Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil
Texto completo: acesso restrito. p. 199–213 A new Re–Os radiometric age date for an organic-rich shale horizon from the Vazante Group in Brazil, coupled with geological observations, provide evidence for late Mesoproterozoic glacial episodes, conflicting with the general view of greenhouse condition...
Published in: | Precambrian Research |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2014
|
Subjects: | |
Online Access: | http://repositorio.ufba.br/ri/handle/ri/15873 |
id |
ftunivfbahia:oai:repositorio.ufba.br:ri/15873 |
---|---|
record_format |
openpolar |
spelling |
ftunivfbahia:oai:repositorio.ufba.br:ri/15873 2023-05-15T15:05:56+02:00 Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil Precambrian Research Geboy, Nicholas J. Kaufman, Alan J. Walker, Richard J. Misi, Aroldo Oliviera, Tolentino Flavio de Miller, Kristen E. Azmy, Karem Kendall, Brian Poulton, Simon W. 2014-09-09T14:36:04Z http://repositorio.ufba.br/ri/handle/ri/15873 en eng 0301-9268 http://repositorio.ufba.br/ri/handle/ri/15873 v. 238 Acesso Aberto http://dx.doi.org/10.1016/j.precamres.2013.10.010 Vazante Group Mesoproterozoic glaciation Re–Os geochronology Fe-speciation Artigo de Periódico 2014 ftunivfbahia https://doi.org/10.1016/j.precamres.2013.10.010 2023-02-01T16:10:13Z Texto completo: acesso restrito. p. 199–213 A new Re–Os radiometric age date for an organic-rich shale horizon from the Vazante Group in Brazil, coupled with geological observations, provide evidence for late Mesoproterozoic glacial episodes, conflicting with the general view of greenhouse conditions marked by a eustatic high stand at this time. Field observations of a reverse fault juxtaposing older Mesoproterozoic sedimentary rocks above younger Neoproterozoic strata provide a new stratigraphic framework and reconcile the apparent inversion of U–Pb detrital zircon ages through the succession. Combined, the geochronological, geochemical and stratigraphic evidence suggest that the Vazante Group sediments accumulated along a passive margin of the São Francisco craton and are correlative with the neighboring Paranoá Group. Biomarker, sulfur isotope and iron speciation analyses support the interpretation of a strongly stratified water column during post-glacial transgression and deposition of one of the bituminous shale horizons. The relationship of the glaciogenic Vazante Group to other late Mesoproterozoic successions, such as the non-glacial Atar Group in West Africa and Bylot Supergroup in arctic Canada, however, remains enigmatic. Article in Journal/Newspaper Arctic Universidade Federal da Bahia: Repositório Institucional da UFBA Arctic Canada Precambrian Research 238 199 213 |
institution |
Open Polar |
collection |
Universidade Federal da Bahia: Repositório Institucional da UFBA |
op_collection_id |
ftunivfbahia |
language |
English |
topic |
Vazante Group Mesoproterozoic glaciation Re–Os geochronology Fe-speciation |
spellingShingle |
Vazante Group Mesoproterozoic glaciation Re–Os geochronology Fe-speciation Geboy, Nicholas J. Kaufman, Alan J. Walker, Richard J. Misi, Aroldo Oliviera, Tolentino Flavio de Miller, Kristen E. Azmy, Karem Kendall, Brian Poulton, Simon W. Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
topic_facet |
Vazante Group Mesoproterozoic glaciation Re–Os geochronology Fe-speciation |
description |
Texto completo: acesso restrito. p. 199–213 A new Re–Os radiometric age date for an organic-rich shale horizon from the Vazante Group in Brazil, coupled with geological observations, provide evidence for late Mesoproterozoic glacial episodes, conflicting with the general view of greenhouse conditions marked by a eustatic high stand at this time. Field observations of a reverse fault juxtaposing older Mesoproterozoic sedimentary rocks above younger Neoproterozoic strata provide a new stratigraphic framework and reconcile the apparent inversion of U–Pb detrital zircon ages through the succession. Combined, the geochronological, geochemical and stratigraphic evidence suggest that the Vazante Group sediments accumulated along a passive margin of the São Francisco craton and are correlative with the neighboring Paranoá Group. Biomarker, sulfur isotope and iron speciation analyses support the interpretation of a strongly stratified water column during post-glacial transgression and deposition of one of the bituminous shale horizons. The relationship of the glaciogenic Vazante Group to other late Mesoproterozoic successions, such as the non-glacial Atar Group in West Africa and Bylot Supergroup in arctic Canada, however, remains enigmatic. |
format |
Article in Journal/Newspaper |
author |
Geboy, Nicholas J. Kaufman, Alan J. Walker, Richard J. Misi, Aroldo Oliviera, Tolentino Flavio de Miller, Kristen E. Azmy, Karem Kendall, Brian Poulton, Simon W. |
author_facet |
Geboy, Nicholas J. Kaufman, Alan J. Walker, Richard J. Misi, Aroldo Oliviera, Tolentino Flavio de Miller, Kristen E. Azmy, Karem Kendall, Brian Poulton, Simon W. |
author_sort |
Geboy, Nicholas J. |
title |
Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
title_short |
Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
title_full |
Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
title_fullStr |
Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
title_full_unstemmed |
Re–Os age constraints and new observations of Proterozoic glacial deposits in the Vazante Group, Brazil |
title_sort |
re–os age constraints and new observations of proterozoic glacial deposits in the vazante group, brazil |
publishDate |
2014 |
url |
http://repositorio.ufba.br/ri/handle/ri/15873 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
http://dx.doi.org/10.1016/j.precamres.2013.10.010 |
op_relation |
0301-9268 http://repositorio.ufba.br/ri/handle/ri/15873 v. 238 |
op_rights |
Acesso Aberto |
op_doi |
https://doi.org/10.1016/j.precamres.2013.10.010 |
container_title |
Precambrian Research |
container_volume |
238 |
container_start_page |
199 |
op_container_end_page |
213 |
_version_ |
1766337616983097344 |