Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina

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Palynomorphs and conodonts are reported from the Ordovician Los Azules Formation, Argentine Precordillera. The formation is mainly made up of argillites, shales and mudstones, and is divided into three informal members. Fourteen species of acritarchs including Gorgonisphaeridiumm granulobrachium Ott...

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Detalles Bibliográficos
Autores principales: Ottone, E.G., Albanesi, G.L., Ortega, G., Holfeltz, G.D.
Formato: JOUR
Materias:
acritarch
biostratigraphy
graptolite
Ordovician
Argentina
Conodonta
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00262803_v45_n3_p225_Ottone
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00262803_v45_n3_p225_Ottone
record_format dspace
spelling todo:paper_00262803_v45_n3_p225_Ottone2023-10-03T14:37:02Z Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina Ottone, E.G. Albanesi, G.L. Ortega, G. Holfeltz, G.D. acritarch biostratigraphy graptolite Ordovician Argentina Conodonta Palynomorphs and conodonts are reported from the Ordovician Los Azules Formation, Argentine Precordillera. The formation is mainly made up of argillites, shales and mudstones, and is divided into three informal members. Fourteen species of acritarchs including Gorgonisphaeridiumm granulobrachium Ottone, Lophosphaeridium ruidum Ottone, and Polygonium echinatus Ottone that are proposed as new; two species of prasinophytes, one of cryptospores and three different morphotypes of phytodebris are identified throughout the middle and upper members of the formation. Two distinct palynomorph assemblages are recognized: the Lower Los Azules Palynological Assemblage (middle member) and the Upper Los Azules Palynological Assemblage (upper member). Eight species of conodonts are preserved as casts on bedding planes of the lower shales of the middle member. This conodont association is correlated with the upper division of the Eoplacognathus suecicus Zone from the late early Llanvirn. The upper part of the middle member contains the eponymous species of the Pygodus serra Zone of Llanvirn age. A calcirudite sample from the upper member yielded a rich and diverse microfauna that includes ten conodont species representing the lower part of the Amorphognathus tvaerensis Zone (early Caradoc). Conodonts and palynomorphs confirm previous graptolite-based dating of the Los Azules Formation (early Llanvirn-early Caradoc). The palynological assemblage exhibits similarities with coeval assemblages from the Northern Hemisphere and Gondwanaland. Fil:Ottone, E.G. 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_00262803_v45_n3_p225_Ottone
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic acritarch
biostratigraphy
graptolite
Ordovician
Argentina
Conodonta
spellingShingle acritarch
biostratigraphy
graptolite
Ordovician
Argentina
Conodonta
Ottone, E.G.
Albanesi, G.L.
Ortega, G.
Holfeltz, G.D.
Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
topic_facet acritarch
biostratigraphy
graptolite
Ordovician
Argentina
Conodonta
description Palynomorphs and conodonts are reported from the Ordovician Los Azules Formation, Argentine Precordillera. The formation is mainly made up of argillites, shales and mudstones, and is divided into three informal members. Fourteen species of acritarchs including Gorgonisphaeridiumm granulobrachium Ottone, Lophosphaeridium ruidum Ottone, and Polygonium echinatus Ottone that are proposed as new; two species of prasinophytes, one of cryptospores and three different morphotypes of phytodebris are identified throughout the middle and upper members of the formation. Two distinct palynomorph assemblages are recognized: the Lower Los Azules Palynological Assemblage (middle member) and the Upper Los Azules Palynological Assemblage (upper member). Eight species of conodonts are preserved as casts on bedding planes of the lower shales of the middle member. This conodont association is correlated with the upper division of the Eoplacognathus suecicus Zone from the late early Llanvirn. The upper part of the middle member contains the eponymous species of the Pygodus serra Zone of Llanvirn age. A calcirudite sample from the upper member yielded a rich and diverse microfauna that includes ten conodont species representing the lower part of the Amorphognathus tvaerensis Zone (early Caradoc). Conodonts and palynomorphs confirm previous graptolite-based dating of the Los Azules Formation (early Llanvirn-early Caradoc). The palynological assemblage exhibits similarities with coeval assemblages from the Northern Hemisphere and Gondwanaland.
format JOUR
author Ottone, E.G.
Albanesi, G.L.
Ortega, G.
Holfeltz, G.D.
author_facet Ottone, E.G.
Albanesi, G.L.
Ortega, G.
Holfeltz, G.D.
author_sort Ottone, E.G.
title Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
title_short Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
title_full Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
title_fullStr Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
title_full_unstemmed Palynomorphs, conodonts and associated graptolites from the Ordovician Los Azules formation, Central Precordillera, Argentina
title_sort palynomorphs, conodonts and associated graptolites from the ordovician los azules formation, central precordillera, argentina
url http://hdl.handle.net/20.500.12110/paper_00262803_v45_n3_p225_Ottone
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AT albanesigl palynomorphsconodontsandassociatedgraptolitesfromtheordovicianlosazulesformationcentralprecordilleraargentina
AT ortegag palynomorphsconodontsandassociatedgraptolitesfromtheordovicianlosazulesformationcentralprecordilleraargentina
AT holfeltzgd palynomorphsconodontsandassociatedgraptolitesfromtheordovicianlosazulesformationcentralprecordilleraargentina
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