The genesis of the Deer Trail Zn–Pb–Ag vein deposits, northeast Washington, U.S.A.: evidence from fluid-inclusion and stable-isotope studies

1987 ◽  
Vol 24 (8) ◽  
pp. 1715-1726 ◽  
Author(s):  
D. W. Fluet ◽  
A. Changkakoti ◽  
R. D. Morton ◽  
J. Gray ◽  
H. R. Krouse
Keyword(s):  
Fluid Inclusion ◽  
Isotope Exchange ◽  
Hydrothermal Fluids ◽  
Geothermal System ◽  
Metasedimentary Rocks ◽  
Isotope Studies ◽  
Three Stages ◽  
Vein Deposits ◽  
Homogenization Temperatures ◽  
Insight Into

The Zn–Pb–Ag-bearing vein deposits of the Deer Trail mine, northeastern Washington, U.S.A., are hosted by Beltian metasediments that have been intruded by the Jurassic–Cretaceous Loon Lake granitoid batholith.Vein infilling took place in three stages: pre-ore, ore, and post-ore. Fluid-inclusion studies revealed homogenization temperatures and salinities of approximately 300 °C and 6.5–8.5 wt. % NaCl equivalent, respectively, for the pre-ore stage; 250–150 °C and 4–7.5 wt. % NaCl equivalent for the ore stage; and less than 150 °C and 3 wt. % NaCl equivlent for the post-ore stage. The calculated δ18O values of the hydrothermal fluids and δD values of fluid inclusion waters were +8 to +11‰ (SMOW) and −128 to −134‰ (SMOW), respectively, for the pre-ore stage; 0 to +10‰ and −89 to −143‰ for the ore stage; and 0 to −5‰ and −139‰ for the post-ore stage. The δ34S(ΣS) of the hydrothermal fluids was approximately +10‰(CDT).The results provide insight into the evolution of a geothermal system dominated by meteoric waters and driven thermally by the cooling batholith. The chemical and isotopic compositions of the veins were influenced by chemical reactions and isotope exchange of the hydrothermal fluids with the Precambrian metasedimentary rocks.

Conditions for emerald formation at Davdar, China: fluid inclusion, trace element and stable isotope studies

2012 ◽  
Vol 76 (1) ◽  
pp. 213-226 ◽  
Author(s):  
D. Marshall ◽  
V. Pardieu ◽  
L. Loughrey ◽  
P. Jones ◽  
G. Xue
Keyword(s):  
Stable Isotope ◽  
Fluid Inclusion ◽  
Trace Element ◽  
Metasedimentary Rocks ◽  
Quartz Veins ◽  
Trace Element Chemistry ◽  
Stable Isotope Signatures ◽  
Swat Valley ◽  
Isotope Studies ◽  
Geological Work

AbstractPreliminary geological work on samples from Davdar in China indicate that emerald occurs in quartz veins hosted within upper greenschist grade Permian metasedimentary rocks including quartzite, marble, phyllite and schist. Fluid inclusion studies indicate highly saline fluids ranging from approximately 34 to 41 wt.% NaCl equivalent, with minimal amounts of CO2 estimated at a mole fraction of 0.003. Fluid inclusion, stable isotope and petrographic studies indicate the Davdar emeralds crystallized from highly saline brines in greenschist facies conditions at a temperature of ∼350°C and a pressure of up to 160 MPa. The highly saline fluid inclusions in the emeralds, the trace-element chemistry and stable isotope signatures indicate that the Davdar emeralds have some similarities to the Khaltaro and Swat Valley emerald deposits in Pakistan, but they show the greatest similarity to neighbouring deposits at Panjshir in Afghanistan.

scholarly journals Fluid inclusion evidence for the magmatic-hydrothermal evolution of closely linked porphyry Au, porphyry Mo, and barren systems, East Qinling, China

2021 ◽  
Author(s):  
Li Tang ◽  
Thomas Wagner ◽  
Tobias Fusswinkel ◽  
Shou-Ting Zhang ◽  
Xin-Kai Hu ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Integrated Approach ◽  
Hydrothermal Fluids ◽  
Central China ◽  
Phase Iii ◽  
Mass Spectrometry Analysis ◽  
Fluid Composition ◽  
Magma Fractionation ◽  
Homogenization Temperatures ◽  
Porphyry Systems

The Xiong’ershan district in central China hosts broadly coeval porphyry Au (Qiyugou deposit), porphyry Mo (Leimengou deposit), and barren (Huashan pluton) systems. The key controls on the ore potential and different mineralization styles in these systems are not well understood, with first-order differences in fluid chemistry and melt sources being the main alternatives. The fluid inclusion characteristics of all three porphyry systems have been studied using an integrated approach that combines field geology, petrography, microthermometry, and laser ablation−inductively coupled plasma−mass spectrometry analysis of single fluid inclusions. The results permit a reconstruction of the magmatic-hydrothermal evolution of the ore-forming fluids, and to elucidate whether specialized hydrothermal fluids strongly enriched in ore metals (i.e., Mo, Au, Cu) were essential to form the economically significant deposits. The fluid compositions across the three hydrothermal stages from the Qiyugou Au deposit remain approximately the same over time, suggesting that progressive magma fractionation, fluid-rock reaction along fluid path, and mineral precipitation had a limited effect on fluid composition. The syn-ore stage fluids of the Leimengou Mo deposit are characterized by higher Cs/Na, Sr/Na, and B/Na, but lower K/Na and Cl/Na ratios, and also have salinities and homogenization temperatures distinct from the earlier fluids. This demonstrates that Mo mineralization was caused by a second pulse of fluid input from a highly fractionated felsic magma subsequent to the pre-ore stage. At the Huashan barren pluton, fluids from phase II have higher Cs/Na, B/Na, Li/Na, and Rb/Na ratios with lower homogenization temperatures than fluids occurring in porphyritic rocks of phase III, reflecting a higher degree of magma fractionation of this plutonic complex. The Huashan pluton does not host economic mineralization which is likely caused by the low ore metal tenor, inefficient fluid extraction from the melt, or the flat-roof geometry preventing accumulation of a large volume of fluid in the apical part. The Au tenor of the Qiyugou deposit was most likely contributed by mantle-derived material of higher Mg/Na, Fe/Na, Pb/Na, and Zn/Na ratios. Taken together, the metal charged magmatic-hydrothermal fluids, steeply dipping geometry, and small volume of the porphyry stocks all suggest that a much larger magma chamber feeding the porphyry systems should be present at deeper levels with good potential for Mo mineralization below the current level of exposure at Qiyugou deposit.

scholarly journals Tungsten Ores of the Dzhida W-Mo Ore Field (Southwestern Transbaikalia, Russia): Mineral Composition and Physical-Chemical Conditions of Formation

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 725
Author(s):  
Ludmila B. Damdinova ◽  
Bulat B. Damdinov
Keyword(s):  
Mineral Composition ◽  
Fluid Inclusions ◽  
Apical Part ◽  
Hydrothermal Fluids ◽  
True Temperature ◽  
Gangue Mineral ◽  
Mineral Formation ◽  
Physical Chemical ◽  
Homogenization Temperatures ◽  
Chemical Conditions

This article discusses the peculiarities of mineral composition and a fluid inclusions (FIs further in the text) study of the Kholtoson W and Inkur W deposits located within the Dzhida W-Mo ore field (Southwestern Transbaikalia, Russia). The Mo mineralization spatially coincides with the apical part of the Pervomaisky stock (Pervomaisky deposit), and the W mineralization forms numerous quartz veins in the western part of the ore field (Kholtoson vein deposit) and the stockwork in the central part (Inkur stockwork deposit). The ore mineral composition is similar at both deposits. Quartz is the main gangue mineral; there are also present muscovite, K-feldspar, and carbonates. The main ore mineral of both deposits is hubnerite. In addition to hubnerite, at both deposits, more than 20 mineral species were identified; they include sulfides (pyrite, chalcopyrite, galena, sphalerite, bornite, etc.), sulfosalts (tetrahedrite, aikinite, stannite, etc.), oxides (scheelite, cassiterite), and tellurides (hessite). The results of mineralogical and fluid inclusions studies allowed us to conclude that the Inkur W and the Kholtoson W deposits were formed by the same hydrothermal fluids, related to the same ore-forming system. For both deposits, the fluid inclusion homogenization temperatures varied within the range ~195–344 °C. The presence of cogenetic liquid- and vapor-dominated inclusions in the quartz from the ores of the Kholtoson deposit allowed us to estimate the true temperature range of mineral formation as 413–350 °C. Ore deposition occurred under similar physical-chemical conditions, differing only in pressures of mineral formation. The main factors of hubnerite deposition from hydrothermal fluids were decreases in temperature.

Cierco Pb-Zn-Ag vein deposits; isotopic and fluid inclusion evidence for formation during the Mesozoic extension in the Pyrenees of Spain

1996 ◽  
Vol 91 (3) ◽  
pp. 497-506 ◽  
Author(s):  
Craig A. Johnson ◽  
Esteve Cardellach ◽  
J. Tritlla ◽  
B. B. Hanan
Keyword(s):  
Fluid Inclusion ◽  
Vein Deposits

Isotopic and fluid-inclusion constraints on the formation of polymetallic vein deposits in the central Argentinian Patagonia

2001 ◽  
Vol 37 (2) ◽  
pp. 158-172 ◽  
Author(s):  
Léon Dejonghe ◽  
Benoît Darras ◽  
Guillermo Hughes ◽  
Philippe Muchez ◽  
James S. Scoates ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Vein Deposits
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