Holocene compression in the Acequión valley (Andes Precordillera, San Juan province, Argentina): Geomorphic, tectonic, and paleoseismic evidence
| Autor: | Carlos R. Avila, Hewart Viete, M. Romina Onorato, Ana Pantano, P L Laura Perucca, Horacio Nicolas Vargas, A M Franck Audemard, Patricia Alvarado |
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| Rok vydání: | 2016 |
| Předmět: |
010506 paleontology
SIERRAS PAMPEANAS Fault (geology) 010502 geochemistry & geophysics OPPOSING VERGENCE STRESS TENSOR 01 natural sciences Ciencias de la Tierra y relacionadas con el Medio Ambiente Neotectonics Convergent boundary Compression (geology) Geomorphology Foreland basin 0105 earth and related environmental sciences Earth-Surface Processes Focal mechanism geography geography.geographical_feature_category FAULT STRIATION Subduction FLEXURAL SCARP Geology ARGENTINEAN PRECORDILLERA Tectonics HOLOCENE FAULTS TRIANGULAR ZONE Meteorología y Ciencias Atmosféricas CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | Journal of South American Earth Sciences. 67:140-157 |
| ISSN: | 0895-9811 |
| DOI: | 10.1016/j.jsames.2016.02.005 |
| Popis: | The Matagusanos-Maradona-Acequión Valley sits within the Andes Precordillera fold-thrust belt of western Argentina. It is an elongated topographic depression bounded by the roughly N-S trending Precordillera Central and Oriental in the San Juan Province. Moreover, it is not a piggy-back basin as we could have expected between two ranges belonging to a fold-thrust belt, but a very active tectonic corridor coinciding with a thick-skinned triangular zone, squeezed between two different tectonic domains. The two domains converge, where the Precordillera Oriental has been incorporated to the Sierras Pampeanas province, becoming the western leading edge of the west-verging broken foreland Sierras Pampeanas domain. This latter province has been in turn incorporated into the active deformation framework of the Andes back-arc at these latitudes as a result of enhanced coupling between the converging plates due to the subduction of the Juan Fernández ridge that flattens the Nazca slab under the South American continent.This study focuses on the neotectonics of the southern tip of this N-S elongated depression, known as Acequión (from the homonym river that crosses the area), between the Del Agua and Los Pozos rivers. This depression dies out against the transversely oriented Precordillera Sur, which exhibits a similar tectonic style as Precordillera Occidental and Central (east-verging fold-thrust belt). This contribution brings supporting evidence of the ongoing deformation during the Late Pleistocene and Holocene of the triangular zone bounded between the two leading and converging edges of Precordillera Central and Oriental thrust fronts, recorded in a multi-episodic lake sequence of the Acequión and Nikes rivers. The herein gathered evidence comprise Late Pleistocene-Holocene landforms of active thrusting, fault kinematics (micro-tectonic) data and outcrop-scale (meso-tectonic) faulting and folding of recent lake and alluvial sequences. In addition, seismically-induced effects already reported in the literature by this working team further support the tectonic activity of neighboring faults in the Holocene. As a concluding remark we could state that the ongoing deformation in the region under study is driven by a compressional regime whose maximum horizontal stress in the late Pleistocene-Holocene is roughly east-west oriented. This is further supported by focal mechanism solutions. Fil: Audemard, Franck Albert. Venezuelan Foundation For Seismological Research; Venezuela. Universidad Central de Venezuela; Venezuela Fil: Perucca, Laura Patricia A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Geología ; Argentina Fil: Pantano, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Geociencias y Medio Ambiente; Argentina Fil: Avila, Carlos Roberto. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Geología "Dr. Emiliano Aparicio". Gabinete de Neotectónica y Geomorfología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; Argentina Fil: Onorato, María Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina Fil: Vargas, Horacio Nicolás. Chisñanco Srl; Argentina Fil: Alvarado, Patricia Monica. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Viete, Hewart. Funvisis; Venezuela |
| Databáze: | OpenAIRE |
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