Pliocene-Quaternary tectono-sedimentary evolution of the Guayaquil-Tumbes forearc basin (Ecuador-Peru)
| Autor: | Peuzin, Andréa, Espurt, Nicolas, Saillard, M., Bulois, Cédric, Michaud, François |
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| Přispěvatelé: | Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), ANR-18-CE31-0022,MARACAS,Les terrasses marines comme proxy pour l'appréhension de l'aléa sismique(2018), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Saillard, Marianne, APPEL À PROJETS GÉNÉRIQUE 2018 - Les terrasses marines comme proxy pour l'appréhension de l'aléa sismique - - MARACAS2018 - ANR-18-CE31-0022 - AAPG2018 - VALID |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | 27e réunion des Sciences de la Terre 27e réunion des Sciences de la Terre, Nov 2021, Lyon, France |
| Popis: | International audience; Forearc systems develop largely offshore above subduction zones between the trenchand the volcanic arc. The associated forearc basins are generally parallel to the trenchand involve vertical movements (subsidence vs. uplift), influencing the dynamics of thewedge. The objectof the study is the Guayaquil-Tumbes forearc basin belonging to theEcuadorian-Peruvian subduction zone. This forearc basin has peculiar characteristics,developing on the southernmost segment of a great active continental strike-slip fault,the Dolores-Guayaquil Fault, delimiting two crustal domains, the North Andean andInca slivers. The divergent motions of the two slivers generate extension in the upperplate whose interaction with the strike-slip tectonics and subduction remains poorlyconstrained. Two major rivers, Chira and Tumbes, draining the Andean reliefs towardsthe Pacific, generate huge Pliocene-Quaternary silico-clastic sedimentary filling trappedin the basin, having an important impact on the growth of the wedge and fault activity.The objective of this study is to constrain the structural architecture of the basin bydetermining the nature, geometry and age of the major structures that controlled itsPliocene-Quaternary development. This study is carried out through the interpretationof offshore seismic profiles correlated with well data. The results show that thestructure of the basin is dominated by gravitational instabilities (classical raft tectonic)detached northwestward and westward, and active through the Pliocene- Quaternarytimes. The syn-tectonic sediments and erosional surfaces indicate that theseinstabilities are progressively younger toward the south. We propose that thisgravitational sliding has been sustained by high sedimentation rates and by the modernpropagation of the Dolores-Guayaquil Fault at depth. This major fault is interpreted asan immature strike-slip system that progressively develops towards the trench. |
| Databáze: | OpenAIRE |
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