Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina

Chronostratigraphic, paleoenvironmental, and tectonic analysis of a 2320 m thick Neogene continental section was conducted along the southern limit of the Campo de Talampaya. Magnetic polarity stratigraphy and fission track ages were used to develop a relatively precise geochronology. The strata rec...

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Autores principales: Malizia, D.C., Reynolds, J.H., Tabbutt, K.D.
Formato: JOUR
Materias:
Neogene
palaeoenvironment
provenance
sedimentation
stratigraphy
tectonics
Argentina, La Rioja, Campo de Talampaya
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00370738_v96_n3-4_p231_Malizia
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00370738_v96_n3-4_p231_Malizia2023-10-03T14:48:07Z Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina Malizia, D.C. Reynolds, J.H. Tabbutt, K.D. Neogene palaeoenvironment provenance sedimentation stratigraphy tectonics Argentina, La Rioja, Campo de Talampaya Chronostratigraphic, paleoenvironmental, and tectonic analysis of a 2320 m thick Neogene continental section was conducted along the southern limit of the Campo de Talampaya. Magnetic polarity stratigraphy and fission track ages were used to develop a relatively precise geochronology. The strata record a period of mixed evaporitic and terrigenous elastic sedimentation (∼20-6.1 Ma) that persisted in the distal Bermejo Basin during eastward migration of the Precordillera fold-thrust belt. A critical transition of depositional environments and a change from western to eastern source areas occurred between 12.9 and 12.3 Ma. The saline mud-flat environment of the Río Mañero Formation, derived from a western source and characterized by fine-grained sandstones, mudstones, and evaporites, yielded to a short period of playa lake deposition. This was soon overwhelmed by deposition of the Desencuentro Formation, composed of sandstones and mudstones with an eastern source area and deposited in a sand-flat/mud-flat environment. We propose that this stratigraphic transition resulted from initiation of uplift of the Sierra de Velasco, a range of the Sierras Pampeanas, located ∼65 km to the east-northeast of the section. Basement clasts, probably derived from the Sierra de Velasco, are found in conglomeratic lenses beginning in the lower part of the Desencuentro Formation. The modern Campo de Talampaya basin formed after deposition of the top of the Alto de San Nicolás paleomagnetic section (6.1 Ma) when west-verging reverse faults uplifted the Sierra Morada and Sierra de los Tarjados. All strata in the section were tilted eastward during these culminating uplift events. © 1995. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00370738_v96_n3-4_p231_Malizia
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Neogene
palaeoenvironment
provenance
sedimentation
stratigraphy
tectonics
Argentina, La Rioja, Campo de Talampaya
spellingShingle Neogene
palaeoenvironment
provenance
sedimentation
stratigraphy
tectonics
Argentina, La Rioja, Campo de Talampaya
Malizia, D.C.
Reynolds, J.H.
Tabbutt, K.D.
Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
topic_facet Neogene
palaeoenvironment
provenance
sedimentation
stratigraphy
tectonics
Argentina, La Rioja, Campo de Talampaya
description Chronostratigraphic, paleoenvironmental, and tectonic analysis of a 2320 m thick Neogene continental section was conducted along the southern limit of the Campo de Talampaya. Magnetic polarity stratigraphy and fission track ages were used to develop a relatively precise geochronology. The strata record a period of mixed evaporitic and terrigenous elastic sedimentation (∼20-6.1 Ma) that persisted in the distal Bermejo Basin during eastward migration of the Precordillera fold-thrust belt. A critical transition of depositional environments and a change from western to eastern source areas occurred between 12.9 and 12.3 Ma. The saline mud-flat environment of the Río Mañero Formation, derived from a western source and characterized by fine-grained sandstones, mudstones, and evaporites, yielded to a short period of playa lake deposition. This was soon overwhelmed by deposition of the Desencuentro Formation, composed of sandstones and mudstones with an eastern source area and deposited in a sand-flat/mud-flat environment. We propose that this stratigraphic transition resulted from initiation of uplift of the Sierra de Velasco, a range of the Sierras Pampeanas, located ∼65 km to the east-northeast of the section. Basement clasts, probably derived from the Sierra de Velasco, are found in conglomeratic lenses beginning in the lower part of the Desencuentro Formation. The modern Campo de Talampaya basin formed after deposition of the top of the Alto de San Nicolás paleomagnetic section (6.1 Ma) when west-verging reverse faults uplifted the Sierra Morada and Sierra de los Tarjados. All strata in the section were tilted eastward during these culminating uplift events. © 1995.
format JOUR
author Malizia, D.C.
Reynolds, J.H.
Tabbutt, K.D.
author_facet Malizia, D.C.
Reynolds, J.H.
Tabbutt, K.D.
author_sort Malizia, D.C.
title Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
title_short Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
title_full Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
title_fullStr Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
title_full_unstemmed Chronology of Neogene sedimentation, stratigraphy, and tectonism in the Campo de Talampaya region, La Rioja Province, Argentina
title_sort chronology of neogene sedimentation, stratigraphy, and tectonism in the campo de talampaya region, la rioja province, argentina
url http://hdl.handle.net/20.500.12110/paper_00370738_v96_n3-4_p231_Malizia
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AT tabbuttkd chronologyofneogenesedimentationstratigraphyandtectonisminthecampodetalampayaregionlariojaprovinceargentina
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