Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry

The Central Patagonian Andes is a particular segment of the Andean Cordillera that has been subjected to the subduction of two spreading ridges during Eocene and Neogene times. In order to understand the Cenozoic geologic evolution of the Central Patagonian Andes, we carried out geochronologic (U-Pb...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Encinas, A., Folguera, A., Riffo, R., Molina, P., Fernández Paz, L., Litvak, V.D., Colwyn, D.A., Valencia, V.A., Carrasco, M.
Formato: INPR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_16749871_v_n_p_Encinas
Aporte de:
id todo:paper_16749871_v_n_p_Encinas
record_format dspace
spelling todo:paper_16749871_v_n_p_Encinas2023-10-03T16:29:37Z Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry Encinas, A. Folguera, A. Riffo, R. Molina, P. Fernández Paz, L. Litvak, V.D. Colwyn, D.A. Valencia, V.A. Carrasco, M. Ar-Ar geochronology Central Patagonian Andes Geochemistry Sedimentology Stratigraphy U-Pb geochronology The Central Patagonian Andes is a particular segment of the Andean Cordillera that has been subjected to the subduction of two spreading ridges during Eocene and Neogene times. In order to understand the Cenozoic geologic evolution of the Central Patagonian Andes, we carried out geochronologic (U-Pb and 40 Ar/ 39 Ar), provenance, stratigraphic, sedimentologic, and geochemical studies on the sedimentary and volcanic Cenozoic deposits that crop out in the Meseta Guadal and Chile Chico areas (∼47°S). Our data indicate the presence of a nearly complete Cenozoic record, which refutes previous interpretations of a hiatus during the middle Eocene–late Oligocene in the Central Patagonian Andes. Our study suggests that the fluvial strata of the Ligorio Márquez Formation and the flood basalts of the Basaltos Inferiores de la Meseta Chile Chico Formation were deposited in an extensional setting related to the subduction of the Aluk-Farallon spreading ridge during the late Paleocene–Eocene. Geochemical data on volcanic rocks interbedded with fluvial strata of the San José Formation suggest that this unit was deposited in an extensional setting during the middle Eocene to late Oligocene. Progressive crustal thinning allowed the transgression of marine waters of Atlantic origin and deposition of the upper Oligocene–lower Miocene Guadal Formation. The fluvial synorogenic strata of the Santa Cruz Formation were deposited as a consequence of an important phase of compressive deformation and Andean uplift during the early–middle Miocene. Finally, alkali flood basalts of the late middle to late Miocene Basaltos Superiores de la Meseta Chile Chico Formation were extruded in the area in response to the suduction of the Chile Ridge under an extensional regime. Our studies indicate that the tectonic evolution of the Central Patagonian Andes is similar to that of the North Patagonian Andes and appears to differ from that of the Southern Patagonian Andes, which is thought to have been the subject of continuous compressive deformation since the late Early Cretaceous. © 2018 China University of Geosciences (Beijing) and Peking University INPR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_16749871_v_n_p_Encinas
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Ar-Ar geochronology
Central Patagonian Andes
Geochemistry
Sedimentology
Stratigraphy
U-Pb geochronology
spellingShingle Ar-Ar geochronology
Central Patagonian Andes
Geochemistry
Sedimentology
Stratigraphy
U-Pb geochronology
Encinas, A.
Folguera, A.
Riffo, R.
Molina, P.
Fernández Paz, L.
Litvak, V.D.
Colwyn, D.A.
Valencia, V.A.
Carrasco, M.
Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
topic_facet Ar-Ar geochronology
Central Patagonian Andes
Geochemistry
Sedimentology
Stratigraphy
U-Pb geochronology
description The Central Patagonian Andes is a particular segment of the Andean Cordillera that has been subjected to the subduction of two spreading ridges during Eocene and Neogene times. In order to understand the Cenozoic geologic evolution of the Central Patagonian Andes, we carried out geochronologic (U-Pb and 40 Ar/ 39 Ar), provenance, stratigraphic, sedimentologic, and geochemical studies on the sedimentary and volcanic Cenozoic deposits that crop out in the Meseta Guadal and Chile Chico areas (∼47°S). Our data indicate the presence of a nearly complete Cenozoic record, which refutes previous interpretations of a hiatus during the middle Eocene–late Oligocene in the Central Patagonian Andes. Our study suggests that the fluvial strata of the Ligorio Márquez Formation and the flood basalts of the Basaltos Inferiores de la Meseta Chile Chico Formation were deposited in an extensional setting related to the subduction of the Aluk-Farallon spreading ridge during the late Paleocene–Eocene. Geochemical data on volcanic rocks interbedded with fluvial strata of the San José Formation suggest that this unit was deposited in an extensional setting during the middle Eocene to late Oligocene. Progressive crustal thinning allowed the transgression of marine waters of Atlantic origin and deposition of the upper Oligocene–lower Miocene Guadal Formation. The fluvial synorogenic strata of the Santa Cruz Formation were deposited as a consequence of an important phase of compressive deformation and Andean uplift during the early–middle Miocene. Finally, alkali flood basalts of the late middle to late Miocene Basaltos Superiores de la Meseta Chile Chico Formation were extruded in the area in response to the suduction of the Chile Ridge under an extensional regime. Our studies indicate that the tectonic evolution of the Central Patagonian Andes is similar to that of the North Patagonian Andes and appears to differ from that of the Southern Patagonian Andes, which is thought to have been the subject of continuous compressive deformation since the late Early Cretaceous. © 2018 China University of Geosciences (Beijing) and Peking University
format INPR
author Encinas, A.
Folguera, A.
Riffo, R.
Molina, P.
Fernández Paz, L.
Litvak, V.D.
Colwyn, D.A.
Valencia, V.A.
Carrasco, M.
author_facet Encinas, A.
Folguera, A.
Riffo, R.
Molina, P.
Fernández Paz, L.
Litvak, V.D.
Colwyn, D.A.
Valencia, V.A.
Carrasco, M.
author_sort Encinas, A.
title Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
title_short Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
title_full Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
title_fullStr Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
title_full_unstemmed Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology, stratigraphy, and geochemistry
title_sort cenozoic basin evolution of the central patagonian andes: evidence from geochronology, stratigraphy, and geochemistry
url http://hdl.handle.net/20.500.12110/paper_16749871_v_n_p_Encinas
work_keys_str_mv AT encinasa cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT folgueraa cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT riffor cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT molinap cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT fernandezpazl cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT litvakvd cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT colwynda cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT valenciava cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
AT carrascom cenozoicbasinevolutionofthecentralpatagonianandesevidencefromgeochronologystratigraphyandgeochemistry
_version_ 1807322897700618240