Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina

ABSTRACT The northern area of Cuyo Basin (west-central Argentina) corresponds to the Rincón Blanco half-graben, whose filling is arranged into the Rincón Blanco and Sorocayense groups. In the present study, we propose a new stratigraphic scheme for the Sorocayense Group in the Barreal depocenter (Sa...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Bodnar,Josefina, Iglesias,Ari, Colombi,Carina E., Drovandi,Juan Martín
Lenguaje:	English
Publicado:	Servicio Nacional de Geología y Minería (SERNAGEOMIN) 2019
Materias:	Triassic Cuyo Basin Southwest Gondwana Barreal-Calingasta depocenter Palaeofloras
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062019000300567
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0718-71062019000300567
record_format	dspace
spelling	oai:scielo:S0718-710620190003005672019-10-21Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, ArgentinaBodnar,JosefinaIglesias,AriColombi,Carina E.Drovandi,Juan Martín Triassic Cuyo Basin Southwest Gondwana Barreal-Calingasta depocenter Palaeofloras ABSTRACT The northern area of Cuyo Basin (west-central Argentina) corresponds to the Rincón Blanco half-graben, whose filling is arranged into the Rincón Blanco and Sorocayense groups. In the present study, we propose a new stratigraphic scheme for the Sorocayense Group in the Barreal depocenter (San Juan Province), revise the palaeoenvironmental interpretations, and organize and analyse the plant assemblages of previous and new fossiliferous levels. We defined three tectosedimentary sequences. The basal sequence represents the initial graben filling with pyroclastic flows, alluvial fan, and ephemeral fluvial systems, and is arranged in a new unit, the Cerro Colorado del Cementerio Formation. The middle sequence, including Barreal and Cortaderita formations, is characterized by sediment gravity flow deposits and different fluvial systems, with development of floodplains with vertisols and calcisols, and temporal ponds/lakes. In turn, the Cortaderita Formation was divided into the following lithostratigraphic members: Don Raúl and La Emilia. The upper sequence, represented by Cepeda Formation, was deposited by distributary fluvial and ephemeral fluvial systems. Twelve fossiliferous strata (EF) were recognized, which were all identified in the middle sequence: EF1 to EF3 in the Barreal Formation, EF4 to EF8 in the Don Raúl Member, and EF9 to EF12 in the La Emilia Member, both of Cortaderita Formation. The taphocoenosis found in the Barreal and Cortaderita formations were dominated by corystosperms, with conifers, cycadales, and peltasperms as subordinate forms. The available evidence from the taphofloras, palaeosols and palaeonvironments indicate the development of seasonal subtropical climates, which vary from arid or semi-arid in the basal sequence, sub-humid to semi-arid in the middle sequence, and arid or semi-arid in the upper sequence. On the basis of the new information, geological correlation and age of the lithostratigraphic units were accurately re-evaluated. Based on the palaeofloristic content and the correlation with the Rincón Blanco Group, it is possible to infer that the basal sequence was accumulated during late Early Triassic-early Middle Triassic, the middle sequence during the Middle Triassic, while the upper sequence was deposited in the early Late Triassic.info:eu-repo/semantics/openAccessServicio Nacional de Geología y Minería (SERNAGEOMIN)Andean geology v.46 n.3 20192019-09-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062019000300567en10.5027/andgeov46n3-3127
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Triassic Cuyo Basin Southwest Gondwana Barreal-Calingasta depocenter Palaeofloras
spellingShingle	Triassic Cuyo Basin Southwest Gondwana Barreal-Calingasta depocenter Palaeofloras Bodnar,Josefina Iglesias,Ari Colombi,Carina E. Drovandi,Juan Martín Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
description	ABSTRACT The northern area of Cuyo Basin (west-central Argentina) corresponds to the Rincón Blanco half-graben, whose filling is arranged into the Rincón Blanco and Sorocayense groups. In the present study, we propose a new stratigraphic scheme for the Sorocayense Group in the Barreal depocenter (San Juan Province), revise the palaeoenvironmental interpretations, and organize and analyse the plant assemblages of previous and new fossiliferous levels. We defined three tectosedimentary sequences. The basal sequence represents the initial graben filling with pyroclastic flows, alluvial fan, and ephemeral fluvial systems, and is arranged in a new unit, the Cerro Colorado del Cementerio Formation. The middle sequence, including Barreal and Cortaderita formations, is characterized by sediment gravity flow deposits and different fluvial systems, with development of floodplains with vertisols and calcisols, and temporal ponds/lakes. In turn, the Cortaderita Formation was divided into the following lithostratigraphic members: Don Raúl and La Emilia. The upper sequence, represented by Cepeda Formation, was deposited by distributary fluvial and ephemeral fluvial systems. Twelve fossiliferous strata (EF) were recognized, which were all identified in the middle sequence: EF1 to EF3 in the Barreal Formation, EF4 to EF8 in the Don Raúl Member, and EF9 to EF12 in the La Emilia Member, both of Cortaderita Formation. The taphocoenosis found in the Barreal and Cortaderita formations were dominated by corystosperms, with conifers, cycadales, and peltasperms as subordinate forms. The available evidence from the taphofloras, palaeosols and palaeonvironments indicate the development of seasonal subtropical climates, which vary from arid or semi-arid in the basal sequence, sub-humid to semi-arid in the middle sequence, and arid or semi-arid in the upper sequence. On the basis of the new information, geological correlation and age of the lithostratigraphic units were accurately re-evaluated. Based on the palaeofloristic content and the correlation with the Rincón Blanco Group, it is possible to infer that the basal sequence was accumulated during late Early Triassic-early Middle Triassic, the middle sequence during the Middle Triassic, while the upper sequence was deposited in the early Late Triassic.
author	Bodnar,Josefina Iglesias,Ari Colombi,Carina E. Drovandi,Juan Martín
author_facet	Bodnar,Josefina Iglesias,Ari Colombi,Carina E. Drovandi,Juan Martín
author_sort	Bodnar,Josefina
title	Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
title_short	Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
title_full	Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
title_fullStr	Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
title_full_unstemmed	Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina
title_sort	stratigraphical, sedimentological and palaeofloristic characterization of the sorocayense group (triassic) in barreal depocenter, san juan province, argentina
publisher	Servicio Nacional de Geología y Minería (SERNAGEOMIN)
publishDate	2019
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062019000300567
work_keys_str_mv	AT bodnarjosefina stratigraphicalsedimentologicalandpalaeofloristiccharacterizationofthesorocayensegrouptriassicinbarrealdepocentersanjuanprovinceargentina AT iglesiasari stratigraphicalsedimentologicalandpalaeofloristiccharacterizationofthesorocayensegrouptriassicinbarrealdepocentersanjuanprovinceargentina AT colombicarinae stratigraphicalsedimentologicalandpalaeofloristiccharacterizationofthesorocayensegrouptriassicinbarrealdepocentersanjuanprovinceargentina AT drovandijuanmartin stratigraphicalsedimentologicalandpalaeofloristiccharacterizationofthesorocayensegrouptriassicinbarrealdepocentersanjuanprovinceargentina
_version_	1714205864145977344

Stratigraphical, sedimentological and palaeofloristic characterization of the Sorocayense Group (Triassic) in Barreal depocenter, San Juan Province, Argentina

Ejemplares similares