Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina

Paleogeography and stratigraphic correlation of the Upper Paleozoic of Sierra de Los Llanos, La Rioja Province. The paleogeographic evolution of the Neopalaeozoic in Sierra de Los Llanos can be divided in three stages on the basis of sedimentary facies distribution. The first stage (Namurian-Westpha...

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Detalles Bibliográficos
Publicado: 1999
Materias:
Carboniferous
paleogeography
Permian
stratigraphy
Argentina
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v54_n3_p229_Net
http://hdl.handle.net/20.500.12110/paper_00044822_v54_n3_p229_Net
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00044822_v54_n3_p229_Net
record_format dspace
spelling paper:paper_00044822_v54_n3_p229_Net2023-06-08T14:25:23Z Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina Carboniferous paleogeography Permian stratigraphy Argentina Paleogeography and stratigraphic correlation of the Upper Paleozoic of Sierra de Los Llanos, La Rioja Province. The paleogeographic evolution of the Neopalaeozoic in Sierra de Los Llanos can be divided in three stages on the basis of sedimentary facies distribution. The first stage (Namurian-Westphalian) is restricted to the Malanzán-Solca and Olta palaeovalleys, where sediments of Malanzån and Loma Larga formations were deposited in water bodies surrounded by alluvial fans and subsequently covered by a fluvio-deltaic system prograding from the west-southwest. Tectonic movements that occurred at approximately the Carboniferous-Permian boundary time, controlled the second stage, and were responsible for the accumulation of the alluvial fan deposits known as Solca Formation in the Solca, Anzulo̊n and Olpas depocenters. There is no evidence of any important tectonic activity in the third stage, as the main control for the fluvial sedimentation seems to have been a slow subsidence, during which sedimentation of Permian red beds (La Colina Formation) onlapped the basement. In this last stage, sedimentation reached its maximum extension, and spread as far as the eastern flank of the Sierra de Los Llanos. The recognition of five stratigraphical horizons allow us to present a model of regional correlation between Sierra de Los Llanos, Paganzo and Huaco stratotypes. The correlation levels comprise: (1) a basal interval of dropstone-bearing mudstones (PC) related to the Gondwana glaciation of early Upper Carboniferous age, (2) a thin level of laminated mudstones (PL) corresponding to a base level rise associated to the deglaciation stage, (3) coals and carbonaceous kaolinitic mudstones (C) formed during humid climatic conditions in Westphalian times, (4) an unconformity (d) produced by tectonic movements in late Upper Carboniferous, and (5) eolian and ephemeral lacustrine deposits resulting from arid climatic conditions (A) widespread during the Permian in the Paganzo Basin. Finally, a redefinition for the stratigraphical position of the Solca Formation is proposed. © 1999 Asociación Geológica Argentina. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v54_n3_p229_Net http://hdl.handle.net/20.500.12110/paper_00044822_v54_n3_p229_Net
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Carboniferous
paleogeography
Permian
stratigraphy
Argentina
spellingShingle Carboniferous
paleogeography
Permian
stratigraphy
Argentina
Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
topic_facet Carboniferous
paleogeography
Permian
stratigraphy
Argentina
description Paleogeography and stratigraphic correlation of the Upper Paleozoic of Sierra de Los Llanos, La Rioja Province. The paleogeographic evolution of the Neopalaeozoic in Sierra de Los Llanos can be divided in three stages on the basis of sedimentary facies distribution. The first stage (Namurian-Westphalian) is restricted to the Malanzán-Solca and Olta palaeovalleys, where sediments of Malanzån and Loma Larga formations were deposited in water bodies surrounded by alluvial fans and subsequently covered by a fluvio-deltaic system prograding from the west-southwest. Tectonic movements that occurred at approximately the Carboniferous-Permian boundary time, controlled the second stage, and were responsible for the accumulation of the alluvial fan deposits known as Solca Formation in the Solca, Anzulo̊n and Olpas depocenters. There is no evidence of any important tectonic activity in the third stage, as the main control for the fluvial sedimentation seems to have been a slow subsidence, during which sedimentation of Permian red beds (La Colina Formation) onlapped the basement. In this last stage, sedimentation reached its maximum extension, and spread as far as the eastern flank of the Sierra de Los Llanos. The recognition of five stratigraphical horizons allow us to present a model of regional correlation between Sierra de Los Llanos, Paganzo and Huaco stratotypes. The correlation levels comprise: (1) a basal interval of dropstone-bearing mudstones (PC) related to the Gondwana glaciation of early Upper Carboniferous age, (2) a thin level of laminated mudstones (PL) corresponding to a base level rise associated to the deglaciation stage, (3) coals and carbonaceous kaolinitic mudstones (C) formed during humid climatic conditions in Westphalian times, (4) an unconformity (d) produced by tectonic movements in late Upper Carboniferous, and (5) eolian and ephemeral lacustrine deposits resulting from arid climatic conditions (A) widespread during the Permian in the Paganzo Basin. Finally, a redefinition for the stratigraphical position of the Solca Formation is proposed. © 1999 Asociación Geológica Argentina.
title Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
title_short Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
title_full Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
title_fullStr Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
title_full_unstemmed Paleogeografía y correlación estratigráfica del Paleozoico Tardío de la Sierra de Los Llanos, Provincia de la Rioja, Argentina
title_sort paleogeografía y correlación estratigráfica del paleozoico tardío de la sierra de los llanos, provincia de la rioja, argentina
publishDate 1999
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v54_n3_p229_Net
http://hdl.handle.net/20.500.12110/paper_00044822_v54_n3_p229_Net
_version_ 1768545168060841984

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