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, A., Lescano, M., Caramés, A., Ballent, S.
Formato: JOUR
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: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 todo:paper_00044822_v65_n2_p342_Concheyro
record_format dspace
spelling todo:paper_00044822_v65_n2_p342_Concheyro2023-10-03T13:58:34Z Micropaleontology of the Agrio Formation (Lower Cretaceous) in different areas of the Neuquén Basin Concheyro, A. Lescano, M. Caramés, A. Ballent, S. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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, A.
Lescano, M.
Caramés, A.
Ballent, S.
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.
format JOUR
author Concheyro, A.
Lescano, M.
Caramés, A.
Ballent, S.
author_facet Concheyro, A.
Lescano, M.
Caramés, A.
Ballent, S.
author_sort Concheyro, A.
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
url http://hdl.handle.net/20.500.12110/paper_00044822_v65_n2_p342_Concheyro
work_keys_str_mv AT concheyroa micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin
AT lescanom micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin
AT caramesa micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin
AT ballents micropaleontologyoftheagrioformationlowercretaceousindifferentareasoftheneuquenbasin
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