Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina

The Ostracoda recovered from sediments of the Cerro de la Gloria and Canal 18 Members of the Las Escobas Formation, at three outcrops (C15, KM1 and KM2) of the northeastern region of Bueonos Aires Province, are analized. Qualitative and quantitative evaluations of the fauna are made in order to obta...

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Autores principales: Bertels, Alwine, Laprida, Cecilia
Publicado: 1998
Materias:
Holocene
micropaleontology
Argentina
Ostracoda
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v35_n2_p151_BertelsPsotka
http://hdl.handle.net/20.500.12110/paper_00027014_v35_n2_p151_BertelsPsotka
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00027014_v35_n2_p151_BertelsPsotka
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spelling paper:paper_00027014_v35_n2_p151_BertelsPsotka2023-06-08T14:22:00Z Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina Bertels, Alwine Laprida, Cecilia Holocene micropaleontology Argentina Ostracoda The Ostracoda recovered from sediments of the Cerro de la Gloria and Canal 18 Members of the Las Escobas Formation, at three outcrops (C15, KM1 and KM2) of the northeastern region of Bueonos Aires Province, are analized. Qualitative and quantitative evaluations of the fauna are made in order to obtain palaeoenvironmental inferences. Section C15 contains marine littoral and sublittoral Ostracoda. Combined analyses of the qualitative information and the quantitative parameters, together with sedimentological evidence, allows the inference of littoral and sublittoral marine palaeoenvironments, particularly in the foreshore and upper shoreface zones successively. Section KM1 contains euryhaline, mesohaline and limnic Ostracoda; the strata represent an environment of very low energy and the final phase of a marsh repletion. Hypoxic levels are registered, probably as a consequence of the accumulation of organic matter which also brought about partially reducing conditions. In the section KM2, both Members - Cerro de la Gloria and Canal 18 - are exposed; it contains Ostracoda whose nature, along the succession, indicates transitional marine environments, partially restricted for the Cerro de la Gloria Member and totally restricted and in part reducing features for the Canal 18 Member. In the case of the deposits of the Cerro de la Gloria Member, a washover sub-environment, associated with a system of barrier islands is proposed; they represent lagoon deposits. The upper section, attributed to the Canal 18 Member of Las Escobas Formation, on the basis of its lithology, colour and structures, in conjunction with the ostracod analysis, indicates that the strata belong to the final filling phase of a lagoon, most probably a marsh; a decrease in the pH values also accounted as evidenced by the scarcity of ostracods, adults and juveniles, caused by the increment of the environmental deterioration and the restricted conditions. Fil:Bertels-Psotka, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Laprida, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1998 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v35_n2_p151_BertelsPsotka http://hdl.handle.net/20.500.12110/paper_00027014_v35_n2_p151_BertelsPsotka
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Holocene
micropaleontology
Argentina
Ostracoda
spellingShingle Holocene
micropaleontology
Argentina
Ostracoda
Bertels, Alwine
Laprida, Cecilia
Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
topic_facet Holocene
micropaleontology
Argentina
Ostracoda
description The Ostracoda recovered from sediments of the Cerro de la Gloria and Canal 18 Members of the Las Escobas Formation, at three outcrops (C15, KM1 and KM2) of the northeastern region of Bueonos Aires Province, are analized. Qualitative and quantitative evaluations of the fauna are made in order to obtain palaeoenvironmental inferences. Section C15 contains marine littoral and sublittoral Ostracoda. Combined analyses of the qualitative information and the quantitative parameters, together with sedimentological evidence, allows the inference of littoral and sublittoral marine palaeoenvironments, particularly in the foreshore and upper shoreface zones successively. Section KM1 contains euryhaline, mesohaline and limnic Ostracoda; the strata represent an environment of very low energy and the final phase of a marsh repletion. Hypoxic levels are registered, probably as a consequence of the accumulation of organic matter which also brought about partially reducing conditions. In the section KM2, both Members - Cerro de la Gloria and Canal 18 - are exposed; it contains Ostracoda whose nature, along the succession, indicates transitional marine environments, partially restricted for the Cerro de la Gloria Member and totally restricted and in part reducing features for the Canal 18 Member. In the case of the deposits of the Cerro de la Gloria Member, a washover sub-environment, associated with a system of barrier islands is proposed; they represent lagoon deposits. The upper section, attributed to the Canal 18 Member of Las Escobas Formation, on the basis of its lithology, colour and structures, in conjunction with the ostracod analysis, indicates that the strata belong to the final filling phase of a lagoon, most probably a marsh; a decrease in the pH values also accounted as evidenced by the scarcity of ostracods, adults and juveniles, caused by the increment of the environmental deterioration and the restricted conditions.
author Bertels, Alwine
Laprida, Cecilia
author_facet Bertels, Alwine
Laprida, Cecilia
author_sort Bertels, Alwine
title Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
title_short Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
title_full Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
title_fullStr Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
title_full_unstemmed Ostracods and Holocene palaeoenvironments of northeastern Buenos Aires Province, Argentina
title_sort ostracods and holocene palaeoenvironments of northeastern buenos aires province, argentina
publishDate 1998
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027014_v35_n2_p151_BertelsPsotka
http://hdl.handle.net/20.500.12110/paper_00027014_v35_n2_p151_BertelsPsotka
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