scholarly journals NEW DATA ON GEOLOGY AND GOLDENCE OF THE PROSPECTIVE AREAS «TAEZHKA» AND «UTRENNAYA» IN THE DAMBUKINSKY ORE DISTRICT (UPPER AMUR PRIAMURYE)

2020 ◽  
pp. 72-80
Author(s):  
ANTON VLADIMIROVICH MELNIKOV ◽  
◽  
PAVEL IVANOVICH ROMANOV ◽  
TATIANA VLADISLAVOVNA ROMANOVA ◽  
◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Structure Formation ◽  
Deep Structure ◽  
Gold Deposits ◽  
Structural Position ◽  
Gold Ore ◽  
Ore Minerals ◽  
Real Composition ◽  
Ore District ◽  
Gold Bearing

Information is given on the gold bearing of the ore-prospective areas «Tayezhka» and «Utrenniya» of the Dambukinsky Оre District of the Upper Priamurye/ Taking into account new data on geology, geochemistry, real composition of ores, description and comparative analysis of gold-ore manifestations are given. The prerequisites for the formation and criteria for the forecast and search of industrial gold deposits in this area of Upper Priamurya are described: geotectonic and structural position, deep structure, formation features, hydrothermal changes of rocks, mineral and geochemical associations, tipomorphism of gold and ore minerals, etc.

scholarly journals Localisation of gold ores in faults of different types

2020 ◽  
pp. 33-43
Author(s):  
E. M. Nekrasov
Keyword(s):  
Fault Zones ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Gold Ores ◽  
Gold Ore ◽  
North East ◽  
Ore Bodies ◽  
Different Types ◽  
Local Shift ◽  
Gold Bearing

The results of the author’s and general works of domestic and foreign geologists, who studied the location of the largest gold deposits in fault zones, characterised by the structure of ore-bearing zones and the concentration of reserves of ores and gold of different scale in them, are presented. The main reasons for such differences are considered. The longest faults on our planet are regional shifts. They are continuously traced for hundreds (up to 1,400) of kilometres along the boundaries of gold-bearing belts and provinces. However, gold ore deposits are located in their zones at extremely limited (point) intervals not exceeding 3—5 km. They are always enclosed between ancient transverse or oblique-oriented fractures of deep, most likely mantle, formation and penetration. In all mineralised faults, gold ore bodies are localised in various geological and structural traps, which are considered in the article and are reflected in the plans and sections. The crossing nodes of regional shifts, as well as overfaults and faults of transverse faults (and dislocations), act as the main promising objects in the deposits search and exploration. Obviously, such nodes should be considered as direct signs of the possible evidence of gold ores. The internal structure of the world leader, gold-bearing Muruntaussky (North-East) local shift (Uzbekistan), studied in detail by the author and other geologists, is given as an example.

scholarly journals Gold deposits in the Earth's history

2019 ◽  
Vol 61 (6) ◽  
pp. 3-18
Author(s):  
Nikolay A. Goryachev
Keyword(s):  
Gold Deposits ◽  
Gold Ore ◽  
The Earth ◽  
History Of ◽  
Rodinia Supercontinent ◽  
Archean Crust ◽  
Crustal Origin ◽  
Gold Bearing

The distribution of the main gold deposits in the history of the Earth is considered. Primary heterogeneity of the Archean crust by gold bearing is shown. The main gold ore metallogenic epochs are characterized. Links of gold deposits with VMS and Cu-Ni in the early periods of the Earth (Archaean-Proterozoic) and, in addition, with deposits of W, Mo, Cu, Sb, Hg and Sn in the Phanerozoic are shown. An analysis of the distribution of mineralogical and geochemical types of the actual Au mineralization also showed significant diversity for the Phanerozoic compared with Precambrian. These data reflect the mantle-crustal origin of Au mineralization as a whole and indicates an increase in the contribution of the crust matter to the balance of Au mineralization with the age of the Earth. The well-known interruption in the formation of Au deposits (1.70.8 billion years) was discussed, which was caused by the stable craton regime of the long-existing Columbia (Nuna) Rodinia supercontinent.

Geologic Structure, Mineralogy, and Geochemistry of the Nerunda Gold Ore Field (Northern Transbaikalia)

2021 ◽  
Vol 62 (10) ◽  
pp. 1139-1156
Author(s):  
I.V. Chetvertakov ◽  
V.A. Vanin ◽  
I.A. Demin
Keyword(s):  
Early Stage ◽  
Gold Deposits ◽  
Geologic Structure ◽  
Gold Ore ◽  
Northern Transbaikalia ◽  
Ore Mineralization ◽  
Two Stages ◽  
Geochemical Studies ◽  
Ore District ◽  
Erosion Zone

Abstract —We consider the geologic structure of the Nerunda gold ore field located in the Nerunda–Mama ore district in northern Transbaikalia. Gold–quartz low-sulfide formation and ore-bearing carbonate-terrigenous strata and intrusive complexes are briefly described. An ore complex of beresite–listvenite metasomatites hosting carbonate–quartz veins and vein–veinlet zones is characterized. Two stages of ore formation have been recognized. Anomalous geochemical associations and the composition of ore mineralization typical of these stages have been established. Mineralogical and geochemical studies of gold-bearing metasomatites of the Nerunda ore field were carried out. The known geochemical and mineralogical search criteria used for the assessment of the erosion zone level of gold deposits were applied to the geologic conditions of the Nerunda ore field and the Nerunda–Mama gold ore district as a whole. The emphasis was made on the express assessment of the erosion zone level at the early stage of prospecting. We draw a conclusion about the gold potential of the poorly studied ore objects at depth and give guidelines for the following geological prospecting.

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 AGE CONSTRAINTS AND METALLOGENIC PREDICTION OF GOLD DEPOSITS IN THE AKZHAL-BOKO-ASHALIN ORE ZONE (ALTAI ACCRETION-COLLISION SYSTEM)

2021 ◽  
Vol 12 (2) ◽  
pp. 392-408
Author(s):  
Yu. A. Kalinin ◽  
K. R. Kovalev ◽  
A. N. Serdyukov ◽  
A. S. Gladkov ◽  
V. P. Sukhorukov ◽  
...  
Keyword(s):  
Gold Mineralization ◽  
Gold Deposits ◽  
Igneous Rocks ◽  
Isotope Geochronology ◽  
Ore Formation ◽  
Gold Ore ◽  
Ore Mineralization ◽  
East Kazakhstan ◽  
Age Constraints ◽  
Gold Bearing

We present new age constraints for igneous rocks and ore-metasomatic formations of the gold deposits in the Akzhal-Boko-Ashalin ore zone. In terms of their ore formation, these deposits correspond mainly to the orogenic type, which generally reflects specific metallogeny of the West Kalba gold-bearing belt in East Kazakhstan. Gold-quartz veins and mineralized zones of the gold-sulphide formation are confined to fractures feathering regional NW-striking and sublatitudinal faults. Their common features include the following: gold-bearing veinlet-disseminated pyrite-arsenopyrite ores that are localized in carbonaceous-sandy-schist and turbidite strata of different ages; structural-tectonic control of mineralization, numerous dikes of medium-basic compositions in ore-control zones; and the presence of post-orogenic heterochronous granite-granodiorite rocks, although their relation to gold-ore mineralization is not obvious. Igneous rocks of the study area have similar ages in a narrow range from 309.1±4.1 to 298.7±3.2 Ma, which is generally consistent with the previously determined age of granitoid massifs of gold-ore fields in East Kazakhstan. A younger age (292.9±1.3 to 296.7±1.6 Ma) is estimated for felsic rocks of the dyke complex. For the ore mineralization, the 40Ar/39Ar dating of sericite from near-ore metasomatites yields two age intervals, 300.4±3.4 Ma and 279.8±4.3 Ma. A gap between of the ages of the ore mineralization and the igneous rocks is almost 20 Ma, which may indicate that the processes of ore formation in the ore field continued in an impulse-like pattern for at least 20 Ma. Nevertheless, this confirms a relationship between the hydrothermal activity in the study area and the formation and evolution of silicic igneous rocks of the given age interval, which belong to the Kunush complex, according to previous studies. This interpretation is supported by reconstructed tectonic paleostress fields, showing that directions of the main normal stress axes changed during the ore mineralization stage, which is why the ore bodies significantly differ in their orientations. The above-mentioned data are the first age constraints for the study area. Additional age determinations are needed to further improve understanding of the chronology of ore-forming processes. Actually, all the features characterizing the gold mineralization of the Akzhal, Ashalin and Dauba ore fields, including the data on lithology, stratigraphy, structural tectonics, magmatism, isotope geochronology, mineralogy and geochemistry, can be used as criteria when searching for similar ore fields in East Kazakhstan.

Gravity-flotation gold-bearing ore concentration

2021 ◽  
Vol 1 (1) ◽  
pp. 4-15
Author(s):  
P. K. Fedotov ◽  
A. E. Senchenko ◽  
K. V. Fedotov ◽  
A. E. Burdonov
Keyword(s):  
High Performance ◽  
Gold Recovery ◽  
Gold Content ◽  
Flotation Concentrate ◽  
Stage Scheme ◽  
Study Results ◽  
Ore Minerals ◽  
Concentrate Yield ◽  
Flotation Concentration ◽  
Gold Bearing

The paper focuses on the study of the gold-bearing ore dressability. According to technological research, the average gold content is 11.88 g/t. The silver content is insignificant – 2.43 g/t. Main ore minerals in the sample are pyrite and pyrrhotite. According to mineralogical and X-ray structural analysis, the average content of these minerals in the ore is about 6 % (in total). Main rock-forming minerals of the original ore are: quartz (60.1 %), quartz-chlorite-mica aggregates (3.8 %), carbonates (7.1 %). According to the study results, it was found that the gold recovery in the GRG test was 72.75 % with a total concentrate yield of 1.34 % and a content of 664.78 g/t. At the same time, the gold content in tailings was 3.29 g/t. A stage test showed that it is advisable to use a two-stage scheme for ore processing by gravity technology only. The first stage is in the grinding cycle with the 60–70 % ore size, and the second stage is with the final classifier overflow size of 90 % –0.071 mm. Centrifugal separation has high performance as a free gold recovery operation in the grinding cycle. A concentrate with a gold content of 2426 g/t was obtained with a yield of 0.31 % and a recovery of 63.74 %. The beneficiation of first stage tailings ground to 90 % –0.071 mm at the KC-CVD concentrator (modeling) made it possible to extract gold into a total gravity concentrate (KC-MD + KC-CVD) of 87.25 % with a concentrate yield of 22.63 %. The gold content in tailings was 1.97 g/t. The results of gravity and flotation concentration of the original ore indicate the feasibility of using a combined gravity-flotation technological scheme. In a closed experiment of the initial ore beneficiation according to the gravity-flotation scheme at a natural pH of the pulp (without adding acid), the following products were obtained: gravity concentrate with a gold content of 2426 g/t at a yield of 0.31 % and recovery of 64.06 %; flotation concentrate (after the II cleaning) with a gold content of 122 g/t at a yield of 2.90 % and recovery of 33.01 %; the total gold recovery in the gravity-flotation concentrate was 94.07 % with a yield of 3.21 % and an Au content of 345.87 g/t, the gold content in the flotation tailings was 0.72 g/t.

Predictive geochemistry of ore gold in Eastern Transbaikalia

2020 ◽  
Vol 26 (10) ◽  
pp. 6-14
Author(s):  
Yu. Pavlenko ◽  
Keyword(s):  
Gold Mineralization ◽  
Geological Mapping ◽  
Earth’S Crust ◽  
Natural Environments ◽  
Gold Concentration ◽  
Gold Ore ◽  
Natural Concentration ◽  
Eastern Transbaikalia ◽  
Earth's Crust ◽  
Gold Bearing

The subject of the research is the methods of forecasting the Eastern Transbaikalia - a large mining region of Russia, in which the main internal and external criteria for ore content are established by modern geological mapping at a scale of 1:1,000,000. The article considers endogenous geochemical criteria for gold concentration in the Earth’s crust of the region, which constitute a mandatory methodological method for predicting gold ore objects at any scale. The aim of the work is to clarify the achieved level of knowledge about the mineralogical and geochemical criteria for gold concentration in the course of the evolution of the Earth’s crust up to the formation of industrial deposits and the isolation of ore formations. The methodology of the study is to systematize a huge amount of factual material concerning the processes of natural concentration of gold, to analyze its representativeness, to assess the completeness and reliability of published and stock information used to clarify the mineralogical and geochemical criteria for predicting ore gold. Using the chemical properties of gold, the forms of finding gold, amount of it in the forming geological complexes and natural environments, their evolution, distribution in structural and tectonic zones, some causes of concentration and mineralogical and geochemical prediction criteria are considered. Special attention is paid to the need to study and account for nanoscale (dispersed) gold. As the main ore-formation units of gold mineralization, standardized ore formations are defined with a division into gold ore proper, complex gold-bearing and gold-bearing and geological and industrial types of deposits. There are 15 geological and industrial types, of which 13 are transbaikal deposits standards and two are attracted from other regions. These types of deposits differ in the number of objects related to them. Due to some similarity in the composition of ore matter, geological and industrial types differ in the most important classification characteristics for the forecast. Areas of distribution of direct and indirect mineralogical and geochemical features grouped into mineralogical and geochemical forecast criteria are promising for endogenous concentration of gold mineralization

scholarly journals A NEW GOLD ORE REGION IN TANZANIA

2018 ◽  
pp. 55-59
Author(s):  
V. Mykhailov ◽  
А. Tots
Keyword(s):  
Gold Deposit ◽  
Shear Zone ◽  
Gold Mineralization ◽  
Lake Victoria ◽  
Gold Deposits ◽  
Mobile Belt ◽  
Gold Content ◽  
Gold Ore ◽  
Metallogenic Zone ◽  
The Republic

Tanzania is one of the leading gold mining countries in the world and the discovery of new gold resources on its territory is an actual task. Known gold deposits are concentrated mainly in the northwest of the country, in the metallogenic zone of Lake Victoria, where they are associated with the Archean greenstone belts, and to a lesser extent – in the southwest, in the ore regions of Lupa and Mpanda, confined to the Ubendian Paleoproterozoic mobile belt. With regard to the eastern regions of Tanzania, where the Proterozoic structures of the Uzagaran mobile belt are developed, until recently in this region any significant manifestations of gold mineralization were not known. As a result of our research in the northern part of the Morogoro province of the Republic of Tanzania, a new previously unknown gold deposit Mananila was discovered. It is represented by a large volume, up to 400–450 m long, up to 60–80 m thick, mineralized shear zone over intensely leached and schistosed migmatites, gneisses, amphibolites, penetrated by echelon systems of quartz veins and veinlet, steeply dipping bodies of quartz breccia up to 1.0–1.5 m thick. Gold contents range from 0.61 to 8.11 g/t, the average zone content is 2.5–3.0 g/t. Parallel to the main zone, similar structures are developed on the site, although they are of lower thickness. The forecast resources of the deposit are estimated at 20 tons of gold. 2.8 km to the east from the Mananila field, the recently discovered Mazizi gold deposit is located, and a number of small occurrences of gold are also known in the region. All these objects are located within a large shear zone of the northeastern strike, up to 4–5 km width, over 20 km in length. This serves as the basis for the identification of a new gold ore region in the northern part of the Morogoro province of the United Republic of Tanzania, within the Proterozoic mobile belt of Usagaran, the possible gold content of which has never been previously discussed in geological literature.

scholarly journals Gold Deposits in Chile

2021 ◽  
Vol 48 (1) ◽  
pp. 1
Author(s):  
José Cabello
Keyword(s):  
Porphyry Copper ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Gold Content ◽  
Base Metals ◽  
Porphyry Copper Deposits ◽  
Copper Deposits ◽  
Mineralization Age ◽  
Low Sulfidation ◽  
Gold Bearing

A review of gold and gold bearing base metals deposits in Chile, indicate the existence of at least six different type of ore deposits, most largely formed during the Cenozoic with predominance in the Miocene. Mesozoic deposits are common but less relevant regarding their size and gold content. These hydrothermal ore deposits are genetically associated with subduction related Andean arc magmatism. Due to its relationship with episodic magmatism migrating eastward, there is a tendency for the deposits to be in distinct, north-south trending, belts with a progressive west to east decrease in mineralization age. After analysing 82 cases in total, main gold concentration can be assigned to high-sulfidation epithermal and porphyry type deposits. Low-sulfidation epithermal, IOCG and mesothermal type appears as less relevant. Gold bearing copper deposits constitute an important part of Chile’s total gold production. Both IOCG type but especially porphyry copper deposits are and will remain as a substantial source to supplement the future output of the gold in the country. The 82 deposits with their tonnage and grade studied, represent a total gold content of 11,662 t equivalent to 375 Moz, excluding past production for those exploited. A number of probable gold bearing base metals high tonnage deposits (IOCG and porphyry copper) do not include their gold content in public format, hence the number delivered could be estimated conservative. Methodical geochronological, ore types and zonation studies are required to better appreciate this metallogenic setting widening current understanding and future exploration results.

Sign in / Sign up

Export Citation Format

Share Document