Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits

Detalhes bibliográficos
Autor(a) principal: Teles, Guilherme S.
Data de Publicação: 2020
Outros Autores: Chemale Jr, Farid, Avila, Janaina N., Ireland, Trevor R., Dias, Airton N. C., Cruz, Daniele C. F., Constantino, Carlos J. L. [UNESP]
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1016/j.gca.2020.01.035
http://hdl.handle.net/11449/197682
Resumo: The Jacobina Basin has a well-preserved sedimentary record, including continental and marine deposits, and hosts Au-(U)Py mineralization in metaconglomerate beds similar to the Witwatersrand gold province. Based on petrographic observations, in situ trace-elements, and multiple sulfur isotope analyses (S-32, S-33, S-34, and S-36) on pyrite from alluvial and marine facies, several types of pyrite were recognized. The pyrite grains identified in the alluvial metaconglomerates resemble those found in several pre-GOE gold-bearing metaconglomerates, including detrital and epigenetic varieties. Detrital inclusion-bearing pyrite is enriched in several redox-sensitive trace-metals as well as Au, which indicate an association with carbonaceous shales. On the other hand, the sources of detrital massive pyrite are more variable and include igneous, metamorphic, and hydrothermal sources from the Paleoarchean hinterland of Jacobina Basin. Epigenetic pyrite in metaconglomerates formed during metamorphism by the recrystallization of detrital pyrite with negligible contributions from external hydrothermal fluids to the basin. Diagenetic and epigenetic pyrite are found in marine lithologies. In a metapelite sample, the pyrite grains formed near the sediment-water column interface, with S sourced from the photolytic sulfate (SO42-, D Delta S-33 < 0) dissolved in the water column. A quartzite sample, in turn, has detrital pyrite grains that were likely reworked from continental deposits, as well as pyrite formed by the assimilation of elemental sulfur (S-8, Delta S-33 > 0) that accumulated in sediment pore water during diagenesis. Significantly, the pyrite associated with terrestrial metasediments shows a wide range in delta S-34 values but quite restricted ranges in Delta S-33 and Delta S-36 values, whereas pyrite associated with the marine metasedimentary rocks exhibits limited delta S-34 values but has a wide range in Delta S-33 values and correlated Delta S-36 values close to the Archean array. These data suggest distinct preservation routes for MIF-S from atmospheric SO42- and S-8 in terrestrial and marine environments. Conditions on the terrestrial surface resulted in re-equilibration of distinct S sources, diminishing the amplitude of the Archean atmospheric signal. In contrast, SO42- dissolved in shallow marine settings while S-8 settled to the floor, favoring the preservation of MIF-S isotopic signatures. Such processes may also explain the apparent differences in interpretations of atmospheric conditions derived from uncharacterized pyrites from Archean sources. Our data suggest that the Earth's atmosphere remained anoxic, and terrestrial conditions were such as to allow the syngenetic accumulation of gold, as recently proposed for the Witwatersrand gold deposits. (C) 2020 Elsevier Ltd. All rights reserved.
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spelling Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) depositsAu-U-pyrite mineralizationMultiple sulfur isotopesJacobina BasinSao Francisco CratonThe Jacobina Basin has a well-preserved sedimentary record, including continental and marine deposits, and hosts Au-(U)Py mineralization in metaconglomerate beds similar to the Witwatersrand gold province. Based on petrographic observations, in situ trace-elements, and multiple sulfur isotope analyses (S-32, S-33, S-34, and S-36) on pyrite from alluvial and marine facies, several types of pyrite were recognized. The pyrite grains identified in the alluvial metaconglomerates resemble those found in several pre-GOE gold-bearing metaconglomerates, including detrital and epigenetic varieties. Detrital inclusion-bearing pyrite is enriched in several redox-sensitive trace-metals as well as Au, which indicate an association with carbonaceous shales. On the other hand, the sources of detrital massive pyrite are more variable and include igneous, metamorphic, and hydrothermal sources from the Paleoarchean hinterland of Jacobina Basin. Epigenetic pyrite in metaconglomerates formed during metamorphism by the recrystallization of detrital pyrite with negligible contributions from external hydrothermal fluids to the basin. Diagenetic and epigenetic pyrite are found in marine lithologies. In a metapelite sample, the pyrite grains formed near the sediment-water column interface, with S sourced from the photolytic sulfate (SO42-, D Delta S-33 < 0) dissolved in the water column. A quartzite sample, in turn, has detrital pyrite grains that were likely reworked from continental deposits, as well as pyrite formed by the assimilation of elemental sulfur (S-8, Delta S-33 > 0) that accumulated in sediment pore water during diagenesis. Significantly, the pyrite associated with terrestrial metasediments shows a wide range in delta S-34 values but quite restricted ranges in Delta S-33 and Delta S-36 values, whereas pyrite associated with the marine metasedimentary rocks exhibits limited delta S-34 values but has a wide range in Delta S-33 values and correlated Delta S-36 values close to the Archean array. These data suggest distinct preservation routes for MIF-S from atmospheric SO42- and S-8 in terrestrial and marine environments. Conditions on the terrestrial surface resulted in re-equilibration of distinct S sources, diminishing the amplitude of the Archean atmospheric signal. In contrast, SO42- dissolved in shallow marine settings while S-8 settled to the floor, favoring the preservation of MIF-S isotopic signatures. Such processes may also explain the apparent differences in interpretations of atmospheric conditions derived from uncharacterized pyrites from Archean sources. Our data suggest that the Earth's atmosphere remained anoxic, and terrestrial conditions were such as to allow the syngenetic accumulation of gold, as recently proposed for the Witwatersrand gold deposits. (C) 2020 Elsevier Ltd. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Australian Research Council - ARCUniv Fed Campina Grande, Unidade Acad Mineracao & Geol, Campina Grande, Paraiba, BrazilUniv Brasilia, Programa Posgrad Geol, Brasilia, DF, BrazilUniv Vale Rio dos Sinos, Programa Posgrad Geol, Sao Leopoldo, BrazilAustralian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2601, AustraliaUniv Fed Sao Carlos, Dept Fis Quim & Matemat, Sorocaba, BrazilUniv Estadual Paulista, Dept Fis, Presidente Prudente, BrazilUniv Estadual Paulista, Dept Fis, Presidente Prudente, BrazilCNPq: 163459/2013-4CNPq: 202267/2014-8Australian Research Council - ARC: DP140103393Elsevier B.V.Univ Fed Campina GrandeUniversidade de Brasília (UnB)Univ Vale Rio dos SinosAustralian Natl UnivUniversidade Federal de São Carlos (UFSCar)Universidade Estadual Paulista (Unesp)Teles, Guilherme S.Chemale Jr, FaridAvila, Janaina N.Ireland, Trevor R.Dias, Airton N. C.Cruz, Daniele C. F.Constantino, Carlos J. L. [UNESP]2020-12-11T09:37:44Z2020-12-11T09:37:44Z2020-03-15info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article331-353http://dx.doi.org/10.1016/j.gca.2020.01.035Geochimica Et Cosmochimica Acta. Oxford: Pergamon-elsevier Science Ltd, v. 273, p. 331-353, 2020.0016-7037http://hdl.handle.net/11449/19768210.1016/j.gca.2020.01.035WOS:000514832600019Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengGeochimica Et Cosmochimica Actainfo:eu-repo/semantics/openAccess2024-06-19T12:44:50Zoai:repositorio.unesp.br:11449/197682Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T22:45:08.796601Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
title Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
spellingShingle Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
Teles, Guilherme S.
Au-U-pyrite mineralization
Multiple sulfur isotopes
Jacobina Basin
Sao Francisco Craton
title_short Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
title_full Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
title_fullStr Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
title_full_unstemmed Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
title_sort Textural and geochemical investigation of pyrite in Jacobina Basin, Sao Francisco Craton, Brazil: Implications for paleoenvironmental conditions and formation of pre-GOE metaconglomerate-hosted Au-(U) deposits
author Teles, Guilherme S.
author_facet Teles, Guilherme S.
Chemale Jr, Farid
Avila, Janaina N.
Ireland, Trevor R.
Dias, Airton N. C.
Cruz, Daniele C. F.
Constantino, Carlos J. L. [UNESP]
author_role author
author2 Chemale Jr, Farid
Avila, Janaina N.
Ireland, Trevor R.
Dias, Airton N. C.
Cruz, Daniele C. F.
Constantino, Carlos J. L. [UNESP]
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Univ Fed Campina Grande
Universidade de Brasília (UnB)
Univ Vale Rio dos Sinos
Australian Natl Univ
Universidade Federal de São Carlos (UFSCar)
Universidade Estadual Paulista (Unesp)
dc.contributor.author.fl_str_mv Teles, Guilherme S.
Chemale Jr, Farid
Avila, Janaina N.
Ireland, Trevor R.
Dias, Airton N. C.
Cruz, Daniele C. F.
Constantino, Carlos J. L. [UNESP]
dc.subject.por.fl_str_mv Au-U-pyrite mineralization
Multiple sulfur isotopes
Jacobina Basin
Sao Francisco Craton
topic Au-U-pyrite mineralization
Multiple sulfur isotopes
Jacobina Basin
Sao Francisco Craton
description The Jacobina Basin has a well-preserved sedimentary record, including continental and marine deposits, and hosts Au-(U)Py mineralization in metaconglomerate beds similar to the Witwatersrand gold province. Based on petrographic observations, in situ trace-elements, and multiple sulfur isotope analyses (S-32, S-33, S-34, and S-36) on pyrite from alluvial and marine facies, several types of pyrite were recognized. The pyrite grains identified in the alluvial metaconglomerates resemble those found in several pre-GOE gold-bearing metaconglomerates, including detrital and epigenetic varieties. Detrital inclusion-bearing pyrite is enriched in several redox-sensitive trace-metals as well as Au, which indicate an association with carbonaceous shales. On the other hand, the sources of detrital massive pyrite are more variable and include igneous, metamorphic, and hydrothermal sources from the Paleoarchean hinterland of Jacobina Basin. Epigenetic pyrite in metaconglomerates formed during metamorphism by the recrystallization of detrital pyrite with negligible contributions from external hydrothermal fluids to the basin. Diagenetic and epigenetic pyrite are found in marine lithologies. In a metapelite sample, the pyrite grains formed near the sediment-water column interface, with S sourced from the photolytic sulfate (SO42-, D Delta S-33 < 0) dissolved in the water column. A quartzite sample, in turn, has detrital pyrite grains that were likely reworked from continental deposits, as well as pyrite formed by the assimilation of elemental sulfur (S-8, Delta S-33 > 0) that accumulated in sediment pore water during diagenesis. Significantly, the pyrite associated with terrestrial metasediments shows a wide range in delta S-34 values but quite restricted ranges in Delta S-33 and Delta S-36 values, whereas pyrite associated with the marine metasedimentary rocks exhibits limited delta S-34 values but has a wide range in Delta S-33 values and correlated Delta S-36 values close to the Archean array. These data suggest distinct preservation routes for MIF-S from atmospheric SO42- and S-8 in terrestrial and marine environments. Conditions on the terrestrial surface resulted in re-equilibration of distinct S sources, diminishing the amplitude of the Archean atmospheric signal. In contrast, SO42- dissolved in shallow marine settings while S-8 settled to the floor, favoring the preservation of MIF-S isotopic signatures. Such processes may also explain the apparent differences in interpretations of atmospheric conditions derived from uncharacterized pyrites from Archean sources. Our data suggest that the Earth's atmosphere remained anoxic, and terrestrial conditions were such as to allow the syngenetic accumulation of gold, as recently proposed for the Witwatersrand gold deposits. (C) 2020 Elsevier Ltd. All rights reserved.
publishDate 2020
dc.date.none.fl_str_mv 2020-12-11T09:37:44Z
2020-12-11T09:37:44Z
2020-03-15
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://dx.doi.org/10.1016/j.gca.2020.01.035
Geochimica Et Cosmochimica Acta. Oxford: Pergamon-elsevier Science Ltd, v. 273, p. 331-353, 2020.
0016-7037
http://hdl.handle.net/11449/197682
10.1016/j.gca.2020.01.035
WOS:000514832600019
url http://dx.doi.org/10.1016/j.gca.2020.01.035
http://hdl.handle.net/11449/197682
identifier_str_mv Geochimica Et Cosmochimica Acta. Oxford: Pergamon-elsevier Science Ltd, v. 273, p. 331-353, 2020.
0016-7037
10.1016/j.gca.2020.01.035
WOS:000514832600019
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Geochimica Et Cosmochimica Acta
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 331-353
dc.publisher.none.fl_str_mv Elsevier B.V.
publisher.none.fl_str_mv Elsevier B.V.
dc.source.none.fl_str_mv Web of Science
reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
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