Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C-
Autor(a) principal: | |
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Data de Publicação: | 2004 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/22606 |
Resumo: | This paper presents the geology, chemical data, Pb-Pb zircon ages, sulfur, carbon, oxygen, strontium isotopes and fluid inclusions of Cerro dos Martins copper deposit. The deposit is hosted by the Neoproterozoic volcano-sedimentary sequence of the Camaquã Basin in the Rio Grande do Sul Shield, southern Brazil. The ores consist of a set of Cu-sulfide NW-trending veins and disseminations within of the Bom Jardim Group. Chalcocite and bornite are the main ore minerals, whereas carbonates, barite, quartz and hematite are the gangue. The volcanic host rocks show an alkaline affinity. An intrusive quartz-diorite body, also shown alkaline affinity, yield a 550±5 Ma zircon age (initial 87Sr/86Sr of 0,704), which is considered the minimum age of the copper mineralization. The d34SCDT of sulfides ranges from –6.2 to +0.9‰. Hematite in the mineral paragenesis suggests oxidizing conditions, which would shift the original magmatic sulfur isotopic compositions (d34S ~ 0‰) to negative values. Barite with d34SCDT from +9.25 to +10.65‰ may also indicate oxidation due to mixing of a hot rising fluid with cold meteoric water. The d13CPDB of calcite from gangue, in the range of – 1,90 to – 4,45% is interpreted as originated from mixing sources – magmatic and fluids contaminated by basement marbles. Studies on primary aqueous biphasic fluid inclusions show homogenisation temperatures with average of 215°C. Water in equilibrium with calcite from hydrothermal fluid show calculated values of d O18 SMOW between 3 and 14‰, suggesting derivation from a magmatic source with some contributions from meteoric water. 87Sr/86Sr from these calcite show values between 0, 7068 – 0, 7087, typical from upper crust. Hence, the Cerro dos Martins copper deposit is interpreted to have had origin by a mixing between a magmatic-hydrotermal fluids related to the alkaline-shoshonitic, post-collisional magmatic event (595-550 Ma) of the Dom Feliciano Orogeny and basement rocks. Exploration models for copper deposits in this shield should consider the alkaline magmatism in the genesis of deposits. |
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Toniolo, João AngeloRemus, Marcus Vinicius DornelesMacambira, Moacir José BuenanoMoura, Cândido Augusto Veloso2010-05-20T04:16:20Z20041518-2398http://hdl.handle.net/10183/22606000501357This paper presents the geology, chemical data, Pb-Pb zircon ages, sulfur, carbon, oxygen, strontium isotopes and fluid inclusions of Cerro dos Martins copper deposit. The deposit is hosted by the Neoproterozoic volcano-sedimentary sequence of the Camaquã Basin in the Rio Grande do Sul Shield, southern Brazil. The ores consist of a set of Cu-sulfide NW-trending veins and disseminations within of the Bom Jardim Group. Chalcocite and bornite are the main ore minerals, whereas carbonates, barite, quartz and hematite are the gangue. The volcanic host rocks show an alkaline affinity. An intrusive quartz-diorite body, also shown alkaline affinity, yield a 550±5 Ma zircon age (initial 87Sr/86Sr of 0,704), which is considered the minimum age of the copper mineralization. The d34SCDT of sulfides ranges from –6.2 to +0.9‰. Hematite in the mineral paragenesis suggests oxidizing conditions, which would shift the original magmatic sulfur isotopic compositions (d34S ~ 0‰) to negative values. Barite with d34SCDT from +9.25 to +10.65‰ may also indicate oxidation due to mixing of a hot rising fluid with cold meteoric water. The d13CPDB of calcite from gangue, in the range of – 1,90 to – 4,45% is interpreted as originated from mixing sources – magmatic and fluids contaminated by basement marbles. Studies on primary aqueous biphasic fluid inclusions show homogenisation temperatures with average of 215°C. Water in equilibrium with calcite from hydrothermal fluid show calculated values of d O18 SMOW between 3 and 14‰, suggesting derivation from a magmatic source with some contributions from meteoric water. 87Sr/86Sr from these calcite show values between 0, 7068 – 0, 7087, typical from upper crust. Hence, the Cerro dos Martins copper deposit is interpreted to have had origin by a mixing between a magmatic-hydrotermal fluids related to the alkaline-shoshonitic, post-collisional magmatic event (595-550 Ma) of the Dom Feliciano Orogeny and basement rocks. Exploration models for copper deposits in this shield should consider the alkaline magmatism in the genesis of deposits.application/pdfporPesquisas em Geociências. Porto Alegre, RS. Vol. 31, n. 2 (2004), p. 41-67CobreGeoquimica isotopicaJazida cerro dos martinsRio Grande do SulMetallogenySedimentary-hosted depositIsotopesBase-metal mineralizationMetalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C-info:eu-repo/semantics/articleinfo:eu-repo/semantics/otherinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSORIGINAL000501357.pdf000501357.pdfTexto completoapplication/pdf2440550http://www.lume.ufrgs.br/bitstream/10183/22606/1/000501357.pdf51c71b94aa489cce31ce34976d1abf25MD51TEXT000501357.pdf.txt000501357.pdf.txtExtracted Texttext/plain98331http://www.lume.ufrgs.br/bitstream/10183/22606/2/000501357.pdf.txtd02fdd009087ce7467ea62828a12eb34MD52THUMBNAIL000501357.pdf.jpg000501357.pdf.jpgGenerated Thumbnailimage/jpeg1619http://www.lume.ufrgs.br/bitstream/10183/22606/3/000501357.pdf.jpg464751432a23c13bc8a8549a44bacfe1MD5310183/226062021-08-18 04:29:32.952541oai:www.lume.ufrgs.br:10183/22606Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2021-08-18T07:29:32Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
title |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
spellingShingle |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- Toniolo, João Angelo Cobre Geoquimica isotopica Jazida cerro dos martins Rio Grande do Sul Metallogeny Sedimentary-hosted deposit Isotopes Base-metal mineralization |
title_short |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
title_full |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
title_fullStr |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
title_full_unstemmed |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
title_sort |
Metalogênese do depósito de cobre Cerro dos Martins, RS: revisão e geoquímica isotópica de SR, O e C- |
author |
Toniolo, João Angelo |
author_facet |
Toniolo, João Angelo Remus, Marcus Vinicius Dorneles Macambira, Moacir José Buenano Moura, Cândido Augusto Veloso |
author_role |
author |
author2 |
Remus, Marcus Vinicius Dorneles Macambira, Moacir José Buenano Moura, Cândido Augusto Veloso |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Toniolo, João Angelo Remus, Marcus Vinicius Dorneles Macambira, Moacir José Buenano Moura, Cândido Augusto Veloso |
dc.subject.por.fl_str_mv |
Cobre Geoquimica isotopica Jazida cerro dos martins Rio Grande do Sul |
topic |
Cobre Geoquimica isotopica Jazida cerro dos martins Rio Grande do Sul Metallogeny Sedimentary-hosted deposit Isotopes Base-metal mineralization |
dc.subject.eng.fl_str_mv |
Metallogeny Sedimentary-hosted deposit Isotopes Base-metal mineralization |
description |
This paper presents the geology, chemical data, Pb-Pb zircon ages, sulfur, carbon, oxygen, strontium isotopes and fluid inclusions of Cerro dos Martins copper deposit. The deposit is hosted by the Neoproterozoic volcano-sedimentary sequence of the Camaquã Basin in the Rio Grande do Sul Shield, southern Brazil. The ores consist of a set of Cu-sulfide NW-trending veins and disseminations within of the Bom Jardim Group. Chalcocite and bornite are the main ore minerals, whereas carbonates, barite, quartz and hematite are the gangue. The volcanic host rocks show an alkaline affinity. An intrusive quartz-diorite body, also shown alkaline affinity, yield a 550±5 Ma zircon age (initial 87Sr/86Sr of 0,704), which is considered the minimum age of the copper mineralization. The d34SCDT of sulfides ranges from –6.2 to +0.9‰. Hematite in the mineral paragenesis suggests oxidizing conditions, which would shift the original magmatic sulfur isotopic compositions (d34S ~ 0‰) to negative values. Barite with d34SCDT from +9.25 to +10.65‰ may also indicate oxidation due to mixing of a hot rising fluid with cold meteoric water. The d13CPDB of calcite from gangue, in the range of – 1,90 to – 4,45% is interpreted as originated from mixing sources – magmatic and fluids contaminated by basement marbles. Studies on primary aqueous biphasic fluid inclusions show homogenisation temperatures with average of 215°C. Water in equilibrium with calcite from hydrothermal fluid show calculated values of d O18 SMOW between 3 and 14‰, suggesting derivation from a magmatic source with some contributions from meteoric water. 87Sr/86Sr from these calcite show values between 0, 7068 – 0, 7087, typical from upper crust. Hence, the Cerro dos Martins copper deposit is interpreted to have had origin by a mixing between a magmatic-hydrotermal fluids related to the alkaline-shoshonitic, post-collisional magmatic event (595-550 Ma) of the Dom Feliciano Orogeny and basement rocks. Exploration models for copper deposits in this shield should consider the alkaline magmatism in the genesis of deposits. |
publishDate |
2004 |
dc.date.issued.fl_str_mv |
2004 |
dc.date.accessioned.fl_str_mv |
2010-05-20T04:16:20Z |
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1518-2398 |
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000501357 |
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http://hdl.handle.net/10183/22606 |
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por |
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por |
dc.relation.ispartof.pt_BR.fl_str_mv |
Pesquisas em Geociências. Porto Alegre, RS. Vol. 31, n. 2 (2004), p. 41-67 |
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