Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Journal of Geology |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000400685 |
Resumo: | ABSTRACT: The Ibaré Lineament is a shear zone that sections the Western portion of Sul-riograndense Shield, affecting the orthogneissic rocks of Santa Maria Chico Granulitic Complex, acting as a conduct for hydrothermal fluids. The studied hydrothermal mineralogy reflects a propylitic alteration paragenesis that is composed of Fe-clinochlore, epidote, albite, calcite and quartz, typical low-pressure paragenesis (< 2,000 bar). This mineral association reflects an equilibrium in a neutral to slightly alkaline pH. Using the new approach for chlorite geothermometry, an average formation temperature of 274°C was obtained, compatible with the stability of polytype IIb chlorite and with the irregular textures of twinning in calcites. The fluid inclusions in quartz establish a low-salinity system (2.45 wt.% NaCl eq.) and an average temperature of 175°C. The obtained temperatures are interpreted as a continuum cooling model with meteoric fluids entrance. The system pressure is evaluated from isochores, reaching an average value of 1,560 bar. This is the first temperature and pressure estimate to the Ibaré Shear Zone, which enabled the establishment of a shallow hydrothermal system (epithermal) with fluid interaction from magmatic and meteoric sources, confirmed by the behavior of carbon and oxygen stable isotopes, which indicated an the origin from mixed sources. |
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Brazilian Journal of Geology |
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Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, BrazilIbaré LineamentChloritizationEpithermalPropylitic alterationGeothermobarometryABSTRACT: The Ibaré Lineament is a shear zone that sections the Western portion of Sul-riograndense Shield, affecting the orthogneissic rocks of Santa Maria Chico Granulitic Complex, acting as a conduct for hydrothermal fluids. The studied hydrothermal mineralogy reflects a propylitic alteration paragenesis that is composed of Fe-clinochlore, epidote, albite, calcite and quartz, typical low-pressure paragenesis (< 2,000 bar). This mineral association reflects an equilibrium in a neutral to slightly alkaline pH. Using the new approach for chlorite geothermometry, an average formation temperature of 274°C was obtained, compatible with the stability of polytype IIb chlorite and with the irregular textures of twinning in calcites. The fluid inclusions in quartz establish a low-salinity system (2.45 wt.% NaCl eq.) and an average temperature of 175°C. The obtained temperatures are interpreted as a continuum cooling model with meteoric fluids entrance. The system pressure is evaluated from isochores, reaching an average value of 1,560 bar. This is the first temperature and pressure estimate to the Ibaré Shear Zone, which enabled the establishment of a shallow hydrothermal system (epithermal) with fluid interaction from magmatic and meteoric sources, confirmed by the behavior of carbon and oxygen stable isotopes, which indicated an the origin from mixed sources.Sociedade Brasileira de Geologia2018-12-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000400685Brazilian Journal of Geology v.48 n.4 2018reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-4889201820180009info:eu-repo/semantics/openAccessRuppel,Kelvyn Mikael VaccariDani,NorbertoRemus,Marcus Vinicius DornelesRonchi,Luiz HenriqueGomes,Marcia Elisa BoscatoSenhorinho,Elieleng2019-01-08T00:00:00Zoai:scielo:S2317-48892018000400685Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2019-01-08T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false |
dc.title.none.fl_str_mv |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
title |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
spellingShingle |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil Ruppel,Kelvyn Mikael Vaccari Ibaré Lineament Chloritization Epithermal Propylitic alteration Geothermobarometry |
title_short |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
title_full |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
title_fullStr |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
title_full_unstemmed |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
title_sort |
Temperature and pressure in the environment of epithermal alteration: a case study at Ibaré Lineament, Rio Grande do Sul, Brazil |
author |
Ruppel,Kelvyn Mikael Vaccari |
author_facet |
Ruppel,Kelvyn Mikael Vaccari Dani,Norberto Remus,Marcus Vinicius Dorneles Ronchi,Luiz Henrique Gomes,Marcia Elisa Boscato Senhorinho,Eliel |
author_role |
author |
author2 |
Dani,Norberto Remus,Marcus Vinicius Dorneles Ronchi,Luiz Henrique Gomes,Marcia Elisa Boscato Senhorinho,Eliel |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Ruppel,Kelvyn Mikael Vaccari Dani,Norberto Remus,Marcus Vinicius Dorneles Ronchi,Luiz Henrique Gomes,Marcia Elisa Boscato Senhorinho,Eliel |
dc.subject.por.fl_str_mv |
Ibaré Lineament Chloritization Epithermal Propylitic alteration Geothermobarometry |
topic |
Ibaré Lineament Chloritization Epithermal Propylitic alteration Geothermobarometry |
description |
ABSTRACT: The Ibaré Lineament is a shear zone that sections the Western portion of Sul-riograndense Shield, affecting the orthogneissic rocks of Santa Maria Chico Granulitic Complex, acting as a conduct for hydrothermal fluids. The studied hydrothermal mineralogy reflects a propylitic alteration paragenesis that is composed of Fe-clinochlore, epidote, albite, calcite and quartz, typical low-pressure paragenesis (< 2,000 bar). This mineral association reflects an equilibrium in a neutral to slightly alkaline pH. Using the new approach for chlorite geothermometry, an average formation temperature of 274°C was obtained, compatible with the stability of polytype IIb chlorite and with the irregular textures of twinning in calcites. The fluid inclusions in quartz establish a low-salinity system (2.45 wt.% NaCl eq.) and an average temperature of 175°C. The obtained temperatures are interpreted as a continuum cooling model with meteoric fluids entrance. The system pressure is evaluated from isochores, reaching an average value of 1,560 bar. This is the first temperature and pressure estimate to the Ibaré Shear Zone, which enabled the establishment of a shallow hydrothermal system (epithermal) with fluid interaction from magmatic and meteoric sources, confirmed by the behavior of carbon and oxygen stable isotopes, which indicated an the origin from mixed sources. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-12-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000400685 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000400685 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2317-4889201820180009 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
publisher.none.fl_str_mv |
Sociedade Brasileira de Geologia |
dc.source.none.fl_str_mv |
Brazilian Journal of Geology v.48 n.4 2018 reponame:Brazilian Journal of Geology instname:Sociedade Brasileira de Geologia (SBGEO) instacron:SBGEO |
instname_str |
Sociedade Brasileira de Geologia (SBGEO) |
instacron_str |
SBGEO |
institution |
SBGEO |
reponame_str |
Brazilian Journal of Geology |
collection |
Brazilian Journal of Geology |
repository.name.fl_str_mv |
Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO) |
repository.mail.fl_str_mv |
sbgsede@sbgeo.org.br||claudio.riccomini@gmail.com |
_version_ |
1752122398904156160 |