Influencia de la carga de los depósitos en la generación de fallas de atajo durante la inversión de una cuenca extensional: El caso de la cuenca de Abanico (Eoceno-Oligoceno), Andes de Chile central (33°-35°S)

Translated title of the contribution: Influence of depositional load on the development of a shortcut fault system during the inversion of an extensional basin: The Eocene-Oligocene Abanico Basin case, central Chile Andes (33°-35°S)

Carolina Muñoz-Sáez, Luisa Pinto, Reynaldo Charrier, Thierry Nalpas

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

The current paper analyzes the evolution of the Abanico Basin, in the Chilean Principal Cordillera in central Chile (33°-35°S). According to previous studies, the basin has been affected by two main deformational episodes: the first, related to extension, and the second, to partial basin inversion. Deposits of the Abanico Formation, Eocene-Oligocene, and the Farellones Formation, Early-Middle Miocene, represent these two deformational episodes, respectively. Studies of the basin deposits and the structural features show that the basin was asymmetric and that it developed two main depocenters. The eastern depocenter is deeper and was controlled by a west-dipping fault system (El Diablo Fault System) that formed its eastern border. We propose that the geometry of the basin and the magnitude of inversion were strongly influenced by the load generated by the thick volcanic and volcaniclastic pile that accumulated in the eastern depocenter. Through analogue modeling, we interpret that the Aconcagua fold-thrust belt was triggered at ~16 Ma by a shortcut thrust rooted in the El Diablo Fault System, which during inversion was blocked because of the high load exerted by the deposits of the Abanico and Farellones formations. In addition, the stratified Mesozoic succession that formed the eastern border of the basin allowed the propagation of the shortcut thrust along the ductile Oxfordian gypsum layer. This would have determined the east vergence of the fold-thrust belt. On the western side of the basin, the absence of weak layers prevented development of a west-vergent fold-thrust belt.

Translated title of the contributionInfluence of depositional load on the development of a shortcut fault system during the inversion of an extensional basin: The Eocene-Oligocene Abanico Basin case, central Chile Andes (33°-35°S)
Original languageSpanish
Pages (from-to)1-28
Number of pages28
JournalAndean Geology
Volume41
Issue number1
DOIs
Publication statusPublished - 2014

ASJC Scopus subject areas

  • Geology
  • Geochemistry and Petrology
  • Stratigraphy
  • Palaeontology

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