Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina

Upper Maastrichtian to lower Paleocene, coarse-grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynologica...

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Autores principales: Cúneo, Nestor Rubén, Scasso, Roberto Adrian
Publicado: 2017
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310239_v60_n4_p519_Vellekoop
http://hdl.handle.net/20.500.12110/paper_00310239_v60_n4_p519_Vellekoop
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spelling paper:paper_00310239_v60_n4_p519_Vellekoop2023-06-08T14:56:53Z Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina Cúneo, Nestor Rubén Scasso, Roberto Adrian Argentina climate Cretaceous dinocysts Palaeogene sea level biostratigraphy Cretaceous-Paleogene boundary depositional environment dinoflagellate cyst fossil assemblage paleoceanography paleoclimate palynomorph sea level change shallow water stratigraphic correlation transgression Argentina Chubut Patagonia Dinophyceae Upper Maastrichtian to lower Paleocene, coarse-grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynological and organic geochemical analyses were performed on the K–Pg boundary interval of the Lefipán Formation at the San Ramón section. The palynological and organic geochemical records from the San Ramón K–Pg boundary section are characteristic of a highly dynamic, nearshore setting. High abundances of terrestrial palynomorphs, high BIT-index values and the occasional presence of plant fossils are indicative of a large input of terrestrial organic material. The organic-walled dinoflagellate cyst (dinocyst) assemblage is generally dominated by Senegalinium and other peridinioid dinocyst taxa, indicative of high-nutrient conditions and decreased salinities, probably associated with a large fluvial input. The reconstructed sea surface temperatures range from 25°C to 27°C, in accordance with the tropical climate inferred by palynological and megafloral studies. As in the Bajada del Jagüel section, ~500 km north-north-east of San Ramón, peaks of Senegalinium spp. were recorded below and above the K–Pg boundary, possibly related to enhanced runoff resulting from more humid climatic conditions. The lithological, palynological and organic geochemical records suggest the occurrence of a sea-level regression across the K–Pg boundary, resulting in a hiatus directly at the boundary in both sections, followed by a transgression in the Danian. © The Palaeontological Association Fil:Cúneo, N.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Scasso, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310239_v60_n4_p519_Vellekoop http://hdl.handle.net/20.500.12110/paper_00310239_v60_n4_p519_Vellekoop
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
climate
Cretaceous
dinocysts
Palaeogene
sea level
biostratigraphy
Cretaceous-Paleogene boundary
depositional environment
dinoflagellate cyst
fossil assemblage
paleoceanography
paleoclimate
palynomorph
sea level change
shallow water
stratigraphic correlation
transgression
Argentina
Chubut
Patagonia
Dinophyceae
spellingShingle Argentina
climate
Cretaceous
dinocysts
Palaeogene
sea level
biostratigraphy
Cretaceous-Paleogene boundary
depositional environment
dinoflagellate cyst
fossil assemblage
paleoceanography
paleoclimate
palynomorph
sea level change
shallow water
stratigraphic correlation
transgression
Argentina
Chubut
Patagonia
Dinophyceae
Cúneo, Nestor Rubén
Scasso, Roberto Adrian
Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
topic_facet Argentina
climate
Cretaceous
dinocysts
Palaeogene
sea level
biostratigraphy
Cretaceous-Paleogene boundary
depositional environment
dinoflagellate cyst
fossil assemblage
paleoceanography
paleoclimate
palynomorph
sea level change
shallow water
stratigraphic correlation
transgression
Argentina
Chubut
Patagonia
Dinophyceae
description Upper Maastrichtian to lower Paleocene, coarse-grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynological and organic geochemical analyses were performed on the K–Pg boundary interval of the Lefipán Formation at the San Ramón section. The palynological and organic geochemical records from the San Ramón K–Pg boundary section are characteristic of a highly dynamic, nearshore setting. High abundances of terrestrial palynomorphs, high BIT-index values and the occasional presence of plant fossils are indicative of a large input of terrestrial organic material. The organic-walled dinoflagellate cyst (dinocyst) assemblage is generally dominated by Senegalinium and other peridinioid dinocyst taxa, indicative of high-nutrient conditions and decreased salinities, probably associated with a large fluvial input. The reconstructed sea surface temperatures range from 25°C to 27°C, in accordance with the tropical climate inferred by palynological and megafloral studies. As in the Bajada del Jagüel section, ~500 km north-north-east of San Ramón, peaks of Senegalinium spp. were recorded below and above the K–Pg boundary, possibly related to enhanced runoff resulting from more humid climatic conditions. The lithological, palynological and organic geochemical records suggest the occurrence of a sea-level regression across the K–Pg boundary, resulting in a hiatus directly at the boundary in both sections, followed by a transgression in the Danian. © The Palaeontological Association
author Cúneo, Nestor Rubén
Scasso, Roberto Adrian
author_facet Cúneo, Nestor Rubén
Scasso, Roberto Adrian
author_sort Cúneo, Nestor Rubén
title Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
title_short Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
title_full Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
title_fullStr Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
title_full_unstemmed Climate and sea-level changes across a shallow marine Cretaceous–Palaeogene boundary succession in Patagonia, Argentina
title_sort climate and sea-level changes across a shallow marine cretaceous–palaeogene boundary succession in patagonia, argentina
publishDate 2017
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310239_v60_n4_p519_Vellekoop
http://hdl.handle.net/20.500.12110/paper_00310239_v60_n4_p519_Vellekoop
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