scholarly journals Ore Geology, Fluid Inclusions, and (H-O-S-Pb) Isotope Geochemistry of the Sediment-Hosted Antimony Mineralization, Lyhamyar Sb Deposit, Southern Shan Plateau, Eastern Myanmar: Implications for Ore Genesis

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 296
Author(s):  
Aung Min Oo ◽  
Lv Xinbiao ◽  
Khin Zaw ◽  
Than Htay ◽  
Sun Binke ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Meteoric Water ◽  
Isotope Geochemistry ◽  
Pb Isotope ◽  
Primary Fluid ◽  
Magmatic Fluids ◽  
Homogenization Temperatures ◽  
Deposit Model ◽  
Fluid Homogenization ◽  
Stage Stage

The Lyhamyar deposit is a large Sb deposit in the Southern Shan Plateau, Eastern Myanmar. The deposit is located in the Early Silurian Linwe Formation, occurring as syntectonic quartz-stibnite veins. The ore body forms an irregular staircase shape, probably related to steep faulting. Based on the mineral assemblages and cross-cutting relationships, the deposit shows two mineralization stages: (1) the pre-ore sedimentary and diagenetic stage, and (2) the main-ore hydrothermal ore-forming stage (including stages I, II, and III), i.e., (i) early-ore stage (stage I) Quartz-Stibnite, (ii) late-ore stage (stage II) Quartz-calcite-Stibnite ± Pyrite, and (iii) post-ore stage (stage III) carbonate. The ore-forming fluid homogenization temperatures from the study of primary fluid inclusions in quartz and calcite indicate that the ore-forming fluid was of a low temperature (143.8–260.4 °C) and moderate to high-salinity (2.9–20.9 wt. % NaCl equivalent). Hydrogen and oxygen isotopes suggest that the ore-forming fluids of the Lyhamyar deposit were derived from circulating meteoric water mixed with magmatic fluids that underwent isotopic exchange with the surrounding rocks. Sulfur in Lyhamyar was dominated by thermochemical sulfate reduction (TSR) with dominant magmatic source sulfur. The lead isotope compositions of the stibnite indicate that the lead from the ore-forming metals was from the upper crustal lead reservoir and orogenic lead reservoir. On the basis of the integrated geological setting, ore geology, fluid inclusions, (H-O-S-Pb) isotope data, and previous literature, we propose a new ore-deposit model for the Lyhamyar Sb deposit: It was involved in an early deposition of pyrite in sedimentary and diagenetic stages and later Sb mineralization by mixing of circulating meteoric water with ascending magmatic fluids during the hydrothermal mineralization stage.

scholarly journals PŮVOD A CHEMICKÉ SLOŽENÍ FLUID POVARISKÉ HYDROTERMÁLNÍ MINERALIZACE NA LOKALITĚ ZLATÝ DŮL U HLUBOČEK (SPODNÍ KARBON NÍZKÉHO JESENÍKU)

2016 ◽  
Vol 23 (1-2) ◽  
Author(s):  
Michaela Kotlánová ◽  
Zdeněk Dolníček
Keyword(s):  
Stable Isotopes ◽  
Organic Matter ◽  
Chemical Composition ◽  
Fluid Inclusions ◽  
Meteoric Water ◽  
Lower Carboniferous ◽  
Primary Fluid ◽  
Moderate Salinity ◽  
Homogenization Temperatures ◽  
Secondary Fluid

Origin and chemical composition of fluids of hydrothermal ore veins at historical deposit Zlatý důl near Hlubočky (Lower Carboniferous of the Nízký Jeseník Upland) were studied using petrography, microthermometry and crush-leach analysis of fluid inclusions and analysis of stable isotopes of oxygen and carbon in carbonates, oxygen in quartz and sulphur in sulphides. Studied mineralization has epithermal and partly mesothermal character (Th = < 50 to 293 °C). The H2O-NaCl-CaCl2 system is mostly enclosed in the primary fluid inclusions in minerals of post-Variscan ore veins. These fluids had low to medium homogenization temperatures (68 to 293 °C) and moderate to high salinities (19–27 wt. % NaCl eq.). In contrast, low to moderate salinity (0–10 wt. % NaCl eq.) fluids of the system H2O-NaCl-KCl-(MgCl2-FeCl2) with low homogenization temperatures (< 50 to 110 °C) were enclosed in secondary fluid inclusions. The main source of water was probably evaporated seawater for older fluids. The source of carbon was in carbon of the homogenized Earth’s crust and partly in carbon of organic matter. Meteoric water is the main source for younger fluids. Origin of sulphur of sulphides is in the surrounding Lower Carboniferous sediments (shales). The high content of SO4 in fluids hosted by Fe-rich dolomite suggests the origin of the fluids in the evaporated Permian basins. Studied older quartz-galena vein is probably Variscan in age. Genetically similar mineralization can be found also at other localities in the Moravo-Silesian Lower Carboniferous (Culm, siliciclastics of the Lower Carboniferous age).

scholarly journals Genesis of the Heiyanshan Tungsten Skarn Deposit in the East Tianshan, NW China: Insights From Geology, Fluid Inclusion, Isotopic Geochemistry and Geochronology

2021 ◽  
Vol 9 ◽  
Author(s):  
Dong Xue ◽  
Xiao-Hua Deng ◽  
Leon Bagas ◽  
Xu-An Chen ◽  
Yan-Shuang Wu ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Meteoric Water ◽  
Tectonic Setting ◽  
Fluid Mixing ◽  
Eastern Tianshan ◽  
Fine Grained ◽  
Magmatic Fluids ◽  
Skarn Deposits ◽  
Altered Zone ◽  
Tungsten Deposits

The eastern Tianshan Terrane is a highly prospective zone that contains several porphyry Cu–Mo, VMS Cu–Zn, magmatic Cu–Ni, epithermal and orogenic Au deposits. However, few attention has been paid to tungsten deposits. Of these, the source and evolution of the mineralising fluids related to the skarn W deposits are poorly understood. The Heiyanshan W deposit is hosted by metamorphosed clastic and carbonate beds in the Mesoproterozoic Jianshanzi Formation deposited on a continental margin tectonic setting. The Jianshanzi Formation is intruded by biotite monzogranite that yield weighted 206Pb/238U age of 326.9 ± 1.6 Ma, which suggest that the Heiyanshan W deposit was formed in the Carboniferous. The mineralisation is hosted by a prograde hydrothermal altered zone represented by a garnet (–pyroxene) skarn, and retrograde skarn characterised by fine-grained scheelite. The paragenesis of the Heiyanshan mineralisation can be subdivided into prograde skarn stage, retrograde skarn stage, quartz-sulphide stage and quartz-calcite vein stage. The types of fluid inclusions recognised in the various minerals in the deposits are liquid-rich aqueous, vapour-rich aqueous, and daughter mineral-bearing. The homogenisation temperatures of fluid inclusions from the Heiyanshan deposit decrease from 290 ± 28°C in garnet, through 232 ± 31°C in scheelite, to 232 ± 36°C in quartz and 158 ± 15°C in non-mineralised calcite, which is typical of W-bearing skarn deposits worldwide. The δ18Owater values from the Heiyanshan deposit range from +4.7 to +6.6‰ in garnet, +1.3 to +1.9‰ in quartz and −6.1 to −4.4‰ in calcite. We have measured δD in fluid inclusions from different minerals, although these bulk analyses are just a mixture of the different FIA’s present in the sample. The δD values of fluid inclusions in garnet, quartz, and calcite are from −121 to −71‰, −84 to −75‰ and −101 to −82‰, respectively, also indicative of deep-sourced magmatic fluids mixed with meteoric water. The decrease in the homogenisation temperatures for the fluid inclusions at the Heiyanshan deposit is accompanied by a drop in salinity indicating that tungsten-bearing minerals precipitated during fluid mixing between magmatic fluids and meteoric water. We conclude that eastern Tianshan Terrane contains two pulse of tungsten metallogenic events of Late Carboniferous and Early Triassic.

Mineralogy, fluid inclusions, and S–Pb isotope geochemistry study of the Tuboh Pb–Zn–Ag polymetallic deposit, Lubuklinggau, Sumatra, Indonesia

2019 ◽  
Vol 112 ◽  
pp. 103032 ◽  
Author(s):  
Jinhong Xu ◽  
Zhengwei Zhang ◽  
Chengquan Wu ◽  
Qiao Shu ◽  
Chaofei Zheng ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Isotope Geochemistry ◽  
Pb Isotope ◽  
Polymetallic Deposit

The Lavrion Pb-Zn-Ag–Rich Vein and Breccia Detachment-Related Deposits (Greece): Involvement of Evaporated Seawater and Meteoric Fluids During Postorogenic Exhumation

2019 ◽  
Vol 114 (7) ◽  
pp. 1415-1442 ◽  
Author(s):  
Christophe Scheffer ◽  
Alexandre Tarantola ◽  
Olivier Vanderhaeghe ◽  
Panagiotis Voudouris ◽  
Paul G. Spry ◽  
...  
Keyword(s):  
High Temperature ◽  
Fluid Inclusions ◽  
Meteoric Water ◽  
Ore Deposits ◽  
Metal Sulfides ◽  
Low Grade ◽  
High Grade ◽  
Base Metal Sulfides ◽  
Wide Range ◽  
Homogenization Temperatures

Abstract The formation of ore deposits in the Lavrion Pb-Zn-Ag district was associated with Miocene detachment that accommodated orogenic collapse and exhumation of high-grade nappes across the ductile-brittle transition. This district consists of (1) low-grade porphyry Mo style, (2) Cu-Fe skarn, (3) high-temperature carbonate replacement Pb-Zn-Ag, and (4) vein and breccia Pb-Zn-Ag mineralization. The vein and breccia mineralization locally contains high-grade silver in base metal sulfides that are cemented by fluorite and carbonate gangue. The rare earth element contents of these gangue minerals, chondrite-normalized patterns, and fluid inclusion studies suggest that they precipitated from a low-temperature hydrothermal fluid. Primary and pseudosecondary fluid inclusions in fluorite and calcite are characterized by a wide range of homogenization temperatures (92°–207°C) and salinities of up to 17.1 wt % NaCl equiv. Secondary fluid inclusions only represent <5 vol % of the total fluid trapped. Fluids extracted from inclusions in fluorite have values of δD = –82.1 to –47.7‰ (Vienna-standard mean ocean water [V-SMOW]) and δ18O = –10.4 to –5.1‰ (V-SMOW). These data and low ratios of Cl/Br measured by crush-leach analyses for fluids in fluorite (102–315) and calcite (162–188) are compatible with the ore fluid being the result of mixing of meteoric water with evaporated seawater. These data suggest that fluids leading to the deposition of late Pb-Zn-Ag–rich vein- and breccia-style mineralization in Lavrion were related to circulation of mixed evaporated seawater and meteoric fluids that was enhanced by brittle deformation. This contrasts with the fluids of magmatic origin related to the formation of low-grade porphyry Mo, Cu-Fe skarn, and high-temperature carbonate replacement deposits spatially related to the Plaka granodiorite.

scholarly journals Geologia e Geoquímica (ETR e Inclusões Fluidas) das Mineralizações (F, BA) da Parte Norte do Distrito Fluorítico de Santa Catrina, Sul do Brasil

1999 ◽  
Vol 26 (2) ◽  
pp. 3
Author(s):  
FLÁVIO FRANÇA DA ROCHA ◽  
ARTHUR CÉZAR BASTOS NETO
Keyword(s):  
Fluid Inclusions ◽  
Meteoric Water ◽  
Normal Fault ◽  
Salinity Range ◽  
Alkaline Magmatism ◽  
Second Phase ◽  
Southern District ◽  
Extensional Tectonic ◽  
Primary Fluid ◽  
Hydrothermal Event

This work deals on the fluorite deposits from the Grão Pará (GP) and Rio Bravo Alto (RBA) veins systems both situated at the northern part of Santa Catarina Fluorite District. The GP deposits are controlled by an ancient shear zone. Ore deposition is related to two tectonic phases: (1) dextral transtensive reactivation related to a NE/SW compression; deposition of green-purple massive or coarse banded fluorite; tectonic and hydraulic breccias assign successive transitions from hydrostatic to tectonic regimes; the ore was affected by latter silicification; (2) reactivation as normal fault, related to a extensional tectonic; deposition of purple and yellow banded fluorite, collapse breccias and cocardes. First phase fluorite was deposited at temperatures decreasing from 170º to 120ºC; silicification temperature is around 140ºC. Second phase fluorite was deposited at temperatures between 140º and 120ºC. The fluid inclusions salinity range from 0 to 2% eq. NaCl. The isotopic composition of water from primary fluid inclusions in the fluorite at RBA (δD ͌ -60‰ SMOW) is typical of meteoric water from interior continental region. The RBA fluorite has the same HREE signature as fluorite from the southern district deposits and regional granites. REE and fluid inclusion data reject a link with alkaline magmatism. Fluorine was leached from accessory fluorite of regional granites. The fluorite deposition was connected to a single hydrothermal event correlated to the earlier hydrothermal event described at the southern district.    

Fluid inclusions in thenardite from northern Mali: experimental stretching and microthermometric investigations

1990 ◽  
Vol 54 (375) ◽  
pp. 305-309 ◽  
Author(s):  
A. Canals-Sabate ◽  
J. C. Touray ◽  
J. Fabre
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Eutectic Temperature ◽  
List Type ◽  
Formation Temperature ◽  
Heating Rates ◽  
Fluid Inclusion Data ◽  
Primary Fluid ◽  
Homogenization Temperatures ◽  
Underground Brines

AbstractLarge thenardite crystals have been sampled at New Agorgott, in the Taoudenni area of northern Mali. They are still in equilibrium with a pressurized NaCl saturated brine capped by a halite layer. Clays located about 1 m above the thenardite occurrence have been dated at 6760 y.BP. The crystals contain numerous, large, brine and solid inclusions. Microcryscopic studies show that the fluids can be explained by the addition of MgCl2 to the Na2SO4-NaCl-H2O system (eutectic temperature: −31 to −35°C; possible bloedite Na2Mg(SO4)2.4H2O formed after freezing). The homogenization temperatures of primary fluid inclusions are in the range 28 to 50°C. In order to understand the significance of the highest Th values, overheating experiments under 1 bar pressure were performed at different heating rates up to 170°C. The results are as follows:(i)When the temperature of stretching (TOh) is higher than about 10°C, overheating is recorded and fossilized (identical Th after some hours, several days or 8 months storage at 5°C).(ii)The lowest Th values (28°C) are probably near the formation temperature of thenardite; the highest ones reflect stretching under present desert conditions.(iii)With TOh lower than about 60°C, a fair correlation is observed between Th and TOh.Finally, taking into account recent natural overheating, the fluid inclusion data are compatible with the formation of thenardite from underground brines later than the beginning of desert conditions in the Taoudenni area (i.e. about 3000 y.BP).

scholarly journals Ore Genesis of Shanmen Ag Deposit in Siping Area of Southern Jilin Province, NE China: Constraints from Fluid Inclusions and H-O, S, Pb Isotopes

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 586 ◽  
Author(s):  
Sun ◽  
Ren ◽  
Cao ◽  
Hao ◽  
Gao
Keyword(s):  
Low Temperature ◽  
Fluid Inclusions ◽  
Stage I ◽  
Ne China ◽  
Two Phase ◽  
Low Salinity ◽  
Temperature Environment ◽  
Homogenization Temperatures ◽  
Late Stages ◽  
Stage Stage

The Shanmen Ag deposit, located in the southeastern part of the Siping area, Jilin Province, is one of the large-scale Ag deposits in Northeastern (NE) China. Almost all Ag orebodies, Ag-bearing quartz-sulfide veins are strictly controlled by NE-trending faults or brittle fractures and are hosted in the Yanshanian monzonite and quartz diorite. In terms of deposit geology, three mineralization stages are recognized: the pyrite-quartz stage (I), the quartz-Ag-polymetallic sulfide stage (II), and the carbonate-quartz stage (III). The research results of the fluid inclusions in the different stages indicate that the early stage (Stage I) mainly contains three types of fluid inclusions: liquid-rich two-phase (L-type), vapor-rich two-phase (V-type), and CO2 aqueous multi-phase (C-type). The fluid belongs to a medium–high temperature and medium–low salinity H2O-NaCl-CO2 system and has boiling characteristics. The middle stage (Stage II) is mainly characterized by liquid-rich two-phase (L-type) and vapor-rich two-phase (V-type) inclusions, in which the mixing of fluids of different nature leads to the escape of CO2. Only liquid-rich two-phase (L-type) inclusions are distinguished in the late stage (Stage III). The fluids of two later stages belong to the medium-low-temperature and low-salinity H2O-NaCl system. Homogenization temperatures from the early to late stages range from 272.2 to 412.5 °C, 124.1 to 313.3 °C, and 128.6 to 224 °C, respectively. Fluid salinities in the early to late stages range from 1.6 to 12.1, 1.4 to 8.9, and 0.4 to 5.8 wt.% NaCl equivalent, respectively. The gradually decreasing trends of homogenization temperatures and salinities and the reduction in the CO2 content indicate that the release of CO2 and the low-temperature environment are important causes of the precipitation of Ag-bearing minerals. The δ18OH2O values of the ore-bearing quartz veins in the different stages range from −3.7 to +8.1‰, and the δD values of fluid inclusions in the quartz range from −113 to −103‰, indicating that the initial ore-forming fluid was mainly derived from magma and that the input of meteoric water gradually increased during the mineralization process. The δ34S values (ranging from −11.4‰ to +1.8‰) and Pb isotope compositions (206Pb/204Pb = 18.143–18.189, 207Pb/204Pb = 15.543–15.599, 208Pb/204Pb = 38.062–38.251) of sulfides suggest that the ore-forming materials have mixed mantle and crustal sources. Therefore, we propose that the release of CO2 and the low-temperature environment are important conditions for silver minerals precipitation, and the mixing of fluids of different nature is the dominant mechanism causing precipitation. The Shanmen Ag deposit can be classified as an intrusion-related medium–low temperature hydrothermal vein-type deposit.

scholarly journals The Lotsberg Salt Formation in Central Alberta (Canada)—Petrology, Geochemistry, and Fluid Inclusions

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 868
Author(s):  
Tomasz Toboła ◽  
Piotr Kukiałka
Keyword(s):  
Fluid Inclusions ◽  
Magnesium Content ◽  
Salt Formation ◽  
High Concentration ◽  
Large Area ◽  
Normal Range ◽  
Salt Rocks ◽  
Primary Fluid ◽  
Homogenization Temperatures ◽  
Devonian Age

The Lotsberg Salt Formation (LSF) of the Lower Devonian age occupies a large area in Alberta (Canada). It has been used for brine production, disposal, and storage purposes since the 1950s. Its petrological and geochemical features remain poorly understood up to now. Previous studies showed that these salt rocks are large crystalline and distinguishable by a very low bromine content (2–5 ppm). Our studies reveal that the main impurity is dolomite with an addition of haematite. It showed, also, a lack of sulphate minerals (anhydrite). Manganite also occurs within the halite crystals. Microthermometric measurements of primary fluid inclusions in halite show a large range of homogenization temperatures from 32.4 °C to 357.0 °C with the highest temperature in the upper part of the salt profile. Geochemical analysis confirms the low bromine contents, which is between 0.67–12.74 ppm. Potassium contents (166–3651 ppm) seem to be in the normal range for salt rocks, but magnesium content (25–177 ppm) is much lower than potassium. Rubidium is, as well, within the normal range, with values between <0.01 ppm and 3.13 ppm, while caesium contents (5.07–211.22 ppm) are almost sixty times higher in comparison to those of rubidium. The high concentration of Cs, Mn, Rb, and the high homogenization temperatures of the host minerals suggest that the LSF underwent extensive ion exchange related to hydrothermal inflow. These hydrothermal solutions originated from the basement of the LSF.

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