Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin

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The nanoflora and microfauna from the Agrio Formation are analyzed in three different areas of the Neuquén Basin to establish its age and paleonvironmental variations. In the northern area of the basin, the oldest Agrio Fomation sedimentites are recognized and assigned to the Lower Valanginian throu...

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Autores principales:	Concheyro, Graciela Andrea, Lescano, Marina Aurora, Carames, Andrea Alejandra
Publicado:	2009
Materias:	Argentina Biostratigraphy Mesozoic Microfossils Nannofossils Paleoecology biostratigraphy calcareous alga fauna foraminifera fossil assemblage microfossil micropaleontology paleoecology paleoenvironment Neuquen Basin Epistomina Foraminifera Ostracoda Platycopida
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n2_p342_Concheyro http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p342_Concheyro
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00044822_v65_n2_p342_Concheyro
record_format	dspace
spelling	paper:paper_00044822_v65_n2_p342_Concheyro2025-07-30T17:09:59Z Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin Concheyro, Graciela Andrea Lescano, Marina Aurora Carames, Andrea Alejandra Argentina Biostratigraphy Mesozoic Microfossils Nannofossils Paleoecology biostratigraphy calcareous alga fauna foraminifera fossil assemblage Mesozoic microfossil micropaleontology paleoecology paleoenvironment Argentina Neuquen Basin Epistomina Foraminifera Ostracoda Platycopida The nanoflora and microfauna from the Agrio Formation are analyzed in three different areas of the Neuquén Basin to establish its age and paleonvironmental variations. In the northern area of the basin, the oldest Agrio Fomation sedimentites are recognized and assigned to the Lower Valanginian through ammonites. A monospecific Epistomina loncochensis Ballent microfauna is recovered from these levels, which indicates disoxic environments. Up to the top of the section, siltstones contain a diverse foraminifera microfauna of normal shelves, which are replaced by an impoverished fauna related to shallowing processes. The age defined by calcareous nannofossils is Late Valanginian-Late Hauterivian. In the central and southern position of the Neuquén Basin, the nannofossil assemblages indicate the Upper Valanginian-Upper Hauterivian for the Agrio Formation. The benthic microfauna suggests frequent eustatic variations ranging from shelves to shallow marine environments. In the austral sector of the basin, a poorly diversified foraminiferal assemblage is recorded and a high ostracods/foraminifera ratio indicates a restricted marine environment, and normal salinity. The presence of a level with abundant attached foraminifera indicates high energy episodes. The high diversified Platycopida ostracods suggest warm-temperate to subtropical waters. Fil:Concheyro, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Lescano, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Caramés, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n2_p342_Concheyro http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p342_Concheyro
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Argentina Biostratigraphy Mesozoic Microfossils Nannofossils Paleoecology biostratigraphy calcareous alga fauna foraminifera fossil assemblage Mesozoic microfossil micropaleontology paleoecology paleoenvironment Argentina Neuquen Basin Epistomina Foraminifera Ostracoda Platycopida
spellingShingle	Argentina Biostratigraphy Mesozoic Microfossils Nannofossils Paleoecology biostratigraphy calcareous alga fauna foraminifera fossil assemblage Mesozoic microfossil micropaleontology paleoecology paleoenvironment Argentina Neuquen Basin Epistomina Foraminifera Ostracoda Platycopida Concheyro, Graciela Andrea Lescano, Marina Aurora Carames, Andrea Alejandra Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
topic_facet	Argentina Biostratigraphy Mesozoic Microfossils Nannofossils Paleoecology biostratigraphy calcareous alga fauna foraminifera fossil assemblage Mesozoic microfossil micropaleontology paleoecology paleoenvironment Argentina Neuquen Basin Epistomina Foraminifera Ostracoda Platycopida
description	The nanoflora and microfauna from the Agrio Formation are analyzed in three different areas of the Neuquén Basin to establish its age and paleonvironmental variations. In the northern area of the basin, the oldest Agrio Fomation sedimentites are recognized and assigned to the Lower Valanginian through ammonites. A monospecific Epistomina loncochensis Ballent microfauna is recovered from these levels, which indicates disoxic environments. Up to the top of the section, siltstones contain a diverse foraminifera microfauna of normal shelves, which are replaced by an impoverished fauna related to shallowing processes. The age defined by calcareous nannofossils is Late Valanginian-Late Hauterivian. In the central and southern position of the Neuquén Basin, the nannofossil assemblages indicate the Upper Valanginian-Upper Hauterivian for the Agrio Formation. The benthic microfauna suggests frequent eustatic variations ranging from shelves to shallow marine environments. In the austral sector of the basin, a poorly diversified foraminiferal assemblage is recorded and a high ostracods/foraminifera ratio indicates a restricted marine environment, and normal salinity. The presence of a level with abundant attached foraminifera indicates high energy episodes. The high diversified Platycopida ostracods suggest warm-temperate to subtropical waters.
author	Concheyro, Graciela Andrea Lescano, Marina Aurora Carames, Andrea Alejandra
author_facet	Concheyro, Graciela Andrea Lescano, Marina Aurora Carames, Andrea Alejandra
author_sort	Concheyro, Graciela Andrea
title	Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
title_short	Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
title_full	Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
title_fullStr	Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
title_full_unstemmed	Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin
title_sort	micropaleontology of the agrio formation (lower cretaceous) in different areas of the neuquén basin
publishDate	2009
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n2_p342_Concheyro http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p342_Concheyro
work_keys_str_mv	AT concheyrogracielaandrea micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin AT lescanomarinaaurora micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin AT caramesandreaalejandra micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin
_version_	1840326105729335296

Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin

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