scholarly journals Geological and mining features of gold deposits development of Ryabinovoe gold deposit

2020 ◽  
Vol 21 (2) ◽  
pp. 113-122
Author(s):  
Sergey V. Ryzhov ◽  
Marina V. Rylnikova ◽  
Ekaterina N. Esina

The significant role of the gold mining industry in the development of the Russian mineral resource system determines the search for new organizational, technical and geotechnical solutions to improve the completeness and efficiency of deposit development. Most of Russia's gold deposits are in remote, sparsely populated areas, where there is a lack of energy, transport communications, and infrastructure. It is shown that the Ryabinovoe gold deposit, located in the Republic of Sakha (Yakutia), is characterized by a complex structure, relatively low occurrence of ore deposits and a widespread in the value of mineral raw materials. Features of the Ryabinovoe deposit consist in a complex structural structure and alternation of mineralized gold-bearing and low-gold-bearing or ore-free areas of various capacities and complex morphology. The main criteria for open Geotechnology have been clarified and justified. This ensures safe and efficient development of the Ryabinovoe field with the achievement of the maximum possible total discounted income and the shortest recoupment period for the project. In general, an integrated approach is the basis of the development strategy of the Ryabinovoe gold deposit. It includes increasing the level of extraction of useful components, increasing the production volume and a differentiated approach to the choice of a method for processing ores of different quality. It is shown that the achievement of rational production capacity in the complex development of the Ryabinovoe gold deposit is based on optimizing the variation of the onboard and average gold content with justification of the ratio of production capacity of the mining and processing cycle.

2021 ◽  
Vol 48 (1) ◽  
pp. 1
Author(s):  
José Cabello

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.


2021 ◽  
Vol 116 (6) ◽  
pp. 1253-1265
Author(s):  
Xiao-Ye Jin ◽  
Jian-Xin Zhao ◽  
Yue-Xing Feng ◽  
Albert H. Hofstra ◽  
Xiao-Dong Deng ◽  
...  

Abstract The ages of Carlin-type gold deposits in the Golden Triangle of South China have long been questioned due to the general lack of minerals unequivocally linked to gold deposition that can be precisely dated using conventional radiogenic isotope techniques. Recent advances in U-Pb methods show that calcite can be used to constrain the ages of hydrothermal processes, but few studies have been applied to ore deposits. Herein, we show that this approach can be used to constrain the timing of hydrothermal activity that generated and overprinted the giant Shuiyindong Carlin-type gold deposit in the Golden Triangle. Three stages of calcite (Cal-1, Cal-2, and Cal-3) have been recognized in this deposit based on crosscutting relationships, cathodoluminescence colors, and chemical (U, Pb, and rare earth element [REE]) and isotope (C, O, Sr) compositions. Cal-1 is texturally associated with ore-stage jasperoid and disseminated Au-bearing arsenian pyrite in hydrothermally altered carbonate rocks, which suggests it is synmineralization. Cal-2 fills open spaces and has a distinct orange cathodoluminescence, suggesting that it precipitated during a second fluid pulse. Cal-1 and Cal-2 have similar carbonate rock-buffered chemical and isotopic compositions. Cal-3 occurs in veins that often contain realgar and/or orpiment and are chemically (low U, Pb, and REE) and isotopically (higher δ13C, lower δ18O and Sri values) distinct from Cal-1 and Cal-2, suggesting that it formed from a third fluid. U-Pb isotope analyses, by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) for U-rich Cal-1 and Cal-2 and by LA-multicollector (MC)-ICP-MS for U-poor Cal-3, yield well-defined age constraints of 204.3 to 202.6, 191.9, and 139.3 to 137.1 Ma for Cal-1, Cal-2, and Cal-3, respectively. These new ages suggest that the Shuiyindong gold deposit formed in the late Triassic and was overprinted by hydrothermal events in the early Jurassic and early Cretaceous. Given the association of Cal-3 with orpiment and realgar, and previous geochronologic studies of several other major gold deposits in the Golden Triangle, we infer that the latest stage of calcite may be associated with an early Cretaceous regional gold metallogenic event. Combined with existing isotopic ages in the region, these new ages lead us to propose that Carlin-type gold deposits in the Golden Triangle formed during two metallogenic episodes in extensional settings, associated with the late Triassic Indochina orogeny and early Cretaceous paleo-Pacific plate subduction. This study shows that the calcite U-Pb method can be used to constrain the timing of Carlin-type gold deposits and successive hydrothermal events.


Author(s):  
V. Mykhailov ◽  
А. Tots

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.


1970 ◽  
Vol 2 (1) ◽  
pp. 4-11
Author(s):  
Hutamadi Hutamadi ◽  
Bambang Nugroho Widi ◽  
Sabtanto Joko Suprapto

Gold deposit at Cineam area is an epithermal gold deposit of low sulphidation type which lies about 180 km southeast of Bandung at an elevation of 400 meter above the mean sea level. The Cineam deposit is administratively belongs to Cineam Subdistrict , Tasikmalaya Regency, West Java Province, which dominantly occurred within volcanic rocks unit of Jampang Formation. Alterations developed in this area namely propylite, argillic, sericitation, and silisification, occurred in andesitic lava, volcanic breccia, and andesitic to dacitic tuff. The thickness of gold bearing quartz veins are commonly from few cm up to > 20 cm, while for the veins of higher grade of gold content the thickness are about 5 cm or less. The average grade of gold content is around 6 - 10 gr/t Au. Although Cineam gold deposits can not be classified as a big scale deposit, itsmineral genesis has an interesting characteristic to be further studied. The Cineam area representing one of the most prospect areas of gold found in the eastern part of West Java Southern Mountain Range. As the Cineam gold deposit is proportionally suitable for a small scale gold mine, the local government had already gave a mining license to a Family Firm in the form of a Village Unit Cooperation or “KUD” such as KUD Mekarjaya which had also been updated to become a B class of Exploitation License category that permitted for the realization of metallic exploitation. This action was in line with the implementation of Autonomy Policy since the year of 2001.Although KUD Mekarjaya’s mining production is relatively so small but in fact the mining activity is still being maintained to be daily earnings for the local gold miners to rely on. Within the long run of the local gold miners activity at Cineam which has been working since 1968, this condition can give rise to many well skilled and experienced labors in seeking for gold ores, in handling small scale gold mining works, and in obtaining for the bullions. In other side, on thecontrary, there are some negative actions must be kept under control such as the disposal of the waste or tailing directly into the river and the unsafely process of heating the amalgam to obtain the bullion including other improper ways done during the handling of their mining activities. Since the whole mining operation so far generally financed by individual investors it is very likely that small scale gold mining lacks of the capital needed for the mining operation. This condition is what the KUD always facing with so that management and financial matters can be a very serious problem affecting the progress of the KUD Mekarjaya From some presentation given by the CCOP-CASM Meeting in Bandung we can compare the condition of small scale mining in Indonesia. and that from other countries which have conducted good management in mining regulation and policy in relation with licensing, mining workers, tax payment and awareness of environment live in the vicinity of mining areas On account of that event this can be expected to motivate and encourage the policy anddecision makers either locally or centrally throughout Indonesia in giving more attention related to the guidance, monitoring and inspection of the implementation of small scale mining activities which is actually growing in numbers.


2021 ◽  
Author(s):  
Wei Gao ◽  
Ruizhong Hu ◽  
Albert H. Hofstra ◽  
Qiuli Li ◽  
Jingjing Zhu ◽  
...  

Abstract The Youjiang basin on the southwestern margin of the Yangtze block in southwestern China is the world’s second largest Carlin-type gold province after Nevada, USA. The lack of precise age determinations on gold deposits in this province has hindered understanding of their genesis and relation to the geodynamic setting. Although most Carlin-type gold deposits in the basin are hosted in calcareous sedimentary rocks, ~70% of the ore in the Badu Carlin-type gold deposit is hosted by altered and sulfidized dolerite. Although in most respects Badu is similar to other Carlin-type gold deposits in the province, alteration of the unusual dolerite host produced hydrothermal rutile and monazite that can be dated. Field observations show that gold mineralization is spatially associated with, but temporally later than, dolerite. In situ secondary ion mass spectrometry (SIMS) U-Pb dating on magmatic zircon from the least altered dolerite yielded a robust emplacement age of 212.2 ± 1.9 Ma (2σ, mean square of weighted deviates [MSWD] = 0.55), providing a maximum age constraint on gold mineralization. The U-Th/He ages of detrital zircons from hydrothermally mineralized sedimentary host rocks at Badu and four other Carlin-type gold deposits yielded consistent weighted mean ages of 146 to 130 Ma that record cooling from a temperature over 180° to 200°C and place a lower limit on the age of gold mineralization in the basin. Hydrothermal rutile and monazite that are coeval with gold mineralization have been identified in the mineralized dolerite. Rutile is closely associated with hydrothermal ankerite, sericite, and gold-bearing pyrite. It has high concentrations of W, Fe, V, Cr, and Nb, as well as growth zones that are variably enriched in W, Fe, Nb, and U. Monazite contains primary two-phase fluid inclusions and is intergrown with gold-bearing pyrite and hydrothermal minerals. In situ SIMS U-Pb dating of rutile yielded a Tera-Wasserburg lower intercept age of 141.7 ± 5.8 Ma (2σ, MSWD = 1.04) that is within error of the in situ SIMS Th-Pb age of 143.5 ± 1.4 Ma (2σ, MSWD = 1.5) on monazite. These ages are ~70 m.y. younger than magmatic zircons in the host dolerite and are similar to the aforementioned U-Th/He cooling ages on detrital zircons from hydrothermally mineralized sedimentary host rocks. We, therefore, conclude that the Badu Carlin-type gold deposit formed at ca. 144 Ma. The agreement of the rutile and monazite ages with the U-Th-He cooling ages of Badu and four other Carlin-type gold deposits in the Youjiang basin suggests that ca. 144 Ma is representative of a regional Early Cretaceous Carlin-type hydrothermal event formed during back-arc extension.


2021 ◽  
pp. SP516-2021-37
Author(s):  
Julien Perret ◽  
Anne-Sylvie André-Mayer ◽  
Aurélien Eglinger ◽  
Julien Feneyrol ◽  
Alexandre Voinot ◽  
...  

AbstractIntegrating structural control on mineralisation and geochemical ore-forming processes is crucial when studying deformed ore deposits. Yet, structural and geochemical data are rarely acquired at the same scale: structural control on mineralisation is typically investigated from the district to the deposit and macroscopic scales whereas geochemical ore processes are described at the microscopic scale. The deciphering of a deformation-mineralisation history valid at every scale thus remains challenging.This study proposes a multi-scale approach that enables the reconciliation of structural and geochemical information collected at every scale, applied to the example of the Galat Sufar South gold deposit, Nubian shield, northeastern Sudan. It gathers field and laboratory information by coupling a classical petrological-structural study with high-resolution X-ray computed tomography, electron back-scattered diffraction and laser ablation inductively-coupled plasma mass spectrometry on mineralised sulphide mineral assemblages.This approach demonstrates that there is a linear control on mineralisation expressed from the district to microscopic scales at the Galat Sufar South gold deposit. We highlight the relationships between Atmur-Delgo suturing tectonics, micro-deformation of sulphide minerals, syn-pyrite recrystallisation metal remobilisation, gold liberation and ore upgrading. Our contribution therefore represents another step forward a holistic field-to-laboratory approach for the study of any other sulphide-bearing, structurally-controlled ore deposit type.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5635726


2021 ◽  
Vol 40 (2) ◽  
pp. 409-432
Author(s):  
KENNETH G. McQUEEN

The discovery of gold in Australia forced many changes to theory on the occurrence and origin of gold deposits. Initial discoveries appeared to confirm existing ideas on the global distribution of gold-bearing terrains. Later discoveries and research would show that this confirmation was largely coincidental, but nevertheless helpful in early prospecting. Prior to the first Australian gold rush, theoretical predictions of payable gold were made by Sir Roderick Murchison and Rev. W. B. Clarke based on knowledge of accidental gold finds and geological analogy with known areas of significant gold occurrence, particularly the Ural region in Russia. These predictions were overwhelmed when Edward Hargraves, realised he might be able to spark a gold rush that would prove the existence of payable gold. Hargraves travelled to the Bathurst region of New South Wales where numerous gold finds had already been made and with local guides, prospected Lewis Ponds Creek and the Macquarie River. He demonstrated the methods of alluvial mining, to John Lister and William and James Tom enabling them to find sufficient alluvial gold to initiate a gold rush. The crowd of attracted diggers demonstrated the existence of a payable goldfield. The unstoppable first rush resulted in the pragmatic introduction of government regulation and administration to allow alluvial gold mining. Other discoveries of payable goldfields quickly followed. As the local scientific expert on gold, W. B. Clarke was commissioned to conduct two extensive surveys of the goldfields between 1851 and 1853. Clarke also drew on his geological knowledge to provide practical advice to the thousands of prospecting gold diggers. Gold-bearing quartz reefs and lodes were discovered, but it was predicted that these could not be mined economically. Theory also predicted that the reef gold would not continue to depth. Practical observations and mining experience from the numerous discoveries led to revision of the widely held dicta on gold occurrence. Alluvial gold was found in a range of settings, including the recent drainage and ancient and buried leads. A wider variety of rock types was recognised as favourable for gold. Different styles of reef gold were identified and found to be economically mineable to great depth. Evolving ideas on the origin of gold deposits were widely discussed, tested, and refined. Of the many players involved in the early discovery of gold in Australia, Clarke, Hargraves and Murchison probably had the greatest overall influence in terms of theoretical predication and practical outcomes that initiated the Australian gold-mining industry.


2021 ◽  
Vol 21 (1) ◽  
pp. 246-261
Author(s):  
Hongye Feng ◽  
Yiwen Ju ◽  
Bo Chen ◽  
Weixuan Fang ◽  
Hongjian Zhu ◽  
...  

The mineralogical and compositional characteristics of gold-bearing minerals and the occurrence of gold are not only of great significance to exploring the sources of ore-forming materials and their formation mechanisms but also helpful for designing reasonable beneficiations and smelting schemes and achieving remarkable economic benefits. This paper presents an integrated study on the crystal characteristics, elemental composition and distribution of pyrite (the main gold-bearing minerals), on the basis of electron probe microanalysis (EPMA), scanning electron microscopy (SEM), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and nano-secondary ion mass spectrometry (NanoSIMS). The occurrence of gold in the Shuiyindong gold deposit and Ashawayi gold deposit has been studied by means of microscopy, SEM, and EPMA images, elemental correlations, S–Fe–As ternary diagrams, logAs–logAu diagrams and Au/As ratios. The gold in pyrite of the Shuiyindong deposit is in the form of nano gold inclusions and lattice gold. The gold in pyrite of the Ashawayi deposit dominantly exists in the form of nano gold inclusions or is present as micro-nano gold particles in the cracks or edges of pyrite, some of which can exist as lattice gold. The ore-forming hydrothermal solution of the Shuiyindong gold deposit is mainly underground hot brine, but it may be reformed by a deep magmatic hydrothermal solution or volcanic-subvolcanic hydrothermal solution. The ore-forming hydrothermal solution of the Ashawayi gold deposit is mainly derived from the metamorphic hydrothermal solution formed during the orogenic process, and the ore-forming process or post-mineralization process may be reformed by the leaching of underground hot brine. Finally, the characteristics of ore-forming fluids and evolution of the two types of deposits are determined via pyrite element surface scanning. This paper shows that micro-nanoscale study of gold-bearing pyrite is of great significance to understanding the gold mineralization process and is worth further study.


2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Ye Cao ◽  
Shengrong Li ◽  
Meijuan Yao ◽  
Huafeng Zhang

AbstractThermoluminescence (TL) of monomineralic separates have been widely used in various geosciences fields in order to trace the thermal history and aid in prospecting for gold deposits. Quartz is a ubiquitous mineral in the Shihu gold deposit, which is situated in the northern part of the Taihang orogenic belt in the North China craton (NCC). The deposit is hosted by ductile-brittle faults within an Archean metamorphic core complex of the Fuping Group. This deposit is characterized by gold-bearing quartz-polymetallic sulfides and quartz veins. New TL results have been obtained for quartz, in which four type-TL glow curves were identified. The gold-bearing quartz present type III glow curves that consist of two peak glow curves at the middle and high peak temperatures with the similar TL intensity. In addition, the cross-sections of peak temperatures and TL intensity highlight the valuable area where the Au-bearing quartz present weak TL intensity and low-middle peak temperatures. Our results significantly enhance the usefulness of quartz in metallogenic studies of the North China craton and as an indicator mineral in mineral exploration of the Taihang Mountain region.


2020 ◽  
Vol 6 (11) ◽  
pp. 104-116
Author(s):  
T. Yarboboev ◽  
Sh. Sultanov ◽  
I. Ochilov

The study of mineralogical and geochemical properties of gold deposits is an urgent task for the geological industry, especially in the new areas under study. Without reliable information about the geological factors that lead to the formation of ore deposits and the mechanisms of deposit accumulation, it is impossible to ensure reliable scientific forecasting of the mineral potential of the regions, the effective creation of mineral resources of enterprises and mining, the stable operation of the mining industry. Our study of gold deposits was aimed at understanding these important issues of the ore formation problem. This is the urgency of the case. The role of the dictators of the Yakhton ore deposit as important structural material and mineral components of the leading types of ore-magmatic systems is being assessed. A peculiar feature of the geological structure of the ore area is the close paragenetic relationship of mineralization by rocks of the dike kids complex. Mineralization is localized in two stages and has bimetallic properties (gold, tungsten). The mineralization in the upper layer is localized in the corpus carbonate rocks of Yakhton (mainly garnet-pyroxene content). In the lower stage, mineralization is governed by a northeastern tectonic attenuation zone, which includes area concentrations of Au and W and areal mineralized zones that are part of the dike of the Yakhton region. Determining the spatial, age, and genetic relationships of mineralization with magmatism is a major problem of metallogeny.


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