Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality

This study includes a thorough systematic analysis of the ichnological record in the uppermost section of the Agua de la Mula Member of the Agrio Formation (Mendoza Group) in the Neuquén Basin (Argentina). The Bajada del Agrio section represents an environment evolving from marine to marginal-marine...

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Autores principales:	Fernandez, Diana Elizabeth, Pazos, Pablo Jose
Publicado:	2012
Materias:	Agrio formation Argentina Cretaceous Ichnology Marginal marine environment Neuquén basin Salinity facies fossil record ichnology marine ecosystem marine sediment salinity tidal flat Neuquen Basin
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v49_n4_p505_Fernandez http://hdl.handle.net/20.500.12110/paper_00027014_v49_n4_p505_Fernandez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00027014_v49_n4_p505_Fernandez
record_format	dspace
spelling	paper:paper_00027014_v49_n4_p505_Fernandez2023-06-08T14:22:26Z Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality Fernandez, Diana Elizabeth Pazos, Pablo Jose Agrio formation Argentina Cretaceous Ichnology Marginal marine environment Neuquén basin Salinity Cretaceous facies fossil record ichnology marine ecosystem marine sediment salinity tidal flat Argentina Neuquen Basin This study includes a thorough systematic analysis of the ichnological record in the uppermost section of the Agua de la Mula Member of the Agrio Formation (Mendoza Group) in the Neuquén Basin (Argentina). The Bajada del Agrio section represents an environment evolving from marine to marginal-marine. Five main facies were defined: (1) an oolitic-skeletal bar; (2) transgressive pelites and coquinas (biodastic conglomerates); (3) progradational coarsening-upward sandstones; (4) heterolithic deposits; and (5) heterolithic and carbonatic deposits. Fluctuating salinity and/or hypersalinity is inferred in the open tidal-flat deposits (facies 4). Sixteen ichnotaxa were identified and three types of trace fossils were described using open nomenclature because of the poor preservation of the material. Three ichnoassemblages are described. The section yielded trace fossils of callianasid decapods, palaeotaxodont bivalves, annelids and small tetrapods. Paleoenvironmental information drawn from trace fossils is coincident with sedimentologic evidence. It also highlights the current lack of accurate ichnological models for marginal marine hypersaline or fluctuating-saline environments, and suggests that sharp salinity changes in the environment not necessarily implie a decrease in ichnodiversity. Fil:Fernández, D.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Pazos, P.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v49_n4_p505_Fernandez http://hdl.handle.net/20.500.12110/paper_00027014_v49_n4_p505_Fernandez
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Agrio formation Argentina Cretaceous Ichnology Marginal marine environment Neuquén basin Salinity Cretaceous facies fossil record ichnology marine ecosystem marine sediment salinity tidal flat Argentina Neuquen Basin
spellingShingle	Agrio formation Argentina Cretaceous Ichnology Marginal marine environment Neuquén basin Salinity Cretaceous facies fossil record ichnology marine ecosystem marine sediment salinity tidal flat Argentina Neuquen Basin Fernandez, Diana Elizabeth Pazos, Pablo Jose Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
topic_facet	Agrio formation Argentina Cretaceous Ichnology Marginal marine environment Neuquén basin Salinity Cretaceous facies fossil record ichnology marine ecosystem marine sediment salinity tidal flat Argentina Neuquen Basin
description	This study includes a thorough systematic analysis of the ichnological record in the uppermost section of the Agua de la Mula Member of the Agrio Formation (Mendoza Group) in the Neuquén Basin (Argentina). The Bajada del Agrio section represents an environment evolving from marine to marginal-marine. Five main facies were defined: (1) an oolitic-skeletal bar; (2) transgressive pelites and coquinas (biodastic conglomerates); (3) progradational coarsening-upward sandstones; (4) heterolithic deposits; and (5) heterolithic and carbonatic deposits. Fluctuating salinity and/or hypersalinity is inferred in the open tidal-flat deposits (facies 4). Sixteen ichnotaxa were identified and three types of trace fossils were described using open nomenclature because of the poor preservation of the material. Three ichnoassemblages are described. The section yielded trace fossils of callianasid decapods, palaeotaxodont bivalves, annelids and small tetrapods. Paleoenvironmental information drawn from trace fossils is coincident with sedimentologic evidence. It also highlights the current lack of accurate ichnological models for marginal marine hypersaline or fluctuating-saline environments, and suggests that sharp salinity changes in the environment not necessarily implie a decrease in ichnodiversity.
author	Fernandez, Diana Elizabeth Pazos, Pablo Jose
author_facet	Fernandez, Diana Elizabeth Pazos, Pablo Jose
author_sort	Fernandez, Diana Elizabeth
title	Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
title_short	Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
title_full	Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
title_fullStr	Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
title_full_unstemmed	Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality
title_sort	ichnology of marginal marine facies of the agrio formation (lower cretaceous, neuquén basin, argentina) at its type locality
publishDate	2012
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v49_n4_p505_Fernandez http://hdl.handle.net/20.500.12110/paper_00027014_v49_n4_p505_Fernandez
work_keys_str_mv	AT fernandezdianaelizabeth ichnologyofmarginalmarinefaciesoftheagrioformationlowercretaceousneuquenbasinargentinaatitstypelocality AT pazospablojose ichnologyofmarginalmarinefaciesoftheagrioformationlowercretaceousneuquenbasinargentinaatitstypelocality
_version_	1768544845901594624

Ichnology of marginal marine facies of the Agrio Formation (lower cretaceous, Neuquén basin, Argentina) at its type locality

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