Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)

The Triassic Ischigualasto-Villa Unión Basin is an extensional basin located in central-western Argentina. It includes the Los Rastros Formation, a lacustrine-deltaic sequence comprising several coarsening-upward cycles of black shale, siltstone, and sandstone. We performed a taphonomic analysis of...

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Autores principales: Mancuso, Adriana Cecilia, Marsicano, Claudia Alicia
Publicado: 2008
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08831351_v23_n8_p535_Mancuso
http://hdl.handle.net/20.500.12110/paper_08831351_v23_n8_p535_Mancuso
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spelling paper:paper_08831351_v23_n8_p535_Mancuso2023-06-08T15:46:28Z Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina) Mancuso, Adriana Cecilia Marsicano, Claudia Alicia black shale deltaic deposit facies analysis fossil assemblage lacustrine environment paleoenvironment sandstone siltstone taphonomy trackway Triassic Argentia Canada Newfoundland Newfoundland and Labrador North America Amphibia Blattaria Coleoptera Conchostraca Coniferophyta Cycadophyta Dinosauria Equisetophyta Ginkgophyta Hemiptera Hexapoda Invertebrata Pteridophyta Therapsida Vertebrata The Triassic Ischigualasto-Villa Unión Basin is an extensional basin located in central-western Argentina. It includes the Los Rastros Formation, a lacustrine-deltaic sequence comprising several coarsening-upward cycles of black shale, siltstone, and sandstone. We performed a taphonomic analysis of the floral and faunal fossils of the Los Rastros succession and have defined five plant taphofacies, four invertebrate taphofacies, and four vertebrate taphofacies. Our taphonomic model characterizes four subenviroments within the lacustrine-deltaic environment of Los Rastros Formation. These include 1) offshore lacustrine, 2) prodelta, 3) deltaic mouth bar, and 4) deltaic plain subenvironment. Our analysis of fossil assemblages allows us to reconstruct the structure of the original ecosystem. The lake margins were vegetated with small ginkgophytes, corystosperms, and sphenophytes. River margins were characterized by riparian thickets of sphenophytes, while the proximal floodplains supported closed woodlands of corystosperms, cycadophytes, and pteridophytes. More distal floodplains were covered with open conifer forests. The invertebrate fauna included insects (Blattoptera, Hemiptera, Coleoptera) associated with lakeshore vegetation and conchostracans that inhabited both the lake shoreline and smaller ponds in the floodplains. Fish and temnospondyl amphibians probably inhabited the delta plain and incoming fluvial systems. The activity of nonmammalian therapsids, crurotarsal archosaurs, and putative dinosaurs is recorded by trackway surfaces in the lake shoreline subenvironment. Copyright © 2008, SEPM (Society for Sedimentary Geology). Fil:Mancuso, A.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Marsicano, C.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08831351_v23_n8_p535_Mancuso http://hdl.handle.net/20.500.12110/paper_08831351_v23_n8_p535_Mancuso
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic black shale
deltaic deposit
facies analysis
fossil assemblage
lacustrine environment
paleoenvironment
sandstone
siltstone
taphonomy
trackway
Triassic
Argentia
Canada
Newfoundland
Newfoundland and Labrador
North America
Amphibia
Blattaria
Coleoptera
Conchostraca
Coniferophyta
Cycadophyta
Dinosauria
Equisetophyta
Ginkgophyta
Hemiptera
Hexapoda
Invertebrata
Pteridophyta
Therapsida
Vertebrata
spellingShingle black shale
deltaic deposit
facies analysis
fossil assemblage
lacustrine environment
paleoenvironment
sandstone
siltstone
taphonomy
trackway
Triassic
Argentia
Canada
Newfoundland
Newfoundland and Labrador
North America
Amphibia
Blattaria
Coleoptera
Conchostraca
Coniferophyta
Cycadophyta
Dinosauria
Equisetophyta
Ginkgophyta
Hemiptera
Hexapoda
Invertebrata
Pteridophyta
Therapsida
Vertebrata
Mancuso, Adriana Cecilia
Marsicano, Claudia Alicia
Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
topic_facet black shale
deltaic deposit
facies analysis
fossil assemblage
lacustrine environment
paleoenvironment
sandstone
siltstone
taphonomy
trackway
Triassic
Argentia
Canada
Newfoundland
Newfoundland and Labrador
North America
Amphibia
Blattaria
Coleoptera
Conchostraca
Coniferophyta
Cycadophyta
Dinosauria
Equisetophyta
Ginkgophyta
Hemiptera
Hexapoda
Invertebrata
Pteridophyta
Therapsida
Vertebrata
description The Triassic Ischigualasto-Villa Unión Basin is an extensional basin located in central-western Argentina. It includes the Los Rastros Formation, a lacustrine-deltaic sequence comprising several coarsening-upward cycles of black shale, siltstone, and sandstone. We performed a taphonomic analysis of the floral and faunal fossils of the Los Rastros succession and have defined five plant taphofacies, four invertebrate taphofacies, and four vertebrate taphofacies. Our taphonomic model characterizes four subenviroments within the lacustrine-deltaic environment of Los Rastros Formation. These include 1) offshore lacustrine, 2) prodelta, 3) deltaic mouth bar, and 4) deltaic plain subenvironment. Our analysis of fossil assemblages allows us to reconstruct the structure of the original ecosystem. The lake margins were vegetated with small ginkgophytes, corystosperms, and sphenophytes. River margins were characterized by riparian thickets of sphenophytes, while the proximal floodplains supported closed woodlands of corystosperms, cycadophytes, and pteridophytes. More distal floodplains were covered with open conifer forests. The invertebrate fauna included insects (Blattoptera, Hemiptera, Coleoptera) associated with lakeshore vegetation and conchostracans that inhabited both the lake shoreline and smaller ponds in the floodplains. Fish and temnospondyl amphibians probably inhabited the delta plain and incoming fluvial systems. The activity of nonmammalian therapsids, crurotarsal archosaurs, and putative dinosaurs is recorded by trackway surfaces in the lake shoreline subenvironment. Copyright © 2008, SEPM (Society for Sedimentary Geology).
author Mancuso, Adriana Cecilia
Marsicano, Claudia Alicia
author_facet Mancuso, Adriana Cecilia
Marsicano, Claudia Alicia
author_sort Mancuso, Adriana Cecilia
title Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
title_short Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
title_full Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
title_fullStr Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
title_full_unstemmed Paleoenvironments and taphonomy of a Triassic lacustrine system (Los Rastros Formation, central-western Argentina)
title_sort paleoenvironments and taphonomy of a triassic lacustrine system (los rastros formation, central-western argentina)
publishDate 2008
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08831351_v23_n8_p535_Mancuso
http://hdl.handle.net/20.500.12110/paper_08831351_v23_n8_p535_Mancuso
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AT marsicanoclaudiaalicia paleoenvironmentsandtaphonomyofatriassiclacustrinesystemlosrastrosformationcentralwesternargentina
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