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Reconstructing the thermal and exhumation history of the Sierras Pampeanas through low-temperature thermochronology: A case study from the Sierra de Velasco

2018; Geological Society of America; Volume: 130; Issue: 11-12 Linguagem: Inglês

10.1130/b31935.1

1943-2674

Andrea Stevens Goddard, Mariano A. Larrovere, Bárbara Carrapa, R. Hernán Aciar, Patricia Alvarado,

Tree-ring climate responses

Research Article| June 29, 2018 Reconstructing the thermal and exhumation history of the Sierras Pampeanas through low-temperature thermochronology: A case study from the Sierra de Velasco Andrea L. Stevens Goddard; Andrea L. Stevens Goddard † 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA †Present address: The Center for Integrative Geosciences, University of Connecticut, Storrs, Connecticut, USA; andrea.stevensgoddard@uconn.edu. Search for other works by this author on: GSW Google Scholar Mariano A. Larrovere; Mariano A. Larrovere 2Centro Regional de Investigaciones Científicas y Transferencia Tecnológica La Rioja, Consejo Nacional de Investigaciones Científicas y Técnicas, Anillaco, Argentina3Instituto de Geología y Recursos Naturales, Centro de Investigación e Innovación Tecnológica, Universidad Nacional de La Rioja, La Rioja, Argentina Search for other works by this author on: GSW Google Scholar Barbara Carrapa; Barbara Carrapa 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar R. Hernán Aciar; R. Hernán Aciar 4Departamento de Geología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina Search for other works by this author on: GSW Google Scholar Patricia Alvarado Patricia Alvarado 5Centro de Investigaciones de la Geósfera y la Biósfera, Departamento de Geofísica y Astronomía, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan-Consejo Nacional de Investigaciones Científicas y Técnicas, San Juan, Argentina Search for other works by this author on: GSW Google Scholar Author and Article Information Andrea L. Stevens Goddard † 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Mariano A. Larrovere 2Centro Regional de Investigaciones Científicas y Transferencia Tecnológica La Rioja, Consejo Nacional de Investigaciones Científicas y Técnicas, Anillaco, Argentina3Instituto de Geología y Recursos Naturales, Centro de Investigación e Innovación Tecnológica, Universidad Nacional de La Rioja, La Rioja, Argentina Barbara Carrapa 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA R. Hernán Aciar 4Departamento de Geología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina Patricia Alvarado 5Centro de Investigaciones de la Geósfera y la Biósfera, Departamento de Geofísica y Astronomía, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan-Consejo Nacional de Investigaciones Científicas y Técnicas, San Juan, Argentina †Present address: The Center for Integrative Geosciences, University of Connecticut, Storrs, Connecticut, USA; andrea.stevensgoddard@uconn.edu. Publisher: Geological Society of America Received: 28 Sep 2017 Revision Received: 12 Mar 2018 Accepted: 17 May 2018 First Online: 29 Jun 2018 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2018 Geological Society of America GSA Bulletin (2018) 130 (11-12): 1842–1858. https://doi.org/10.1130/B31935.1 Article history Received: 28 Sep 2017 Revision Received: 12 Mar 2018 Accepted: 17 May 2018 First Online: 29 Jun 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Andrea L. Stevens Goddard, Mariano A. Larrovere, Barbara Carrapa, R. Hernán Aciar, Patricia Alvarado; Reconstructing the thermal and exhumation history of the Sierras Pampeanas through low-temperature thermochronology: A case study from the Sierra de Velasco. GSA Bulletin 2018;; 130 (11-12): 1842–1858. doi: https://doi.org/10.1130/B31935.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Sierras Pampeanas of Argentina have been used as a classic case study to understand the processes and mechanisms involved in thick-skinned deformation; however, the history of exhumation and uplift of these ranges remains enigmatic. This study presents new thermochronology and field observations from the Sierra de Velasco, one of the highest relief (>4 km) and least studied mountains in the Sierras Pampeanas. Advances in the annealing and diffusion kinetics of the apatite fission track and (U-Th-Sm)/He systems provide the tools to interpret a data set with a complex Carboniferous to Miocene cooling history. Our results show that rocks sampled across 2 km of structural depth have experienced protracted exposure to temperatures at or above ∼60 °C from ca. 320 to 120 Ma. The well-constrained thermal history allows us to identify subsequent thermal perturbations including an elevated geothermal gradient during Cretaceous rifting, late Cretaceous–Paleocene cooling due to isothermal relaxation and/or exhumation, and accelerated Miocene exhumation. Quantitative estimates of the minimum rock overburden suggest that 1.0 ± 0.8 km of rock has been eroded from the Sierra de Velasco since the early Miocene. Although a low geothermal gradient (≤25 °C/km) may support the exhumation of Sierra de Velasco coincident with the onset of flat-slab subduction in the late Miocene, we suggest inherited paleotopography existed before the Miocene and possibly since the Paleozoic. Final cooling and exhumation beginning in the early to middle Miocene, concurrent with the onset of flat slab subduction, contributed to the topography observed today, but cannot explain the entirety of the modern relief. We propose that a history of long-lived topography may be extrapolated throughout the Sierras Pampeanas region. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.