Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina

A new locality where Carboniferous glacial diamictite appears confined to paleovalleys is described in the north of the Argentinian Precordillera. The glacial deposits of the lower part of the Carboniferous Quebrada Larga Formation are divided in three stratigraphic intervals, all of them confined t...

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Detalles Bibliográficos
Autores principales: Limarino, C.O., Alonso-Muruaga, P.J., Ciccioli, P.L., Perez Loinaze, V.S., Césari, S.N.
Formato: JOUR
Materias:
Argentina
Carboniferous
Glacial
Palynology
Stratigraphy
deglaciation
diamictite
Paleozoic
palynology
quantitative analysis
remediation
sandstone
Serpukhovian
stratigraphy
vegetation
Precordillera
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00310182_v412_n_p223_Limarino
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00310182_v412_n_p223_Limarino
record_format dspace
spelling todo:paper_00310182_v412_n_p223_Limarino2023-10-03T14:40:57Z Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina Limarino, C.O. Alonso-Muruaga, P.J. Ciccioli, P.L. Perez Loinaze, V.S. Césari, S.N. Argentina Carboniferous Glacial Palynology Stratigraphy Carboniferous deglaciation diamictite Paleozoic palynology quantitative analysis remediation sandstone Serpukhovian stratigraphy vegetation Argentina Precordillera A new locality where Carboniferous glacial diamictite appears confined to paleovalleys is described in the north of the Argentinian Precordillera. The glacial deposits of the lower part of the Carboniferous Quebrada Larga Formation are divided in three stratigraphic intervals, all of them confined to a paleovalley carved into the granitic and high-grade metamorphic basement. The lower section is composed of different types of massive and stratified diamictite interpreted to record reworking of previously deposited poorly sorted glacial sediments. The middle section comprises shale with dropstones, lenticular beds of diamictite and large-scale cross-bedded sets of sandstone and conglomerate. These rocks represent a more advanced stage of deglaciation that comprises the following succeeding steps: 1) amelioration of the climatic conditions, melting of glaciers, fluvial erosion, 2) the formation of a water body (onset of the fjord system) and 3) a later progradation of Gilbert-type deltas. Diamictite is missing in the upper section, which is chiefly formed by cross-bedded sandstone and conglomerate deposited in braided fluvial plains. A quantitative analysis of palynological assemblages through the sequence allowed a reconstruction of the dynamics of the vegetation developed during the filling of the paleovalley. The presence of monosaccate pollen grains supports an age not older than Serpukhovian and the recognition of the characteristic species of the Raistrickia densa-Convolutispora muriornata Biozone reinforces a late Serpukhovian-Bashkirian age for the assemblages. © 2014 Elsevier B.V. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00310182_v412_n_p223_Limarino
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
Carboniferous
Glacial
Palynology
Stratigraphy
Carboniferous
deglaciation
diamictite
Paleozoic
palynology
quantitative analysis
remediation
sandstone
Serpukhovian
stratigraphy
vegetation
Argentina
Precordillera
spellingShingle Argentina
Carboniferous
Glacial
Palynology
Stratigraphy
Carboniferous
deglaciation
diamictite
Paleozoic
palynology
quantitative analysis
remediation
sandstone
Serpukhovian
stratigraphy
vegetation
Argentina
Precordillera
Limarino, C.O.
Alonso-Muruaga, P.J.
Ciccioli, P.L.
Perez Loinaze, V.S.
Césari, S.N.
Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
topic_facet Argentina
Carboniferous
Glacial
Palynology
Stratigraphy
Carboniferous
deglaciation
diamictite
Paleozoic
palynology
quantitative analysis
remediation
sandstone
Serpukhovian
stratigraphy
vegetation
Argentina
Precordillera
description A new locality where Carboniferous glacial diamictite appears confined to paleovalleys is described in the north of the Argentinian Precordillera. The glacial deposits of the lower part of the Carboniferous Quebrada Larga Formation are divided in three stratigraphic intervals, all of them confined to a paleovalley carved into the granitic and high-grade metamorphic basement. The lower section is composed of different types of massive and stratified diamictite interpreted to record reworking of previously deposited poorly sorted glacial sediments. The middle section comprises shale with dropstones, lenticular beds of diamictite and large-scale cross-bedded sets of sandstone and conglomerate. These rocks represent a more advanced stage of deglaciation that comprises the following succeeding steps: 1) amelioration of the climatic conditions, melting of glaciers, fluvial erosion, 2) the formation of a water body (onset of the fjord system) and 3) a later progradation of Gilbert-type deltas. Diamictite is missing in the upper section, which is chiefly formed by cross-bedded sandstone and conglomerate deposited in braided fluvial plains. A quantitative analysis of palynological assemblages through the sequence allowed a reconstruction of the dynamics of the vegetation developed during the filling of the paleovalley. The presence of monosaccate pollen grains supports an age not older than Serpukhovian and the recognition of the characteristic species of the Raistrickia densa-Convolutispora muriornata Biozone reinforces a late Serpukhovian-Bashkirian age for the assemblages. © 2014 Elsevier B.V.
format JOUR
author Limarino, C.O.
Alonso-Muruaga, P.J.
Ciccioli, P.L.
Perez Loinaze, V.S.
Césari, S.N.
author_facet Limarino, C.O.
Alonso-Muruaga, P.J.
Ciccioli, P.L.
Perez Loinaze, V.S.
Césari, S.N.
author_sort Limarino, C.O.
title Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
title_short Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
title_full Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
title_fullStr Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
title_full_unstemmed Stratigraphy and palynology of a late Paleozoic glacial paleovalley in the Andean Precordillera, Argentina
title_sort stratigraphy and palynology of a late paleozoic glacial paleovalley in the andean precordillera, argentina
url http://hdl.handle.net/20.500.12110/paper_00310182_v412_n_p223_Limarino
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