scholarly journals Sphalerite Composition in Low- and Intermediate-Sulfidation Epithermal Ore Bodies from the Roșia Montană Au-Ag Ore Deposit, Apuseni Mountains, Romania

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 634
Author(s):  
Călin Gabriel Tămaș ◽  
Mădălina Paula Andrii ◽  
Réka Kovács ◽  
Sergiu Drăgușanu ◽  
Béatrice Cauuet
Keyword(s):  
Manganese Content ◽  
Ore Deposits ◽  
Ore Deposit ◽  
Apuseni Mountains ◽  
Epithermal Deposits ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Baia Mare ◽  
Low Sulfidation ◽  
Rosia Montana

We evaluated the significance of the iron and manganese content in sphalerite as a tool for distinguishing between low-sulfidation and intermediate-sulfidation epithermal deposits on the basis of new and previously published electron probe microanalyses data on the Roșia Montană epithermal ore deposit and available microchemical data from the Neogene epithermal ore deposits located in the Apuseni Mountains and Baia Mare region, Romania. Two compositional trends of the Fe vs. Mn content in sphalerite were delineated, a Fe-dominant and a Mn-dominant, which are poor in Mn and Fe, respectively. The overlapping compositional range of Fe and Mn in sphalerite in low-sulfidation and intermediate-sulfidation ores suggests that these microchemical parameters are not a reliable tool for distinguishing these epithermal mineralization styles.

scholarly journals HERMIONE, EVOLUTION OF ATe-BEARING EPITHERMAL MINERALIZATION, ARGOLIS, HELLAS

2007 ◽  
Vol 40 (2) ◽  
pp. 996 ◽  
Author(s):  
S. Tombros ◽  
K. St. Seymour
Keyword(s):  
Sedimentary Rocks ◽  
Ore Deposits ◽  
Stage I ◽  
Stage Ii ◽  
Quartz Veins ◽  
Minor Contribution ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Calcite Veins ◽  
Sandstone Formation

The Cu-Te-bearing pyrite deposits of Hermione, Argolis are hosted in Miocenic ophiolites. The ophiolites are overlain by a shale-sandstone formation with intercalations of limestones and manganiferous sedimentary rocks. The ore deposits form irregular lenticular or stratiform ore bodies, and veins. These ore bodies are related to volcanic activity in an arc-related rift at the margins of a palaeocontinent. Late N- to NNE-trending, sinistral, milky quartz-pyrite-calcite veins cut the host ophiolites. Alteration haloes of quartz-calcite, albite-sericitechlorite, and chalcedony-epidote-clay minerals are developed in the lavas as concentric shells, or as envelops that parallel the quartz veins. The telluriumbearing mineralization is developed in two successive stages, characterized by the assemblages: pyrite-(pyrrhotite)-magnetite-chalcopyrite-sphalerite (Stage I) and galena-sphalerite-freibergite-marcasite-chalcocite (Stage II), followed by a supergene stage. The cobaltiferous pyrite-chalcopyrite geothermometer defined two ranges of last-equilibration temperatures: 220° to 250°Cfor Stage I, and 120° to 195°Cfor Stage II. The calculated δ18 Ο and SD compositions of the mineralizing fluids, at 200° and 250°C, reflect the dominance of a magmatic component. The calculated δ SH2S fluid values reveal a magmatic source for the sulphur, with minor contribution from submarine sediments, whereas tellurium is proposed to be derived from a mafic-ultramafic source.

scholarly journals ON THE AGE AND GEODYNAMIC FACTORS OF THE FORMATION OF GOLD MINERALIZATION AT THE MALINOVKA DEPOSIT

2021 ◽  
Vol 40 (3) ◽  
pp. 28-40
Author(s):  
K.N. Dobroshevsky ◽  
◽  
N.A. Goryachev ◽  
◽  
Keyword(s):  
Gold Mineralization ◽  
Structural Features ◽  
Ore Deposits ◽  
Geodynamic Setting ◽  
Ore Deposit ◽  
Gold Ore ◽  
Shear Structures ◽  
Ore Bodies ◽  
Transform Margin ◽  
Gold Ore Deposit

An interpretation of the first obtained Re-Os dating of pyrite and arsenopyrite of the Malinovsky gold ore deposit is given. A comparison of the obtained data and the known dates of the ore-bearing granitoids of the ore field made it possible to determine the age of mineralization at 100-90 Ma. This age corresponds to the time of completion of the Alb-Cenomanian transform margin of Asia continent geodynamic setting with significant left-shear kinematics, as indicated in the article by the structural features of the localization of ore bodies and magmatic bodies. The distribution of gold ore deposits in this time within the Sikhote-Alin orogenic belt and in the shear structures of the south of the Korean Peninsula are noticeably shown.

scholarly journals Hydrothermal Sphalerites from Ore Deposits of Baia Mare Area

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1323
Author(s):  
Gheorghe Damian ◽  
Andrei Buzatu ◽  
Andrei Ionuţ Apopei ◽  
Floarea Damian ◽  
Andreea Elena Maftei
Keyword(s):  
Manganese Content ◽  
Ore Deposits ◽  
Main Element ◽  
Cadmium Content ◽  
Important Indicator ◽  
Physico Chemical ◽  
Fe Content ◽  
Baia Mare ◽  
Iron And Zinc ◽  
Chemical Conditions

Sphalerite is an abundant mineral in the hydrothermal deposits from the Baia Mare and Oaș areas (northwestern Romania). Sphalerite samples were analyzed with an electron probe microanalyzer and Raman spectroscopy. The obtained results indicated different amounts of Fe in the various deposits from the Baia Mare and Oaș areas. The sphalerites from Baia Sprie, Cavnic, Iba, Turț Penigher, and Breiner have a low Fe wt.% content. High Fe wt.% contents are at Herja and partly at Ghezuri and Nistru (copper stage) where sphalerite is associated with pyrrhotite. The correlation between iron and zinc from sphalerites is strongly negative. The negative correlation shows that iron is the main element that replaces zinc in the sphalerite structure. The manganese content of sphalerites in the Baia Mare and Oaș area is up to 0.84 wt.%. The cadmium content is quite uniform in the Baia Mare and Oaș area with contents ranging from 0.01 to 0.72 wt.%. The Fe content of sphalerites is an important indicator of the physico-chemical conditions of deposit formation because it is a function of temperature, pressure, and sulfur fugacity.

Te-Rich argyrodite occurrence in Roşia Montană ore deposit, Apuseni Mountains, Romania

2005 ◽  
Vol 337 (8) ◽  
pp. 755-762 ◽  
Author(s):  
Laurent Bailly ◽  
Călin-Gabriel Tămaş ◽  
Adrian Minuţ
Keyword(s):  
Ore Deposit ◽  
Apuseni Mountains ◽  
Rosia Montana

Geoelectrochemical-Extraction Measurement Method to Look for Hidden Lead-Zinc Ore Deposit and Prospecting Effect

2013 ◽  
Vol 734-737 ◽  
pp. 95-99 ◽  
Author(s):  
Yun Hu Hu ◽  
Xi Jun Liu ◽  
Xiang Rong Luo
Keyword(s):  
Electric Field ◽  
Metal Ions ◽  
Measurement Method ◽  
Ore Deposits ◽  
Ore Deposit ◽  
Ore Bodies ◽  
Lead Zinc ◽  
Ore Prospecting ◽  
Polymetallic Ore

The geoelectrochemical-extraction measurement is a ore prospecting method of deep-penetrating geochemistry, by using the element receptors to extract the mobile metal ions from the soil under the artificial electric field to look for the hidden ore deposit. The study of using the geoelectrochemical-extraction measurement method to look for blind lead-zinc ore deposit has been carried out in the Fuzichong lead-zinc polymetallic ore deposit and Panlong lead-zinc ore deposit of Guangxi, which resulted in the clearly geoelectrochemical anormaly above the known ore bodies. And the ore prospecting forecast conducted in the unknown ore regions shows that it is feasible to use the geoelectrochemical-extraction measurement method to expore the deep hidden lead-zinc ore deposits.

scholarly journals The Ag- and Au-bearing phases in the Escondida epithermal vein, Cerro Moro deposit, Santa Cruz, Argentina

2020 ◽  
Vol 58 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Ana C. Mugas Lobos ◽  
María Florencia Márquez-Zavalía ◽  
Laura B. Hernández
Keyword(s):  
Partial Substitution ◽  
Critical Element ◽  
Santa Cruz ◽  
Epithermal Deposits ◽  
Fine Grained ◽  
Quartz Veins ◽  
Epithermal Mineralization ◽  
Ore Minerals ◽  
The Usa ◽  
Low Sulfidation

ABSTRACT The Cerro Moro deposit is located at 48°5′55″S, 66°39′1.6″W and 100 m.o.s.l. in Santa Cruz province, southern Argentina. It is a low sulfidation Au-Ag epithermal mineralization hosted by numerous NW–SE structurally controlled quartz veins developed in close spatial and temporal proximity to the products of Jurassic extension and magmatism. The Escondida vein is the most significant mineralized structure, as it hosts the base metal-rich and Au-Ag high grade mineralization. In this vein and the Zoe ore-shoot, ore minerals are abundant (sphalerite, galena, chalcopyrite, acanthite, and less abundant pyrite and marcasite) and frequently related to dark grey, fine-grained quartz with massive, porous, crustiform, and banded textures; variable quantities of fine-grained flakes of muscovite are locally present. The Ag- and Au-bearing mineral association is represented by acanthite, argyrodite, polybasite, pearceite, stromeyerite, mckinstryite, and jalpaite. Abundant acanthite occurs commonly associated with gold and silver; copper enrichments were detected and interpreted as nanoinclusions of Cu-bearing minerals. The occurrence of Se- and Te-enriched minerals (acanthite, argyrodite, polybasite, pearceite, stromeyerite, and mckinstryite), rather than silver selenides and/or tellurides, indicates the presence of reduced mineralizing fluids and may be ascribed to partial substitution of S by Se or Te. Polybasite and pearceite were differentiated by their chemistry. Although the presence of argyrodite in epithermal deposits with silver sulfosalts is relatively common, this first mention in Cerro Moro is highly encouraging for exploration for germanium, a critical element, which is also considered strategic by countries such as the USA and China.

scholarly journals The Jbel Saghro Au(–Ag, Cu) and Ag–Hg Metallogenetic Province: Product of a Long-Lived Ediacaran Tectono-Magmatic Evolution in the Moroccan Anti-Atlas

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 592 ◽  
Author(s):  
Johann Tuduri ◽  
Alain Chauvet ◽  
Luc Barbanson ◽  
Jean-Louis Bourdier ◽  
Mohamed Labriki ◽  
...  
Keyword(s):  
Shear Zones ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Large Igneous Province ◽  
Epithermal Deposits ◽  
Igneous Province ◽  
Magmatic Stage ◽  
Dextral Shear ◽  
Low Sulfidation ◽  
Extensional Structures

The Jbel Saghro is interpreted as part of a long-lived silicic large igneous province. The area comprises two lithostructural complexes. The Lower Complex consists of folded metagreywackes and N070–090°E dextral shear zones, which roughly results from a NW–SE to NNW–SSE shortening direction related to a D1 transpressive tectonic stage. D1 is also combined with syntectonic plutons emplaced between ca. 615 and 575 Ma. The Upper Complex is defined by ash-flow caldera emplacements, thick and widespread ignimbrites, lavas and volcaniclastic sedimentary rocks with related intrusives that were emplaced in three main magmatic flare ups at ca. 575, 565 and 555 Ma. It lies unconformably on the Lower Complex units and was affected by a D2 trantensive tectonic stage. Between 550 and 540 Ma, the magmatic activity became slightly alkaline and of lower extent. Ore deposits show specific features, but remain controlled by the same structural setting: a NNW–SSE shortening direction related to both D1 and D2 stages. Porphyry Au(–Cu–Mo) and intrusion-related gold deposits were emplaced in an earlier stage between 580 and 565 Ma. Intermediate sulfidation epithermal deposits may have been emplaced during lull periods after the second and (or) the third flare-ups (560–550 Ma). Low sulfidation epithermal deposits were emplaced late during the felsic alkaline magmatic stage (550–520 Ma). The D2 stage, therefore, provided extensional structures that enabled fluid circulations and magmatic-hydrothermal ore forming processes.

scholarly journals Золотая минерализация штокового рудного поля (Магаданская область)

2021 ◽  
pp. 13-29
Author(s):  
A. N. Glukhov ◽  
◽  
M. I. Fomina ◽  
E. E. Kolova ◽  
◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Rare Metal ◽  
Geological Structure ◽  
Physicochemical Conditions ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Mineral Associations ◽  
Rare Metal Mineralization ◽  
Chukotka Volcanic Belt ◽  
Formation Conditions

The authors briefly characterize the geology and structure of the Shtokovoye ore field attached to the area where the Khurchan-Orotukan zone of tectonic-magmatic activation overlays the structures of the Yana-Kolyma ore-bearing belt. Studied are mineral associations and physicochemical conditions of gold ore bodies, located both in granites and in hornfelsed sedimentary masses. By the main features of its geological structure, ore composition, and physicochemical formation conditions, the Shtokovoye ore field mineralization corresponds to the "depth" group of the gold-rare-metal formation, analogous to the Butarnoye, Basugunyinskiye, Dubach, and Nadezhda occurrences. Its ores are peculiar in the late epithermal mineralization, which is associated with the Okhotsk-Chukotka volcanic belt and overlays the sinaccretional gold-rare-metal mineralization.

scholarly journals Conditions of ore formation of the Aunikskoye F-Be deposit (Western Transbaikal)

2019 ◽  
Vol 61 (1) ◽  
pp. 18-38
Author(s):  
L. B. Damdinova ◽  
B. B. Damdinov ◽  
M. O. Rampilov ◽  
S. V. Kanakin
Keyword(s):  
Pressure Range ◽  
Deposition Process ◽  
Isotopic Signature ◽  
Ore Deposits ◽  
Ore Formation ◽  
Ore Deposit ◽  
Temperature Range ◽  
Main Factors ◽  
Low Solubility

This study examines the compositions of the ore and the ore formation solutions, conditions of formation, and sources of Be mineralization using the Aunikskoye F-Be deposit, which is an integral part of the Western Transbaikal beryllium-bearing provinces, as a representative example. Further, the main factors responsible for the formation of beryllium mineralization were evaluated. The ore deposits are presented by the feldsparic–fluorspar–phenacite–bertrandite metasomatites formed in the carboniferous limestones during their metasomatic alternation with hydrothermal solutions by introducing F, Be, and other associated elements. The formation of early phenacite–fluorspar association occurred in high-fluorite СО2-containing solutions of elevated alkalinity with a salinity of ~10.5%–12% wt eq. NaCl in a temperature range of ~ 370–260 °С at pressures ranging from 1873 to 1248 bar. More recent fluorite and bertrandite deposits were formed by solutions with a salinity of 6.4%–7.7% wt eq. NaCl in a temperature range of ~156 °C–110 °C and a pressure range of 639–427 bar. The examination of the isotopic signature of the ore association minerals confirmed the apocarbonate nature of the main ore deposit and allowed the determination of the magmatogene nature of the ore-forming paleothermal springs, which are the source of subalkaline leucogranites. The primary factors that influenced the formation of the F-Be ore included the reduction of the F activity in solutions because of the binding of Ca and F in fluorite as well as because of the decrease in temperature during the ore deposition process. The elevated alkalinity of the ore-formation solutions resulted in the low solubility of the Be complexes, which caused a relatively low Be content in the ore and a relatively small amount of mineralization in the deposit.

scholarly journals THERMOCHRONOLOGY AND MATHEMATICAL MODELING OF THE FORMATION DYNAMICS OF RARE‐METAL‐GRANITE DEPOSITS OF THE ALTAI COLLISION SYSTEM

2019 ◽  
Vol 10 (2) ◽  
pp. 375-404 ◽  
Author(s):  
N. G. Murzintsev ◽  
I. Yu. Annikova ◽  
A. V. Travin ◽  
A. G. Vladimirov ◽  
B. A. Dyachkov ◽  
...  
Keyword(s):  
Rare Metal ◽  
Ore Deposits ◽  
Event Correlation ◽  
Magmatic Differentiation ◽  
Collision System ◽  
Rare Metal Granite ◽  
Development History ◽  
Ore Bodies ◽  
Thermal Cooling

The article presents an event correlation of the Permian‐Triassic granites of the Altai collision system, which are associated with industrial ore deposits and occurrences (Mo‐W, Sn‐W, Li‐Ta‐Be). The multi‐system and multi‐mineral isotope datings of igneous rocks and ore bodies (U/Pb, Re/Os, Rb/Sr, Ar/Ar‐methods) suggest the postcollisional (intraplate) formation of ore‐magmatic systems (OMS), the duration of which depended on the crustmantle interaction and the rates of tectonic exposure of geoblocks to the upper crustal levels.Two cases of the OMS thermal history are described: (1) Kalguty Mo‐W deposit associated with rare‐metal granite‐leucogranites and ongonite‐ elvan dykes, and (2) Novo‐Akhmirov Li‐Ta deposit represented by topaz‐zinnwaldite granites and the contemporary lamprophyre and ongonit‐elvan dykes. For these geological objects, numerical modeling was carried out. The proposed models show thermal cooling of the deep magmatic chambers of granite composition, resulting in the residual foci of rare‐metal‐granite melts, which are known as the petrological indicators of industrial ore deposits (Mo‐W, Sn‐W, Li‐Ta‐Be). According to the simulation results concerning the framework of a closed magmatic system with a complex multistage development history, the magmatic chamber has a lower underlying observable massif and a reservoir associated with it. A long‐term magmatic differentiation of the parental melt (a source of rare‐metal‐granite melts and ore hydrothermal fluids) takes place in this reservoir.

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