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

Evolutionary-genetic method for forecasting ore gold objects

2020 ◽  
Vol 26 (10) ◽  
pp. 15-27
Author(s):  
Yu. Pavlenko ◽  
◽  
S. Karelin ◽  
Keyword(s):  
Gold Mineralization ◽  
Granite Gneiss ◽  
Gold Content ◽  
Genetic Method ◽  
Geological Processes ◽  
Initial Substrate ◽  
Evolutionary Genetic ◽  
Eastern Transbaikalia ◽  
Reliable Knowledge ◽  
Gold Bearing

The subject of the research is methods for predicting natural heterogeneities containing mineralized areas of the earth’s interior, accumulations of ore gold, which allow obtaining reliable knowledge about a mineral object, applying effective methods for its assessment, study and practical use. The topic of research is an evolutionary-genetic method for predicting ore gold objects, which was used to assess the prospects for gold content in Eastern Transbaikalia on a scale of 1: 500,000 at the beginning of this century. The purpose of the work is to present a new forecasting method, which boils down to identifying geological formations specialized for gold (geoblocks, strata, horizons, zones), and within them - areas of multiple gold concentration. The research methodology consists in identifying the main stages, geological processes leading to the concentration of gold in the process of long-term evolution of natural facies and formations, clarifying the sources of gold and gold-bearing objects in them. As a result of forecasting, it was found that at high initial gold contents in the initial substrate, one or two stages of its mobilization formation and redistribution are sufficient, at low gold contents, multiple redistribution and concentration are required. The likelihood of the industrial and larger-scale gold mineralization is directly correlated with the prospects of geological structures for the localization of endogenous mineralization, conditions that exclude the dispersion of matter in the final phase of ore formation, and the number of concentration stages. The method makes it possible to exclude from the perspective huge areas of the central parts of granite-gneiss domes and granite plutons and requires careful attention to mafic blocks that are not exposed according to geophysical data by erosion, as well as to xenoliths and remnants of potentially gold-bearing host rocks among granitoids

Deep structure of the earth's crust in the vicinity of the Streltsovsky uranium ore field (Eastern Transbaikalia) from the data of microseismic sounding

2010 ◽  
Vol 2 (6) ◽  
pp. 33-37
Author(s):  
A. P. Aleshin ◽  
V. I. Velichkin ◽  
A. V. Gorbatikov ◽  
M. Yu. Stepanova ◽  
Vik. B. Komarov ◽  
...  
Keyword(s):  
Deep Structure ◽  
Earth’S Crust ◽  
Uranium Ore ◽  
Microseismic Sounding ◽  
Eastern Transbaikalia ◽  
Earth's Crust

scholarly journals A model of the deep structure of the Earth’s crust and upper mantle in the area of the Karymshinsky gold-ore cluster according to geophysical data (South Kamchatka)

Georesursy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 63-72
Author(s):  
Alexandr G. Nurmukhamedov ◽  
Mikhail D. Sidorov ◽  
Yury F. Moroz
Keyword(s):  
Upper Mantle ◽  
Deep Structure ◽  
Hydrothermal Systems ◽  
Earth’S Crust ◽  
The South ◽  
Converted Wave ◽  
Crust And Upper Mantle ◽  
Gold Ore ◽  
Dominant Feature ◽  
Earth's Crust

In the South of Kamchatka, modern geodynamic processes are actively taking place. A deep geological and geophysical model of the structure of the Earth’s crust and upper mantle along the regional profile of the Apacha Village-Mutnaya Bay in the zone of Tolmachevsky active magmatic center is presented. The profile passes near the South-Western border of the Karymshinskaya volcano-tectonic structure (VTS) and crosses the Ahomtenskaya VTS. The model created on the basis of integrated interpretation of materials of the earthquake converted-wave method (ECWM), gravity and magnetotelluric sounding (MTS). The thickness of the Earth’s crust along the profile varies from 30-33 km at the edges reaching 44-46 km, in its central part. The dominant feature of the model is a high-density formation – a block of the Earth’s crust, saturated with intrusions of the main and ultrabasic composition. The formation of the block is associated with a permeable zone between the crust and the upper mantle. In the block correlation of seismic boundaries is disturbed and in a density model the area with massive heterogeneity is allocated. A significant increase in depth to the M-Boundary in the center of the model is explained by the presence of a “bloated” transition layer between bark and mantle in this place. The thickness of the layer is about 10 km, and the density of the mantle reaches 3.4 g/cm3. It is assumed that this is a site of eklogization of breeds in a zone of paleosubduction of oceanic lithosphere under a continental. The area is favorable for the accumulation of meteor waters, which are in contact with high-temperature environment and postmagmatic solutions of intrusions, which leads to the formation of hydrothermal systems. The genetic connection of Karymshinsky gold-ore cluster with the intrusive array of medium-sour composition, allocated in the zone of the Tolmachevsky active Magmatic Center is shown.

scholarly journals DISCOVERY, DEVELOPMENT AND STUDY OF THE KIROVSKYI GOLD ORE DEPOSIT OF AMUR PROVINCE (AMUR REGION, RUSSIA)

2021 ◽  
pp. 108-116
Author(s):  
VITALY ALEKSEEVICH STEPANOV ◽  
◽  
ANTON VLADIMIROVICH MELNIKOV ◽  
Keyword(s):  
Gold Mineralization ◽  
Isotopic Age ◽  
Ore Deposit ◽  
Gold Ore ◽  
Ore Bodies ◽  
History Of ◽  
Gold Ore Deposit ◽  
Gold Sulfide ◽  
Sr Method ◽  
Gold Bearing

The history of the discovery, development and study of the Kirovskyi gold ore deposit in the Priamur gold-bearing province is considered. The deposit is attributed to the gold-bismuth type of vein deposits of the gold-sulfide-quartz formation. Gold mineralization is genetically related to the formation of the Dzhalinda intrusion of Early Cretaceous granitoids or a series of later dikes of «variegated» composition. The isotopic age of gold mineralization, determined by the Rb-Sr method, is in the fork 131-126 Ma. Further prospects of the deposit are associated with the search for large-volume deposits with stockwork type ore bodies.

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.

Tides in the Earth's Crust

1915 ◽  
Vol 79 (2058supp) ◽  
pp. 382-383
Author(s):  
Alphonse Berget
Keyword(s):  
Earth’S Crust ◽  
Earth's Crust
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