Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil

Detalhes bibliográficos
Autor(a) principal: Misi, Aroldo
Data de Publicação: 2001
Outros Autores: Sanches, Andreia Lima, Azmy, Karem, Veizer, Jan, Dardenne, Marcel Auguste
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UFBA
Texto Completo: http://repositorio.ufba.br/ri/handle/ri/18090
Resumo: Texto completo: acesso restrito. p. 303–329
id UFBA-2_ed265708dd49e500b588b4125075f118
oai_identifier_str oai:repositorio.ufba.br:ri/18090
network_acronym_str UFBA-2
network_name_str Repositório Institucional da UFBA
repository_id_str 1932
spelling Misi, AroldoSanches, Andreia LimaAzmy, KaremVeizer, JanDardenne, Marcel Auguste2015-10-09T18:46:34Z20010301-9268http://repositorio.ufba.br/ri/handle/ri/18090v. 112, n. 3-4Texto completo: acesso restrito. p. 303–329The Vazante Formation consists of approximately 1700 m of mainly microbial mats and stromatolitic reefal lenses that were deposited on shallow marine platform and have been entirely dolomitized. Samples representing different dolomite generations were taken from three boreholes covering the entire spectrum of the Vazante carbonates. Dolomites can be classified, based on petrography and geochemistry, into four generations ranging in crystal size between ∼4 μm (almost micritic) and 3 mm and occurring as both replacements and cements. The Sr/Ca molar ratios, calculated for the dolomitizing fluid (0.0006–0.0138), suggest a contribution from a non-marine, possibly meteoric, water component. The δ18O and δ13C values vary from −0.1 to −14.3‰ (PDB) and 0.2 to −2.3‰ (PDB), respectively. Fluid-inclusion study suggests that dolomitization must have commenced at a temperature lower than about 50 °C. A mixing-zone model of dolomitization for Dolomites I–III satisfies the constraints from elemental chemistry, δ18O, 87Sr/86Sr and fluid inclusions. The petrographic and chemical criteria of the latest generation, Dolomite IV, reflect conditions of deep burial environment at temperatures above 120–130 °C. The δ13C values show only small variations at the base of the formation, followed by a major negative plunge (∼4‰) at the top, this plunge correlated with the Sturtian glacial phase. In contrast to C-isotopes, only few samples may have retained their near-primary 87Sr/86Sr values of 0.70614–0.70734. The lowest 87Sr/86Sr value (0.70614), from fibrous cement in the upper part of the formation, correlates with the negative δ13C shift and is also consistent with the Sr-isotope signature proposed for the glacial Sturtian seawater. The δ34S values, obtained from sulfates trapped in carbonates, range between 10.8 and 16.9‰ with a jump to 21.3‰ in the overlying formation. All isotope signals are within the range suggested for the early Neoproterozoic seawater, but the Precambrian baseline is poorly known and additional work is required to confirm this tentative assignment.Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-02-05T14:23:11Z No. of bitstreams: 1 Aroldo Misi.pdf: 1475684 bytes, checksum: 2cf690d3f8ad6bc11020176429d6cd67 (MD5)Approved for entry into archive by Rodrigo Meirelles (rodrigomei@ufba.br) on 2015-10-09T18:46:34Z (GMT) No. of bitstreams: 1 Aroldo Misi.pdf: 1475684 bytes, checksum: 2cf690d3f8ad6bc11020176429d6cd67 (MD5)Made available in DSpace on 2015-10-09T18:46:34Z (GMT). No. of bitstreams: 1 Aroldo Misi.pdf: 1475684 bytes, checksum: 2cf690d3f8ad6bc11020176429d6cd67 (MD5) Previous issue date: 2001http://dx.doi.org/10.1016/S0301-9268(01)00194-2reponame:Repositório Institucional da UFBAinstname:Universidade Federal da Bahia (UFBA)instacron:UFBAProterozoic carbonatesDolomitesGeochemistryIsotope stratigraphyVazante FormationBrazilDolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, BrazilPrecambrian Researchinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article10000-01-01Brasilinfo:eu-repo/semantics/openAccessengORIGINALAroldo Misi.pdfAroldo Misi.pdfapplication/pdf1475684https://repositorio.ufba.br/bitstream/ri/18090/1/Aroldo%20Misi.pdf2cf690d3f8ad6bc11020176429d6cd67MD51LICENSElicense.txtlicense.txttext/plain1345https://repositorio.ufba.br/bitstream/ri/18090/2/license.txtff6eaa8b858ea317fded99f125f5fcd0MD52TEXTAroldo Misi.pdf.txtAroldo Misi.pdf.txtExtracted texttext/plain76447https://repositorio.ufba.br/bitstream/ri/18090/3/Aroldo%20Misi.pdf.txt34fbbbda43d678a0f0c287e84666abfaMD53ri/180902022-03-23 20:24:03.536oai:repositorio.ufba.br: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Repositório InstitucionalPUBhttp://192.188.11.11:8080/oai/requestopendoar:19322022-03-23T23:24:03Repositório Institucional da UFBA - Universidade Federal da Bahia (UFBA)false
dc.title.pt_BR.fl_str_mv Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
dc.title.alternative.pt_BR.fl_str_mv Precambrian Research
title Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
spellingShingle Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
Misi, Aroldo
Proterozoic carbonates
Dolomites
Geochemistry
Isotope stratigraphy
Vazante Formation
Brazil
title_short Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
title_full Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
title_fullStr Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
title_full_unstemmed Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
title_sort Dolomitization and isotope stratigraphy of the Vazante Formation, São Francisco Basin, Brazil
author Misi, Aroldo
author_facet Misi, Aroldo
Sanches, Andreia Lima
Azmy, Karem
Veizer, Jan
Dardenne, Marcel Auguste
author_role author
author2 Sanches, Andreia Lima
Azmy, Karem
Veizer, Jan
Dardenne, Marcel Auguste
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Misi, Aroldo
Sanches, Andreia Lima
Azmy, Karem
Veizer, Jan
Dardenne, Marcel Auguste
dc.subject.por.fl_str_mv Proterozoic carbonates
Dolomites
Geochemistry
Isotope stratigraphy
Vazante Formation
Brazil
topic Proterozoic carbonates
Dolomites
Geochemistry
Isotope stratigraphy
Vazante Formation
Brazil
description Texto completo: acesso restrito. p. 303–329
publishDate 2001
dc.date.issued.fl_str_mv 2001
dc.date.accessioned.fl_str_mv 2015-10-09T18:46:34Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://repositorio.ufba.br/ri/handle/ri/18090
dc.identifier.issn.none.fl_str_mv 0301-9268
dc.identifier.number.pt_BR.fl_str_mv v. 112, n. 3-4
identifier_str_mv 0301-9268
v. 112, n. 3-4
url http://repositorio.ufba.br/ri/handle/ri/18090
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.country.fl_str_mv Brasil
dc.source.pt_BR.fl_str_mv http://dx.doi.org/10.1016/S0301-9268(01)00194-2
dc.source.none.fl_str_mv reponame:Repositório Institucional da UFBA
instname:Universidade Federal da Bahia (UFBA)
instacron:UFBA
instname_str Universidade Federal da Bahia (UFBA)
instacron_str UFBA
institution UFBA
reponame_str Repositório Institucional da UFBA
collection Repositório Institucional da UFBA
bitstream.url.fl_str_mv https://repositorio.ufba.br/bitstream/ri/18090/1/Aroldo%20Misi.pdf
https://repositorio.ufba.br/bitstream/ri/18090/2/license.txt
https://repositorio.ufba.br/bitstream/ri/18090/3/Aroldo%20Misi.pdf.txt
bitstream.checksum.fl_str_mv 2cf690d3f8ad6bc11020176429d6cd67
ff6eaa8b858ea317fded99f125f5fcd0
34fbbbda43d678a0f0c287e84666abfa
bitstream.checksumAlgorithm.fl_str_mv MD5
MD5
MD5
repository.name.fl_str_mv Repositório Institucional da UFBA - Universidade Federal da Bahia (UFBA)
repository.mail.fl_str_mv
_version_ 1808459471423275008

Registros relacionados