scholarly journals Dawsonite as a daughter mineral in hydrothermal fluid inclusions

1971 ◽  
Vol 32 (4) ◽  
pp. 334-342 ◽  
Author(s):  
Raymond M. Coveney ◽  
William C. Kelly
Keyword(s):  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Daughter Mineral

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.

scholarly journals Genesis of Dolomite in Middle Permian Maokou Formation in Eastern Sichuan: Constraints from In Situ Geochemistry, Sr-Mg Isotopes, and Fluid Inclusions

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Yanxia Jiang ◽  
Xianfeng Tan ◽  
Chengjiang Zhang ◽  
Wei Jiang ◽  
Jia Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Trace Element ◽  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Middle Permian ◽  
Late Permian ◽  
Trace Element Contents ◽  
Mg Isotopes ◽  
Eastern Sichuan

The dolostone reservoir of the Middle Permian Maokou Formation in Eastern Sichuan has good prospects for oil and gas exploration. Study of dolomitizing genesis of the Maokou Formation is essential for predicting the distribution of the dolostone reservoir. Petrography, in situ geochemistry, Sr-Mg isotopes, and fluid inclusions were carried out on samples from the Maokou Formation in Eastern Sichuan in order to discuss the dolomitizing process. Based on mineral and textural characteristics, dolomites were divided into four components: partially clouded dolomite (PCD), mosaic-like dolomite (MLD), cloudy-centered and clear-rimmed dolomite (CACD), and saddle dolomite (SDD). Results indicate that the Maokou Formation in Eastern Sichuan mainly experienced two stages of dolomitization. PCD, MLD, and cloudy-centered dolomite (CCD) were formed during the early dolomitization. They all show turbid crystal planes and bright orange-red CL and have similar trace element contents, 87Sr/86Sr ratios, and rare-earth patterns, indicating that they might be formed in the same fluid. This is a period when dolomitizing fluids mainly migrated along pores or microcracks and replaced protogenetic calcites, which occurred in the shallow burial stage of the Maokou Formation before the Late Permian. Clear-rimmed dolomite (CRD) and SDD were formed in the late stage of dolomitization. They all have clean crystal planes and darkly red CL. CRD of the ERY profile has trace element contents, 87Sr/86Sr ratios, and rare-earth patterns similar to SDD of the HLCH profile and Well TL6, inferring that both may be formed in the same fluid. Combined with high SrO contents and homogenous temperatures of fluid inclusions of CRD and SDD and Mg-isotopic compositions, they were generated by hydrothermal dolomitization. The hydrothermal fluid stage is related to the movement of the Emeishan Large Igneous Province, which was made up of basaltic magmatic fluids mixing with the surface water. The hydrothermal fluid mainly migrated upwards along structural fractures or faults and filled in structural fractures, occurring in the Late Permian to Middle-Late Triassic.

Evolution of fluid phases associated with lithium pegmatites from SE Ireland

1989 ◽  
Vol 53 (371) ◽  
pp. 271-284 ◽  
Author(s):  
Martin P. Whitworth ◽  
Andrew H. Rankin
Keyword(s):  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Unknown Origin ◽  
Hydrothermal Fluids ◽  
Stability Field ◽  
Model Type ◽  
Moderate Salinity ◽  
Optical Examination

AbstractFluid inclusions in quartz from internally zoned barren and spodumene-bearing pegmatites associated with the Leinster granite of SE Ireland represent a variety of early and late hydrothermal fluids responsible for the development of pegmatites. Microthermometry and optical examination reveal two main populations of inclusions. The first (Type 1) comprises low-moderate salinity brines which homogenized at temperatures up to about 400 °C. The second (Type 2) appear to postdate the first population and are characteristically more saline and homogenized at temperatures mostly below 250 °C. Isochores for model type 1 inclusion fluids indicate that a late-magmatic/early-hydrothermal fluid developed from the Leinster granite at 675 °C. and 2.5 kbar and cooled isobarically into the spodumene stability field where complete crystallization of the pegmatites took place. Later, more saline, type 2 fluids of unknown origin may have contributed to the alteration of spodumene to muscovite and albite with the accompanying release of lithium from the lattice of spodumene.

Fluid Inclusion Study on the Duobaoshan Porphyry Deposit and Sankuanggou Skarn Deposit, Heilongjiang, China

2014 ◽  
Vol 962-965 ◽  
pp. 41-44
Author(s):  
Hao Wei ◽  
Jiu Hua Xu ◽  
Guo Rui Zhang
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Field Data ◽  
Hydrothermal Fluids ◽  
Fluid Inclusion Study ◽  
Skarn Deposit ◽  
Porphyry Deposit ◽  
Porphyry Cu ◽  
Inclusion Study

In this paper we use new field data, fluid inclummsions, and table isotopes (O, H, and S) to refine the roles of the hydrothermal evolution, evaluate changes in the hydrothermal fluids of Duobaoshan porphyry Cu (Mo) deposit and Sankuanggou skarn Fe-Cu deposit. Four ore-forming stages are recognized at The Duobaoshan porphyry Cu (Mo) deposit. Fluid inclusions are abundant in quartz of various stages. Estimated trapping pressures for stage I, II, III are 110-160MPa, 58-80MPa, and 8-17MPa, corresponding trapping temperatures are 375-650°C, 310-350°C, 210-290°C. The δD and δ18O values of fluids indicate a evolution process from magmtic hydrothermal fluid to a mixing magmtic and meteoric fluid. The δ34S values of sulfides mainly suggest predominantly source of deep magma chamber.

Isotopic (S, Sr, Sm/Nd, D, Pb) evidences for multiple sources in the Early Jurassic Chaillac F-Ba ore deposit (Indre, France)

2009 ◽  
Vol 180 (2) ◽  
pp. 83-94 ◽  
Author(s):  
Stanislas Sizaret ◽  
Eric Marcoux ◽  
Alice Boyce ◽  
Michel Jebrak ◽  
Roos Stevenson ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Hydrothermal Fluid ◽  
Western Europe ◽  
Isotopic Ratio ◽  
Deposition Process ◽  
Ore Deposits ◽  
French Massif Central ◽  
Multiple Sources ◽  
Massif Central ◽  
Ore Deposit

AbstractDuring the earliest Jurassic, a widespread hydrothermal event occurred in western Europe producing large veins and stratiform F-Ba-Pb-Zn ore deposits. Previous work argued about genetic processes involving circulation of mineralising brines. Two main alternative genetic models are proposed. The first one proposes a convection of brines through the crust to produce ore deposits, the second an early infiltration of brine in the basement followed by expulsion during Mesozoic extension. In the northern French Massif Central, new data on the F-Ba Chaillac deposit suggest that the genesis of these mineralising brines requires a new discussion.Located in the northern French Massif Central, the Chaillac barite and fluorite ore deposit is an exceptional site where a stratiform deposit is rooted onto a vein. The ore deposition is split in two stages: 1) precipitation of green and purple fluorite within the vein (Fg-p stage), with associated fluid inclusions indicating 135°C for deposition from a low salinity fluid, and 2) yellow fluorite and barite stage (Fy-Ba) filling the vein and forming the stratiform deposit. Fluid inclusions depict a mineralising brine at 110°C. The 87Sr/86Sr and 143Nd/144Nd isotopic ratios measured in the fluorite are compared to those of French Massif Central rocks. The ratios in green and purple fluorite are similar to those of monzogranite and granodiorite of the basement; those measured in yellow fluorite involve the granulites and other metamorphic rocks of the basement. Measurements of the Sr isotopic ratio and δ34SCDT in barite and δD in fluorite fluid inclusions suggest a deposition process by the mixing of a hydrothermal fluid with meteoric water.At the scale of the northern Massif Central district, the successive hydrothermal fluid salinities are highly contrasted as in Chaillac deposit. We propose that the two types of hydrothermal fluids have been produced by the boiling of a single fluid at depth.

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