The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFMT |
Texto Completo: | http://ri.ufmt.br/handle/1/4277 |
Resumo: | The Ag-rich Pallancata epithermal district is located in the Huaylilllas magmatic arc along the Neogene belt of southern Peru, which historically produced more than 58 Moz of Ag. The mineralization occurs in quartz veins hosted by 16.58±016 Ma dacitic ignimbrites. Ore minerals include proustite-pirargirite, polibasite-pearceite and argentite with sphalerite, galena and chalcopyrite to a lesser extent; quartz, pyrite, adularia and sericite represent the main gangue minerals. Hydrothermal alteration evolved from regional propylitic to proximal quartz-illite+pyrite and quartz-adularia+pyrite±illite. The mineralized veins fill open spaces in NW-trending, high-angle, subparallel, transtensional faults with sinistral movement and in related extension fractures. Veins are 1 to 30 m wide and up to 3 Km in length with a recognized depth of 350 m. The Pallancata evolution is complex and multiepidsodic and recorded by gangue mineral textures, which include crustiform-, colloform-, cockade- and comb-textured quartz, rhombic adularia and bladed calcite replaced by quartz; the latter two suggests boiling as a precipitation mechanism. The vein evolution records seven stages of gangue and ore deposition with the main mineralization event related to the stage 5, the bonanza stage. The fluid inclusion petrography and microthermometry in quartz from bonanza stage revealed FIA’s mostly consisting of biphasic inclusions (LH2O-VH2O). Homogenization temperatures (Th) and calculated salinities are low with a mean, respectively, around 1.77 % NaCl eq. and 207°C. Raman spectroscopic studies showed SO2 as a minor additional vapor phase and confirmed the lack of CO2. Oxygen isotopes ratios in quartz and adularia and the resulting mean isotopic δ18O composition for water in equilibrium with both minerals is around -7.0 ‰ suggesting a meteoric source for the mineralizing fluid. All the above presented characteristics suggests the Pallancata mineralization as a low-sulphidation epithermal system. |
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The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern PeruEpitermalInclusão fluídaEspectrometria RamanIsótopos estáveisCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIASEpithermalFluid inclusionRaman SpectrometryStable isotopesThe Ag-rich Pallancata epithermal district is located in the Huaylilllas magmatic arc along the Neogene belt of southern Peru, which historically produced more than 58 Moz of Ag. The mineralization occurs in quartz veins hosted by 16.58±016 Ma dacitic ignimbrites. Ore minerals include proustite-pirargirite, polibasite-pearceite and argentite with sphalerite, galena and chalcopyrite to a lesser extent; quartz, pyrite, adularia and sericite represent the main gangue minerals. Hydrothermal alteration evolved from regional propylitic to proximal quartz-illite+pyrite and quartz-adularia+pyrite±illite. The mineralized veins fill open spaces in NW-trending, high-angle, subparallel, transtensional faults with sinistral movement and in related extension fractures. Veins are 1 to 30 m wide and up to 3 Km in length with a recognized depth of 350 m. The Pallancata evolution is complex and multiepidsodic and recorded by gangue mineral textures, which include crustiform-, colloform-, cockade- and comb-textured quartz, rhombic adularia and bladed calcite replaced by quartz; the latter two suggests boiling as a precipitation mechanism. The vein evolution records seven stages of gangue and ore deposition with the main mineralization event related to the stage 5, the bonanza stage. The fluid inclusion petrography and microthermometry in quartz from bonanza stage revealed FIA’s mostly consisting of biphasic inclusions (LH2O-VH2O). Homogenization temperatures (Th) and calculated salinities are low with a mean, respectively, around 1.77 % NaCl eq. and 207°C. Raman spectroscopic studies showed SO2 as a minor additional vapor phase and confirmed the lack of CO2. Oxygen isotopes ratios in quartz and adularia and the resulting mean isotopic δ18O composition for water in equilibrium with both minerals is around -7.0 ‰ suggesting a meteoric source for the mineralizing fluid. All the above presented characteristics suggests the Pallancata mineralization as a low-sulphidation epithermal system.CAPESO distrito argentífero epitermal de Pallancata está localizado no arco magmático de Huaylillas ao longo do cinturão neogênico do Sul do Perú que historicamente produziu mais de 58 milhões de onças de Prata. A mineralização ocorre em veios de quartzo hospedados em dacitos ignimbriticos de 16.5±0.1 Ma. Os minerais de minério incluem: proustita-pirargirita, polibasita-pearceita e argentita com esfalerita, galena e calcopirita subordinadas. Quartzo, pirita, adularia e sericita representam os principais minerais da ganga. A evolução hidrotermal varia de alteração propilítica regional para quartzo- ilita±pirita e quartzo-adularia±pirita±ilita proximais. Os veios mineralizados preenchem espaços vazios em falhas transtensionais de alto ângulo e de direção NW com movimentação sinistral e também em fraturas relacionadas. Os veios mostram espessuras variáveis entre 1 e 30 metros, comprimentos de até 3 Km e uma profundidade reconhecida de 350 metros. A evolução do depósito de Pallancata é complexa e multiepisódica sendo registrada pelas texturas dos minerais de ganga que incluem quartzo com crustiforme, colofome, cockade e comb, adularia rômbica e calcita substituída por quartzo; as duas últimas variedades texturais sugerem a ebulição como mecanismo principal de deposição da ganga. A evolução do veio Pallanca registra sete estágios de deposição de ganga e minério sendo que a mineralização mais rica, estágio de bonanza, está relacionada ao estágio 5. A petrografia e microtermometria de inclusões fluidas em quartzo depositado no estágio 5 revelou que a assembleia de inclusão fluída é dominada por inclusões aquosas bifásicas com temperaturas de homogeneização em torno de 207°C e salinidades médias de 1.77%NaCl equivalente. Estudos de espectrometria Raman mostram SO2 como fase vapor subordinada e confirmam a ausência de CO2. As razões isotópicas de Oxigenio em quartzo e adularia varia entre -2 e 6 ‰ enquanto que o fluido em equilíbrio com este minerais apresenta razões δ18O em torno de -6 ‰ compatível com uma fonte meteórica para o fluído. Todas as características acima apresentadas sugerem uma mineralização do Epitermal de baixa-sulfetação para o depósito de Pallancata.Universidade Federal de Mato GrossoBrasilFaculdade de Geociências (FAGEO)UFMT CUC - CuiabáPrograma de Pós-Graduação em GeociênciasLeite, Jayme Alfredo Dexheimerhttp://lattes.cnpq.br/5219722626641443Leite, Jayme Alfredo Dexheimer266.176.500-00http://lattes.cnpq.br/5219722626641443Pinho, Francisco Egidio Cavalcante159.303.271-49http://lattes.cnpq.br/5549482211923085266.176.500-00Barros, Antonio João Paes de242.041.291-53http://lattes.cnpq.br/9289477031030869Gutierrez, Neper Klein Condori2023-06-23T15:29:09Z2016-10-202023-06-23T15:29:09Z2016-06-22info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisGUTIERREZ, Neper Klein Condori. The Ag-Au Pallancata mine: a low-sulphidation epithermal system in southern Peru. 2016. 39 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Mato Grosso, Faculdade de Geociências, Cuiabá, 2016.http://ri.ufmt.br/handle/1/4277porinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMTinstname:Universidade Federal de Mato Grosso (UFMT)instacron:UFMT2023-06-24T07:05:44Zoai:localhost:1/4277Repositório InstitucionalPUBhttp://ri.ufmt.br/oai/requestjordanbiblio@gmail.comopendoar:2023-06-24T07:05:44Repositório Institucional da UFMT - Universidade Federal de Mato Grosso (UFMT)false |
dc.title.none.fl_str_mv |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
title |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
spellingShingle |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru Gutierrez, Neper Klein Condori Epitermal Inclusão fluída Espectrometria Raman Isótopos estáveis CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS Epithermal Fluid inclusion Raman Spectrometry Stable isotopes |
title_short |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
title_full |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
title_fullStr |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
title_full_unstemmed |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
title_sort |
The Ag-Au Pallancata mine : a low-sulphidation epithermal system in southern Peru |
author |
Gutierrez, Neper Klein Condori |
author_facet |
Gutierrez, Neper Klein Condori |
author_role |
author |
dc.contributor.none.fl_str_mv |
Leite, Jayme Alfredo Dexheimer http://lattes.cnpq.br/5219722626641443 Leite, Jayme Alfredo Dexheimer 266.176.500-00 http://lattes.cnpq.br/5219722626641443 Pinho, Francisco Egidio Cavalcante 159.303.271-49 http://lattes.cnpq.br/5549482211923085 266.176.500-00 Barros, Antonio João Paes de 242.041.291-53 http://lattes.cnpq.br/9289477031030869 |
dc.contributor.author.fl_str_mv |
Gutierrez, Neper Klein Condori |
dc.subject.por.fl_str_mv |
Epitermal Inclusão fluída Espectrometria Raman Isótopos estáveis CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS Epithermal Fluid inclusion Raman Spectrometry Stable isotopes |
topic |
Epitermal Inclusão fluída Espectrometria Raman Isótopos estáveis CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS Epithermal Fluid inclusion Raman Spectrometry Stable isotopes |
description |
The Ag-rich Pallancata epithermal district is located in the Huaylilllas magmatic arc along the Neogene belt of southern Peru, which historically produced more than 58 Moz of Ag. The mineralization occurs in quartz veins hosted by 16.58±016 Ma dacitic ignimbrites. Ore minerals include proustite-pirargirite, polibasite-pearceite and argentite with sphalerite, galena and chalcopyrite to a lesser extent; quartz, pyrite, adularia and sericite represent the main gangue minerals. Hydrothermal alteration evolved from regional propylitic to proximal quartz-illite+pyrite and quartz-adularia+pyrite±illite. The mineralized veins fill open spaces in NW-trending, high-angle, subparallel, transtensional faults with sinistral movement and in related extension fractures. Veins are 1 to 30 m wide and up to 3 Km in length with a recognized depth of 350 m. The Pallancata evolution is complex and multiepidsodic and recorded by gangue mineral textures, which include crustiform-, colloform-, cockade- and comb-textured quartz, rhombic adularia and bladed calcite replaced by quartz; the latter two suggests boiling as a precipitation mechanism. The vein evolution records seven stages of gangue and ore deposition with the main mineralization event related to the stage 5, the bonanza stage. The fluid inclusion petrography and microthermometry in quartz from bonanza stage revealed FIA’s mostly consisting of biphasic inclusions (LH2O-VH2O). Homogenization temperatures (Th) and calculated salinities are low with a mean, respectively, around 1.77 % NaCl eq. and 207°C. Raman spectroscopic studies showed SO2 as a minor additional vapor phase and confirmed the lack of CO2. Oxygen isotopes ratios in quartz and adularia and the resulting mean isotopic δ18O composition for water in equilibrium with both minerals is around -7.0 ‰ suggesting a meteoric source for the mineralizing fluid. All the above presented characteristics suggests the Pallancata mineralization as a low-sulphidation epithermal system. |
publishDate |
2016 |
dc.date.none.fl_str_mv |
2016-10-20 2016-06-22 2023-06-23T15:29:09Z 2023-06-23T15:29:09Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
GUTIERREZ, Neper Klein Condori. The Ag-Au Pallancata mine: a low-sulphidation epithermal system in southern Peru. 2016. 39 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Mato Grosso, Faculdade de Geociências, Cuiabá, 2016. http://ri.ufmt.br/handle/1/4277 |
identifier_str_mv |
GUTIERREZ, Neper Klein Condori. The Ag-Au Pallancata mine: a low-sulphidation epithermal system in southern Peru. 2016. 39 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Mato Grosso, Faculdade de Geociências, Cuiabá, 2016. |
url |
http://ri.ufmt.br/handle/1/4277 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de Mato Grosso Brasil Faculdade de Geociências (FAGEO) UFMT CUC - Cuiabá Programa de Pós-Graduação em Geociências |
publisher.none.fl_str_mv |
Universidade Federal de Mato Grosso Brasil Faculdade de Geociências (FAGEO) UFMT CUC - Cuiabá Programa de Pós-Graduação em Geociências |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFMT instname:Universidade Federal de Mato Grosso (UFMT) instacron:UFMT |
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Universidade Federal de Mato Grosso (UFMT) |
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UFMT |
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UFMT |
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Repositório Institucional da UFMT |
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Repositório Institucional da UFMT |
repository.name.fl_str_mv |
Repositório Institucional da UFMT - Universidade Federal de Mato Grosso (UFMT) |
repository.mail.fl_str_mv |
jordanbiblio@gmail.com |
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1804648517416779776 |