CHARACTERIZING THE STRUCTURE, MINERALOGY, AND PARAGENETIC SEQUENCE OF SHEETED QUARTZ VEINS IN THE ERTSBERG EAST SKARN SYSTEM, PAPUA, INDONESIA

2016 ◽  
Author(s):  
Daniel Young ◽  
◽  
Matthew Ledvina ◽  
J. Richard Kyle
Keyword(s):  
Paragenetic Sequence ◽  
Quartz Veins

CHARACTERIZATION OF PALEOPROTEROZOIC STRUCTURES, AURIFEROUS QUARTZ VEINS, AND HOST ROCKS, FISHER PROPERTY, SEABEE GOLD OPERATION, SASKATCHEWAN, CANADA

2019 ◽  
Author(s):  
Courtney Carol Onstad ◽  
◽  
Kevin M. Ansdell ◽  
Camille A. Partin ◽  
Anders Carlson
Keyword(s):  
Quartz Veins ◽  
Host Rocks

scholarly journals PARAGUAY BELT LITHOSTRATIGRAPHIC AND TECTONIC CHARACTERIZATION: IMPLICATIONS IN THE EVOLUTION OF THE OROGEN (MATO GROSSO-BRAZIL) / CARACTERIZAÇÃO LITOESTRATIGRÁFICA E TECTÔNICA DO CINTURÃO PARAGUAY : IMPLICAÇÕES NA EVOLUÇÃO DO ORÓGENO (MATO GROSSO-BRASIL)

2018 ◽  
Vol 3 (2) ◽  
pp. 54-73
Author(s):  
Elzio Da Silva Barboza ◽  
Anderson Costa dos Santos ◽  
Carlos José Fernandes ◽  
Mauro César Geraldes
Keyword(s):  
Gold Content ◽  
Mato Grosso ◽  
Quartz Veins ◽  
Marine Sedimentation ◽  
Amazonian Craton ◽  
Gondwana Supercontinent ◽  
Surrounding Areas ◽  
Shelf Region ◽  
High Gold Content

The Paraguay Belt is composed by sediments deposited due to extensional events followed by inversion with deformation and magmatism and lastly collision of the Amazonian Craton and Paranapanema Block. The marine sedimentation, with Neoproterozoic ages, should have occurred in a continental shelf region, at about 800-550 Ma, when the closing of many oceans gave place to the amalgamation of the Gondwana supercontinent. Three areas were selected for this study which configuration define the perpendicular profile of the Paraguay Belt and allow the characterization of the main regional structures.The structural analysis in the sites here reported and surrounding areas allow suggesting that three deformational events are recorded in the rocks of this region. The sedimentary bedding S0, marked by alternations of dark gray and whitish coloration in the seritic phyllites is folded and the axial plane (Sn) is marked by a cleavage of ardosian. These surfaces are cut by two other deformations, Sn + 1 surface that plunges at high angles to SE as fracture cleavage and Sn + 2 that is orthogonal to the previous deformations and has NW-SE direction with vertical dips, where sometimes occurs quartz veins with high gold content. The Paraguay Belt fan geometry observed in the Sn foliation was developed during the closing of a Brazilian ocean that evolved between the Paranapanema Block and the Amazonian Craton. ResumoO Cinturão Paraguai é composto por sedimentos depositados durante eventos extencionais  seguidos de inversão com deformação e magmatismo e, por último, colisão do Craton Amazônico e do Bloco Paranapanema. A sedimentação marinha, com idades Neoproterozóicas, ocorreu  em uma região de plataforma continental, entre 800-550 Ma, quando o fechamento de muitos oceanos deu lugar à fusão do supercontinente Gondwana. Três áreas foram selecionadas para este estudo cuja configuração define um  perfil perpendicular do Cinturão do Paraguai e permite a caracterização das principais estruturas regionais.A análise estrutural nos locais aqui relatados e áreas adjacentes permite sugerir que as rochas do orógeno passou por três eventos deformacionais. O acamamento  sedimentar S0, marcado por alternâncias de coloração cinza-escura e esbranquiçada nos filitos e siltitos, é dobrado e o plano axial (Sn) é marcado por uma clivagem ardosiana. Estas superfícies são cortadas por outras duas deformações, Sn + 1 que mergulha em ângulos elevados para SE como clivagem de fratura e Sn + 2 que é ortogonal às deformações anteriores e tem direção NW-SE com mergulhos verticais, onde às vezes ocorrem veios de quartzo com alto teor de ouro. A geometria em leque  do Cinturão Paraguay observada na foliação de Sn foi desenvolvida durante o fechamento de um oceano brasileiro que evoluiu entre o Bloco Paranapanema e o Craton Amazônico.

Multistage hydrothermal quartz veins record the ore-forming fluid evolution in the Meiling Cu–Zn (Au) deposit, NW China

2021 ◽  
Vol 131 ◽  
pp. 104002
Author(s):  
Zhiyuan Sun ◽  
Jingbin Wang ◽  
Yang Wang ◽  
Yan Zhang ◽  
Lutong Zhao
Keyword(s):  
Nw China ◽  
Quartz Veins ◽  
Hydrothermal Quartz ◽  
Fluid Evolution

scholarly journals Ore Genesis at the Jinchang Gold–Copper Deposit in Heilongjiang Province, Northeastern China: Evidence from Geology, Fluid Inclusions, and H–O–S Isotopes

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 99 ◽  
Author(s):  
Shunda Li ◽  
Xuebing Zhang ◽  
Lingling Gao
Keyword(s):  
Fluid Inclusions ◽  
Copper Deposit ◽  
Northeastern China ◽  
Heilongjiang Province ◽  
Quartz Veins ◽  
Daughter Mineral ◽  
Rich Liquid ◽  
Three Stages ◽  
Stage 1 ◽  
Late Stages

The Jinchang gold–copper deposit is located in Eastern Heilongjiang Province,Northeastern China. The orebody comprises primarily hydrothermal breccias, quartz veins, anddisseminated ores within granite, diorite, and granodiorite. Three paragenetic stages are identified:early quartz–pyrite–arsenopyrite (Stage 1), quartz–pyrite–chalcopyrite (Stage 2), and latequartz–pyrite–galena–sphalerite (Stage 3). Gold was deposited during all three stages and Stage 1was the major gold-producing stage. Copper is associated with the mineralization but has loweconomic value. Fluid inclusions (FIs) within the deposit are liquid-rich aqueous, vapor-rich aqueous,and daughter-mineral-bearing types. Microthermometric data for the FIs reveal decreasinghomogenization temperatures (Th) and salinities of the ore-forming fluids over time. The Th forStages 1–3 of the mineralization are 421–479, 363–408, and 296–347 °C, respectively. Stage 1 fluidsin vapor-rich and daughter-mineral-bearing inclusions have salinities of 5.7–8.7 and 49.8–54.4 wt%NaCl equivalent, respectively. Stage 2 fluids in vapor-rich, liquid-rich, and daughter-mineral-bearinginclusions have salinities of 1.2–5.4, 9.5–16.0, and 43.3–48.3 wt% NaCl, respectively. Stage 3 fluids inliquid-rich and daughter-mineral-bearing inclusions have salinities of 7.9–12.6 and 38.3–42.0 wt% NaClequivalent, respectively. The estimated trapping pressures are 160–220 bar, corresponding toan entrapment depth of 1.6–1.2 km in the paleo-water table. Oxygen and hydrogen isotope data(δ18OV-SMOW = 8.6‰ to 11.4‰; δDV-SMOW = −92.2‰ to −72.1‰) suggest that the ore-forming fluidswere derived from magmatic fluids during the early stages of mineralization and subsequentlyincorporated meteoric water during the late stages. The sulfide minerals have δ34SVCDT values of0.2‰–3.5‰, suggesting that the sulfur has a magmatic origin. The Jinchang deposit is a typicalgold-rich gold–copper porphyry deposit.

Bismuth-bearing assemblages from the Northern Pennine Orefield

1996 ◽  
Vol 60 (399) ◽  
pp. 317-324 ◽  
Author(s):  
R. A. Ixer ◽  
B. Young ◽  
C. J. Stanley
Keyword(s):  
Qualitative Analysis ◽  
Fine Grained ◽  
Quartz Veins ◽  
The North ◽  
Data Form ◽  
Form Part ◽  
Native Bismuth ◽  
Monoclinic Pyrrhotite ◽  
Early Phases ◽  
And Tungsten

AbstractBismuthinite-bearing quartz veins from the Alston Block of the North Pennine Orefield are all close to, or above, the Rookhope and Tynehead cupolas of the buried Weardale Granite. They are uniform in composition and paragenesis and are earlier than the main fluorite-baryte-galena-sphalerite mineralization of the orefield. Rhythmical crystallization of quartz, chalcopyrite and minor pyrite is followed by fluorite-quartz-chalcopyrite-minor sphalerite-altered pyrrhotite mineralization. Early tin-bearing (up to 0.29 wt.% Sn) chalcopyrite encloses trace amounts of bismuthinite (Bi2S3), synchysite (CaREE(CO3)F2), argentopentlandite (Ag(FeNi)8S8) (close to being stoichiometric), pyrrhotite, cubanite and cosalite (Pb2Bi2S5), while early pyrite carries monoclinic pyrrhotite (close to Fe7S8) and tungsten-bearing cassiterite (up to 1.03 wt.% WO3). Bismuthinite is macroscopically visible and is associated with native bismuth and small, fine-grained, spherical aggregates that qualitative analysis suggests may be cosalite crystals. Synchysite and more rarely monazite, xenotime and adularia are intergrown with bismuthinite. These mineralogical data form part of the basis for an increasing awareness of the contribution of the Weardale Granite to the early phases of mineralization in the Alston Block.

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