Mesozoic - Cenozoic evolution of the Southern Patagonian Andes fold and thrust belt (47°-48°S): Influence of the Rocas Verdes basin inversion and onset of Patagonian glaciations
| Autor: | Jonathan Tobal, Isabelle Coutand, Matías C. Ghiglione, Vanesa Barberon, Gonzalo Ronda |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
Inversion (geology) Trough (geology) TECTONIC INVERSION 010502 geochemistry & geophysics Geociencias multidisciplinaria 01 natural sciences Ciencias de la Tierra y relacionadas con el Medio Ambiente Paleontology Geología 0105 earth and related environmental sciences Earth-Surface Processes geography Décollement geography.geographical_feature_category Fold (geology) BALANCED CROSS SECTIONS Cretaceous Tectonics AUTRAL-MAGALLANES\ROCAS VERDES BASIN INVERSION Geophysics PATAGONIAN ANDES CRETACEOUS DEFORMATION Fold and thrust belt Cenozoic Geology CIENCIAS NATURALES Y EXACTAS |
| Popis: | The Southern Patagonian Andes (SPA)between 47°?48°S are characterized by relatively high elevations (1500?4000 m)and a 200-km-wide, largely exhumed, basement domain along the backbone of the Cordillera, bounded by a narrow 30-km-wide fold and thrust-belt to the east. The tectonic evolution of the SPA includes widespread Jurassic extension during the opening of the Austral-Magallanes basin and the Rocas Verdes back-arc oceanic basin (RVB), followed by Cretaceous to Cenozoic shortening. Although the main phases of deformation that affected this Andean segment have been the focus of previous studies, its finite geometry and step by step structural and kinematic evolution have not been quantitatively determined. In this work, we present kinematically restored cross sections, showing the variable geometry, trough time, of the eastern basement domain and the fold and thrust-belt. A regional westward-dipping listric decollement, interpreted as formed during the Jurassic extensional event, was reactivated during the Andean deformation constituting the main detachment surface of basement structures and the fold and thrust belt. West verging faults systems are considered a consequence of inversion of north-south trending extensional features as passive roof high-angle west-vergent faults. Using regional data such as field relations, unconformities, and existing ages to differentiate deformational stages, three main phases of contractional deformation are proposed for the area, starting with an Aptian - Cenomanian? phase related to inversion of the extensional depocenter in inmediate response to the closure of northernmost RVB. A second, Miocene phase responsible for most of the shortening occurred between 18 Ma and 10 Ma. Finally, the onset of glaciations and glacial erosion might have triggered out-of-sequence thrusting in the interior of the orogen after 7 Ma. Fil: Ronda, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Ghiglione, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Barberon, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina Fil: Coutand, Isabelle. Dalhousie University Halifax; Canadá Fil: Tobal, Jonathan Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|