A fluid inclusion study of an amethyst deposit in the Cretaceous Kyongsang Basin, South Korea

AbstractThe Eonyang amethyst deposit is thought to be spatially and temporally associated with the biotite granite of the Cretaceous Kyongsang Basin, South Korea. The euhedral quartz crystals in cavities in the aplite which intrudes biotite granite are colour-zoned from white at the base to amethystine at the top. Fluid inclusions from rock-forming quartz in granitic rocks and euhedral quartz crystals in cavities were examined. Three types of primary inclusions were observed and three isochores for inclusions representing each type are constructed to constrain the trapping conditions and fluid evolution involved during the formation of the amethyst. The intersection of the isochore representing the early fluid inclusions with solidus temperature of the host granite indicates initial quartz formation at ~600°C and 1.0–1.5 kbar. Intermediate quartz formation, associated with the high-salinity inclusions, occurred at somewhat lower temperatures (400°C) and pressures of ~1 kbar. The amethystine quartz formed from H2O–CO2–NaCl fluids at temperatures between 280 and 400°C, and pressures of ~1 kbar. Based on the texture and mineralogy of host minerals and on the fluid inclusion characteristics, the euhedral quartz began growing at near solidus conditions of the granite and the pressure did not vary significantly until the end of crystallization of amethystine quartz crystals in cavities. Early quartz in cavities formed from moderately saline fluids that either exsolved from or were in equilibrium with the granite, whereas the amethystine quartz apparently grew from fluids of at least partial sedimentary origin. The granite crystallized at considerable depth under relatively low water pressures probably in the root zones of porphyry-type systems. Hydrothermal activities, fluid compositions and erosion factors combined to provide favourable conditions for the formation of the Eonyang amethyst deposit and its presence near the Earth's surface today.

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Geochemical Data and Fluid Inclusion Study of the Middle Miocene Halite from Deep Borehole Huwniki-1, Situated in the Inner Zone of the Carpathian Foredeep in Poland

Minerals ◽

10.3390/min10121113 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1113

Author(s):

Krzysztof Bukowski ◽

Anatoliy Galamay ◽

Piotr Krzywiec ◽

Andrzej Maksym

Keyword(s):

Fluid Inclusion ◽

Fluid Inclusions ◽

Fluid Inclusion Study ◽

Geochemical Data ◽

Sulfate Ions ◽

Deep Well ◽

Evolutionary Changes ◽

Orogenic Wedge ◽

Inclusion Study ◽

Salinity Water

The geochemical data and the study of fluid inclusions in primary halite are invaluable sources of saline basin information. Most of the previous analyses of salt from the Carpathian area have been obtained by studying the halite samples collected from depths not exceeding 1000 m (i.e., from salt mine outcrops or boreholes). In this article, for the first time, we present the results of samples obtained from a deep well where salt occurs below the frontal orogenic wedge at a depth of ~5000 m. The salt core’s petrological studies showed, quite unexpectedly, the presence of the chevron relics, typical for primary halite. Their geochemical data and fluid inclusion study can be used to reconstruct the environment of the salt sedimentation. The bromine, strontium, and rubidium content values indicated that primary brines were of marine origin, and salts may have undergone partial dissolution and redeposition under lower salinity water inflows. The main ions’ (K, Mg, SO4) ratios in the fluid inclusions were typical for those of the Badenian brines collected from the Carpathian Foredeep’s eastern part. Compared with modern seawater’s chemical composition, this brine contained a slightly lower content of sulfate ions. This was associated with evolutionary changes occurring in the contents of sulfate ions during the Cenozoic.

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Characteristics and applications of fluid inclusions in the Eogene system of the Biyang Depression—I. a fluid inclusion study

Chinese Journal of Geochemistry ◽

10.1007/bf02869068 ◽

1992 ◽

Vol 11 (4) ◽

pp. 370-383 ◽

Cited By ~ 3

Author(s):

Bixian Mai ◽

Benshan Wang

Keyword(s):

Fluid Inclusion ◽

Fluid Inclusions ◽

Fluid Inclusion Study ◽

Inclusion Study ◽

Biyang Depression

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Emeralds from the Delbegetey deposit (Kazakhstan): mineralogical characteristics and fluid-inclusion study

Mineralogical Magazine ◽

10.1180/0026461067020321 ◽

2006 ◽

Vol 70 (2) ◽

pp. 159-173 ◽

Cited By ~ 8

Author(s):

E.V. Gavrilenko ◽

B. Calvo Pérez ◽

R. Castroviejo Bolibar ◽

D. García del Amo

Keyword(s):

Fluid Inclusion ◽

Fluid Inclusions ◽

Isotope Composition ◽

Aqueous Fluid ◽

Fluid Inclusion Study ◽

Refractive Indices ◽

Mineralogical Characteristics ◽

Primary Fluid ◽

Inclusion Study ◽

Characteristic Features

AbstractThe aim of this study is to provide the first detailed mineralogical and fluid-inclusion description of emeralds from the Delbegetey deposit (Kazakhstan). The characteristic features of Delbegetey emeralds are established: they have dissolution figures on crystal faces, bluish colour and distinct colour zoning; the refractive indices are ω = 1.566–1.570, ε = 1.558–1.562, and the specific gravity is 2.65±0.005, relatively low for natural emeralds; they have very small concentrations of the impurities (Fe, Mg, Na and others) typical of other emeralds, and contain Cr and V; there is a significant preponderance of vapour in fluid inclusions of all types and there is liquid-to-vapour homogenization of primary fluid inclusions (at 395–420°C). The lattice oxygen isotope composition data obtained (δ18O SMOW value of 11.3%o) situate the deposit within the range characteristic of other granite-related emerald deposits. Emerald crystallization took place in low-density (0.40–0.55 g/cm3) aqueous fluid, with the following chemical composition (mol.%): 75.6-97.4 H2O, 0.0-18.4 CO2, 0.0-0.9 CH4, and 4.06-9.65 wt.% NaCl equiv. salinity. According to the calculated isochores, the pressure of formation of the Delbegetey emeralds can be estimated at 570–1240 bar.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.41 ◽

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.

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Fluid Inclusion Study of The Tumpangpitu High Sulfidation Epithermal Gold Deposit in Banyuwangi District, East Java, Indonesia

Journal of Geoscience Engineering Environment and Technology ◽

10.24273/jgeet.2018.3.01.1039 ◽

2018 ◽

Vol 3 (1) ◽

pp. 8

Author(s):

Yu Yu Myaing ◽

Arifudin Idrus ◽

Anastasia Dewi Titisari

Keyword(s):

Fluid Inclusion ◽

Fluid Inclusions ◽

Homogenization Temperature ◽

Fluid Inclusion Study ◽

Epithermal Gold ◽

High Sulfidation ◽

Epithermal Mineralization ◽

Epithermal Gold Deposit ◽

Inclusion Study ◽

Low K

The Tumpangpitu high sulfidation (HS) epithermal gold deposit is located in the south coast of East Java, Banyuwangi District, East Java Province, Indonesia. This area lies within the central portion of the Cenozoic Sunda‐Banda magmatic arc which trends southeast from northern Sumatra to west Java then eastward through east Java, Bali, Lombok, Sumbawa and terminating at Banda sea. The geology of the Tumpangpitu is predominantly occupied by Late Oligocene to Middle Miocene low-K calc-alkaline to alkaline andesitic volcanic rocks and interbedded with volcaniclastic rock sequences, which are associated with low-K intermediate intrusions. The mineralization style at the Tumpangpitu area is composed of a high‐sulfidation (HS) epithermal gold-copper system which is typically associated with concealed gold-rich porphyry copper system. The HS epithermal mineralization is hosted by volcanic and volcaniclastic rocks in this research area. The mineralization domains are divided into Zone A, Zone B and Zone C which are situated along NW-SE-trending silica ledges zones. The HS epithermal mineralization is texturally occurs as vuggy replacements mineralization as well as stockworks, disseminated forms, fractures and veins. Fluid inclusion study was conducted for 6 quartz vein samples which petrographically entrapped fluid inclusions. Homogenization temperature (Th) and melting temperature (Tm) can microthermometrically be determined by fluid inclusion analysis. The average homogenization temperature (Th) of the fluid inclusions gives 180˚C to 342˚C and melting temperature are from -0.1 ˚C to -1.4˚C. Tm corresponds to the salinities ranging from 0.1 to 4.5 wt% NaCl equivalent. The paleodepth of ore formation can be estimated from the salinity of fluid. Since the deposit was not formed at boiling condition, the minimum paleodepth of ore (quartz) samples taken from both shallow level (53.35 m) and deep level (135.15 m) is determined at 650m and 1,220 m, respectively. The microthermometric data point out that the Tumpangpitu deposit formed at moderate temperature and low salinity by magmatic fluid mixing and dilution by meteoric water during the hydrothermal fluid evolution. On the basis of the fluid inclusion microthermometric data and its other key characteristics, the Tumpangpitu gold mineralization shares some similarities compared to other typical HS-epithermal gold deposits worlwide although it also shares few differences.

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Common Problems and Pitfalls in Fluid Inclusion Study: A Review and Discussion

Minerals ◽

10.3390/min11010007 ◽

2020 ◽

Vol 11 (1) ◽

pp. 7

Author(s):

Guoxiang Chi ◽

Larryn W. Diamond ◽

Huanzhang Lu ◽

Jianqing Lai ◽

Haixia Chu

Keyword(s):

Fluid Inclusion ◽

Fluid Inclusions ◽

Fluid Phase ◽

Fluid Inclusion Study ◽

Fluid Temperature ◽

Bulk Fluid ◽

Inclusion Study ◽

Common Problems ◽

Potential Impact ◽

Phase Relationships

The study of fluid inclusions is important for understanding various geologic processes involving geofluids. However, there are a number of problems that are frequently encountered in the study of fluid inclusions, especially by beginners, and many of these problems are critical for the validity of the fluid inclusion data and their interpretations. This paper discusses some of the most common problems and/or pitfalls, including those related to fluid inclusion petrography, metastability, fluid phase relationships, fluid temperature and pressure calculation and interpretation, bulk fluid inclusion analysis, and data presentation. A total of 16 problems, many of which have been discussed in the literature, are described and analyzed systematically. The causes of the problems, their potential impact on data quality and interpretation, as well as possible remediation or alleviation, are discussed.

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