- 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.…
MetadatenVerfasserangaben: | 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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Titel des übergeordneten Werks (Englisch): | Journal of structural geology |
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Verlag: | Elsevier |
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Verlagsort: | Oxford |
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Publikationstyp: | Wissenschaftlicher Artikel |
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Sprache: | Englisch |
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Jahr der Erstveröffentlichung: | 2019 |
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Erscheinungsjahr: | 2019 |
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Datum der Freischaltung: | 20.10.2020 |
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Freies Schlagwort / Tag: | Neotectonics; OSL and C-14 geochronology; Seismogenic sources; Structural geology; Syntectonic sedimentation |
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Band: | 128 |
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Seitenanzahl: | 17 |
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Fördernde 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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Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
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DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
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Peer Review: | Referiert |
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