scholarly journals About the ore conduits at the near-surface deposits of gold-silver ores

2017 ◽  
pp. 37-49
Author(s):  
E. M. Necrasov ◽  
L. A. Dorozhkina
Keyword(s):  
Noble Metals ◽  
Ore Deposits ◽  
Depth Interval ◽  
Near Surface ◽  
Ore Bodies ◽  
Gold Silver ◽  
Exploration Drilling ◽  
Gold Bearing

It is shown that at the rather numerous near-surface gold-silver ore deposits (sometimes with tellurides), developed in the East of Russia, the fractured ore conduits can be revealed. From them, the bundles and a series of vein-veinlet ore bodies or metasomatic gold-bearing rocks start. In both cases the areas with bonanza contents of the noble metals are established. The portion of their stocks sometimes reaches 70% in a total. Exploration drilling along the barren flanks of the ore-conducting channels can identify new ore, hidden in the depth interval from 100-200 to 400 meters or more, and replenish stocks of the deposits.

scholarly journals EXPECTED OCCURRENCE OF THE BLIND ORE BODIES AT THE LOWER LEVELS OF THE BALEI DEPOSIT AND A MECHANISM OF THE RICH ORES FORMATION AT THE NEAR-SURFACE GOLD-SILVER ORE DEPOSITS

2017 ◽  
pp. 40-51 ◽  
Author(s):  
E. M. Nekrasov
Keyword(s):  
Ore Deposits ◽  
The South ◽  
Near Surface ◽  
Gold Ore ◽  
Ore Bodies ◽  
Gold Silver ◽  
The Rich ◽  
Main Vein ◽  
Bulk Gold

The gold ore chimneys of 2 types have been shown to be developed at the near-surface deposits of gold and silver ores. These types are: 1 - bulk ones, of the vein-nested-veinlet ore bodies of stockwork shapes and 2 - small pay streaks of the ore bodies, appeared either in single veins or in the veins, being a part of the wide ore bundles. The example of the first type is the Central ore column of Balei deposit and the column of the Glavnaya (Main) vein of the Karamkenskoe deposit. A deiailed analyses of the graphic material, made by N.V. Petranovskaya for Balei deposit, confirms, that under the bottom of the ore controling vein №2 in the vertical interval from 100 to 250-350 m the rich ores can be prevailed in the zones, which are likely to join with ore bodies of Taseevsky site. The discovery of the new bulk gold ore chimnies is likely to be there. With this, an additional exploration of the south-east flanks of the Balei deposit is needed, that can lead to the discovery of the new bulk gold ore chimnies.

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 Radiological Identification of Near-Surface Mineralogical Deposits Using Low-Altitude Unmanned Aerial Vehicle

2020 ◽  
Vol 12 (21) ◽  
pp. 3562
Author(s):  
Peter G. Martin ◽  
Dean T. Connor ◽  
Natalia Estrada ◽  
Adel El-Turke ◽  
David Megson-Smith ◽  
...  
Keyword(s):  
Large Scale ◽  
Mineral Resources ◽  
Radiation Detectors ◽  
Developed Countries ◽  
Ore Deposits ◽  
Integrated System ◽  
Near Surface ◽  
Ore Bodies ◽  
Resource Exploration ◽  
Low Altitude

An ever-increasing global population and unabating technological growth have resulted in a relentless appetite for mineral resources, namely rare earth elements, fuel minerals and those utilised in electronics applications, with the price of such species continuing to climb. In contrast to more established large-scale and high-cost exploration methodologies, this work details the application of novel multi-rotor unmanned aerial vehicles equipped with miniaturised radiation detectors for the objective of undertaking resource exploration at lower costs, with greater autonomy and at considerably enhanced higher spatial resolutions; utilizing the ore material’s inherent low levels of characteristic radioactivity. As we demonstrate at the former Wooley Mine site in Arizona, USA, a legacy Cu/Fe prospect where the 600 by 275 m ore body (with a maximum deposit depth of 150 m), it is shown that such a fusion of commercially available low-altitude multi-rotor aerial technology combined with cutting-edge micro-electronics and detector materials is capable of accurately assessing the spatial distribution and associated radiogenic signatures of commercially valuable surface/near-surface ore bodies. This integrated system, deployed at an autonomously controlled consistent survey altitude and using constant grid transects/separations, is shown to be able to delineate the mineral-containing ore deposits on the site, the location(s) of former mine workings and other surface manifestations. Owing to its advantageous costs alongside its ease of operation and subsequent data-processing, through the adoption of this system, it is envisaged that less economically developed countries would now possess the means through which to evaluate and appropriately quantify their mineral wealth without the significant initial expenditure needed to equip themselves with otherwise prohibitively expensive technologies.

scholarly journals Mustard Gold in the Oleninskoe Gold Deposit, Kolmozero–Voronya Greenstone Belt, Kola Peninsula, Russia

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 786 ◽  
Author(s):  
Arkadii A. Kalinin ◽  
Yevgeny E. Savchenko ◽  
Ekaterina A. Selivanova
Keyword(s):  
Kola Peninsula ◽  
Gold Deposit ◽  
Greenstone Belt ◽  
Noble Metals ◽  
Fennoscandian Shield ◽  
Silver Deposit ◽  
Partial Removal ◽  
Gold Silver ◽  
The Matrix ◽  
Gold Bearing

The Oleninskoe intrusion-related gold–silver deposit is the first deposit in the Precambrian of the Fennoscandian Shield, where mustard gold has been identified. The mustard gold replaces küstelite with impurities of Sb and, probably, gold-bearing dyscrasite and aurostibite. The mosaic structure of the mustard gold grains is due to different orientations and sizes of pores in the matrix of noble metals. Zonation in the mustard gold grains is connected with mobilization and partial removal of silver from küstelite, corresponding enrichment of the residual matter in gold, and also with the change in the composition of the substance filling the pores. Micropores in the mustard gold are filled with iron, antimony or thallium oxides, silver chlorides, bromides, and sulfides. The formation of mustard gold with chlorides and bromides shows that halogens played an important role in the remobilization of noble metals at the stage of hypergene transformation of the Oleninskoe deposit.

MAGNETIC PROSPECTING FOR IRON ORES IN JAMAICA

Geophysics ◽  
1955 ◽  
Vol 20 (3) ◽  
pp. 593-614 ◽  
Author(s):  
S. A. Vincenz
Keyword(s):  
Remanent Magnetization ◽  
Iron Ore ◽  
Ground Surface ◽  
Natural Remanent Magnetization ◽  
Ore Deposits ◽  
Small Scale ◽  
Rough Terrain ◽  
Near Surface ◽  
Ore Bodies ◽  
Iron Ore Deposits

Two ground magnetometer surveys over iron ore deposits in Jamaica are described and the results of the observations interpreted. An improvised but economical technique is used to measure the main magnetic properties of ore samples obtained from surface exposures, and a suitable statistical analysis is applied to determine the significance of these observations. The interpretation of the magnetic profiles, carried out on the basis of these observations, is complicated by the non‐uniformity of the natural remanent magnetization of the ores and the roughness of Jamaican topography. The ambiguities due to the latter factor are diminished by taking into account in the computations the changes in the elevation of the ground surface. The results of the interpretation are on the whole successful and give the approximate sizes and positions of the main ore bodies. A conclusion is reached that, in the case of small‐scale near‐surface deposits whose approximate position is already known, ground magnetometer surveys can be superior to those made from the air because of their smaller cost and greater power of resolution in rough terrain.

scholarly journals HERMIONE, EVOLUTION OF ATe-BEARING EPITHERMAL MINERALIZATION, ARGOLIS, HELLAS

2007 ◽  
Vol 40 (2) ◽  
pp. 996 ◽  
Author(s):  
S. Tombros ◽  
K. St. Seymour
Keyword(s):  
Sedimentary Rocks ◽  
Ore Deposits ◽  
Stage I ◽  
Stage Ii ◽  
Quartz Veins ◽  
Minor Contribution ◽  
Epithermal Mineralization ◽  
Ore Bodies ◽  
Calcite Veins ◽  
Sandstone Formation

The Cu-Te-bearing pyrite deposits of Hermione, Argolis are hosted in Miocenic ophiolites. The ophiolites are overlain by a shale-sandstone formation with intercalations of limestones and manganiferous sedimentary rocks. The ore deposits form irregular lenticular or stratiform ore bodies, and veins. These ore bodies are related to volcanic activity in an arc-related rift at the margins of a palaeocontinent. Late N- to NNE-trending, sinistral, milky quartz-pyrite-calcite veins cut the host ophiolites. Alteration haloes of quartz-calcite, albite-sericitechlorite, and chalcedony-epidote-clay minerals are developed in the lavas as concentric shells, or as envelops that parallel the quartz veins. The telluriumbearing mineralization is developed in two successive stages, characterized by the assemblages: pyrite-(pyrrhotite)-magnetite-chalcopyrite-sphalerite (Stage I) and galena-sphalerite-freibergite-marcasite-chalcocite (Stage II), followed by a supergene stage. The cobaltiferous pyrite-chalcopyrite geothermometer defined two ranges of last-equilibration temperatures: 220° to 250°Cfor Stage I, and 120° to 195°Cfor Stage II. The calculated δ18 Ο and SD compositions of the mineralizing fluids, at 200° and 250°C, reflect the dominance of a magmatic component. The calculated δ SH2S fluid values reveal a magmatic source for the sulphur, with minor contribution from submarine sediments, whereas tellurium is proposed to be derived from a mafic-ultramafic source.

scholarly journals О геологическом и изотопном возрасте золоторудных месторождений на примере золото-серебряного месторождения Кубака (Северо-Восток России)

2021 ◽  
pp. 3-12
Author(s):  
V. A. Stepanov ◽  
Keyword(s):  
Gold Mineralization ◽  
Early Carboniferous ◽  
North East ◽  
The North ◽  
Ore Bodies ◽  
Geological Age ◽  
Gold Silver ◽  
Devonian Age ◽  
Isotope Dating ◽  
Silver Mineralization

Information on the geological and isotopic age of the Kubaka gold-silver deposit in the Omolon middle massif in the North-East of Russia is presented. It has been established that the Kubaka deposit geological age lies in between the Late Devonian age of the Kedon series volcanites, containing the gold-silver mineralization, and the Early Carboniferous age of the Korbinsky suite terrigenous rocks, overlapping the volcanites and the mineralization. The post-ore nature of the Omolon complex dykes, which produce no significant impact on the distribution of gold mineralization in ore bodies, is shown. According to isotope dating, the following stages of the Kubaka deposit formation are distinguished: the accumulation of the Kubaka suite tuffs (369 Ma); the introduction of subvolcanic intrusions (344 and 337 Ma); the formation of ore metasomatites (335±5 Ma); the formation of gold-silver mineralization (330 and 334 - 324 Ma); the introduction of post-ore dikes (179±8 - 176±10 Ma).

scholarly journals THERMOCHRONOLOGY AND MATHEMATICAL MODELING OF THE FORMATION DYNAMICS OF RARE‐METAL‐GRANITE DEPOSITS OF THE ALTAI COLLISION SYSTEM

2019 ◽  
Vol 10 (2) ◽  
pp. 375-404 ◽  
Author(s):  
N. G. Murzintsev ◽  
I. Yu. Annikova ◽  
A. V. Travin ◽  
A. G. Vladimirov ◽  
B. A. Dyachkov ◽  
...  
Keyword(s):  
Rare Metal ◽  
Ore Deposits ◽  
Event Correlation ◽  
Magmatic Differentiation ◽  
Collision System ◽  
Rare Metal Granite ◽  
Development History ◽  
Ore Bodies ◽  
Thermal Cooling

The article presents an event correlation of the Permian‐Triassic granites of the Altai collision system, which are associated with industrial ore deposits and occurrences (Mo‐W, Sn‐W, Li‐Ta‐Be). The multi‐system and multi‐mineral isotope datings of igneous rocks and ore bodies (U/Pb, Re/Os, Rb/Sr, Ar/Ar‐methods) suggest the postcollisional (intraplate) formation of ore‐magmatic systems (OMS), the duration of which depended on the crustmantle interaction and the rates of tectonic exposure of geoblocks to the upper crustal levels.Two cases of the OMS thermal history are described: (1) Kalguty Mo‐W deposit associated with rare‐metal granite‐leucogranites and ongonite‐ elvan dykes, and (2) Novo‐Akhmirov Li‐Ta deposit represented by topaz‐zinnwaldite granites and the contemporary lamprophyre and ongonit‐elvan dykes. For these geological objects, numerical modeling was carried out. The proposed models show thermal cooling of the deep magmatic chambers of granite composition, resulting in the residual foci of rare‐metal‐granite melts, which are known as the petrological indicators of industrial ore deposits (Mo‐W, Sn‐W, Li‐Ta‐Be). According to the simulation results concerning the framework of a closed magmatic system with a complex multistage development history, the magmatic chamber has a lower underlying observable massif and a reservoir associated with it. A long‐term magmatic differentiation of the parental melt (a source of rare‐metal‐granite melts and ore hydrothermal fluids) takes place in this reservoir.

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.

INTENSIFICATION OF DISPERSED AND FINE-GRAINED SILVER EXTRACTION IN CYANIDE HEAP LEACHING OF GOLD

2020 ◽  
Vol 26 (8) ◽  
pp. 40-48
Author(s):  
Yu. Rubtsov ◽  
◽  
А. Trubachev ◽  
E. Voronov ◽  
A. Lavrov ◽  
...  
Keyword(s):  
Noble Metals ◽  
Ph Value ◽  
Chemical Activation ◽  
Precious Metals ◽  
Federal District ◽  
Heap Leaching ◽  
Sodium Cyanide ◽  
Cycle Duration ◽  
Mining Equipment ◽  
Gold Bearing

Since the cost of gold has increased by an order of magnitude over the past 20 years, gold mining began to be carried out from ores that are not previously acceptable for heap leaching (HL) technology – these are refractory ores with thin and ultrafine inclusions of precious metals, ore with an increased silver content. In the Russian Federation, classical representations in the field of gold and silver HL prevail in design solutions. At the same time, the problem of silver leaching is considered in terms of the associated extraction of the main component. This approach is determined by a limited set of technological measures that have become an integral part of the classic technological regulation: ore crushing to the class –200–40 mm, sodium cyanide consumption at the level of 0,5 kg/t; pH value – 10,5; cycle duration 65 days or more; gold concentration in production solutions – fractions, mg/l; using activated carbon for sorption of noble metals. Processing ores with silver contents of 30 g/t and a more classical approach to gold HL does not allow to increase the degree of extraction. There is a need to modernize the circuit or change the parameters of the technological regulations. The object of the study was a sample of poor quartz ore provided by the customer developing one of the gold and silver deposits of the Far Eastern Federal District, the object was to increase the degree of leaching of silver from poor gold-bearing ores without changing the technological scheme and without attracting additional mining equipment. Critical analysis of literary data was carried out and the main directions of gold production from poor gold-bearing ores were identified. Chemical and mineralogical compositions of silver-containing minerals and ore rocks were investigated. Forms of association of silver with ore minerals and rocks have been established. The option of physical and chemical activation of increase of reactivity of cyanide solutions during heap leaching of silver from poor gold-bearing ores is chosen. In laboratory conditions, it was found that an increase in the concentration of sodium cyanide by 6 times or more contributes to a satisfactory extraction of gold both in agitation and percolation leaching of silver. However, in the latter case, the positive result was obtained only with the use of solutions with increased reactivity

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