Ore Mineralization in Adular-Fluorite Metasomatites: Evidence of the Podgolechnoe Alkalic-Type Epithermal Gold Deposit (Central Aldan Ore District, Russia)

2017 ◽  
Vol 743 ◽  
pp. 417-421 ◽  
Author(s):  
Vasilii Ivanovich Leontev ◽  
Yackov Yur’evich Bushuev
Keyword(s):  
Ore Deposits ◽  
Epithermal Gold ◽  
Gold Ore ◽  
Ore Bodies ◽  
Epithermal Gold Deposit ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Gold Ore Deposit ◽  
Host Rocks ◽  
Ore District

The Podgolechnoe deposit, which belongs to the alkalic-type (A-type) epithermal gold-ore deposits, lies in the Central Aldan ore district (Russia). Gold-ore mineralization is associated with a volcano-plutonic complex made of rocks of the monzonite-syenite formation (J3–K1). The ore bodies are localized in the crushing zones developed after crystalline schists, gneisses, and granites of the crystalline basement complexes (Ar–Pr). Metasomatic alterations in host rocks have potassic specialization. Vein ore minerals are adular, fluorite, roscoelite, sericite, and carbonate. Ore minerals are pyrite, galena, sphalerite, cinnabar, brannerite, monazite, bismuth telluride, stutzite, hessite, petzite, montbraite, and native gold. The deposit has been explored as a gold-ore deposit, however, due to complex composition of ores there is a need to reveal the possibilities of the integrated development of this deposit. This could provide for a reserve increment and an increase in the gross recoverable value of ores due to the extraction of associated components.

Ore Mineralization of the Epithermal Samolazovskoe Gold-Ore Deposit, Aldan Shield (Russia)

2018 ◽  
Vol 769 ◽  
pp. 213-219 ◽  
Author(s):  
Vasilii Ivanovich Leontev ◽  
Konstantin Chernigovtsev
Keyword(s):  
Aldan Shield ◽  
Crystalline Basement ◽  
Linear Type ◽  
Ore Deposit ◽  
Gold Ore ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Gold Ore Deposit ◽  
Full Volume ◽  
Ore District

The Samolazovskoe gold-ore deposit is located in the Central Aldan ore district (Russia) within the Yukhta multiphase volcano-plutonic massif, consisted of rocks of the monzonite-syenite formation (J3–K1). Four hydrothermal-metasomatic mineral parageneses are distinguished in the deposit: skarn, developed at the contact of syenites and rocks of the carbonate cover (V–Є); gumbeite, superimposed on the rocks of the intrusive massif; feldspatholite, developed in granite gneisses of the crystalline basement (PR) at their contact with the intrusive massif; ore-bearing fluorite–roscoelite–carbonate–quartz, superimposed on all above-mentioned types of mineralization. The main types of mineralization in the Samolazovskoe deposit are the following: (1) vein-disseminated linear type (now recovered in full volume); (2) vein-disseminated stockwork type; and (3) breccia-like type. Vein-filling minerals of the ores are quartz, fluorite, roscoelite, and carbonate. The main ore minerals are pyrite and marcasite; the secondary ones are bournonite, fahlore, sphalerite, galena, and chalcopyrite. Coloradoite and calaverite are less common; native gold occurs very rarely. Pyrite and marcasite are characterized by the following impurities (wt%): Sb (0.64–1.90), As (0.94–5.25), Te (1.02–3.82), and V ( 0.21–0.31).

scholarly journals DEPENDENCE OF QUALITATIVE AND QUANTITATIVE INDICATORS OF ORE RESERVES ON THE MAXIMUM PERMISSIBLE INTERVAL OF UNCONDITIONAL ORES OF THE SOTK GOLD ORE DEPOSIT

2021 ◽  
pp. 106-115
Keyword(s):  
Bulk Density ◽  
Spatial Location ◽  
Gold Content ◽  
Ore Deposit ◽  
Gold Ore ◽  
Content Ratio ◽  
Ore Bodies ◽  
Gold Ore Deposit ◽  
Host Rocks ◽  
Enclosing Rocks

At the Sotk gold ore deposit, the following morphological types of ore bodies can be distinguished: vein zones; veins and vein-like bodies; mineralized dykes and a vein zone in gabbro - massifs. The deposit is characterized by rather difficult mining and technical conditions. The enclosing rocks of the near-ore bodies have undergone intense hydrothermal changes at a distance of 5,0...10,0 m to 50,0 m, as a result of which, within the boundaries of these zones, the enclosing rocks have lost their strength and stability. The stability of the host rocks is also greatly influenced by postore tectonic faults, which are widespread in the field. The ore is also volatile. The strength factor of ore and host rocks varies from 3 to 20, with a predominance of 8...13. Hydrothermally altered metasomatites, which make up the mineralized zones, are prone to caking. The ore loosening factor is 1,25...1,40. The average bulk density of ore is 2,6 t / m3, and the bulk density of the host rocks is 2,3... 3,2 t / m3. At the deposit, conditioned and substandard intervals alternate with each other and there is no clearly expressed regularity of their spatial location, which predetermines the use of the ore-bearing factor when calculating ore reserves. The ore content ratio is determined by the ratio of the amount of conditioned ores to the total amount of ore mass, and the amount of conditioned ores is determined using the condition parameter “maximum - allowable range of substandard ores or waste rocks” included in the reserve calculation. For the Sotk gold ore deposit, the regularities of changes in ore reserves in the subsoil, the gold content in the ore massif and the ore content factor from the “maximum allowable to an increase in ore reserves in the subsoil and the ore content ratio with a decrease in the gold content in the ore massif and vice versa are revealed.

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.

The Geochemical Features of Epithermal Gold-Telluride (Au-Te) Ores of the Podgolechnoe Deposit (Central Aldan Ore District, Yakutia)

2017 ◽  
Vol 743 ◽  
pp. 422-425 ◽  
Author(s):  
Yackov Yur’evich Bushuev ◽  
Vasilii Ivanovich Leontev
Keyword(s):  
Sedimentary Cover ◽  
Ore Deposits ◽  
Crystalline Basement ◽  
Alkaline Magmatism ◽  
Epithermal Gold ◽  
Geochemical Composition ◽  
Gold Ores ◽  
Gold Ore ◽  
Gold Telluride ◽  
Ore District

The Central Aldan ore district is a geologically unique area, representing the conjunction zone of the ancient structures of the Archean–Proterozoic crystalline shield, overlain by the Vendian–Cambrian sedimentary cover. The latter was formed in the Mesozoic by intensive alkaline magmatism. Within the Central Aldan ore district, most of primary gold-ore deposits are confined to the sedimentary cover. Until recently it was considered that only ancient complexes in the crystalline basement contain commercial Au-U mineralization. As a result of the geological exploration works over the period of 2003–2006, the Podgolechnoe deposit was discovered. Gold mineralization in this deposit occurs both in rocks of sedimentary cover and crystalline basement. Ore bodies in rocks of the crystalline basement (A-type alkaline deposits) contain epithermal gold-telluride (Au-Te) mineralization, which is new for Central Aldan ore district. This work presents results of the study of geochemical composition of the Podgolechnoe deposit ores and their comparison with typical epithermal gold-ore deposits. In total, 15 samples were studied. The homogeneity of the sample collection, the correlation between Au and other elements, the enrichment coefficients of elements-admixtures, and the REE distribution were analyzed. It was established that gold ores of the Podgolechnoe deposit are geochemically heterogeneous, but, in general, they correspond to the geochemical spectrum characteristic of the gold ores of A-type epithermal deposits. In contrast to Au-U deposits, common in the studied area, ores of the Podgolechnoe deposit show no correlation between gold and uranium.

scholarly journals GEOLOGY AND ORE MINERALISATION OF NEOGENE SEDIMENTARY ROCK HOSTED LS EPITHERMAL GOLD DEPOSIT AT PANINGKABAN, BANYUMAS REGENCY, CENTRAL JAVA, INDONESIA

2015 ◽  
Vol 7 (2) ◽  
pp. 75
Author(s):  
Arifudin Idrus ◽  
Fahmi Hakim ◽  
I Wayan Warmada ◽  
Mochammad Aziz ◽  
Jochen Kolb ◽  
...  
Keyword(s):  
Base Metal ◽  
Gold Mineralization ◽  
Early Stage ◽  
Gold Deposits ◽  
Epithermal Gold ◽  
Central Java ◽  
Epithermal Gold Deposit ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Gold Miners

Low suphidation (LS) epithermal gold deposits were recently found in the Paningkaban area, Central Java province, Indonesia, with more than five hundred artisanal gold miners currently operating in the area. This study is aimed to understand the geological factors controlling the gold mineralization and to characterize the alteration and ore mineralogy of the deposit. Several epithermal veins/veinlets trending N–S, NW–SE, and NE–SW are hosted by Tertiary turbiditic volcanoclastic sedimentary rocks of the Halang formation. This formation is composed of looping gradation of sandstone and siltstone units. Pre- and syn-mineralization structures such as extension joints, normal sinitral fault and sinitral fault control the gold mineralization. Fault movements formed dilational jogs manifested by NW-SE-trending en-echelon tension gash veins. Four main alteration zones are identified: (a) phyllic, (b) argillic, (c) sub propylitic and (d) weak subpropylitic. Ore minerals consist of native gold, electrum, native silver, pyrite, chalcopyrite, sphalerite, galena, arsenopyrite, cubanite, marcasite, covellite and tennantite, which are commonly associated withargillic alteration. Vein structures such as massive, swarm and low angle veins, stockwork and veins dispersed in diatreme breccia are present. Normal banded, cockade, crustiform, bladed carbonates as well as, comb and saccharoidal features are the typical vein textures. It is noteworthy that the veins are basically composed of carbonate with minor quartz at gold grades of up to 83 g/t Au. Based on the vein structures and textures, four stages of ore mineralization were developed consisting of (a) early stage (fluidized breccia and quartz vein), (b) middle stage (carbonate base metal), (c) late stage (late carbonate), and supergene stage. Gold mineralization originated mainly during middle and late stages, particularly in association with cockade, crustiform, bladed carbonate base metal veins. Based on those various features, the LS epithermal deposit in the study area is categorized as carbonate-base metalgold mineralization type.

Compositional peculiarities of the host rocks and ores of the Lazursky ore field, Zmeinogorsk ore region of the Rudny Altai minerogenic zone

2021 ◽  
pp. 36-47
Author(s):  
Tatyana SERAVINA ◽  
Svetlana KUZNETSOVA ◽  
Ludmila FILATOVA
Keyword(s):  
Massive Sulfide ◽  
Ore Deposits ◽  
Sulfide Ores ◽  
Volcanogenic Massive Sulfide ◽  
Sulfide Deposits ◽  
Ore Bodies ◽  
Ore Minerals ◽  
Copper Pyrite ◽  
Host Rocks ◽  
Volcanogenic Massive Sulfide Deposits

The article describes composition of the host rocks and ores of the Lazursky and Maslyansky polymetallic volcanogenic massive sulfide deposits of the Lazursky ore field located within the Zmeinogorsk ore region of the Rudny Altai minerogenic zone. The ore field is composed of various facies of the Devonian (Late Givetian – Frasnian) ore-bearing siliceous-terrigenous basalt-rhyolite formation containing horizons of synvolcanic metasomatites. All rocks of the ore field were subjected to folding and schistosity with zones of tectonic brecciation. Hydrothermal alterations are represented by carbonatization and chloritization. The ore bodies exposed at the Lazursky and Maslyansky ore deposits are represented by copper-pyrite, copper, and zinc-copper-pyrite massive sulfide ores and other varieties. The major ore minerals of the deposits are chalcopyrite, pyrite, sphalerite, marcasite, and pyrrhotite.

scholarly journals Origin of the Kyaukmyet Low-Sulfidation Epithermal Gold Prospect, Monywa District, Central Myanmar

2021 ◽  
Vol 54 (1E) ◽  
pp. 1-18
Author(s):  
Toe Oo ◽  
Agung Harijoko ◽  
Lucas Setijadji
Keyword(s):  
Magmatic Fluid ◽  
Epithermal Gold ◽  
Quartz Veins ◽  
Mineral Assemblages ◽  
Epithermal Gold Deposit ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Alteration Minerals ◽  
Homogenization Temperatures ◽  
Low Sulfidation

The Kyaukmyet prospect is one of the principal epithermal gold prospects in the Monywa District, Central Myanmar; its gold- and base metal-bearing quartz veins contain around 3 g/t gold. Ore minerals are mainly hosted by volcanic and volcaniclastic rocks of the Late Oligocene to Middle Miocene Magyigon Formation. The distribution of magmatic intrusions in the area is controlled by ENE-WSW trending faults; these faults are likely related to ore mineralization. Common ore minerals at the Kyaukmyet prospect include pyrite, sphalerite, galena, chalcopyrite, and electrum. They occur in mineralized crustiform-textured brecciated quartz veins and banded (colloform) and massive quartz veins. Mineralized rock is accompanied by silicification and propylitic and argillic alterations. The alteration mineral assemblages include quartz, adularia, calcite, chlorite, illite/smectite, sericite, and illite. Fluid inclusions in the quartz veins have homogenization temperatures ranging from 148 °C to 304 °C and salinities from 0.35 wt % to 2.75 wt % NaCl equiv. The quartz in the mineralized quartz veins was most likely precipitated at a depth ranges165-256 m below the paleosurface. The precipitation of gold at the Kyaukmyet prospect may have been formed by mixing large amounts of meteoric fluid with small amounts of magmatic fluid. The coexistence of liquid-rich and vapor-rich inclusions and presence of adularia and bladed calcite indicate that fluid boiling is caused the main mechanism of ore formation. The vein textures, ore mineral assemblages, alteration minerals and fluid inclusion data suggest that the Kyaukmyet prospect is a polymetallic low-sulfidation epithermal gold deposit.

Sulfur Isotopic Composition of Sulfides of the Au-Te Ore Mineralization in Podgolechnoe and Samolazovskoe Gold-Ore Deposits (Aldan Shield, Russia)

2018 ◽  
Vol 769 ◽  
pp. 227-232
Author(s):  
Nataliya Rusinova ◽  
Vasilii Ivanovich Leontev
Keyword(s):  
Isotopic Composition ◽  
Significant Contribution ◽  
Isotopic Ratio ◽  
Aldan Shield ◽  
Ore Deposits ◽  
Sulfur Isotopic Composition ◽  
Magmatic Source ◽  
Ore Mineralization ◽  
Sulfur Isotopic Ratio ◽  
Ore District

This work presents the results of an analysis of the sulfur isotopic composition of pyrites from different metasomatic rocks of the Samolazovskoe and Podgolechnoe (Central Aldan ore district) deposits. The sulfur isotopic ratio of pyrite from ore-bearing metasomatic rocks of the Podgolechnoe deposit is characterized by δ34S values varying in a range from –1.8 to –5.5 ‰; that of pyrite from the Samolazovskoe deposit is in a range from –6.9 to –12.3‰. This is in agreement with the suggestion that a magmatic source made a significant contribution to the formation of the ore-forming fluid.

scholarly journals Selenium-Rich Ag–Au Mineralization at the Kremnica Au–Ag Epithermal Deposit, Slovak Republic

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 572 ◽  
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček ◽  
Pavel Škácha
Keyword(s):  
Base Metal ◽  
Slovak Republic ◽  
Epithermal Deposit ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Ore Mineralogy ◽  
Chemical Trends ◽  
New Phase ◽  
Epithermal Au ◽  
Ore District

Selenium-rich Au–Ag mineralization has been discovered in the Kremnica ore district, central Slovakia. The mineralization is hosted by a single quartz–dolomite vein hosted by Neogene propyllitized andesites of the Kremnica stratovolcano. Ore mineralogy and crystal chemistry of individual ore minerals have been studied here. The early base-metal ore mineralization composed of pyrite, sphalerite, and chalcopyrite lacks selenium, whereas the superimposed Au–Ag paragenesis is Se-enriched. The Au–Ag alloys, uytenbogaardtite, minerals of the galena–clausthalite series, acanthite–naumannite series, diaphorite, miargyrite, pyrargyrite–proustite, polybasite group, minerals of the tetrahedrite group and andorite branch (andorite IV, andorite VI, Ag-excess fizélyite), freieslebenite, and rare Pb–Sb sulphosalts (scaiinite, robinsonite, plagionite) have been identified here. Besides selenides, the most Se-enriched phases are miargyrite, proustite–pyrargyrite, and polybasite–pearceite, whose Se contents are among the highest reported worldwide. In addition, one new phase has been found, corresponding to a Se-analogue of pearceite containing 2.08–3.54 apfu Se. The style of mineralization, paragenetic situation, and chemical trends observed in individual minerals are comparable to those of Au–Ag low-sulphidation epithermal Au–Ag mineralizations of the Kremnica and neighboring Štiavnica and Hodruša-Hámre ore districts. However, the pronounced enrichment in selenium is a specific feature of the studied vein only.

On genesis of massive sulfide polymetallic ore deposits of Rudny Altai

2021 ◽  
pp. 3-16
Author(s):  
B. DIYACHKOV ◽  
M. MIZERNAYA ◽  
A. PYATKOVA ◽  
A. BISATOVA ◽  
A. MIROSHNIKOVA ◽  
...  
Keyword(s):  
Precious Metals ◽  
Massive Sulfide ◽  
Ore Deposits ◽  
Vertical Range ◽  
Long Duration ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
High Concentrations ◽  
Individual Grains ◽  
Polymetallic Ore

Many geologists assign most of large- and medium-sized massive sulfide polymetallic ore deposits of Eastern Kazakhstan to the VMS type. These ore deposits formed in the Devonian, under conditions of rifting and active basalt-andesite-rhyolite volcanism. Ore bodies of these deposits are noted to be clearly confined to formations of several geochronologic levels (D1e to D3fm). Hydrothermal-sedimentary syngenetic and hydrothermal-metasomatic ores are distinguished. High concentrations of base metals in the ores (above 10 % sum metals) and their rather simple mineral composition (chalcopyrite, pyrite, galena, and sphalerite) are a characteristic feature of all the massive sulfide polymetallic ore deposits of Rudny Altai. The ores are noted to be multicomponental, with elevated contents of the admixtures of precious metals and rare elements (Cd, Se, Bi, Te, Ta, W, etc.). Mineralogical investigations of the ores have demonstrated an intricate relationships of the major ore minerals (chalcopyrite, pyrite, sphalerite, galena) that exhibit several generations and different geochemical specialization. Minerals of Au, Ag, Te, Bi, and other elements are encountered as individual grains or microscopic inclusions and stringers in minerals of Cu, Pb, and Zn. A significant vertical range of the ore mineralization (more than 100 m), the complexity and long duration of the ore-forming processes, the clearly defined confinement of the ore mineralization to certain geochronologic levels, – all these allow us to suppose a possibility of discovery of new ore lodes or individual ore deposits within the already known ore fields of the Kazakhstan segment of Rudny Altai

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