scholarly journals Formation of Diagenetic Minerals in the Carboniferous Rock Complex from the Fore-Sudetic Monocline (SW Poland): Fluid Inclusion, Isotopic and Raman Constraints

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 976
Author(s):  
Aleksandra Kozłowska ◽  
Katarzyna Jarmołowicz-Szulc ◽  
Marta Kuberska ◽  
Krystyna Wołkowicz
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Regional Metamorphism ◽  
Microscopic Analysis ◽  
Thin Sections ◽  
Mineralogical Characteristics ◽  
Low Degree ◽  
Isotopic Analyses ◽  
Homogenization Temperatures ◽  
Clastic Sedimentary

The paper presents the latest state of knowledge on clastic sedimentary rocks from the Carboniferous complex in the SW part of the Polish Lowlands, studied to help determine their potential prospectivity for the occurrence of oil and/or gas deposits. Rocks were analyzed with respect to the petrographic-mineralogical characteristics of the Carboniferous deposits, their diagenesis, determinations of pressure-temperature conditions of mineral formation and the hydrocarbon occurrence. Analyses were carried out on samples from four selected boreholes in the Fore-Sudetic Monocline. After microscopic analysis of rocks and minerals in thin sections, the following techniques were used: luminescence analysis (UV, blue light), microthermometric analysis of fluid inclusions in double-sided polished wafers, XRD analyses, stable isotopic analyses (carbon, oxygen) on calcite and dolomite-ankerite and Raman spectra of fluid inclusions. Orthochemical components, such as carbonates and authigenic quartz, that form cements or fill the veins cutting the sample material have been studied. Fluid inclusion data in quartz and carbonates result in homogenization temperatures of 74–233 °C. The Raman analysis gives temperature estimations for the organic matter of about 164 °C and 197 °C, depending on the borehole, which points to a low coalification degree. The post-sedimentary processes of compaction, cementation and diagenetic dissolution under eo- and meso-diagenetic conditions to temperatures of over 160 °C influenced the present character of the deposits. P-T conditions of brines and methane trapping have been estimated to be ~850–920 bars and 185–210 °C (vein calcite) and ~1140 bars and 220 °C (Fe-dolomite/ankerite). However, locally, temperatures might have been higher (>200 °C), which may be a symptom of local regional metamorphism of a very low degree.

COMPARISON OF PALAEO OIL CHARGES WITH CURRENTLY RESERVOIRED HYDROCARBONS USING MOLECULAR AND ISOTOPIC ANALYSES OF OIL-BEARING FLUID INCLUSIONS: JABIRU OIL FIELD, TIMOR SEA

1997 ◽  
Vol 37 (1) ◽  
pp. 490 ◽  
Author(s):  
S.C. George ◽  
P.F. Greenwood ◽  
G.A. Logan ◽  
R.A. Quezada ◽  
L.S.K. Pang ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Hydrocarbon Composition ◽  
Polar Compounds ◽  
Oil Field ◽  
Geochemical Data ◽  
Peak Oil ◽  
Adsorption Effect ◽  
Isotopic Analyses ◽  
Oil Source

Geochemical techniques have been used to compare the composition of oil trapped in fluid inclusions from the Jabiru oil field with currently reservoired oil. The inclusion oil is preferentially enriched in polar compounds, probably due to an adsorption effect during trapping, but this has not affected the hydrocarbon composition of the trapped oil. Source characterisation using biomarker and gasoline range hydrocarbon parameters shows that the fluid inclusion oils have the same source affinity as the current production oil. This is corroborated by the carbon isotopic compositions of high molecuJar weight n-alkanes trapped in oil-bearing fluid inclusions, which are similar to those of the production oil. Both oils have maturities in the peak oil generative window, but aromatic hydrocarbon ratios demonstrate that the fluid inclusion oil is less mature (calculated reflectance [RJ = 0.84 per cent) than the currently reservoired charge (0.92 per cent Rc). Fluid inclusion abundance data and residual oil saturations indicate the Jabiru oil column was previously significantly larger, with subsequent leakage reducing the column to its present size. The geochemical data collected for the fluid inclusion oil suggests that it is representative of early charge to the Jabiru structure. The difference between the fluid inclusion oil and the production oil is thought to reflect continued charging of the trap with progressively more mature oil from the same or similar source rock facies. The change in the molecular composition of the oil in the Jabiru structure probably occurred by dilution of earlier, lower maturity charge with larger volumes of more mature oil.

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

2006 ◽  
Vol 70 (2) ◽  
pp. 159-173 ◽  
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.

High-temperature brine in chalcopyrite-rich quartz vein 40 km southwest of Sudbury, Ontario

2011 ◽  
Vol 48 (10) ◽  
pp. 1369-1385 ◽  
Author(s):  
Eva S. Schandl ◽  
Michael P. Gorton ◽  
Colin J. Bray
Keyword(s):  
High Temperature ◽  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Minimum Temperature ◽  
Tectonic Evolution ◽  
Quartz Vein ◽  
Regional Metamorphism ◽  
Dissolved Metals ◽  
Igneous Complex ◽  
Sudbury Igneous Complex

The Lac Panache (Nipissing) gabbro intrudes Huronian metasediments ca. 40 km southwest of the Sudbury Igneous Complex. The gabbro contains disseminated sulfides and is in contact with a chalcopyrite-rich quartz vein that crystallized from highly saline fluids (46.8 ± 3 equivalent wt.% NaCl) at a minimum temperature of 420 ± 27 °C. Chloride and carbonate inclusions in opened fluid inclusion cavities in the vein suggest that the brine contained dissolved metals (in addition to NaCl), such as Fe, Cu, Mn, and Co. The weakly altered quartz vein postdated regional metamorphism and was probably contemporaneous with the 1.7 Ga felsic magmatism and attendant albite alteration in the area. Cl-rich scapolite in the gabbro and highly saline fluid inclusions in the quartz vein suggest the existence of circulating hot brine throughout the tectonic evolution of the region. The 2.2 Ga old gabbro contains an abundance of Cl-rich scapolite intergrown with pyrrhotite and chalcopyrite that formed during the early hydrothermal (deuteric) alteration of the gabbro.

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 The Niederschlag fluorite-(barite) deposit, Erzgebirge/Germany—a fluid inclusion and trace element study

2021 ◽  
Author(s):  
Sebastian Haschke ◽  
Jens Gutzmer ◽  
Cora C. Wohlgemuth-Ueberwasser ◽  
Dennis Kraemer ◽  
Mathias Burisch
Keyword(s):  
Fluid Inclusion ◽  
Trace Element ◽  
Fluid Inclusions ◽  
Open Space ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Fine Grained ◽  
Trace Element Study ◽  
Northern Atlantic ◽  
Homogenization Temperatures

AbstractThe Niederschlag fluorite-barite vein deposit in the Western Erzgebirge, Germany, has been actively mined since 2013. We present the results of a first comprehensive study of the mineralogy, petrography, fluid inclusions, and trace element geochemistry of fluorite related to the Niederschlag deposit. Two different stages of fluorite mineralization are recognized. Stage I fluorite is older, fine-grained, associated with quartz, and forms complex breccia and replacement textures. Conversely, the younger Stage II fluorite is accompanied by barite and often occurs as banded and coarse crystalline open-space infill. Fluid inclusion and REY systematics are distinctly different for these two fluorite stages. Fluid inclusions in fluorite I reveal the presence of a low to medium saline (7–20% eq. w (NaCl+CaCl2)) fluid with homogenization temperatures of 140–180 °C, whereas fluorite II inclusions yield distinctly lower (80–120 °C) homogenization temperatures with at least two high salinity fluids involved (18–27% eq. w (NaCl+CaCl2)). In the absence of geochronological data, the genesis of the earlier generation of fluorite-quartz mineralization remains enigmatic but is tentatively related to Permian magmatism in the Erzgebirge. The younger fluorite-barite mineralization, on the other hand, has similarities to many fluorite-barite-Pb-Zn-Cu vein deposits in Europe that are widely accepted to be related to the Mesozoic opening of the northern Atlantic Ocean.

scholarly journals Gangue mineral textures and fluid inclusion characteristics of the Santa Margarita Vein in the Guanajuato Mining District, Mexico

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Daniel Moncada ◽  
Robert Bodnar
Keyword(s):  
Fluid Inclusion ◽  
Fluid Inclusions ◽  
Homogenization Temperature ◽  
High Potential ◽  
Mining District ◽  
Gangue Mineral ◽  
Gold Silver ◽  
Continuous Mining ◽  
Homogenization Temperatures ◽  
Silver Mineralization

AbstractSuccessful exploration for mineral deposits requires tools that the explorationist can use to distinguish between targets with high potential for mineralization and those with lower economic potential. In this study, we describe a technique based on gangue mineral textures and fluid inclusion characteristics that has been applied to identify an area of high potential for gold-silver mineralization in the epithermal Ag-Au deposits at Guanajuato, Mexico. The Guanajuato mining district in Mexico is one of the largest silver producing districts in the world with continuous mining activity for nearly 500 years. Previous work conducted on the Veta Madre vein system that is located in the central part of this district identified favorable areas for further exploration in the deepest levels that have been developed and explored. The resulting exploration program discovered one of the richest gold-silver veins ever found in the district. This newly discovered vein that runs parallel to the Veta Madre was named the Santa Margarita vein. Selected mineralized samples from this vein contain up to 249 g/t of Au and up to 2,280 g/t Ag. Fluid inclusions in these samples show homogenization temperatures that range from 184 to 300°C and salinities ranging from 0 to 5 wt.% NaCl. Barren samples show the same range in homogenization temperature, but salinities range only up to 3 wt.% NaCl. Evidence of boiling was observed in most of the samples based on fluid inclusions and/or quartz and calcite textures. Liquid-rich inclusions with trapped illite are closely associated with high silver grades. The presence of assemblages of vapor-rich-only fluid inclusions, indicative of intense boiling or “flashing”, shows the best correlation with high gold grades.

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.

Telluride Mineralogy of the Deer Horn Au-Ag-Te-(Bi-Pb-W) Deposit, British Columbia: Implications for the Generation of Tellurides

2021 ◽  
Author(s):  
Jordan A. Roberts ◽  
Lee A. Groat ◽  
Paul G. Spry ◽  
Jan Cempírek
Keyword(s):  
British Columbia ◽  
Fluid Inclusions ◽  
Hanging Wall ◽  
Oscillatory Zoning ◽  
Stage Iii ◽  
Fine Grained ◽  
Melting Temperatures ◽  
Homogenization Temperatures ◽  
Intrusive Suite ◽  
Cathodoluminescence Imaging

ABSTRACT The Deer Horn deposit, located 150 km south of Smithers in west-central British Columbia, is an Eocene polymetallic system enriched in Au-Ag-Te with lesser amounts of Bi-Pb-W; the Au and Ag are hosted in Te-bearing minerals and Ag-rich gold (Au-Ag alloy). A quartz-sulfide vein system containing the main zones of Au-Ag-Te mineralization and attendant sericite alteration occurs in the hanging wall of a local, spatially related thrust fault and is genetically related to the nearby Eocene Nanika granodiorite intrusive suite. Tellurium-bearing minerals commonly form isolated euhedral to subhedral grains or composite grains (up to 525 μm in size) of Ag-, Bi-, Pb-, and Au-rich tellurium-bearing minerals (e.g., hessite, tellurobismuthite, volynskite, altaite, and petzite). Panchromatic cathodoluminescence imaging revealed four generations of quartz. Within remnant cores of quartz I, local oscillatory zoning occurs in quartz II. Fine-grained veinlets of quartz III and IV crosscut quartz I and II, showing evidence of at least two deformation events; late-forming veinlets of calcite crosscut all generations of quartz. The tellurides and Ag-rich gold occur in stage III quartz. Three types of fluid inclusions were observed in stage III and IV quartz: (1) aqueous liquid and vapor inclusions (L-V); (2) aqueous carbonic inclusions (L-L-V); and (3) carbonic inclusions (vapor-rich). Primary fluid inclusions related to the telluride mineralization within quartz III were tested with microthermometry, along with a few primary inclusions from quartz IV. Homogenization temperatures are 130.0–240.5 °C for L-V inclusions and 268.0–336.4 °C for L-L-V inclusions. Aqueous carbonic inclusions had solid CO2 melting temperatures from –62.1 to –56.8 °C, indicating the presence of ≈1 to 30 mol.% dissolved methane in these inclusions. The Deer Horn Au-Ag-Te-(Bi-Pb-W) deposit is a reduced intrusion-related gold system characterized by sheeted veins, metal zoning, low salinity aqueous-carbonic fluids, and a genetic relationship to an Eocene granodiorite. Values of δ34S of pyrite vary from –1.6 to 1.6 per mil and are compatible with a magmatic source of sulfur.

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