried out with colleagues from centers abroad as a result of these study trips. Section 6 describes the situation of Astronomy professionals within the Spanish job market, the different positions available and the time taken to find a job after graduation. Section 7 examines Astronomy as a discipline in Spain, including the astronomers' own opinions of the social status of the discipline within Spanish society. Particular attention is paid to how Spanish astronomers view the status of Astronomy in Spain in comparison with that of other European countries.

  12. Sociological profile of astronomers in Spain.

    NASA Astrophysics Data System (ADS)

    de Ussel, J. I.; Trinidad, A.; Ruíz, D.; Battaner, E.; Delgado, A. J.; Rodríguez-Espinosa, J. M.; Salvador-Solé, E.; Torrelles, J. M.

    In this paper the main findings are presented of a recent study made by a team of sociologists from the University of Granada on the professional astronomers currently working in Spain. Despite the peculiarities of this group - its youth, twentyfold increase in size over the last 20 years, and extremely high rate of specialization abroad - in comparison with other Spanish professionals, this is the first time that the sociological characteristics of the group have been studied discretely. The most significant results of the study are presented in the following sections. Section 1 gives a brief historical background of the development of astronomy in Spain. Section 2 analyzes the socio-demographic profile of Spanish astronomy professionals (sex, age, marital status, etc.). Sections 3-5 are devoted to the college education and study programs followed by Spanish astronomers, focusing on the features and evaluations of the training received, and pre- and postdoctoral study trips made to research centers abroad. The results for the latter clearly show the importance that Spanish astronomers place on having experience abroad. Special attention is paid to scientific papers published as a result of joint research projects carried out with colleagues from centers abroad as a result of these study trips. Section 6 describes the situation of astronomy professionals within the Spanish job market, the different positions available and the time taken to find a job after graduation. Section 7 examines astronomy as a discipline in Spain, including the astronomers' own opinions of the social status of the discipline within Spanish society. Particular attention is paid to how Spanish astronomers view the status of astronomy in Spain in comparison with that of other European countries.

  13. [Medicine and enlightenment in New Spain].

    PubMed

    de Micheli, A

    1998-01-01

    Fundamental ideas of the cultural movement of Enlightenment were drawn up and encouraged in England by John Locke and introduced into continental Europe by Voltaire. The essence of this movement was defined by I. Kant in 1784. These new ideas were projected into the field of medicine initially with the systematization of anatomical studies by Winslow, Vicq d' Azyr and Sénac in France, by S. Th. Sömmerring and von Haller in Germany, and by Paolo Mascagni and other anatomists in Italy. This movement settled in Spain toward the middle of the XVIII century, due to Father Feijóo and his pupils such as Piquer and Casal. In New Spain, which maintained cultural and scientific relationship with the Old World, the leaders of the movement were José Antonio Alzate in the field of biology and José Ignacio Bartolache in that of medicine. These were the founders of the first scientific journals: the "Diario Literario" (Literary Journal) by Alzate (1768) and the "Mercurio Volante" (Flying Mercury) by Bartolache (1772). Latter this physician had to face the great epidemic outbreak of smallpox in 1779. Due to that, he attributed great importance to the psychological aspect of the problem and supported the variolization proceeding introduced into Mexico by Doctor Henri Morel. Moreover, two scientific expeditions, which reached New Spain at the end of the XVIII century, allowed to systematize the study of the American vegetables and to acknowledge the usefulness of botany and chemistry as auxiliary sciences of medicine.

  14. [Could malaria and dengue reappear in Spain?].

    PubMed

    Bueno Marí, Rubén; Jiménez Peydró, Ricardo

    2010-01-01

    The recent increase in immigration to Spain has facilitated the importation of many tropical diseases. Among these diseases, those of vectorial origin are among the most difficult to study. Some of the reasons for this difficulty are the complexity due to the variety of hosts involved in the transmission cycles and the need to know all the physiological, bioecological and biogeographic parameters related to the vector in order to infer the actual possibilities of the emergence or reemergence of these diseases. This article provides information on imported diseases of unquestionable epidemiological interest for the population in Spain due to the presence of several species of culicid mosquitoes (Diptera, Culicidae) capable of transmitting these diseases in our country. Parasitic diseases such as malaria, which was highly endemic in Spain until 50 years ago, and other arboviral infections such as dengue and yellow fever, are analyzed in these terms. Various aspects related to the health system, as well as the different ways of tackling these issues, are also discussed.

  15. Paleoenvironmental reconstruction of the early Neolithic to middle Bronze Age Peña Larga rock shelter (Álava, Spain) from the small mammal record

    NASA Astrophysics Data System (ADS)

    Rofes, Juan; Zuluaga, Mari Cruz; Murelaga, Xabier; Fernández-Eraso, Javier; Bailon, Salvador; Iriarte, María José; Ortega, Luis Ángel; Alonso-Olazabal, Ainhoa

    2013-03-01

    The Peña Larga site, a rock shelter on the southern slopes of the Cantabrian cordillera (north Spain), is an archeological deposit covering nearly 4000 years, from the early Neolithic to the middle Bronze Age (Atlantic/Subboreal chronozones). It was used both as a household and as a stable, with a hiatus in the Chalcolithic when it was used as a collective sepulcher. Nearly twenty-eight thousand small vertebrate elements were recovered from its seven stratigraphic units, of which 2553 items were identified to the genus and/or species levels. The assemblage is composed of mammals, birds, reptiles, and amphibians. Of these, small mammals were used for paleoenvironmental reconstruction since they are very sensitive to climatic conditions, the sample sizes are large, and their preservation is good. Their distributions over time, measured in terms of relative abundance, serve as reliable proxies of habitat and climate change. The reconstruction of Peña Larga's past environments based on small mammals roughly coincides with the pollen and the amphibian/reptile records on the local scale, and with that of an ice core from Central Greenland on the global scale. This makes it a valuable tool for comparative purposes both in the regional and continental scales.

  16. Description of industrial pollution in Spain

    PubMed Central

    García-Pérez, Javier; Boldo, Elena; Ramis, Rebeca; Pollán, Marina; Pérez-Gómez, Beatriz; Aragonés, Nuria; López-Abente, Gonzalo

    2007-01-01

    Background Toxic substances released into the environment (to both air and water) by many types of industries might be related with the occurrence of some malignant tumours and other diseases. The publication of the EPER (European Pollutant Emission Register) Spanish data allows to investigate the presence of geographical mortality patterns related to industrial pollution. The aim of this paper is to describe industrial air and water pollution in Spain in 2001, broken down by activity group and specific pollutant, and to plot maps depicting emissions of carcinogenic substances. Methods All information on industrial pollution discharge in 2001 was drawn from EPER-Spain public records provided by the European Commission server. We described the distribution of the number of industries and amounts discharged for each pollutant, as well as emission by pollutant group and the industrial activities associated with each pollutant. Maps of Spain were drawn up, with UTM coordinates being used to plot pollutant foci, and circles with an area proportional to the emission to depict pollution emission values. Results The EPER-Spain contained information on 1,437 industrial installations. The industrial plants that discharge pollutant substances into air and water above the pollutant-specific EPER threshold were mainly situated in the Autonomous Regions of Aragon, Andalusia and Catalonia and in Catalonia, the Basque Country and Andalusia respectively. Pollution released in 2001 into air approached 158 million Mt. Emissions into water were over 8 million Mt. Conclusion A few single industrial plants are responsible for the highest percentage of emissions, thus rendering monitoring of their possible health impact on the surrounding population that much simpler. Among European countries Spain is the leading polluter in almost one third of all EPER-registered pollutant substances released into the air and ranks among the top three leading polluters in two-thirds of all such

  17. New drilling of the early Aptian OAE1a: the Cau core (Prebetic Zone, south-eastern Spain)

    NASA Astrophysics Data System (ADS)

    Alejandro Ruiz-Ortiz, Pedro; Castro, José Manuel; de Gea, Ginés Alfonso; Jarvis, Ian; Molina, José Miguel; Nieto, Luis Miguel; Pancost, Richard David; Quijano, María Luisa; Reolid, Matías; Skelton, Peter William; Jürg Weissert, Helmut

    2016-08-01

    The Cretaceous was punctuated by several episodes of accelerated global change, defined as Oceanic Anoxic Events (OAEs), that reflect abrupt changes in global carbon cycling. The Aptian Oceanic Anoxic Event (OAE1a; 120 Ma) represents an excellent example, recorded in all major ocean basins, and associated with massive burial of organic matter in marine sediments. The OAE1a is concomitant with the "nannoconid crisis", which is characterized by a major biotic turnover, and a widespread demise of carbonate platforms. Many studies have been published over the last decades on OAE1a's from different sections in the world, and provide a detailed C-isotope stratigraphy for the event. Nevertheless, new high-resolution studies across the event are essential to shed light on the precise timing and rates of the multiple environmental and biotic changes that occurred during this critical period of Earth history. Here we present a new drill core recovering an Aptian section spanning the OAE1a in southern Spain. The so-called Cau section was drilled in the last quarter of 2015. The Cau section is located in the easternmost part of the Prebetic Zone (Betic Cordillera), which represents platform deposits of the southern Iberian palaeomargin. The lower Aptian deposits of the Cau section belong to a hemipelagic unit (Almadich Formation), deposited in a highly subsident sector of the distal parts of the Prebetic Platform. Previous work on the early Aptian of the Cau succession has focused on stratigraphy, bioevents, C-isotope stratigraphy, and organic and elemental geochemistry. A more recent study based on biomarkers has presented a detailed record of the pCO2 evolution across the OAE1a (Naafs et al., 2016). All these studies reveal that the Cau section represents an excellent site to further investigate the OAE1a, based on its unusually high sedimentation rate and stratigraphic continuity, the quality and preservation of fossils, and the well-expressed geochemical signatures.

  18. [Moroccan migration to Spain. Data, opinions, and predictions].

    PubMed

    Cazorla, J

    1995-01-01

    "In this article, the author analyzes the migration flows between Spain and [Morocco] within the most general context of relations between European Union (EU) and the Maghrebian countries. Since the beginning of the eighties the migration flows toward and from Spain changed [dramatically], so... Spanish society has shifted toward an inmigration country. [The author analyzes] where such inmigrants come from and their motivations to choose Spain [as a] destination. The results of a survey financed partly by the EU...[for] institutions related directly with the migration problem from [Morocco] to Spain are the base of the information included in this article." (SUMMARY IN ENG)

  19. Salt lake Laguna de Fuente de Piedra (S-Spain) as Late Quaternary palaeoenvironmental archive

    NASA Astrophysics Data System (ADS)

    Höbig, Nicole; Melles, Martin; Reicherter, Klaus

    2014-05-01

    This study deals with Late Quaternary palaeoenvironmental variability in Iberia reconstructed from terrestrial archives. In southern Iberia, endorheic basins of the Betic Cordilleras are relatively common and contain salt or fresh-water lakes due to subsurface dissolution of Triassic evaporites. Such precipitation or ground-water fed lakes (called Lagunas in Spanish) are vulnerable to changes in hydrology, climate or anthropogenic modifications. The largest Spanish salt lake, Laguna de Fuente de Piedra (Antequera region, S-Spain), has been investigated and serves as a palaeoenvironmental archive for the Late Pleistocene to Holocene time interval. Several sediment cores taken during drilling campaigns in 2012 and 2013 have revealed sedimentary sequences (up to 14 m length) along the shoreline. A multi-proxy study, including sedimentology, geochemistry and physical properties (magnetic susceptibility) has been performed on the cores. The sedimentary history is highly variable: several decimetre thick silty variegated clay deposits, laminated evaporites, and even few-centimetre thick massive gypsum crystals (i.e., selenites). XRF analysis was focussed on valuable palaeoclimatic proxies (e.g., S, Zr, Ti, and element ratios) to identify the composition and provenance of the sediments and to delineate palaeoenvironmental conditions. First age control has been realized by AMS-radiocarbon dating. The records start with approximately 2-3 m Holocene deposits and reach back to the middle of MIS 3 (GS-3). The sequences contain changes in sedimentation rates as well as colour changes, which can be summarized as brownish-beige deposits at the top and more greenish-grey deposits below as well as highly variegated lamination and selenites below ca. 6 m depth. The Younger Dryas, Bølling/Allerød, and the so-called Mystery Interval/Last Glacial Maximum have presumably been identified in the sediment cores and aligned to other climate records. In general, the cores of the Laguna de

  20. Multispecies dendroclimatic reconstruction of drought index (SPI) in the eastern Iberian Range (Spain)

    NASA Astrophysics Data System (ADS)

    Tejedor, Ernesto; Saz, Miguel Angel; María Cuadrat, José; De Luis, Martín; Serrano-Notivoli, Roberto; Barriendos, Mariano

    2015-04-01

    Nowadays there is a high consensus on the possible increase of the average temperature of the planet in the upcoming decades. However, this consensus is not so evident regarding the precipitation signal. A probable decline and an increase in the frequency and magnitude of droughts have been largely described for the Mediterranean basin. Although there are several works concerning droughts over the last decades in Spain, there is, in fact, a lack of droughts data of the last centuries. Besides, droughts reconstructions may have an important role for the validation of climate models. In this communication, we present the first results obtained for the potential reconstruction of drought indexes along the eastern sector of the Iberian Cordillera with a broad set of multi-species dendrochronological series. In the framework of the projects 'CGL2011-28255' and 'CGL2012-31668' 294 new cores from 10 locations were extracted. In addition, 126 series available in the ITRDB and 84 series available from the project 'CLI96-1862' project were added as well to this database. Therefore, we generate the greatest dendrochronological database for the Iberian Range. We developed a 314 long tree-ring width chronology for the eastern Iberian range which presents a high significant correlation with the SPI series calculated from a regional series in the period of calibration: 0.634 with the August SPI4, 0.629 with the July SPI3 and 0,60 with the July SPI12. The multi-species chronologies developed with samples obtained between 1400 - 1600 meters above sea level present a correlation with the August SPI12 of 0,729. Nevertheless, the chronology developed with trees located at lower altitude, presents greater sensitivity with the SPI between 2 and 4 months. These results emphasize the need to improve the instrumental climatic database in height, as long as improvement in the standardization of growth series in order to develop the first SPI reconstruction of the Iberian Peninsula and the

  1. Erosion surfaces and Neogene landscape evolution in the NE Duero Basin (north-central Spain)

    NASA Astrophysics Data System (ADS)

    Benito-Calvo, Alfonso; Pérez-González, Alfredo

    2007-08-01

    We present a chronological model of erosion surface development in the Iberian and Cantabrian Ranges of north-central Spain. We map four erosion surfaces and interpret these to be related to Duero basin continental sediments and tectonic activity from Upper Oligocene to Plio-Pleistocene. The oldest erosion surface, SE1, formed across Upper Oligocene-Lower Miocene synorogenic deposits; while surface SE2 was contemporaneous with the Middle Miocene alluvial systems, ending with an uplift stage in the Astaracian. The two most recent erosion surfaces, SE3 and SE4, developed during extensional tectonic episodes and are associated with the deposition of Upper Páramo sedimentary units at the end of the Miocene (Upper Turolian) and alluvial fan deposits, known as rañas (Plio-Pleistocene). With the exception of SE1, which seems to be associated with a relatively wet climate, the surfaces formed during periods of marked aridity and generally warm temperatures. Through geostatistical reconstruction of the best preserved surface (SE2), applying ordinary kriging method to the topography (DEM) of the erosion surface and its correlating sedimentary plains, we identify the deformation processes which occurred on this surface after its formation.

  2. Cretaceous Exhumation of the North American Cordillera Measured through Mineral Multi-Dating: Insights into Basin Filling Models and Orogenic Architecture

    NASA Astrophysics Data System (ADS)

    Painter, C. S.; Carrapa, B.; DeCelles, P. G.; Gehrels, G. E.; Thomson, S. N.

    2015-12-01

    Apatite fission track (AFT) thermochronology is an effective thermochronometer to measure source exhumation in the North American Cordillera, western U.S.A. We use a combination of thermochronology and geochronology to measure lag times, i.e., the difference in time between the cooling and depositional ages of a mineral crystal. These lag-time measurements using source exhumation ages, measured with AFT thermochronology, and depositional ages, measured with biostratigraphy and detrital zircon U-Pb geochronology, indicate constant to decreasing lag times of 0-5 m.y. throughout the Cretaceous. These lag times are consistent with rapid exhumation rates of ~0.9->1 km/m.y. One pitfall of using detrital thermochronology to measure source exhumation is assuring that the apatite crystals are exhumed apatites and not volcanic apatites introduced into the system from the volcanic arc. To do this we use U-Pb geochronology to remove samples contaminated with young arc derived apatites and keep those with old exhumed apatites. Five of the seven detrital AFT samples were significantly contaminated with young volcanic apatites, showing that U-Pb geochronology should be a routine step in measuring lag times. Our findings demonstrate that coarse-grained foreland basin deposits in the Cretaceous Western Interior, in both the proximal and distal settings, were deposited during times of active tectonism and exhumation and that sediments are not stored in wedge-top and proximal foredeep settings for long periods of time, i.e. >5 m.y., and then subsequently reworked distally. Exhumation rates of ~0.9->1 km/m.y. are not sustainable over the entire orogenic belt for the duration of the Sevier orogeny, indicated by the lack of deep-crustal material exhumed in the North American Cordillera. High exhumation rates were likely concentrated over the eastward-propagating Sevier fold-thrust belt, whereas the Nevadaplano and hinterland experienced much slower rates of exhumation. This variation in

  3. Reducing risks from hazardous glacier lakes in the Cordillera Blanca (Peru): Six decades of experience and perspectives for the future

    NASA Astrophysics Data System (ADS)

    Portocarrero, Cesar; Cochachin, Alejo; Frey, Holger; González, Cesar; Haeberli, Wilfried; Huggel, Christian

    2016-04-01

    Outbursts from glacier lakes at various spatial and temporal scales have had marked geomorphological effects in many mountain ranges. In many glacierized Andean mountain regions substrates of human settlements made out of flood and debris-flow deposits are testimonies of such events. Examples in the Cordillera Blanca, Peru, are the towns of Caraz, Carhuaz or parts of Huaraz. Continued glacier shrinking since the end of the Little Ice Age caused the formation or enlargement of numerous lakes. The outburst of Laguna Palcacocha, destroying the centre of Huaraz and causing more than 1800 losses of life in December 1941, marked the beginning of systematic risk reduction work in Peru. Corresponding efforts included glacier and lake inventories, hazard assessments, definition of high-risk situations, and completion of engineering work for lake-level lowering in more than 30 cases. The latter comprises outlet reinforcements on morainic dams as well as artificial tunnels in bedrock thresholds. This work has been remarkably efficient as documented in the latest case of the Laguna Huallcacocha (Carhuaz-Ancash), where the earlier made installations withstood the erosive power of an impact wave from an ice avalanche in 2015. In the case of the Laguna 513, the impact wave and far-reaching flood caused by a rock/ice avalanche from Nevado Hualcán in April 2010 showed that the risk had been essentially reduced by the preventive lake-level lowering in the early 1990s but not to zero. Risk assessments, planning, construction and non-structural risk reduction efforts continue. Work is in progress to increase the safety of Laguna Palcacocha where extensive assessments and model calculations had been carried out. Risks related to rock/ice avalanches into lakes from steep icy slopes and related to de-buttressing processes as well as long-term permafrost degradation increases. Based on morphological indications and numerical modelling (GlabTop) an inventory of possible future lakes

  4. [Medicine and enlightenment in New Spain].

    PubMed

    de Micheli, A

    1998-01-01

    Fundamental ideas of the cultural movement of Enlightenment were drawn up and encouraged in England by John Locke and introduced into continental Europe by Voltaire. The essence of this movement was defined by I. Kant in 1784. These new ideas were projected into the field of medicine initially with the systematization of anatomical studies by Winslow, Vicq d' Azyr and Sénac in France, by S. Th. Sömmerring and von Haller in Germany, and by Paolo Mascagni and other anatomists in Italy. This movement settled in Spain toward the middle of the XVIII century, due to Father Feijóo and his pupils such as Piquer and Casal. In New Spain, which maintained cultural and scientific relationship with the Old World, the leaders of the movement were José Antonio Alzate in the field of biology and José Ignacio Bartolache in that of medicine. These were the founders of the first scientific journals: the "Diario Literario" (Literary Journal) by Alzate (1768) and the "Mercurio Volante" (Flying Mercury) by Bartolache (1772). Latter this physician had to face the great epidemic outbreak of smallpox in 1779. Due to that, he attributed great importance to the psychological aspect of the problem and supported the variolization proceeding introduced into Mexico by Doctor Henri Morel. Moreover, two scientific expeditions, which reached New Spain at the end of the XVIII century, allowed to systematize the study of the American vegetables and to acknowledge the usefulness of botany and chemistry as auxiliary sciences of medicine. PMID:9780494

  5. Pediatric allergy and immunology in Spain.

    PubMed

    Nieto, Antonio; Mazon, Angel; Martin-Mateos, Maria Anunciacion; Plaza, Ana-Maria; Garde, Jesus; Alonso, Elena; Martorell, Antonio; Boquete, Manuel; Lorente, Felix; Ibero, Marcel; Bone, Javier; Pamies, Rafael; Garcia, Juan Miguel; Echeverria, Luis; Nevot, Santiago; Martinez-Cañavate, Ana; Fernandez-Benitez, Margarita; Garcia-Marcos, Luis

    2011-11-01

    The data of the ISAAC project in Spain show a prevalence of childhood asthma ranging from 7.1% to 15.3%, with regional differences; a higher prevalence, 22.6% to 35.8%, is described for rhinitis, and atopic dermatitis is found in 4.1% to 7.6% of children. The prevalence of food allergy is 3%. All children in Spain have the right to be visited in the National Health System. The medical care at the primary level is provided by pediatricians, who have obtained their titles through a 4-yr medical residency training program. The education on pediatric allergy during that period is not compulsory and thus very variable. There are currently 112 certified European pediatric allergists in Spain, who have obtained the accreditation of the European Union of Medical Specialist for proven skills and experience in pediatric allergy. Future specialists in pediatric allergy should obtain their titles through a specific education program to be developed in one of the four accredited training units on pediatric allergy, after obtaining the title on pediatrics. The Spanish Society of Pediatric Allergy and Clinical Immunology (SEICAP) gathers over 350 pediatric allergists and pediatricians working in this field. SEICAP has a growing activity including yearly congresses, continued education courses, elaboration of technical clinical documents and protocols, education of patients, and collaboration with other scientific societies and associations of patients. The official journal of SEICAP is Allergologia et Immunophatologia, published every 2 months since 1972. The web site of SEICAP, http://www.seicap.es, open since 2004, offers information for professionals and extensive information on pediatric allergic and immunologic disorders for the lay public; the web site is receiving 750 daily visits during 2011. The pediatric allergy units are very active in clinical work, procedures as immunotherapy or induction of oral tolerance in food allergy, contribution to scientific literature, and

  6. A personal view of nutrition in Spain.

    PubMed

    Zamora, Salvador

    2014-04-01

    This paper stems from the special lecture given by the author at 20th International Congress of Nutrition, held from 16 to 20 September 2013 in Granada (Spain), following for his appointment as "Living Legend" of the International Union of nutritional sciences (IUNS), in recognition of his outstanding contribution to research and development in nutritional science. The development of nutrition in Spain from the 1960s to the present, which the author had the opportunity to experience first hand, is described. The contribution covers an extensive period in the history of this science, and highlights the advances made in our knowledge of nutrition and several of the misunderstandings that existed and still exist in this science: 1) The Anglo-Saxon dietary pattern and the high incidence of death from myocardial infarction, and the subsequent recognition of the Mediterranean diet as a model of a varied and balanced and healthy eating. 2) The relationship between cardiovascular disease and the consumption of oily fish. Since the discovery of the syn - thesis of prostaglandins makes it clear that fish fat is heart-healthy. 3) The epidemic of prosperity, overweight and obesity and the appearance of miracle diets. However, there are not miracles, the only solution being a healthy lifestyle and a balanced hypocaloric diet. 4) In the field of nutrition, diet and health, the harmful effect of: "In my opinion", a single allusion that undermines all science. The author also acknowledges all the researchers whose efforts, tenacity and enthusiasm have contributed to the advances made in nutrition science in Spain.

  7. Quality of death certificates in Valencia, Spain.

    PubMed Central

    Benavides, F G; Bolumar, F; Peris, R

    1989-01-01

    Certificates of 1,454 deaths occurring over 11 months were retrieved from the Civil Register in Valencia, Spain. Relevant medical information was systematically gathered from hospital records, questionnaires, and Coroner reports. We compared the underlying cause of death (UCD) from the original death certificate, and a reference cause of death (RCD) determined by a panel of experts based on all available information. Overall, 80.2 percent of the certificates were concordant for disease category, but there was a great disparity among some specific disease categories. PMID:2782500

  8. Involuntary outpatient treatment (IOT) in Spain.

    PubMed

    Hernández-Viadel, M; Cañete-Nicolás, C; Bellido-Rodriguez, C; Asensio-Pascual, P; Lera-Calatayud, G; Calabuig-Crespo, R; Leal-Cercós, C

    2015-01-01

    In recent decades there have been significant legislative changes in Spain. Society develops faster than laws, however, and new challenges have emerged. In 2004, the Spanish Association of Relatives of the Mentally Ill (FEAFES) proposed amending the existing legislation to allow for the implementation of involuntary outpatient treatment (IOT) for patients with severe mental illness. Currently, and after having made several attempts at change, there is no specific legislation governing the application of this measure. Although IOT may be implemented in local programmes, we consider legal regulation to be needed in this matter.

  9. Major tanker spill off Spain under control

    SciTech Connect

    Not Available

    1992-12-14

    This paper reports that a 23 sq mile oil slick along Spain's northwest coast, spreading form the wreckage of the Greek oil tanker Aegean Sea, was for the most part under control as of Dec. 10, Spanish authorities reported. Various press reports put the total spill volume at 490,000 bbl, about double that leaked by the Exxon Valdez supertanker off Alaska in 1989. If initial reports of the spill volume are borne out, the Aegean Sea spill would rank at least as one of the 10 biggest tanker spills.

  10. The epidemiology of cocaine use in Spain.

    PubMed

    Barrio Anta, G; Vicente Orta, J; Bravo Portela, M J; de la Fuente de Hoz, L

    1993-12-01

    Trends and patterns of cocaine use in Spain are described with the aid of different information sources such as population surveys, the State Information System on Drug Abuse, and anthropological studies. In recent years the magnitude of cocaine supply indicators has increased greatly. High levels of last-month prevalence of cocaine use have been detected among the general population--consistently higher than those for heroin-- and cocaine consumption among heroin users has increased. Although the frequency of some health problems related to cocaine use--treatment admissions, hospital emergency admissions--has increased, it is still 30 times less than for heroin. Various hypotheses to explain these discrepancies are discussed.

  11. Nuptiality patterns in Spain in the eighties.

    PubMed

    Miret-gamundi, P

    1997-01-01

    "The marriage patterns in Spain are analysed, highlighting some associated socio-economic, political and cultural factors.... It seems there is a quite clear match between economic and nuptiality trends; as accompanying the rise of unemployment and the general economic crisis, there was undoubtedly a decrease in the levels of adult nuptiality. But this is not enough to fully explain the nuptiality age patterns, and we need to refer to other possible reasons for the trends in nuptiality, as we do here with the evolution of the housing market." (EXCERPT)

  12. Household water saving: Evidence from Spain

    NASA Astrophysics Data System (ADS)

    Aisa, Rosa; Larramona, Gemma

    2012-12-01

    This article focuses on household water use in Spain by analyzing the influence of a detailed set of factors. We find that, although the presence of both water-saving equipment and water-conservation habits leads to water savings, the factors that influence each are not the same. In particular, our results show that those individuals most committed to the adoption of water-saving equipment and, at the same time, less committed to water-conservation habits tend to have higher incomes.

  13. Setting and occurrence of Late Paleozoic radiolarians in the Sylvester allochthon, part of a proto-Pacific ocean floor terrane in the Canadian Cordillera

    USGS Publications Warehouse

    Harms, T.A.; Murchey, B.L.

    1992-01-01

    Late Paleozoic radiolarians have been used to establish th allochthon of the Slide Mountain terrane in British Columbia, and have thereby greatly clarified the geology and tectonic history of the terrane. As the Sylvester radiolarian fauna is limited, age assignments were based on a few distinctive and diagnostic robust forms. Radiolarians occur in cherts from a wide variety of different oceanic sequences that are structurally juxtaposed within the Sylvester allochthon. Like others in a suite of correlative terranes that lie along the length of the Cordillera, the Sylvester allochthon and the radiolarian bearing cherts in it derive from the telescoping together of slices from what was, in the late Paleozoic, a large area of the proto-Pacific ocean. ?? 1992.

  14. 7 CFR 319.56-34 - Clementines from Spain.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Mediterranean fruit fly management program established by the Government of Spain. (c) Management program for Mediterranean fruit fly; monitoring. The Government of Spain's Mediterranean fruit fly (Ceratitis capitata) management program must be approved by APHIS, and must contain the fruit fly trapping and...

  15. Autochthonous Nocardia cerradoensis Infection in Humans, Spain, 2011 and 2014

    PubMed Central

    Ercibengoa, Maria; Pérez-Trallero, Emilio

    2016-01-01

    Nocardia cerradoensis was first isolated in 2003 in the El Cerrado region of Brazil; since then, only 2 human infections, in France and Spain, have been reported. We describe 3 autochthonous cases in residents of Spain during 2011 and 2014. Together these cases support the idea of an emerging global pathogenic microorganism. PMID:26691545

  16. 7 CFR 319.56-31 - Peppers from Spain.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... October 1, and continuing through April 30, MAFF must set and maintain Mediterranean fruit fly (Ceratitis... transit other fruit fly-supporting areas unless shipping containers are sealed by MAFF with an official... from Spain. Peppers (fruit) (Capsicum spp.) may be imported into the United States from Spain...

  17. Teaching Digital Libraries in Spain: Context and Experiences

    ERIC Educational Resources Information Center

    Garcia-Marco, Francisco-Javier

    2009-01-01

    The situation of digital libraries teaching and learning in Spain up to 2008 is examined. A detailed analysis of the different curricula and subjects is provided both at undergraduate and postgraduate level. Digital libraries have been mostly a postgraduate topic in Spain, but they should become mainstream, with special subjects devoted to them,…

  18. The Queen's Two Bodies: Sor Juana and New Spain's Vicereines

    ERIC Educational Resources Information Center

    Thomas, George Anthony

    2009-01-01

    The work of Sor Juana Ines de la Cruz contains many examples of positive representations of the Queens of Spain and the Vicereines of New Spain. These poetic portraits serve to counter the primarily misogynistic portrayals of ruling women of the seventeenth century. Most importantly, Sor Juana increased the visibility of the vicereine in colonial…

  19. The History of the Democratic Adult Education Movement in Spain

    ERIC Educational Resources Information Center

    Oliver, Esther; Tellado, Itxaso; Yuste, Montserrat; Larena-Fernández, Rosa

    2016-01-01

    Background/Context: Traditional adult education in Spain treated the learner as a mere object that could be shaped by the educator. Although current practices of the democratic adult education movement in Spain reveals a completely opposite standpoint on adult education, there has been little analysis of the several influences converging and…

  20. Sex Education in Spain: Teachers' Views of Obstacles

    ERIC Educational Resources Information Center

    Martinez, Jose L.; Carcedo, Rodrigo J.; Fuertes, Antonio; Vicario-Molina, Isabel; Fernandez-Fuertes, Andres A.; Orgaz, Begona

    2012-01-01

    This paper offers an overview of the current state, difficulties, limitations and future possibilities for sex education in Spain. On the basis of a study involving 3760 teachers from all provinces in Spain, a detailed analysis of the obstacles at legislative, school and teacher levels was developed. Significant weaknesses were found at each of…

  1. Autochthonous Nocardia cerradoensis Infection in Humans, Spain, 2011 and 2014.

    PubMed

    Ercibengoa, Maria; Pérez-Trallero, Emilio; Marimón, José Maria

    2016-01-01

    Nocardia cerradoensis was first isolated in 2003 in the El Cerrado region of Brazil; since then, only 2 human infections, in France and Spain, have been reported. We describe 3 autochthonous cases in residents of Spain during 2011 and 2014. Together these cases support the idea of an emerging global pathogenic microorganism.

  2. Early School-Leaving in Spain: Evolution, Intensity and Determinants

    ERIC Educational Resources Information Center

    Fernandez-Macias, Enrique; Anton, Jose-Ignacio; Brana, Francisco-Javier; De Bustillo, Rafael Munoz

    2013-01-01

    Spain has one of the highest levels of early school leaving and educational failure of the European Union. The purpose of this paper is to analyse the anatomy of early school leaving in Spain and its characteristics. In order to do so, in the first part we discuss the measurement problems related with this concept and the evolution of drop-out…

  3. Intergenerational Educational and Occupational Mobility in Spain: Does Gender Matter?

    ERIC Educational Resources Information Center

    De Pablos Escobar, Laura; Gil Izquierdo, María

    2016-01-01

    This paper explores the changes in intergenerational mobility seen in Spain during the last century. It examines educational and occupational mobility, paying particular attention to the existence of a differentiated gender effect. The magnitude of the historical changes that have taken place in Spain during the twentieth century and the scarcity…

  4. 78 FR 6222 - Importation of Avocados From Continental Spain

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... described in a notice we published on May 10, 2006, in the Federal Register (71 FR 27221-27224, Docket No... of Avocados From Continental Spain AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... importation of avocados from continental Spain (excluding the Balaeric Islands and Canary Islands) into...

  5. 78 FR 32183 - Importation of Avocados From Continental Spain

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... Federal Register (78 FR 6222-6227, Docket No. APHIS-2012-0002), a proposal \\1\\ to amend the fruits and... Continental Spain AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Proposed rule; reopening... allow the importation of avocados from continental Spain (excluding the Balearic Islands and...

  6. Espana: Building Bridges of Understanding with the People of Spain.

    ERIC Educational Resources Information Center

    Brigham Young Univ., Provo, UT. Language Research Center.

    This booklet was designed to facilitate interactions and communication with the people of Spain by providing information about their customs, attitudes and other cultural characteristics which influence their actions and values. A brief description of Spain is given, which covers the following: geography, weather, history, ethnic roots, regional…

  7. Spatiotemporal variability and differentiation between anthropogenic and natural contamination of heavy metals of surface water: a case study in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Guittard, A.; Baraer, M.; McKenzie, J. M.; Mark, B. G.; Fernandez, A.; Walsh, E.; Santos Perez, A.

    2015-12-01

    The Rio Santa, Peru, drains the western slopes of the glacierized Cordillera Blanca and provides water resources at almost all levels of the watershed. As it flows away from the valleys of the Cordillera Blanca, the Rio Santa takes out pollution from numerous sources, including acid mine drainage and natural sulfide oxidation by-products. The Rio Santa dry season discharge decline that is projected to be a consequence of glaciers retreat will probably have implications for the evolution of water pollution. This threat makes the characterization of the actual contamination mechanisms of primary importance. The present study focuses, first, on the spatiotemporal variability of heavy metal contamination across the entire Rio Santa Watershed and secondly on differentiating anthropogenic and natural contaminated sites. First, a macroscale sampling has been done during the summer 2013 to provide an overview of the contamination by trace metal, in water, suspended sediments and riverbed sediments. In addition, 30 water samples were taken from a point next to the city of Huaraz at a frequency of once every 2 weeks and analyzed for trace metals. Secondly, in order to identify hydrochemical contaminant origin dependant signatures in the Rio Santa watershed, 5 areas of known contamination origins were sampled during the summer 2014.Spatially speaking, we observed that most pollution is located in the south of the watershed, and that a large part of the arsenic that reaches the Santa in an aqueous phase does not make it to the outlet but remains trapped in the riverbed. Annual variation in water shows a very unusual fluctuation in Mn compare to other trace metal which are relatively stable. By differencing anthropogenic and natural sites and by considering glaciers melt and decrease water in future what would be the impact of the part of natural contaminated sites versus anthropogenic, mining and cities, on the water quality? Preliminary results show that anthropogenic sites

  8. A new tectonic model for the development of the Eastern Cordillera, Altiplano, and Subandean zones, Bolivian Central Andes, 20[degrees]S latitude

    SciTech Connect

    Gubbels, T.L.; Isacks, B.L. ); Koch, R.W. )

    1993-02-01

    Construction of a regional transect across the central Andes at 20[degrees]S sheds new light on the relationship between the Altiplano, Eastern Cordillera (EC), and Subandean zones and allows us to refine the two-stage model of Isacks (1988) for the growth of the Central Andes. This new model is based on examination of the regional geology and geophysics, coupled with field investigations, satellite image analysis, and new Ar-Ar geochronology. In this model, widespread Oligocene to mid-Miocene compressional deformation in the Altiplano and EC was followed in the late-Miocene and Pliocene by thrusting localized east of the EC within the Subandean fold-thrust belt. During the first stage of deformation, the Altiplano basin underwent important subsidence and internal deformation. The EC was both deformed internally and thrust westwards over the Altiplano basin, while the present Subandean zone was the site of an early, broad foreland basin which received material eroded from the EC. During the second stage, beginning at [approximately]10 ma, deformation terminated within the EC and became concentrated within the fold-thrust belt in response to large scale overthrusting of the EC above the Brazilian shield; this resulted in major thrusting along the Cabalgamiento Frontal Principal (CFP), which soles into the master Subandean decollement, and [approximately]100 km of telescoping within the early, broad foreland basin. In the EC, this second stage is marked by the elaboration of a regionally extensive erosion surface, ponding of gravels in shallow basins, and the emplacement of giant ignimbrite sheets. The Eastern Cordillera can thus be thought of as a crustal-scale wedge which has been extruded upward and outward on alternate sides during successive stages of late Cenozoic deformation. This motion has served to drive subsidence in both the Altiplano and Subandean foreland basins, as well as shortening in the fold-thrust belt.

  9. The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela.

    PubMed

    Gutiérrez, Eliécer E; Maldonado, Jesús E; Radosavljevic, Aleksandar; Molinari, Jesús; Patterson, Bruce D; Martínez-C, Juan M; Rutter, Amy R; Hawkins, Melissa T R; Garcia, Franger J; Helgen, Kristofer M

    2015-01-01

    We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics. PMID

  10. The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela.

    PubMed

    Gutiérrez, Eliécer E; Maldonado, Jesús E; Radosavljevic, Aleksandar; Molinari, Jesús; Patterson, Bruce D; Martínez-C, Juan M; Rutter, Amy R; Hawkins, Melissa T R; Garcia, Franger J; Helgen, Kristofer M

    2015-01-01

    We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics.

  11. The Taxonomic Status of Mazama bricenii and the Significance of the Táchira Depression for Mammalian Endemism in the Cordillera de Mérida, Venezuela

    PubMed Central

    Gutiérrez, Eliécer E.; Maldonado, Jesús E.; Radosavljevic, Aleksandar; Molinari, Jesús; Patterson, Bruce D.; Martínez-C., Juan M.; Rutter, Amy R.; Hawkins, Melissa T. R.; Garcia, Franger J.; Helgen, Kristofer M.

    2015-01-01

    We studied the taxonomy and biogeography of Mazama bricenii, a brocket deer classified as Vulnerable by the IUCN, drawing on qualitative and quantitative morphology and sequences of the mitochondrial cytochrome-b gene. We used Ecological Niche Modeling (ENM) to evaluate the hypothesis that M. bricenii of the Venezuelan Cordillera de Mérida (CM) might have become isolated from populations of its putative sister species, Mazama rufina, in the Colombian Cordillera Oriental (CO). This hypothesis assumes that warm, dry climatic conditions in the Táchira Depression were unsuitable for the species. Our analyses did not reveal morphological differences between specimens geographically attributable to M. bricenii and M. rufina, and phylogenetic analyses of molecular data recovered M. bricenii nested within the diversity of M. rufina. These results indicate that M. bricenii should be regarded as a junior synonym of M. rufina. ENM analyses revealed the existence of suitable climatic conditions for M. rufina in the Táchira Depression during the last glacial maximum and even at present, suggesting that gene flow between populations in the CO and CM may have occurred until at least the beginning of the current interglacial period and may continue today. Because this pattern might characterize other mammals currently considered endemic to the CM, we examined which of these species match two criteria that we propose herein to estimate if they can be regarded as endemic to the CM with confidence: (1) that morphological or molecular evidence exists indicating that the putative endemic taxon is distinctive from congeneric populations in the CO; and (2) that the putative endemic taxon is restricted to either cloud forest or páramo, or both. Only Aepeomys reigi, Cryptotis meridensis, and Nasuella meridensis matched both criteria; hence, additional research is necessary to assess the true taxonomic status and distribution of the remaining species thought to be CM endemics. PMID

  12. [Present and future of neurology in Spain].

    PubMed

    Illa Sendra, I; García De Yébenes Prous, J; Ramo Tello, C; Polo Esteban, J M; Molinuevo Guix, J L; Robles Bayón, A; Mulas Delgado, F; Alvarez Sabín, J; Aguilar Barbera, M; Berciano Blanco JA, J A; Blesa González, R; Carnero Pardo, C; Castillo Sánchez, J; Del Ser Quijano, T; Ferrer Abizanda, I; García-Albea Ristol, E; Gómez Isla, T; Graus Ribas, F; Jiménez Hernández, M D; Liaño Martínez, H; Matías Guiu-Guia, J; Zarranz Imirizaldu, J J; Paradas López, C; Elena Martínez, G; Maltas Pérez, G; Ponce Rodríguez, M T

    2001-11-01

    This is a document prepared by the Spanish Society of Neurology (SEN), which was given to the President of Spain (Mr. José María Aznar) last September with the main aim of examining the current situation of Neurology in our country. It analyses the present and future of Neurology in clinical assistance, teaching and research. To prepare this document the criteria of patients' associations has been considered, including the Declaration of Madrid which has been subscribed by thirty of these associations. In spite of its relevant development in the previous decades, the current situation of Neurology in Spain is far from the ideal. To reach the recommendable menber of 3 or 4 neurologists per 100,000 inhabitants it is necessary to duplicate the present number of neurologists which has been estimated around 2/100,000; this situation is especially urgent in some Autonomous Communities. The most important problems in neurological assistance are: inadequate follow-up of the chronic outpatients, low numbers of neurological beds and of duties of Neurology, as well as of neurological case of patients with urgent neurological disorders. It is also necessary to increase the number of professors of Neurology to adequately cover pregraduate teaching; again there are important differences in teaching positions among Autonomous Communities. Neurology residence should be prolonged from 4 to 5 years. Finally, it is necessary to support the appearance of superespecialised units and to promote a coordinated research with other close specialities including basic neuroscience. PMID:11742621

  13. [Lessons learned from tobacco control in Spain].

    PubMed

    Fernández, Esteve; Villalbí, Joan R; Córdoba, Rodrigo

    2006-01-01

    The growing involvement in Spain by civil society in the demand for tobacco control policies has been notable. The basis for the creation of the National Committee for Tobacco Prevention was established in 2004. At the end of that year, an intensive intervention was aimed at specifying, in law, the regulatory actions in the National Plan for Tobacco Prevention. This would facilitate a qualitative leap, taking advantage of the legal transposition of the European directive on advertising. With broad political consensus, the Law 28/2005 was established regarding sanitary measures for tobacco and the regulation of the sale, supply and consumption of tobacco products. The objective stated in this law is to prevent the initiation of tobacco consumption, especially among youth, guarantee the right of non-smokers to breathe air free from tobacco smoke and make quitting this habit easier for people who wish to do so. The main issues included are the prohibition of tobacco advertising and the limitation of tobacco consumption in common work areas and enclosed public spaces. The new law has replaced the previous rules in Spain, which were some of the most permissive in the European Union in terms of tobacco sales, advertising limitations and restrictions on smoking locations. It is clear that there is still much to be done. At this time, more social support needs to be generated in favor of the new regulations, and an important effort needs to be made to educate the public.

  14. The state of psychiatry in Spain.

    PubMed

    Bobes, Julio; Garcia-Portilla, Maria Paz; Bobes-Bascaran, Maria-Teresa; Parellada, Mara; Bascaran, Maria-Teresa; Saiz, Pilar Alejandra; Bousoño, Manuel; Arango, Celso

    2012-08-01

    The 1986 General Health Act and the so-called 'psychiatric reform' were key issues in the development of the mental healthcare system (MHCS) in Spain. The World Health Organization Declaration and Action Plan on Mental Health in 2005 gave it a revitalizing impetus and resulted in the first National Health System (NHS) Mental Health Strategy in 2006. A literature search was performed using MEDLINE, Spanish journals, reference lists, national databases, and European and Spanish official documents to describe the current state of the MHCS in Spain. The main results were: (1) existence of great variability among the autonomous communities with respect to mental health resources and provision of care; (2) lack of national epidemiological information on mental disorders with the exception of substance use disorders and suicide, which comprise powerful longitudinal national data, (3) training in psychiatry is well established, although there is no specialism of child and adolescent psychiatry, and (4) a dramatic increase in scientific productivity in the last decade among research groups, in part due to the creation of the Spanish Mental Health Network, the Centro de Investigación Biomédica en Red en el Área de Salud Mental (CIBERSAM). Quantifiable and reliable indicators are needed to provide efficient monitoring and analysis of epidemiological events and subsequently to understand the status of the Spanish MHCS.

  15. Tornadoes and severe storms in Spain

    NASA Astrophysics Data System (ADS)

    Gayà, Miquel

    2011-06-01

    A climatology of tornadoes, waterspouts, and straight winds linked to convection in Spain is presented. The database is divided into three periods according to the main source of information. The three distributions of severe weather are very sensitive to the sources of information, much more than to a possible change in climate. The early period, up to 1825, comprises cases that contain the real facts together with spurious inputs such as religion, myths, beliefs, etc, mixed in an unknown proportion. The period between 1826 and 1975, and the most recent one, up to 2009, enable us to observe geographical and temporal variations as a function of societal changes. The analysis of temporal and geographical distributions allows us to frame the risk in the face of severe storms, and the changes in their perception and management that have come about over time. Although the most recent tornadoes have been weak or strong, the Cádiz tornado of 1671 demonstrates that an extremely rare and violent event can occur in Spain. The large number of victims claimed by this tornado makes it one of the most important in the world.

  16. Publication output in telemedicine in Spain.

    PubMed

    Gonzalez, Francisco; Castro, Adrian F

    2005-01-01

    We searched the MEDLINE database for publications about telemedicine from 1966 to 2003. Only publications with a first institutional address in Spain and from journals listed in the JCR Science Edition 2002 were included in the study. A total of 118 publications were found. The first publication appeared in 1988 and publication output showed a sudden increase starting in 1995, reaching a maximum in 2002 with 21 publications. The number of authors per publication in non-multicentre studies ranged from 1 to 14 (median 6.5). Most authors (79%) contributed to only a single publication; 10% of authors participated in three or more publications. Most publications were full papers (88%). The most active Autonomous Community in the number of publications relative to inhabitants was Galicia (0.91 publications per 100,000 inhabitants). The Community that produced the highest absolute number of publications was Madrid (29% of the total). The mean impact factor of the journals in which the publications appeared was 0.961. Production of telemedicine publications in Spain has followed the same temporal course as has been observed worldwide. There is an unequal geographical and institutional distribution of publications. The highest production is concentrated in a few institutions and only a small number of authors show steady research activity.

  17. [Books published in Spain on smoking].

    PubMed

    Guardiola, E; Sánchez-Carbonell, J

    1996-12-01

    Tobacco dependence, considered for a long time as a habit and, more recently, as an addiction, has many bad effects in health. The objective of this study was to analyse books published in this field in Spain. Books indexed in the ISBN Spanish database in CD-ROM (updated to 1993) dealing with addiction to tobacco, that included one of the following words: tabac*, tabak*, tabaq*, fuma*, fumad*, nicotine*, alquitran*, antitabac*, antitabaq*, cigarro*, cigarri*, exfumad*, pipa*, puro*, picadura* or filtro, were included in the study. Authors, ISBN classification, year of publication, language (of publication and original) and publishers were descriptively analysed. One hundred and four books were analysed. The highest number was published during the period 1990-1993 (42%); being 1993 (n = 15) and 1991 (n = 14) the most productive years. A big increase was observed from 1985. A great number (76% of books, n = 79) was written by personal authors and the 14% (n = 14) by public organizations. Most of the books (n = 88; 85%); were published in Spanish, followed by Catalan (n = 13; 13%); 21 books (20%) were translations: most of them from English (n = 12; 60%) or from French (n = 3; 14%). Forty six per cent of books was published by trade publishers and 31% by public organizations. According to the ISBN classification, these books were grouped in 20 different topics; but, most of them (70%) were included in three of these topics: hygiene (n = 42, 40%), pharmacology-toxicology-drugs (n = 18, 17%) and pathology-diseases and medical/therapeutical clinical practice (n = 14; 13%). The number of books published in Spain dealing with tobacco dependence has increased very much from 1985; it suggests that interest in this area in SPain has also increased. Most of the books are published in Spanish, and the most frequently translated language is English. These books are basically published by trade publishers and public organizations. These results have to be considered taking into

  18. State of emergency medicine in Spain

    PubMed Central

    2010-01-01

    Spain has universal public health care coverage. Emergency care provisions are offered to patients in different modalities and levels according to the characteristics of the medical complaint: at primary care centers (PCC), in an extrahospital setting by emergency medical services (EMS) and at hospital emergency departments (ED). We have more than 3,000 PCCs, which are run by family doctors (general practitioners) and pediatricians. On average, there is 1 PCC for every 15,000 to 20,000 inhabitants, and every family doctor is in charge of 1,500 to 2,000 citizens, although less populated zones tend to have lower ratios. Doctors spend part of their duty time in providing emergency care to their own patients. While not fully devoted to emergency medicine (EM) practice, they do manage minor emergencies. However, Spanish EMSs contribute hugely to guarantee population coverage in all situations. These EMS are run by EM technicians (EMT), nurses and doctors, who usually work exclusively in the emergency arena. EDs dealt with more than 25 million consultations in 2008, which implies, on average, that one out of two Spaniards visited an ED during this time. They are usually equipped with a wide range of diagnostic tools, most including ultrasonography and computerized tomography scans. The academic and training background of doctors working in the ED varies: nearly half lack any structured specialty residence training, but many have done specific master or postgraduate studies within the EM field. The demand for emergency care has grown at an annual rate of over 4% during the last decade. This percentage, which was greater than the 2% population increase during the same period, has outpaced the growth in ED capacity. Therefore, Spanish EDs become overcrowded when the system exerts minimal stress. Despite the high EM caseload and the potential severity of the conditions, training in EM is still unregulated in Spain. However, in April 2009 the Spanish Minister of Health

  19. [Books published in Spain on smoking].

    PubMed

    Guardiola, E; Sánchez-Carbonell, J

    1996-12-01

    Tobacco dependence, considered for a long time as a habit and, more recently, as an addiction, has many bad effects in health. The objective of this study was to analyse books published in this field in Spain. Books indexed in the ISBN Spanish database in CD-ROM (updated to 1993) dealing with addiction to tobacco, that included one of the following words: tabac*, tabak*, tabaq*, fuma*, fumad*, nicotine*, alquitran*, antitabac*, antitabaq*, cigarro*, cigarri*, exfumad*, pipa*, puro*, picadura* or filtro, were included in the study. Authors, ISBN classification, year of publication, language (of publication and original) and publishers were descriptively analysed. One hundred and four books were analysed. The highest number was published during the period 1990-1993 (42%); being 1993 (n = 15) and 1991 (n = 14) the most productive years. A big increase was observed from 1985. A great number (76% of books, n = 79) was written by personal authors and the 14% (n = 14) by public organizations. Most of the books (n = 88; 85%); were published in Spanish, followed by Catalan (n = 13; 13%); 21 books (20%) were translations: most of them from English (n = 12; 60%) or from French (n = 3; 14%). Forty six per cent of books was published by trade publishers and 31% by public organizations. According to the ISBN classification, these books were grouped in 20 different topics; but, most of them (70%) were included in three of these topics: hygiene (n = 42, 40%), pharmacology-toxicology-drugs (n = 18, 17%) and pathology-diseases and medical/therapeutical clinical practice (n = 14; 13%). The number of books published in Spain dealing with tobacco dependence has increased very much from 1985; it suggests that interest in this area in SPain has also increased. Most of the books are published in Spanish, and the most frequently translated language is English. These books are basically published by trade publishers and public organizations. These results have to be considered taking into

  20. [Abortion. Spain: the keys to the controversy].

    PubMed

    1983-01-01

    For many years, illegal abortion has been denounced in Spain. The estimate of 300,000 abortions annually is widely quoted but poorly founded in fact. Weekend "charters" to London and Amsterdam for women seeking abortions have been commented upon, denounced, and caricatured. The evidence indicates that abortions occur in Spain despite their illegality, just as they occur in every other country and have always occurred. Poor women abort in a poor way, with traditional healers, while rich women abort in a rich way, with physicians. "Charters" are the solution of the middle class. Proposed legislation in Spain would permit abortion on 3 grounds: rape, fetal malformation, and risk to the woman's life if the pregnancy continued. Excesses have been committed both by those opposing abortion and by those struggling for liberalization of laws. Defenders of abortion, such as radical feminists, appear to forget that abortion is a medical procedure with possible dangerous psychophysical consequences, and that preventive measures such as sex education and diffusion of contraception or social measures such as assistance for unwed mothers and their children would be preferrable to abortion. There is the question of whether medical personnel should be excused from assisting in abortions on grounds of conscience and whether those who do assist in abortions automatically become "progressive" by doing so. The staunchest defenders of fetal life are not moved to contribute anything beyond words to improvement of the plight of the many millions of already born who live in miserable conditions of hunger and want. Abortion is a violent act against the fetus and the pregnant woman. Its criminalization is a violent act against the woman and a social intrusion into matters better left to personal ethics. The government which proposes abortion on a few grounds fails to initiate a program to promote life through social protection of single mothers and their children or of families in general

  1. Constitutional guarantees to health care in Spain.

    PubMed

    Mendoza, E M; Henderson, B J

    1995-07-01

    This analysis of the Spanish health care system is one in a series of such studies undertaken by the author, following a grid of factors that influence the delivery and financing of health care. The purpose of the national analyses is to facilitate a comparison of the United States' and other health care systems in terms of anticipated reform of the U.S. system. Analyses of the U.S. and nine other national systems are included in a book that has just been published by the College. Spain and nine additional countries will be studied in a book due for publication later this year. A final book with ten additional national analyses will appear in 1996.

  2. Municipal pleural cancer mortality in Spain

    PubMed Central

    Lopez-Abente, G; Hernandez-Barrera, V; Pollan, M; Aragones, N; Perez-Gomez, B

    2005-01-01

    Background: Pleural cancer is a recognised indicator of exposure to asbestos and mesothelioma mortality. Aims: To investigate the distribution of municipal mortality due to this tumour, using the autoregressive spatial model proposed by Besag, York, and Molliè. Methods: It was possible to compile and ascertain the posterior distribution of relative risk on the basis of a single Bayesian spatial model covering all of Spain's 8077 municipal areas. Maps were plotted depicting standardised mortality ratios, smoothed relative risk (RR) estimates, and the distribution of the posterior probability that RR >1. Results: There was a higher risk of death due to pleural cancer in well defined towns and areas, many of which correspond to municipalities where asbestos using industries once existed for many years, the prime example being the municipal pattern registered for Barcelona Province. The quality of mortality data, the suitability of the model used, and the usefulness of municipal atlases for environmental surveillance are discussed. PMID:15723885

  3. The problems of asbestosis in Spain.

    PubMed

    Segarra, F

    1979-04-01

    About 50 cases of asbestosis have been descirbed in Spain from 1948 through 1974. Since 1975 the Instituto Territorial de Barcelona, Servicio Social de Higiene y Seguridad del Trabajo, has initiated a survey of all the industries with an asbestosis risk in the Barcelona area. Nearly 300 cases of asbestosis have been detected to date. Given the poor hygienic conditions of most of the industries, with an asbestosis risk, and the considerably large number of exposed people, it can easily be predicted that a rapid increase of the incidence of the disease in the years to come will occur. Most of the observed cases in Barcelona were from two fibrocement industries. Of a total of 1003 workers examined, 247 (about 25%) had asbestosis.

  4. Oestrosis in red deer from Spain.

    PubMed

    Bueno-de la Fuente, M L; Moreno, V; Peréz, J M; Ruiz-Martinez, I; Soriguer, R C

    1998-10-01

    A survey of naso-pharyngeal myiasis affecting red deer (Cervus elaphus) in southern Spain was conducted. The parasites involved were the larvae of Pharyngomyia picta and Cephenemyia auribarbis (Diptera:Oestridae), which coexist sympatrically within this host. Males and older animals had higher prevalences and intensities of fly larvae. Differences in behaviour and habitat use by male and female deer, and the increase of head size in older males are possibly responsible for this. There were low densities of C. auribarbis while P. picta was the species most frequently observed, although both oestrids were located in the same host cavities. The earlier larviposition by C. auribarbis, and its faster larval development may reflect asynchronous life-cycles of both oestrids; this may decrease inter-specific competition between these sympatric species. PMID:9813856

  5. Phenolic profile of Asturian (Spain) natural cider.

    PubMed

    Rodríguez Madrera, Roberto; Picinelli Lobo, Anna; Suárez Valles, Belén

    2006-01-11

    The polyphenolic composition of natural ciders from the Asturian community (Spain), during 2 consecutive years, was analyzed by RP-HPLC and the photodiode-array detection system, without previous extraction (direct injection). A total of 16 phenolic compounds (catechol, tyrosol, protocatechuic acid, hydrocaffeic acid, chlorogenic acid, hydrocoumaric acid, ferulic acid, (-)-epicatechin, (+)-catechin, procyanidins B2 and B5, phloretin-2'-xyloglucoside, phloridzin, hyperin, avicularin, and quercitrin) were identified and quantified. A fourth quercetin derivative, one dihydrochalcone-related compound, two unknown procyanidins, three hydroxycinnamic derivatives, and two unknown compounds were also found. Among the low-molecular-mass polyphenols analyzed, hydrocaffeic acid was the most abundant compound, representing more than 80% of the total polyphenolic acids. Procyanidins were the most important family among the flavonoid compounds. Discriminant analysis was allowed to correctly classify more than 93% of the ciders, according to the harvest year; the most discriminant variables were an unknown procyanidin and quercitrin. PMID:16390187

  6. Oestrosis in red deer from Spain.

    PubMed

    Bueno-de la Fuente, M L; Moreno, V; Peréz, J M; Ruiz-Martinez, I; Soriguer, R C

    1998-10-01

    A survey of naso-pharyngeal myiasis affecting red deer (Cervus elaphus) in southern Spain was conducted. The parasites involved were the larvae of Pharyngomyia picta and Cephenemyia auribarbis (Diptera:Oestridae), which coexist sympatrically within this host. Males and older animals had higher prevalences and intensities of fly larvae. Differences in behaviour and habitat use by male and female deer, and the increase of head size in older males are possibly responsible for this. There were low densities of C. auribarbis while P. picta was the species most frequently observed, although both oestrids were located in the same host cavities. The earlier larviposition by C. auribarbis, and its faster larval development may reflect asynchronous life-cycles of both oestrids; this may decrease inter-specific competition between these sympatric species.

  7. Spain's greatest and most recent mine disaster.

    PubMed

    Guerrero, Flor Ma; Lozano, Macarena; Rueda-Cantuche, José M

    2008-03-01

    On 25 April 1998, the mineral waste retaining wall at the Swedish-owned pyrite mine at Aznalcóllar (Seville, Spain) burst, causing the most harmful environmental and socio-economic disaster in the history of the River Guadiamar basin. The damage was so great that the regional government decided in May 1998 to finance a comprehensive, multidisciplinary research initiative with the objective of eradicating or at least minimising all of the negative social, economic and environmental impacts. This paper utilises a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis to identify eight strategic measures aimed at providing policymakers with key guidelines on implementing a sustainable development model, in a broad sense. Empirical evidence, though, reveals that, to date, major efforts to tackle the negative impacts have centred on environmental concerns and that the socio-economic consequences have not been completely mitigated. PMID:18217916

  8. Legionnaires’ Disease Outbreak in Murcia, Spain

    PubMed Central

    Navarro, Carmen; Fenoll, Daniel; García, José; González-Diego, Paulino; Jiménez-Buñuales, Teresa; Rodriguez, Miguel; Lopez, Rosa; Pacheco, Francisco; Ruiz, Joaquín; Segovia, Manuel; Baladrón, Beatriz; Pelaz, Carmen

    2003-01-01

    An explosive outbreak of Legionnaires’ disease occurred in Murcia, Spain, in July 2001. More than 800 suspected cases were reported; 449 of these cases were confirmed, which made this the world’s largest outbreak of the disease reported to date. Dates of onset for confirmed cases ranged from June 26 to July 19 , with a case-fatality rate of 1%. The epidemic curve and geographic pattern from the 600 completed epidemiologic questionnaires indicated an outdoor point-source exposure in the northern part of the city. A case-control study matching 85 patients living outside the city of Murcia with two controls each was undertaken to identify the outbreak source; the epidemiologic investigation implicated the cooling towers at a city hospital. An environmental isolate from these towers with an identical molecular pattern as the clinical isolates was subsequently identified and supported that epidemiologic conclusion. PMID:12967487

  9. Spain: from the decree to the proposal.

    PubMed

    Gracia, Diego

    1987-06-01

    This is one in a series of four country reports published together in the Hastings Center Report. Gracia, a bioethicist, compares health care policy before and after Franco's dictatorship. Under Franco, compulsory health insurance was enacted, and modern hospitals were built at the expense of primary services. Patient care was governed by the principle of beneficence "in its extreme and paternalistic sense." Medicine in the democratic post-Franco period has reflected changes in Spanish society as political freedom has led to an increased moral pluralism and the formation of public policy through debate and compromise. Gracia identifies three bioethical issues where changes in attitudes and policies have been the greatest: resource allocation, abortion, and organ transplantation. He concludes his report by briefly describing the role bioethics plays in public policy formation in Spain today. PMID:11644028

  10. Reactivation of coccidioidomycosis: a prosthetic joint infection in Spain.

    PubMed

    Arbeloa-Gutierrez, L; Kuberski, T; Johnson, S M; Sagastibelza, I; Alaez, J I; Pappagianis, D

    2016-02-01

    A resident of Spain was found to have a prosthetic knee infection due to coccidioidomycosis. He had a history of having pneumonia which resolved while living in an area of California endemic for Coccidioides in 1957-1961. The patient left California in 1961 returned to Spain and never left Spain thereafter. In 2006, a total knee replacement was done. In 2013, a prosthetic knee infection was documented due to coccidioidomycosis. By molecular DNA analysis, Coccidioides immitis was identified from the knee tissue, a species most commonly found in California. This represents reactivation of a Coccidioides infection 56 years after leaving the endemic area.

  11. Raptor ecotoxicology in Spain: a review on persistent environmental contaminants.

    PubMed

    García-Fernández, Antonio J; Calvo, José F; Martínez-López, Emma; María-Mojica, Pedro; Martínez, José E

    2008-09-01

    Initial studies on the pressure from environmental contaminants on raptor populations in Spain date back to the 1980s, and they have been carried out from a range of viewpoints using a range of sentinel raptor species. However, there is no national monitoring scheme, and therefore the research carried out has been sporadic both spatially and temporally. The exposure to metals has not varied over time, except in the case of lead, whose concentration in eggs and tissues has diminished. In general, the concentrations of metals detected in raptor samples from Spain are generally low and not sufficient to produce toxic effects. Excepting DDT and DDE, most organochlorine-based pesticides in raptors from Spain have diminished over the last 2 decades. The concentrations of DDE found in the eggs of various species could in part explain problems in the reproductive success of raptors in Spain.

  12. [Beginnings of bariatric and metabolic surgery in Spain].

    PubMed

    Baltasar, Aniceto; Domínguez-Adame, Eduardo

    2013-01-01

    When bariatric and metabolic surgery initially began in Spain, it was a subject of debate, due to not knowing exactly who were the first surgeons to perform it. A study has revealed the authors of the first interventions.

  13. The Other Women: Students of Literature in Spain.

    ERIC Educational Resources Information Center

    Puigvert, Lidia

    2000-01-01

    Provides an account of engaging women in Spain who come from uneducated backgrounds in literacy circles through which Freirean radicalization approaches are being effectively pursued. (Adjunct ERIC Clearinghouse for ESL Literacy Education) (Author/VWL)

  14. Raptor ecotoxicology in Spain: a review on persistent environmental contaminants.

    PubMed

    García-Fernández, Antonio J; Calvo, José F; Martínez-López, Emma; María-Mojica, Pedro; Martínez, José E

    2008-09-01

    Initial studies on the pressure from environmental contaminants on raptor populations in Spain date back to the 1980s, and they have been carried out from a range of viewpoints using a range of sentinel raptor species. However, there is no national monitoring scheme, and therefore the research carried out has been sporadic both spatially and temporally. The exposure to metals has not varied over time, except in the case of lead, whose concentration in eggs and tissues has diminished. In general, the concentrations of metals detected in raptor samples from Spain are generally low and not sufficient to produce toxic effects. Excepting DDT and DDE, most organochlorine-based pesticides in raptors from Spain have diminished over the last 2 decades. The concentrations of DDE found in the eggs of various species could in part explain problems in the reproductive success of raptors in Spain. PMID:18833796

  15. Outbound Near-Earth Asteroid, as Seen from Spain

    NASA Video Gallery

    This set of images from the La Sagra Sky Survey, operated by theAstronomical Observatory of Mallorca in Spain, shows the passage ofasteroid 2012 DA14 shortly after its closest – and safe -- app...

  16. History of Information Science in Spain: A Selected Bibliography.

    ERIC Educational Resources Information Center

    Fernandez, Felix Sagredo; Moreno, Antonia Garcia

    1997-01-01

    Presents a selected annotated bibliography of 18 works on historical periods of information science in Spain. It is classified into five areas: bibliographies, databases, history of information science, information policy, and training of information scientists. (Author/LRW)

  17. Pedological and mineralogical investigations on a soil-paleosoil sequence within Andosols in the Western Cordillera of the Peruvian Andes (region Laramate, 14.5S)

    NASA Astrophysics Data System (ADS)

    Leceta Gobitz, Fernando; Mächtle, Bertil; Schukraft, Gerd; Meyer, Hans-Peter; Eitel, Bernhard

    2016-04-01

    An integrated research project of environmental sciences focuses on a group of four Andosol profiles in Western flank of the Peruvian southern Andes. Aim of this study is to contribute to the reconstruction of the paleo environmental conditions in the Western Cordillera of the Peruvian Andes. Standard pedological and sedimentological analysis has been conducted in order to identify morphological and geochemical features generated by climatic variations during the middle and late Holocene. Though a provenance analysis of sediments, all potential lithological sources around the town of Laramate are being examined under the scanning electron microscope, in order to find significant mineralogical associations downward the soil-profile. Preliminary results reveal two edaphic cycles within a soil-paleo soil-sequence: a relative poor developed "Ah" topsoil, mostly composed by fine grain sediments, is underlain by a well preserved "2Ah" paleo soil; a "2Bwt" subsoil exhibits signs of alteration and clay translocation; parent material in slight weathered statement at "2C" culminates the sequence. Mineralogical analytical data supports the premise, that materials in the uppermost horizons are relatable to distal geological units of the Western and Eastern Cordillera, therefore also related to other described aeolian archives from the region: "Desert Margin Loess" at the Andean foot-zone and "Mixed Loess" in the Puna grassland. The amphibole varieties Actinolite, Mg-Hornblende and Edenite could be only distinguished within the soil sediments. The fluvial transport to its current position is excluded, insofar mentioned varieties stem from the granodiorites of Coastal Batholite (downstream the study area), and the vulcanites of the Anta und Andahuaylas Formation (eastward the continental divide). References: Eitel, B., et al. (2005). "Geoarchaeological evidence from desert loess in the Nazca-Palpa region, southern Peru : Palaeoenvironmental changes and their impact on Pre

  18. Glacial areas, lake areas, and snowlines from 1975 to 2012: status of the Cordillera Vilcanota, including the Quelccaya Ice Cap, northern central Andes, Peru

    NASA Astrophysics Data System (ADS)

    Hanshaw, M. N.; Bookhagen, B.

    2013-02-01

    Glaciers in the tropical Andes of southern Peru have received limited attention compared to glaciers in other regions (both near and far), yet remain of vital importance to agriculture, fresh water, and hydropower supplies of downstream communities. Little is known about recent glacial-area changes and how the glaciers in this region respond to climate changes, and, ultimately, how these changes will affect lake and water supplies. To remedy this, we have used 144 multi-spectral satellite images spanning almost four decades, from 1975-2012, to obtain glacial and lake-area outlines for the understudied Cordillera Vilcanota region, including the Quelccaya Ice Cap. In a second step, we have estimated the snowline altitude of the Quelccaya Ice Cap using spectral unmixing methods. We have made the following four key observations: first, since 1988 glacial areas throughout the Cordillera Vilcanota have been declining at a rate of 5.46 ± 1.70 km2 yr-1 (22-yr average, 1988-2010, with 95% confidence interval). The Quelccaya Ica Cap, specifically, has been declining at a rate of 0.67 ± 0.18 km2 yr-1 since 1980 (31-yr average, 1980-2011, also with 95% confidence interval); Second, decline rates for individual glacierized regions have been accelerating during the past decade (2000-2011) as compared to the preceding decade (1990-2000); Third, the snowline of the Quelccaya Ice Cap is retreating to higher elevations as glacial areas decrease, by a total of almost 300 m between its lowest recorded elevation in 1989 and its highest in 1998; and fourth, as glacial regions have decreased, 61% of lakes connected to glacial watersheds have shown a roughly synchronous increase in lake area, while 84% of lakes not connected to glacial watersheds have remained stable or have declined in area. Our new and detailed data on glacial and lake areas over 37 yr provide an important spatiotemporal assessment of climate variability in this area. These data can be integrated into further studies

  19. Glacial areas, lake areas, and snow lines from 1975 to 2012: status of the Cordillera Vilcanota, including the Quelccaya Ice Cap, northern central Andes, Peru

    NASA Astrophysics Data System (ADS)

    Hanshaw, M. N.; Bookhagen, B.

    2014-03-01

    Glaciers in the tropical Andes of southern Peru have received limited attention compared to glaciers in other regions (both near and far), yet remain of vital importance to agriculture, fresh water, and hydropower supplies of downstream communities. Little is known about recent glacial-area changes and how the glaciers in this region respond to climate changes, and, ultimately, how these changes will affect lake and water supplies. To remedy this, we have used 158 multi-spectral satellite images spanning almost 4 decades, from 1975 to 2012, to obtain glacial- and lake-area outlines for the understudied Cordillera Vilcanota region, including the Quelccaya Ice Cap. Additionally, we have estimated the snow-line altitude of the Quelccaya Ice Cap using spectral unmixing methods. We have made the following four key observations: first, since 1988 glacial areas throughout the Cordillera Vilcanota (1988 glacial area: 361 km2) have been declining at a rate of 3.99 ± 1.15 km2 yr-1 (22 year average, 1988-2010, with 95% confidence interval (CI), n = 8 images). Since 1980, the Quelccaya Ice Cap (1980 glacial area: 63.1 km2) has been declining at a rate of 0.57 ± 0.10 km2 yr-1 (30 year average, 1980-2010, with 95% CI, n = 14). Second, decline rates for individual glacierized regions have been accelerating during the past decade (2000-2010) as compared to the preceding decade (1988-1999) with an average increase from 37.5 to 42.3 × 10-3 km2 yr-1 km-2 (13%). Third, glaciers with lower median elevations are declining at higher rates than those with higher median elevations. Specifically, glaciers with median elevations around 5200 m a.s.l. are retreating to higher elevations at a rate of ~1 m yr-1 faster than glaciers with median elevations around 5400 m a.s.l. Fourth, as glacial regions have decreased, 77% of lakes connected to glacial watersheds have either remained stable or shown a roughly synchronous increase in lake area, while 42% of lakes not connected to glacial