@article{277a74a7b3b94d39860a5583776a86c6,
title = "Fault reactivation in the Sierras Pampeanas resolved across Andean extensional and compressional regimes using thermochronologic modeling",
abstract = "The reactivation of existing faults has long been recognized to control the location and style of deformation in orogenic systems including the Sierras Pampeanas in the southern Central Andes; however, it can remain difficult to resolve the timing and fault kinematics across multiple orogenic phases. In the Sierras Pampeanas, basement-cored range-bounding faults mark a Paleozoic terrane boundary and are seismically active; however, the protracted history of deformation along this lithospheric-scale regional fault system - located ~400 km from the plate boundary - has been poorly constrained. In this study, we present new apatite (U–Th-Sm)/He and fission track thermochronology data and thermal history models from ten samples from the Sierra de Valle F{\'e}rtil-La Huerta in the Western Sierras Pampeanas of Argentina. The spatio-temporal patterns of rock heating and cooling identified by our thermal history models throughout this fault system are consistent with four discrete phases of deformation. Thermal patterns indicative of Mesozoic extensional deformation and latest Miocene - Pliocene compressional deformation corroborate previous interpretations of regional deformation episodes in the Sierras Pampeanas. Our study also identifies a period of middle-Miocene cooling that revises the location of the Andean thrust front. This episode of deformation was previously unrecognized in the Sierras Pampeanas and is contemporaneous with thin-skinned deformation in the adjacent Precordillera thrust belt. A Paleogene phase of cooling may also support a phase of compressional deformation in the Sierras Pampeanas during a period in which neutral tectonic conditions have been proposed along the Andean margin. Our findings outline a history of fault reactivation suggesting that the long-lived fault systems in the Sierras Pampeanas are sensitive to plate-margin processes.",
keywords = "Flat-slab subduction, Low-temperature thermochronology, Rift inversion, Sierras Pampeanas, Thick-skinned tectonics, Valle F{\'e}rtil Fault",
author = "Gustavo Ortiz and {Stevens Goddard}, {Andrea L.} and Fosdick, {Julie C.} and Patricia Alvarado and Barbara Carrapa and Eber Cristofolini",
note = "Funding Information: This research was carried out as part of G. Ortiz's PhD research. Financial support was granted by the Internship Program for Training Abroad in Science and Technology , Ministry of Science and Technology (grant BecAr-Fulbright 2016), National Agency for Scientific and Technological Promotion – MINCyT of Argentina ( PICT2016-46 ; PICT2017-676 and PDTS-2016 , 2018 projects ), State Secretary for Science, Technology and Innovation (SECITI) of the San Juan Government and CONICET research grants. We thank Lic. Paola Orozco, M. Sc. Mauro Saez and undergraduate student Nicolas Arancibia from the Universidad Nacional de San Juan for valuable work and help in the field and the computer lab in San Juan. We are very grateful for Dr. Peter Reiners help and the analytical support from Erin Abel and Dr. Uttam Chowdhury at the Arizona Radiogenic Helium Dating Laboratory at the University of Arizona, USA. Reviews by Sebastian Zapata and an anonymous reviewer significantly helped to improve this manuscript. Funding Information: This research was carried out as part of G. Ortiz's PhD research. Financial support was granted by the Internship Program for Training Abroad in Science and Technology, Ministry of Science and Technology (grant BecAr-Fulbright 2016), National Agency for Scientific and Technological Promotion ? MINCyT of Argentina (PICT2016-46; PICT2017-676 and PDTS-2016, 2018 projects), State Secretary for Science, Technology and Innovation (SECITI) of the San Juan Government and CONICET research grants. We thank Lic. Paola Orozco, M. Sc. Mauro Saez and undergraduate student Nicolas Arancibia from the Universidad Nacional de San Juan for valuable work and help in the field and the computer lab in San Juan. We are very grateful for Dr. Peter Reiners help and the analytical support from Erin Abel and Dr. Uttam Chowdhury at the Arizona Radiogenic Helium Dating Laboratory at the University of Arizona, USA. Reviews by Sebastian Zapata and an anonymous reviewer significantly helped to improve this manuscript. Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = dec,
doi = "10.1016/j.jsames.2021.103533",
language = "English (US)",
volume = "112",
journal = "Journal of South American Earth Sciences",
issn = "0895-9811",
publisher = "Elsevier BV",
}