Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data
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=S2317-48892018000300457 |
Resumo: | ABSTRACT: The Fazenda Bonfim emerald deposit, State of Rio Grande do Norte, is within the regional geological domain known as Seridó Mobile Belt, Borborema Tectonic Province. It was formed from metasomatic fluids interaction at along lithological contacts between Be-rich albite-granite intrusions and Cr (±V)-rich mafic-ultramafic host-rocks, enclosed in the lens-shaped “hornfels” phlogopite schist. Emerald crystals display relatively high contents of Mg and Na, as well as trace amounts of Ca, K, Cs, Li, P, Sc, Ti, Mn, Co, Ni, Zn, Ga and Rb. Cr is the main chromophore element, followed by Fe and some V. Display also concentric growth zones and randomly-oriented mineral micro-inclusions, indicative for static growth. This zoning is linked to cationic substitution of alkalis accompanied by Cr loss, which favors irregular coloration of crystals. Metasomatic fluids contemporaneous with emerald growth are aqueous (H 2 O+NaCl), with low to moderate salinity and low density, although trace amounts of CO 2 ± CH 4 were also observed. These fluids showed a field-trapped between 375-430ºC and 200-600 bars, based on combination of fluid inclusions isochores. In addition, oxygen isotope data (δ 18 O = 6.9-7.4‰) suggest an igneous-metasomatic source for fluids and emerald components. |
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Brazilian Journal of Geology |
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Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope dataFazenda Bonfim Emerald DepositSeridó Mobile BeltBorborema Tectonic ProvinceChemical MineralFluid InclusionsOxygen IsotopeABSTRACT: The Fazenda Bonfim emerald deposit, State of Rio Grande do Norte, is within the regional geological domain known as Seridó Mobile Belt, Borborema Tectonic Province. It was formed from metasomatic fluids interaction at along lithological contacts between Be-rich albite-granite intrusions and Cr (±V)-rich mafic-ultramafic host-rocks, enclosed in the lens-shaped “hornfels” phlogopite schist. Emerald crystals display relatively high contents of Mg and Na, as well as trace amounts of Ca, K, Cs, Li, P, Sc, Ti, Mn, Co, Ni, Zn, Ga and Rb. Cr is the main chromophore element, followed by Fe and some V. Display also concentric growth zones and randomly-oriented mineral micro-inclusions, indicative for static growth. This zoning is linked to cationic substitution of alkalis accompanied by Cr loss, which favors irregular coloration of crystals. Metasomatic fluids contemporaneous with emerald growth are aqueous (H 2 O+NaCl), with low to moderate salinity and low density, although trace amounts of CO 2 ± CH 4 were also observed. These fluids showed a field-trapped between 375-430ºC and 200-600 bars, based on combination of fluid inclusions isochores. In addition, oxygen isotope data (δ 18 O = 6.9-7.4‰) suggest an igneous-metasomatic source for fluids and emerald components.Sociedade Brasileira de Geologia2018-07-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000300457Brazilian Journal of Geology v.48 n.3 2018reponame:Brazilian Journal of Geologyinstname:Sociedade Brasileira de Geologia (SBGEO)instacron:SBGEO10.1590/2317-4889201820170130info:eu-repo/semantics/openAccessSantiago,Judiron SantosSouza,Valmir da SilvaFilgueiras,Bernardo de CarvalhoJiménez,Federico Alberto Cuadroseng2018-10-03T00:00:00Zoai:scielo:S2317-48892018000300457Revistahttp://bjg.siteoficial.ws/index.htmhttps://old.scielo.br/oai/scielo-oai.phpsbgsede@sbgeo.org.br||claudio.riccomini@gmail.com2317-46922317-4692opendoar:2018-10-03T00:00Brazilian Journal of Geology - Sociedade Brasileira de Geologia (SBGEO)false |
dc.title.none.fl_str_mv |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
title |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
spellingShingle |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data Santiago,Judiron Santos Fazenda Bonfim Emerald Deposit Seridó Mobile Belt Borborema Tectonic Province Chemical Mineral Fluid Inclusions Oxygen Isotope |
title_short |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
title_full |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
title_fullStr |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
title_full_unstemmed |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
title_sort |
Emerald from the Fazenda Bonfim Deposit, northeastern Brazil: chemical, fluid inclusions and oxygen isotope data |
author |
Santiago,Judiron Santos |
author_facet |
Santiago,Judiron Santos Souza,Valmir da Silva Filgueiras,Bernardo de Carvalho Jiménez,Federico Alberto Cuadros |
author_role |
author |
author2 |
Souza,Valmir da Silva Filgueiras,Bernardo de Carvalho Jiménez,Federico Alberto Cuadros |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Santiago,Judiron Santos Souza,Valmir da Silva Filgueiras,Bernardo de Carvalho Jiménez,Federico Alberto Cuadros |
dc.subject.por.fl_str_mv |
Fazenda Bonfim Emerald Deposit Seridó Mobile Belt Borborema Tectonic Province Chemical Mineral Fluid Inclusions Oxygen Isotope |
topic |
Fazenda Bonfim Emerald Deposit Seridó Mobile Belt Borborema Tectonic Province Chemical Mineral Fluid Inclusions Oxygen Isotope |
description |
ABSTRACT: The Fazenda Bonfim emerald deposit, State of Rio Grande do Norte, is within the regional geological domain known as Seridó Mobile Belt, Borborema Tectonic Province. It was formed from metasomatic fluids interaction at along lithological contacts between Be-rich albite-granite intrusions and Cr (±V)-rich mafic-ultramafic host-rocks, enclosed in the lens-shaped “hornfels” phlogopite schist. Emerald crystals display relatively high contents of Mg and Na, as well as trace amounts of Ca, K, Cs, Li, P, Sc, Ti, Mn, Co, Ni, Zn, Ga and Rb. Cr is the main chromophore element, followed by Fe and some V. Display also concentric growth zones and randomly-oriented mineral micro-inclusions, indicative for static growth. This zoning is linked to cationic substitution of alkalis accompanied by Cr loss, which favors irregular coloration of crystals. Metasomatic fluids contemporaneous with emerald growth are aqueous (H 2 O+NaCl), with low to moderate salinity and low density, although trace amounts of CO 2 ± CH 4 were also observed. These fluids showed a field-trapped between 375-430ºC and 200-600 bars, based on combination of fluid inclusions isochores. In addition, oxygen isotope data (δ 18 O = 6.9-7.4‰) suggest an igneous-metasomatic source for fluids and emerald components. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-07-01 |
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=S2317-48892018000300457 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892018000300457 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2317-4889201820170130 |
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.3 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_ |
1752122398937710592 |