scholarly journals THE MECHANISMS OF THE DISTRIBUTION OF HYDROTHERMAL-METASOMATIC GOLD- BEARING FORMATIONS (EAST OF THE SIBERIAN PLATFORM)

2021 ◽  
Vol 1 (74) ◽  
pp. 09-12
Author(s):  
Z. Nikiforova
Keyword(s):  
Siberian Platform ◽  
Gold Ore ◽  
First Time ◽  
Gold Bearing

Hydrothermal-metasomatic formations with Au content from 0.5 to 3.0 g/t, sometimes up to 24-32 g/t, were found in the east of the Siberian platform in the brecciated zones. They form, along ancient faults activated in the Mesozoic, extended narrow formations in terrigenous-carbonate and sandy layers of PZ-MZ age. The comparison of metasomatites with gold-ore metasomatites of the Kuranakh and Tabornoye deposits makes it possible for the first time to predict ore sources formed as a result of hydrothermal-metasomatic processes. Perhaps these sources represent a huge metallogenic potential.

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 The first find of silver nuggets in gold placers of Subpolar Urals

2019 ◽  
Vol 486 (6) ◽  
pp. 714-717
Author(s):  
T. P. Mayorova ◽  
S. K. Kuznetsov ◽  
V. N. Filippov
Keyword(s):  
Primary Sources ◽  
Small Particles ◽  
Research Results ◽  
Subpolar Urals ◽  
Mineral Phases ◽  
Gold Silver ◽  
Native Bismuth ◽  
First Time ◽  
Gold Bearing

For the first time, silver nuggets were found in the gold-bearing placers of the Subpolar Urals. Galena, cassiterite, wolframite, cosalite, tetradymite, ferberite, cobaltine, joseite-B, native bismuth associate with silver and gold. Silver is mainly represented by poorly rounded and non-round gray lumpy, slightly flattened, elongated particles of 2-2.5 cm size. As part of silver, Au and Hg sometimes contain impurities. Inclusions are represented by small particles of gold, bismuth and tellurium mineral phases. Research results indicate a fairly widespread development of Au-Ag-Bi-Te mineralization, the primary manifestations of which are not yet known in the region. Relatively weak roundness of silver nuggets, presence of major and poorly rounded gold indicates the proximity of the primary sources to gold-bearing placers.

scholarly journals BEHAVIOUR OF SULFUR, ARSENIC AND ORGANIC CARBON IN A GRAVITY CONCENTRATION OF GOLD FROM REFRACTORY ORE

2020 ◽  
Vol 5 (443) ◽  
pp. 116-125
Author(s):  
Surimbayev Bauyrzhan Nurzhanovich, ◽  
◽  
Kanaly Yernazar Serikuly, ◽  
Bolotova Lyudmila Sergeevna, ◽  
Shalgymbayev Serikbol Tleulesovich, ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Sulfide Ores ◽  
Sulfide Sulfur ◽  
Gravity Concentration ◽  
Gold Extraction ◽  
Gold Ore ◽  
Primary Zone ◽  
Degree Of Oxidation ◽  
Concentrate Yield ◽  
Gold Bearing

The results of assay-gravimetric, chemical, mineralogical analyzes of gold ore are presented. According to the content of sulfide sulfur and the degree of oxidation of sulfur gold-bearing ore is assigned to the poor sulfide type of ore in the primary zone. Gold ore refers to refractory carbonaceous arsenic-containing sulfide ores. The gravity concentration of ore was assessed using a laboratory 3-inch Knelson KC-MD3 centrifugal concentrator. According to the results of the GRG test, the total gold extraction was 39.58% with the total concentrate yield of 3.96%. The extraction of gold in the first stage is lower than in the subsequent stages. This indicates the absence of large gold in the ore. The behavior of sulfur and arsenic during gravity concentration is similar to the behavior of gold. These data confirm that the main amount of gold is associated with arsenopyrite (arsenic pyrite) and pyrite. The behavior of organic carbon during gravity is significantly different. Only 3.39% of organic carbon passes into the gravity concentrate from ore, which reduces the persistence of the concentrate. Most of the organic carbon (96.61%) remains in the tails of gravity. The content of components in the total gravity concentrate was: Au 21.63 g/t, S 6.40%, As 0.82%, C(organic) 0.58%. The extraction of the components in the total concentrate is as follows, %: Au 39.58; S 34.52; As 27.27; C(organic) 3.39.

scholarly journals Sm-Nd isotopy of the dykes of the Vorontsovskoe gold-ore deposit (Northern Urals)

2020 ◽  
Vol 9 ◽  
pp. 3-6
Author(s):  
O. B. Azovskova ◽  
◽  
E. I. Soroka ◽  
M. Yu. Rovnushkin ◽  
N. G. Soloshenko
Keyword(s):  
Chemical Composition ◽  
Ore Deposit ◽  
Nd Isotope ◽  
Magmatic Source ◽  
Gold Ore ◽  
Northern Urals ◽  
Isotope Studies ◽  
Gold Ore Deposit ◽  
First Time

The Vorontsovskoye gold-ore deposit (Northern Urals) generally corresponds to the Carlin-type. One of the deposit features is the presence of numerous dykes of mafic and middle chemical composition, of normal and increased alkalinity. Sm-Nd isotope studies for the first time confirmed the dykes formation age 340 ± 35 Ma. These data can be indicative of the post-collisional stage of magmatism in this area. The positive Nd values suggest a probable abyssal magmatic source of Nd.

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 Mineralogy of the Drazhnoye gold ore deposit, the Republic of Sakha (Yakutia)

2019 ◽  
pp. 57-63
Author(s):  
V. Yu. Chikatueva ◽  
S. A. Sitkevich
Keyword(s):  
Native Gold ◽  
Hydrothermal Solutions ◽  
Mineral Formation ◽  
Ore Deposit ◽  
Gold Ore ◽  
Ore Mineralization ◽  
The Republic ◽  
Deep Source ◽  
Gold Ore Deposit ◽  
Gold Bearing

New data on the mineral composition of the Drazhnoye gold deposit, located within the Taryn ore field, have been presented. The samples from the central and flank areas of the deposit, which characterize ore and barren zones, have been studied. Based on the detailed studies of the interrelationship and the form of mineral exhalations and their aggregates, the stages of mineral formation have been proposed, including two main stages: sediment-diagenetic and hydrothermal-metasomatic. It has been revealed that the main precipitator of early native gold was pyrrhotite, which later, with an increase in fugacity of sulfur, was almost replaced by later pyrite. At the end of hydrothermalmetasomatic stage, native gold is formed from gold-bearing solutions and is located often in quartz and quartzcarbonate veinlets as independent precipitates, less commonly associated with polymetallic minerals, pyrite and arsenopyrite. Previous researchers of the Drazhnoye deposit established its genetic relationship with hydrothermal solutions. The data obtained confirm this. According to the type of gold ore mineralization and the type of prospective deep source of solution, this field is previously attributed to a hydrothermal pluton-related gold — quartz formation.

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.

scholarly journals Current issues of search of gold placers in the south of Ukraine

2020 ◽  
Vol 16 (4) ◽  
pp. 32-40
Author(s):  
I.E. Lomakin ◽  
E.A. Sarvirov ◽  
V.V. Kochelab
Keyword(s):  
Ukrainian Shield ◽  
High Mass ◽  
Market Force ◽  
The South ◽  
Placer Gold ◽  
Gold Ore ◽  
Size Classes ◽  
Gold Market ◽  
The World ◽  
Gold Bearing

The main gold ore territory of Ukraine is Ukrainian shield, mainly its central and eastern parts. Currently, the potential of Ukrainian shield is estimated at 2.4 thousand tons of gold. Gold ore deposits are insufficiently studied and not brought to development. The same can be said about the development of gold placers. But in the case of shallow deposits its study and development may be economically justified, it does not require large capital investments and allows to recoup costs in a short time. This is especially true given the extremely favorable situation on the world gold market in recent years. Erosion and denudation of native deposits certainly led to the formation of deposits of native placer gold in the sedimentary cover on the territory of the Ukrainian shield and its slopes. Significant amounts of geological information on the widespread distribution of placer gold in loose sediments, in the modern basins of the Dnieper, Southern Bug, Don, Black and Azov Sea shelf, have been accumulated. This corresponds to the location of indigenous sources of gold and the general direction of unloading of river systems. Previous geological studies in this area have revealed numerous manifestations of placer gold of various scales, but no industrial facilities have been recorded. Placer gold in the south of Ukraine is characterized by a high mass fraction of gold of small and thin size classes and significantly aleurite-clay composition of gold-bearing deposits. Such characteristics complicate the geological search and real assessment of gold-bearing objects and, provided that standard sampling and processing methods are used in geological works, lead to underestimation of the real gold content. Studies conducted on the most studied placer sites convincingly show that gold is lost when washing samples, even under careful control. And this is a typical situation for many objects (not only Ukrainian), which were studied using the standard method of extracting free gold by gravity. That is why there are reasonable doubts about the reliability and quality of the current assessment of placer gold deposits. In our opinion, the prospects for the search for loose gold on the Ukrainian shield and its slopes are significantly underestimated. The presence of indigenous sources with great resource potential and at the same time numerous known manifestations of different ages and scales of placer gold clearly indicate the possibility of the formation of placers with industrial characteristics in the sedimentary stratum of southern Ukraine. The use of modern technologies for the gold enrichment and extraction, high-precision analytical research and the favorable state of the world gold market force to urgently review the results of previous geological work. The problem of conducting new comprehensive research aimed at auditing the accumulated data, identifying, and studying of placer deposits namely with gold of small and thin size classes is becoming urgent. The result of such work should be the discovery and industrial development of gold placers, which can be the basis of gold production in Ukraine.

scholarly journals The model of the Bodaibo graben formation: geological and geophysical aspects

2019 ◽  
pp. 11-17
Author(s):  
G. A. Stogny ◽  
V. V. Stogny
Keyword(s):  
Siberian Platform ◽  
Crystalline Basement ◽  
Metamorphic Rocks ◽  
Fold Belt ◽  
Frontal Part ◽  
Detrital Material ◽  
Marginal Part ◽  
Tectonic Scheme ◽  
Gold Bearing

The problem of the Bodaibo graben formation has been considered within the framework of the proposed tectonic scheme of the Baikal-Patom fold belt crystalline basement — the Paleoproterozoic Baikal-Viluisk granulite-gneiss belt, which divides the foundation of the Siberian platform into Anabar-Mirninsky, Nepsko-Botuobinsky and Aldan-Stanovoi geoblocks. The Baikal-Viluisk granulite-gneiss belt is expressed by a system of blocks having a common northeastern direction and forming uplifts and grabens. As a result of the transpession interaction of the Nepsko-Botuobinsky and Anabar-Myrninsky geoblocks with Aldan-Stanovoi one in the Paleoproterozoic, the frontal part of the former was elevated with the formation of metamorphic rocks of Sarma-Tonod zone of outcrops and with the simultaneous descending of the Aldan-Stanovoi geoblock marginal part and the formation of the Olokit and Bodaibo grabens. The Olokyt graben was filled with the detrital material from the Nepsko-Botuobinsky and Anabar-Mirninsky geoblocks, and the Bodaibo graben — mainly by the products of the metamorphic rocks destruction of the Aldano-Stanovoy shield, including the gold-bearing metabasite complexes.

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