- We analyzed the Lomas de Carabajal area in the intermontane Lerma valley of the Cordillera Oriental to assess the level of neotectonic activity in a densely populated region of northwestern Argentina. In this region, Plio-Pleistocene synorogenic conglomerates are deformed, locally associated with high-angle faults, and NNW-SSE oriented en-echelon folds characterized by wavelengths of < 1 km. The deformed Quaternary units follow the same pattern of deformation as observed in the underlying Neogene deposits; growth-strata geometries are observed near faults. This configuration is compatible with local left-lateral transpressional tectonism driven by ENE-WSW buttressing against the NW-oriented border of a Cretaceous extensional basin (Alemania sub-basin). Optically Stimulated Luminescence analysis of sandy-silty layers interbedded within the folded late Pleistocene conglomeratic sequence helps to determine uplift rates of 0.83-0.87 mm/a during the last 30-40 ka. Nearby the Lomas de Carabajal, a WNW-striking, 3-m-high fault scarp disruptsWe analyzed the Lomas de Carabajal area in the intermontane Lerma valley of the Cordillera Oriental to assess the level of neotectonic activity in a densely populated region of northwestern Argentina. In this region, Plio-Pleistocene synorogenic conglomerates are deformed, locally associated with high-angle faults, and NNW-SSE oriented en-echelon folds characterized by wavelengths of < 1 km. The deformed Quaternary units follow the same pattern of deformation as observed in the underlying Neogene deposits; growth-strata geometries are observed near faults. This configuration is compatible with local left-lateral transpressional tectonism driven by ENE-WSW buttressing against the NW-oriented border of a Cretaceous extensional basin (Alemania sub-basin). Optically Stimulated Luminescence analysis of sandy-silty layers interbedded within the folded late Pleistocene conglomeratic sequence helps to determine uplift rates of 0.83-0.87 mm/a during the last 30-40 ka. Nearby the Lomas de Carabajal, a WNW-striking, 3-m-high fault scarp disrupts radiocarbon dated, 10-ka-old loessic deposits providing a Holocene mean uplift rate of 0.30 mm/a. Our data unambiguously show that shallow crustal deformation in the intermontane Lerma valley is ongoing; some of this deformation may be associated with seismicity. Our findings support the notion of temporally and spatially disparate deformation processes in the broken foreland of the northwestern Argentinean Andes.…
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MetadatenAuthor details: | Victor H. GarciaORCiD, Fernando D. HongnORCiD, Daniel YagupskyORCiD, Heiko PingelORCiDGND, Timothy Kinnaird, Diego WinocurORCiD, Ernesto CristalliniORCiD, Ruth Aj Robinson, Manfred StreckerORCiDGND |
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DOI: | https://doi.org/10.1016/j.jsg.2019.103875 |
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ISSN: | 0191-8141 |
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Title of parent work (English): | Journal of structural geology |
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Publisher: | Elsevier |
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Place of publishing: | Oxford |
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Publication type: | Article |
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Language: | English |
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Year of first publication: | 2019 |
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Publication year: | 2019 |
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Release date: | 2020/10/20 |
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Tag: | Neotectonics; OSL and C-14 geochronology; Seismogenic sources; Structural geology; Syntectonic sedimentation |
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Volume: | 128 |
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Number of pages: | 17 |
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Funding institution: | Agencia Nacional de Promocion Cientifica y TecnologicaANPCyT [PICT 07-38295, PICT 2010-1441, PICT 2013-1264, PICTO UNRN 2010-0175, PICT 2017-1928]; Universidad Nacional de Rio Negro [PI 40-B-243]; Universidad Nacional de Salta [CIUNSa 2336]; IBIGEO PUE-CONICET; StRATEGy, the international research training group IGK2018 SuRfAce processes, Tectonics and Georesources: The Andean foreland basin of Argentina of the German Science Foundation [STR 373/34-1]; StRATEGy, the international research training group IGK2018 SuRfAce processes, Tectonics and Georesources: The Andean foreland basin of Argentina of the German Science Foundation (Potsdam University-CONICET); CAPES Foundation Postdoctoral Research FellowshipCAPES |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
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DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
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Peer review: | Referiert |
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