scholarly journals Baikal–Vilyui Paleoproterozoic Belt of The Siberian Platform: Regional Gold-Controlling Structure

2021 ◽  
Author(s):  
V. V. Stogny ◽  
G. A. Stogny
Keyword(s):  
Siberian Platform ◽  
Sedimentary Cover ◽  
Field Structure ◽  
Gold Content ◽  
Regional Structure ◽  
Early Precambrian ◽  
Gold Silver ◽  
Low Sulfidation ◽  
Primary Gold ◽  
Gold Bearing

Abstract The article demonstrates that the placer gold content of the Vilyui Syneclise is governed by the regional structure of the crystalline basement of the Siberian Platform—the Baikal–Vilyui Paleoproterozoic belt, the boundaries and tectonics of which are substantiated by analysis of the gravitational field structure. The belt includes a system of basement blocks with a common northeastern strike, which form horsts (of the Suntar type) and grabens (of the Kempendyai type). The gold-bearing placers of the Vilyui Syneclise are mainly confined to the Suntar, Tyukyan, and Chybyda blocks of the belt, the metamorphic and igneous rocks of which were the primary gold sources in the sedimentary cover. The suture zone of the Baikal–Vilyui belt was very permeable to deep fluids responsible for gold migration. The types of possible primary gold sources (gold–platinoid, low-sulfidation gold-quartz, and gold–silver) reflect the peculiarities in the evolution of Early Precambrian gold during sedimentation in the Vilyui Syneclise. The areas controlled by the Suntar, Kempendyai, Tyukyan, Chybyda, and Khapchagai blocks of Early Precambrian rocks, which may contain gold objects, should be considered promising for buried gold placers in the Vilyui Syneclise.

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.

scholarly journals Geological-structural control and criteria of forecasting the types of primary sources of placer gold on the East of Siberian platform

2018 ◽  
pp. 17-24
Author(s):  
Z. S. Nikiforova
Keyword(s):  
Siberian Platform ◽  
Structural Control ◽  
Sedimentary Cover ◽  
Rare Metal ◽  
Gold Deposits ◽  
Primary Sources ◽  
Correct Selection ◽  
Placer Gold ◽  
Deep Faults ◽  
Gold Silver

Identification of indicators on placer gold allowed predicting formation types of primary sources of gold and their location in the East Siberian platform, overlapped by thick cover of Meso-Cenozoic deposits, where traditional methods of prospecting of gold deposits are ineffective. Each gold-ore formation is known to have the corresponding geological-structural control. Based on study of mineralogical-geochemical features of placer gold and regularity of its distribution, it has been determined that primary sources of low-sulfide gold-quartz, gold-copper-porphyritic, gold-ferruginous-quartzite, gold—rare-metal and gold-platinoid formations are confined to basement outcrops and their framings; gold-sulfide-quartz formation — to metasomatites, developed within the zones of deep faults, tracing the terrigenous-carbonate series; and manifestations of gold-silver formation are localized in the zones of intracontinental paleorifts. In general, identification of geological-structural location of specific types of gold sources favors more correct selection of prospecting methods for gold deposits in areas with thick sedimentary cover, and evaluating their potential.

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.

Sr Isotope Chemostratigraphy and Pb–Pb Age of the Riphean Carbonate Deposits of the Kharaulakh Uplift (Northeastern Margin of the Siberian Platform)

2021 ◽  
Vol 62 (03) ◽  
pp. 377-387
Author(s):  
B.B. Kochnev ◽  
A.B. Kuznetsov ◽  
D.R. Sitkina ◽  
A.Yu. Kramchaninov
Keyword(s):  
Siberian Platform ◽  
Sedimentary Cover ◽  
Complex Structure ◽  
The Arctic ◽  
86Sr Ratio ◽  
Sr Isotope ◽  
Upper Riphean ◽  
Carbonate Deposits

Abstract —The least altered limestones of the Ukta and Eselekh formations in the Precambrian section of the Kharaulakh uplift have a minimum 87Sr/86Sr ratio of 0.70673–0.70715. The lowest 87Sr/86Sr ratio of the overlying Neleger and Sietachan formations is 0.70791–0.70817. Based on these data, along with the earlier obtained positive δ13С values (up to 8‰) for the Kharaulakh section, we have estimated the age of the Ukta and Eselekh formations at 800–670 Ma and the age of the Neleger and Sietachan formations at ~640–580 Ma. The Pb–Pb isochron age of the least altered limestones of the Eselekh Formation calculated from eight samples is 720 ± 30 Ma. This age permits us to define the lower part of the Kharaulakh section of the Ukta and Eselekh formations to be the late Tonian of the International Chronostratigraphic Chart or to the Upper Riphean of the General Stratigraphic Scale of Russia. The presence of reliably dated Upper Riphean sediments in the Kharaulakh uplift indicates a more complex structure of the Precambrian sedimentary cover on the Arctic margin of the Siberian Platform than assumed earlier.

scholarly journals Geochemistry of Umm Rus gold - quartz veins, Central Eastern Desert Egypt. A new contribution

2001 ◽  
Vol 34 (3) ◽  
pp. 1139
Author(s):  
O. A. KAMEL ◽  
M. M. EL MAHALLAWI ◽  
H. M. HELMY
Keyword(s):  
Hybrid Zone ◽  
Eastern Desert ◽  
Quartz Diorite ◽  
Low Grade ◽  
Gold Content ◽  
Strongly Correlated ◽  
Quartz Veins ◽  
Central Eastern Desert ◽  
Pan African ◽  
Gold Bearing

Gold-bearing quartz veins of the Umm Rus area occur at the south-eastern contact of a Precambrian granodiorite cupola within younger gabbros of 573-615 Ma belonging to the Pan African orogenic belt. The rocks are intruded within low-grade metasediments. At such contact, a hybrid zone is developed characterized by the occurrence of quartz diorite which grades into diorite and meta-ferrogabro. A limited number of mineralized quartz veins cut the granodiorite-gabbro complex. Different alteration zones are developed in the vicinity of the quartz veins. The quartz veins have two main trends; NS and N30 E, the latter one is usaually gold-bearing. The mineralized parts of the veins commonly consist of highly sheared and banded smoky quartz, and the gold content depends on the relation with the dykes. The element is strongly correlated with As and Ag, but moderately with Cu. Near to intermediate and basic dykes, the contents of Au, Ag and As are noticably increased

Geostatistical and GIS analysis of the spatial variability of alluvial gold content in Ngoura-Colomines area, Eastern Cameroon: Implications for the exploration of primary gold deposit

2018 ◽  
Vol 142 ◽  
pp. 138-157 ◽  
Author(s):  
Jonas Didero Takodjou Wambo ◽  
Sylvestre Ganno ◽  
Yannick Sthopira Djonthu Lahe ◽  
Gus Djibril Kouankap Nono ◽  
Donald Hermann Fossi ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Gold Deposit ◽  
Gold Content ◽  
Gis Analysis ◽  
Alluvial Gold ◽  
Primary Gold ◽  
Eastern Cameroon

Thermal history of the Siberian platform: Apatite Fission-Track data from the Permian-Triassic magmatic complexes

2021 ◽  
Author(s):  
Tatyana Bagdasaryan ◽  
Roman Veselovskiy ◽  
Viktor Zaitsev ◽  
Anton Latyshev
Keyword(s):  
Siberian Platform ◽  
Thermal History ◽  
Fission Track ◽  
Sedimentary Cover ◽  
Geothermal Gradient ◽  
State University ◽  
Apatite Fission Track ◽  
History Of ◽  
Cover Up ◽  
Moscow State University

<p>The largest continental igneous province, the Siberian Traps, was formed within the Siberian platform at the Paleozoic-Mesozoic boundary, ca. 252 million years ago. Despite the continuous and extensive investigation of the duration and rate of trap magmatism on the Siberian platform, these questions are still debated. Moreover, the post-Paleozoic thermal history of the Siberian platform is almost unknown. This study aims to reconstruct the thermal history of the Siberian platform during the last 250 Myr using the low-temperature thermochronometry. We have studied intrusive complexes from different parts of the Siberian platform, such as the Kotuy dike, the Odikhincha, Magan and Essey ultrabasic alkaline massifs, the Norilsk-1 and Kontayskaya intrusions, and the Padunsky sill. We use apatite fission-track (AFT) thermochronology to assess the time since the rocks were cooled below 110℃. Obtained AFT ages (207-173 Ma) are much younger than available U-Pb and Ar/Ar ages of the traps. This pattern might be interpreted as a long cooling of the studied rocks after their emplacement ca. 250 Ma, but this looks quite unlikely because contradicts to the geological observations. Most likely, the rocks were buried under a thick volcanic-sedimentary cover and then exhumed and cooled below 110℃ ca. 207-173 Ma. Considering the increased geothermal gradient up to 50℃/km at that times, we can estimate the thickness of the removed overlying volcanic-sedimentary cover up to 207-173 Ma as about 2-3 km.</p><p>The research was carried out with the support of RFBR (grants 20-35-90066, 18-35-20058, 18-05-00590 and 18-05-70094) and the Program of development of Lomonosov Moscow State University.</p>

STALE GOLD-BEARING TAILINGS OF THE BALEIZOLOTO PLANT AND THE PROBLEM OF THEIR DISPOSAL

2021 ◽  
Vol 27 (4) ◽  
pp. 45-54
Author(s):  
G. Yurgenson ◽  
◽  
L. Shumilova ◽  
А. Khatkova ◽  
◽  
...  
Keyword(s):  
Negative Impact ◽  
Chemical Elements ◽  
Raw Materials ◽  
Precious Metals ◽  
Gold Content ◽  
Residential Areas ◽  
Extraction Technology ◽  
Useful Components ◽  
Technogenic Raw Materials ◽  
Gold Bearing

The relevance of the research is the need to recultivate the waste from the enrichment of gold-bearing ores that lie in the immediate vicinity of the residential areas of Baley city, which have a negative impact on the environmental situation in it, as well as to develop a technological approach to the extraction of gold and silver. The purpose of the study is to study the material composition and develop a technology for extracting precious metals. The object of the study is the stale tailings of the ZIF-1 plant “Baleizoloto”. The subject of the study is mineral composition of stale tailings, content of useful components and their extraction technology, the method and methodology presented by mineralogical and chemical analyses of enrichment tailings. Results. The analysis of the tailings dumps’ state of the gold recovery factories of the Baleizoloto plant was carried out. The contents of gold and other chemical elements, among which arsenic, zinc, copper, antimony, and lead predominate, were determined. The gold content prevails in the stale tailings of the ZIF-1 factory, which processed the ores of the Baley deposit, and is in the range of 1.09-1.37 g / t, on average – 1.17 g/t. This determines the prospects for their primary processing. The gold in the clay-sand fraction of the stale tailings is mainly found in thin accretions with quartz, carbonates, pyrite, arsenopyrite, sulfosols, and tellurides. The field of application is processing of technogenic raw materials. Conclusions. It was determined that the sizes of gold inclusions are in the range of 0.7-0.03 mm, the gold penetration varies from 63 to 91.15, and on average is 82.13; the main impurity in gold is silver with a content of 8.85-37%; the average silver content in the tailings of the ZIF-1 factory is 1.85 g/t; the recommended technological scheme for processing stale tailings of ZIF-1 of the Baleizoloto plant has been developed, including the following operations: photoelectron-activation preparation, pelletizing with active solution, heap leaching, two-stage sorption with bubbling with ozone

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

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