The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils
The stratigraphy of Cretaceous marine mudstones in the Fuegian Andes, roughly equivalent to Charles Darwin's clay-slate formation, remains a still unsolved problem. Previous records of Albian, Turonian-Coniacian, and Santonian-Campanian bivalves are combined with new findings of the Late Albian...
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v64_n1_p60_Olivero http://hdl.handle.net/20.500.12110/paper_00044822_v64_n1_p60_Olivero |
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paper:paper_00044822_v64_n1_p60_Olivero2023-06-08T14:26:13Z The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils Olivero, Eduardo B. Medina, Francisco Alberto Ammonites Clay-slate formation Cretaceous Fuegian andes Inoceramid Trace fossils ammonite biostratigraphy bivalve Cretaceous mudstone new record trace fossil Andes South America Anagaudryceras Bivalvia Coniacian Diplomoceras Inoceramidae Inoceramus Nereites Pachydiscus Zoophycos The stratigraphy of Cretaceous marine mudstones in the Fuegian Andes, roughly equivalent to Charles Darwin's clay-slate formation, remains a still unsolved problem. Previous records of Albian, Turonian-Coniacian, and Santonian-Campanian bivalves are combined with new findings of the Late Albian inoceramid Inoceramus anglicus Woods, and the Maastrichtian ammonites Diplomoceras sp., Anagaudryceras sp., Maorites densicostatus (Kilian and Reboul), Maorites sp., and Pachydiscus (Neodesmoceras) sp. to further constrain the Cretaceous stratigraphy of the eastern Fuegian Andes. In addition, new records of distinctive trace fossils and ichnofabric are meaningful for stratigraphic division and delineation of paleoenvironmental settings in these Cretaceous mudstones. The Lower Cretaceous ichnoassemblage of Chondrites targioni (Brongniart) and Zoophycos isp. is consistent with the inferred slope-volcaniclastic apron settings of the Yahgan Formation; Nereites missouriensis (Weller) reflects distal basin plain depositional settings for the Beauvoir Formation. In the Upper Cretaceous, the "Estratos de Buen Suceso" record the earliest extensively bioturbated horizons, reflecting prolonged well-oxygenated bottom conditions. In the Bahía Thetis Formation, organic-rich, channel margin or distal basin slaty mudstones record the last occurrence of inoceramid bivalves in the Austral Basin; the generalized absence of trace fossils is consistent with dysoxic bottom conditions. The thoroughly bioturbated Policarpo Formation, records a marked change in paleoceanographic conditions. The strong contrast in the intensity of bioturbation between the Upper Campanian-Maastrichtian Bahía Thetis Formation, almost devoid of trace fossils, and the highly bioturbated Maastrichtian-Danian Policarpo Formation reflects a change from dysoxic-anoxic to well ventilated conditions, probably associated with a cooling trend of bottom waters in the austral deep oceans. Fil:Olivero, E.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Medina, F.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v64_n1_p60_Olivero http://hdl.handle.net/20.500.12110/paper_00044822_v64_n1_p60_Olivero |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Ammonites Clay-slate formation Cretaceous Fuegian andes Inoceramid Trace fossils ammonite biostratigraphy bivalve Cretaceous mudstone new record trace fossil Andes South America Anagaudryceras Bivalvia Coniacian Diplomoceras Inoceramidae Inoceramus Nereites Pachydiscus Zoophycos |
spellingShingle |
Ammonites Clay-slate formation Cretaceous Fuegian andes Inoceramid Trace fossils ammonite biostratigraphy bivalve Cretaceous mudstone new record trace fossil Andes South America Anagaudryceras Bivalvia Coniacian Diplomoceras Inoceramidae Inoceramus Nereites Pachydiscus Zoophycos Olivero, Eduardo B. Medina, Francisco Alberto The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
topic_facet |
Ammonites Clay-slate formation Cretaceous Fuegian andes Inoceramid Trace fossils ammonite biostratigraphy bivalve Cretaceous mudstone new record trace fossil Andes South America Anagaudryceras Bivalvia Coniacian Diplomoceras Inoceramidae Inoceramus Nereites Pachydiscus Zoophycos |
description |
The stratigraphy of Cretaceous marine mudstones in the Fuegian Andes, roughly equivalent to Charles Darwin's clay-slate formation, remains a still unsolved problem. Previous records of Albian, Turonian-Coniacian, and Santonian-Campanian bivalves are combined with new findings of the Late Albian inoceramid Inoceramus anglicus Woods, and the Maastrichtian ammonites Diplomoceras sp., Anagaudryceras sp., Maorites densicostatus (Kilian and Reboul), Maorites sp., and Pachydiscus (Neodesmoceras) sp. to further constrain the Cretaceous stratigraphy of the eastern Fuegian Andes. In addition, new records of distinctive trace fossils and ichnofabric are meaningful for stratigraphic division and delineation of paleoenvironmental settings in these Cretaceous mudstones. The Lower Cretaceous ichnoassemblage of Chondrites targioni (Brongniart) and Zoophycos isp. is consistent with the inferred slope-volcaniclastic apron settings of the Yahgan Formation; Nereites missouriensis (Weller) reflects distal basin plain depositional settings for the Beauvoir Formation. In the Upper Cretaceous, the "Estratos de Buen Suceso" record the earliest extensively bioturbated horizons, reflecting prolonged well-oxygenated bottom conditions. In the Bahía Thetis Formation, organic-rich, channel margin or distal basin slaty mudstones record the last occurrence of inoceramid bivalves in the Austral Basin; the generalized absence of trace fossils is consistent with dysoxic bottom conditions. The thoroughly bioturbated Policarpo Formation, records a marked change in paleoceanographic conditions. The strong contrast in the intensity of bioturbation between the Upper Campanian-Maastrichtian Bahía Thetis Formation, almost devoid of trace fossils, and the highly bioturbated Maastrichtian-Danian Policarpo Formation reflects a change from dysoxic-anoxic to well ventilated conditions, probably associated with a cooling trend of bottom waters in the austral deep oceans. |
author |
Olivero, Eduardo B. Medina, Francisco Alberto |
author_facet |
Olivero, Eduardo B. Medina, Francisco Alberto |
author_sort |
Olivero, Eduardo B. |
title |
The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
title_short |
The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
title_full |
The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
title_fullStr |
The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
title_full_unstemmed |
The stratigraphy of Cretaceous mudstones in the eastern Fuegian Andes: New data from body and trace fossils |
title_sort |
stratigraphy of cretaceous mudstones in the eastern fuegian andes: new data from body and trace fossils |
publishDate |
2009 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v64_n1_p60_Olivero http://hdl.handle.net/20.500.12110/paper_00044822_v64_n1_p60_Olivero |
work_keys_str_mv |
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