Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study
Autor(a) principal: | |
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Data de Publicação: | 2000 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/210110 |
Resumo: | The Caxias deposit is situated in the Gurupi Auriferous Province of the Paleoproterozoic São Luís Craton, northern Brazil. It is a lode-type gold mineralization associated with a narrow, steeply dipping, NE-trending, shear zone crosscutting a hydrothermalized microtonalite (northern sector) and schists (southern sector). Fluid inclusion studies on vein quartz crosscutting the microtonalite (northern sector) have identified early carbonic and aqueous-carbonic inclusions and late aqueous inclusions, unrelated to the mineralizing event. The CO2/H2O ratio and the other microthermometric properties show a wide range of values, which are interpreted as product of heterogeneous trapping of two (partially) immiscible fluids and to deformation-related post-formational processes. The resulting mineralizing fluid has XCO2- 6-45 mol %; XN2: <2.5 mol %; XH2O: 55-95 mol %; mean salinity of 4.5 wt % NaCl equiv., and moderate density (0.7-1.0 g/cm3). Bulk isochores coupled with chlorite geothermometry constrained the P-T entrapment conditions between 262-307ºC and 1.6-3.7 kb. Log ¦O2 for this P-T-X range was estimated between –29.8 and –34.2. Geological characteristics and fluid properties found in the northern sector of Caxias gold mineralization are similar to those described for metamorphic fluids of mesothermal gold deposits. |
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Klein, Evandro LuizFuzikawa, KazuoKoppe, Jair CarlosDantas, Maria Sylvia Silva2020-06-05T03:48:10Z20000375-7536http://hdl.handle.net/10183/210110000296052The Caxias deposit is situated in the Gurupi Auriferous Province of the Paleoproterozoic São Luís Craton, northern Brazil. It is a lode-type gold mineralization associated with a narrow, steeply dipping, NE-trending, shear zone crosscutting a hydrothermalized microtonalite (northern sector) and schists (southern sector). Fluid inclusion studies on vein quartz crosscutting the microtonalite (northern sector) have identified early carbonic and aqueous-carbonic inclusions and late aqueous inclusions, unrelated to the mineralizing event. The CO2/H2O ratio and the other microthermometric properties show a wide range of values, which are interpreted as product of heterogeneous trapping of two (partially) immiscible fluids and to deformation-related post-formational processes. The resulting mineralizing fluid has XCO2- 6-45 mol %; XN2: <2.5 mol %; XH2O: 55-95 mol %; mean salinity of 4.5 wt % NaCl equiv., and moderate density (0.7-1.0 g/cm3). Bulk isochores coupled with chlorite geothermometry constrained the P-T entrapment conditions between 262-307ºC and 1.6-3.7 kb. Log ¦O2 for this P-T-X range was estimated between –29.8 and –34.2. Geological characteristics and fluid properties found in the northern sector of Caxias gold mineralization are similar to those described for metamorphic fluids of mesothermal gold deposits.application/pdfporRevista brasileira de geociências. São Paulo. Vol. 30, n. 2 (jun. 2000), p. 322-326GeoquímicaGeotectônicaMineraçãoOuroGoldAqueous-carbonic fluidsMesothermalPaleoproterozoicFluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion studyinfo: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:UFRGSTEXT000296052.pdf.txt000296052.pdf.txtExtracted Texttext/plain22724http://www.lume.ufrgs.br/bitstream/10183/210110/2/000296052.pdf.txtd58cdc7949c1e621ecc9b8ea554f8e73MD52ORIGINAL000296052.pdfTexto completo (inglês)application/pdf212037http://www.lume.ufrgs.br/bitstream/10183/210110/1/000296052.pdf72cafb4963440e1788a7dc354ea9a55bMD5110183/2101102023-08-09 03:47:30.844463oai:www.lume.ufrgs.br:10183/210110Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2023-08-09T06:47:30Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
title |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
spellingShingle |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study Klein, Evandro Luiz Geoquímica Geotectônica Mineração Ouro Gold Aqueous-carbonic fluids Mesothermal Paleoproterozoic |
title_short |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
title_full |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
title_fullStr |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
title_full_unstemmed |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
title_sort |
Fluids associated with the Caxias mesothermal gold mineralization, São Luis Craton, northern Brazil: a fluid inclusion study |
author |
Klein, Evandro Luiz |
author_facet |
Klein, Evandro Luiz Fuzikawa, Kazuo Koppe, Jair Carlos Dantas, Maria Sylvia Silva |
author_role |
author |
author2 |
Fuzikawa, Kazuo Koppe, Jair Carlos Dantas, Maria Sylvia Silva |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Klein, Evandro Luiz Fuzikawa, Kazuo Koppe, Jair Carlos Dantas, Maria Sylvia Silva |
dc.subject.por.fl_str_mv |
Geoquímica Geotectônica Mineração Ouro |
topic |
Geoquímica Geotectônica Mineração Ouro Gold Aqueous-carbonic fluids Mesothermal Paleoproterozoic |
dc.subject.eng.fl_str_mv |
Gold Aqueous-carbonic fluids Mesothermal Paleoproterozoic |
description |
The Caxias deposit is situated in the Gurupi Auriferous Province of the Paleoproterozoic São Luís Craton, northern Brazil. It is a lode-type gold mineralization associated with a narrow, steeply dipping, NE-trending, shear zone crosscutting a hydrothermalized microtonalite (northern sector) and schists (southern sector). Fluid inclusion studies on vein quartz crosscutting the microtonalite (northern sector) have identified early carbonic and aqueous-carbonic inclusions and late aqueous inclusions, unrelated to the mineralizing event. The CO2/H2O ratio and the other microthermometric properties show a wide range of values, which are interpreted as product of heterogeneous trapping of two (partially) immiscible fluids and to deformation-related post-formational processes. The resulting mineralizing fluid has XCO2- 6-45 mol %; XN2: <2.5 mol %; XH2O: 55-95 mol %; mean salinity of 4.5 wt % NaCl equiv., and moderate density (0.7-1.0 g/cm3). Bulk isochores coupled with chlorite geothermometry constrained the P-T entrapment conditions between 262-307ºC and 1.6-3.7 kb. Log ¦O2 for this P-T-X range was estimated between –29.8 and –34.2. Geological characteristics and fluid properties found in the northern sector of Caxias gold mineralization are similar to those described for metamorphic fluids of mesothermal gold deposits. |
publishDate |
2000 |
dc.date.issued.fl_str_mv |
2000 |
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2020-06-05T03:48:10Z |
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por |
language |
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dc.relation.ispartof.pt_BR.fl_str_mv |
Revista brasileira de geociências. São Paulo. Vol. 30, n. 2 (jun. 2000), p. 322-326 |
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