Prospects of primary gold potential in southern Siberian platform based on study results for placer gold morphological and geochemical features

2021 ◽  
pp. 97-114
Author(s):  
Ivan Chetvertakov ◽  
Alexey Ivanov ◽  
Ekaterina Mikheeva ◽  
Tatyana Chikisheva ◽  
Tamara Yakich
Keyword(s):  
Siberian Platform ◽  
Geological Structure ◽  
Gold Deposits ◽  
Primary Sources ◽  
Placer Gold ◽  
Genetic Types ◽  
Study Results ◽  
Geochemical Property ◽  
Geochemical Studies ◽  
Primary Gold

Data on geological structure and minerals of the southern Siberian platform are presented. Placer and primary gold occurrences widespread in this region are briefly characterized. Based on placer gold morphological and geochemical property studies using electron microscopy, its four types are revealed. Conclusions are made about potential primary sources of various placer gold types. Using retrospective data and based on the authors’ placer gold morphological and geochemical studies, Ust-Ilimskaya, Chernorechinskaya and Buraevskaya gold areas are characterized, their prospects for discovering primary gold deposits of various genetic types are determined.

scholarly journals Placer gold occurrences along the major rivers of Nepal Himalaya and their possible primary sources

1996 ◽  
Vol 13 ◽  
Author(s):  
K. P. Kaphle ◽  
P. R. Joshi ◽  
H. R. Khan
Keyword(s):  
Gold Mineralization ◽  
Gold Deposits ◽  
Primary Sources ◽  
Gold Content ◽  
Lower Paleozoic ◽  
Nepal Himalaya ◽  
Placer Gold ◽  
Flood Plains ◽  
River Flood ◽  
Primary Gold

Recent exploration in Lungri Khola area, Rolpa district, midwestern Nepal helped to delineate a discontinuous 1.5 to 40 m thick and about 30 km long primary gold mineralization zone in the Precambrian greenschists and Lower Paleozoic micaceous marbles of the Lesser Himalaya. The gold content in these lodes vary from 0.01 to 6.7 ppm. In eastern Nepal occurrences of primary gold is recorded in quartz-biotiteschist, amphibolite and pegmatite bodies in Sunmai and Bering Khola of Ilam district. Fine flakes of gold also occur in the pyritiferous quartz beds/lenses in chlorite-sericite phyllite and quartzite of Bamangaon polymetallic prospect, Dadeldhura district, far western Nepal. In this prospect the gold content is from 0.2 to 0.8 ppm, and one sample showed up to 14 ppm. Primary gold occurrences are also detected in few irregular quartz-pyrite veins and iron-copper sulphide bearing quartzite lying close to the amphibolite bodies. Some pyrite bearing radioactive quartzite beds in Banku Quartzite of Purchauni Crystalline Complex exposed at Boregad, Bangabagar, Baggoth and Jamari Gad area in Darchula and Baitadi districts, far western Nepal also contain gold. The gold content in the radioactive quartzite varies from 0.2 to 1.2 ppm and in some pyritiferous radioactive quartzite floats it reaches up to 5.06 ppm. The primary gold appears to be of synsedimentary, hydrothermal and possibly volcanogenic in origin. Placer gold is derived from primary sources and deposited at favourable locations along the river flood plains. Further investigations in similar geological terrain may help to identify economically viable primary as well as placer gold deposits in the Nepal Himalaya.

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.

scholarly journals Typomorphic Features of Placer Gold from the Billyakh Tectonic Melange Zone of the Anabar Shield and Its Potential Ore Sources (Northeastern Siberian Platform)

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 281
Author(s):  
Boris Gerasimov ◽  
Vasily Beryozkin ◽  
Alexander Kravchenko
Keyword(s):  
Native Gold ◽  
Gold Mineralization ◽  
Coarse Fraction ◽  
Gold Deposits ◽  
Primary Sources ◽  
The Arctic ◽  
Geochemical Data ◽  
Placer Gold ◽  
Anabar Shield ◽  
Tectonic Mélange

Precambrian shields and outcropped Precambrian rock complexes in the Arctic may serve as the most important sources of various types of mineral raw materials, including gold. The gold potential of the Anabar shield in the territory of Siberia has, thus far, been poorly studied. A number of primary and placer gold occurrences have been discovered there, but criteria for the prediction of and search for gold mineralization remain unclear. The main purpose of this paper was to study the typomorphic features of placer gold in the central part of the Billyakh tectonic mélange zone in the Anabar shield and to compare them to mineralization from primary sources. To achieve this, we utilized common methods for mineralogical, petrographic, and mineragraphic analyses. Additionally, geochemical data were used. As a result of this investigation, important prospecting guides were identified, and essential criteria for the prediction of and search for gold deposits were elucidated. The characteristics of the studied placer gold were specific for gold derived from a proximal provenance. These characteristics included the poor roundness of the native gold grains, a cloddy–angular and dendritic form, an uneven surface, and a high content of coarse-fraction native gold (0.5–2 mm), which was as high as 24% of the volume of analyzed native gold. In addition, we conducted a study on the mineralogical features of the gold-sulfide mineralization that was disseminated throughout a small exposure area of paleo-Proterozoic para- and orthogneisses in the Anabar shield basement. A comparison of mineral inclusions in the coarse-fraction native gold and mineral assemblages in the ore deposits showed that one of the possible primary sources for placer gold might be small bodies of metasomatically altered orthogneisses associated with large granitoid plutons.

Indicative features of placer gold for the prediction of the formation types of gold deposits (east of the Siberian Platform)

2018 ◽  
Vol 59 (10) ◽  
pp. 1318-1329 ◽  
Author(s):  
Z.S. Nikiforova ◽  
B.B. Gerasimov ◽  
E.G. Glushkova ◽  
A.G. Kazhenkina
Keyword(s):  
Siberian Platform ◽  
Gold Deposits ◽  
Placer Gold

scholarly journals Giant Placers of the Victorian Gold Province

SEG Discovery ◽  
2004 ◽  
pp. 1-18
Author(s):  
Martin J. Hughes ◽  
G. Neil Phillips ◽  
Stephen P. Carey
Keyword(s):  
Late Cretaceous ◽  
Quartz Vein ◽  
Late Eocene ◽  
Gold Deposits ◽  
Gold Production ◽  
Placer Gold ◽  
High Rainfall ◽  
Hydrothermal Quartz ◽  
Alluvial Gold ◽  
Primary Gold

ABSTRACT The Victorian gold province has yielded 2500 tonnes (t) Au, nearly 2 percent of cumulative world gold production, mostly mined between 1851 and 1910. Fifty-five percent (1375 t) was placer gold from modern and paleostream systems, and from eluvial deposits, and the remainder came from primary quartz vein-related deposits. Most of the alluvial gold placers are in unconsolidated or weakly cemented quartz pebble conglomerate and gravel, dominated by hydrothermal quartz, although a few paleoplacers are within duricrusted conglomerate that required crushing. Large and abundant gold nuggets were common. Placer gold deposits formed in three intervals following uplift in the Late Cretaceous, Late Eocene, and Pliocene. An important factor in the preservation of the paleoplacers has been their burial by younger sediments and basalt flows, with consequent protection from erosion and dispersal. Factors in the formation of the giant gold placers of Victoria include the following: (1) the existence of a major primary gold province with several multimillion-ounce gold deposits; (2) uplift and reactivation of older faults; and (3) high rainfall and deep Paleogene weathering.

scholarly journals The Process Designing of Gold Extraction from Placers of Passu to Shimshal (Hunza Valley) Gilgit-Baltistan by Mercury Amalgamation and Cyanidation Leached Method

2020 ◽  
Vol 10 (4) ◽  
pp. 25-29
Author(s):  
Muhammad Alam ◽  
Javed Akhter Qureshi ◽  
Garee Khan ◽  
Manzoor Ali ◽  
Naeem Abbas ◽  
...  
Keyword(s):  
Chemical Process ◽  
Gold Deposits ◽  
Shaking Table ◽  
Fluvial Sediments ◽  
Gold Extraction ◽  
Placer Gold ◽  
Study Results ◽  
Reagent Consumption ◽  
Gilgit Baltistan ◽  
River Banks

Gold wash through panning or washing in the fluvial sediments or sands is done on the river banks inSkardu, Hunza and other places. The method of gold washing is very crude, primitive and most of the gold is washedaway back into the river. The current study mainly focused on extraction of placer gold deposits. Pneumatic machinesfrom Passu to Shimshal (Hunza valley) Gilgit-Baltistan. The mercury amalgamation and cyanide leached methods havebeen used for placer gold deposits extraction from the concentrate obtained from shaking table. The amount of goldrecovered from amalgamation method with mercury was 30.9%. The alloyed gold with other metals, gold dust, and finegold was recovered by chemical process. The reagent consumption, i.e. 1.4 kg/ton of NACN and 6 Kg / ton of CaOwere used for extraction of placer gold deposits. The extracted gold is 10.24 g /t and silver 22 g /t and the remaininggold like the amalgamation residue, tailings and middlings are extracted by cyanidation leached method. The extractionof gold by cyanidation process was compared graphically, and study results revealed that extraction of gold usingcyanidation leached method was 91.40% and silver 100%, respectively.

scholarly journals The Internal Structure of Placer Gold of the North-East of the Siberian Platform as a Reliable Search Sign of Primary Sources

2021 ◽  
Vol 906 (1) ◽  
pp. 012082
Author(s):  
Boris Gerasimov
Keyword(s):  
Internal Structure ◽  
Siberian Platform ◽  
Native Gold ◽  
Primary Source ◽  
Primary Sources ◽  
Placer Gold ◽  
North East ◽  
The North ◽  
History Of ◽  
Gold Sulfide

Abstract Typomorphic features of placer gold are carriers of the most important information necessary for the reconstruction of the history of the formation of placer and ore occurrences of gold and can be used as mineralogical criteria in the search for primary sources of placers. The study of these features is relevant for placer areas with unidentified gold sources, which include the territory of the north-east of the Siberian Platform. The internal structure of native gold is one of the most informative typomorphic features is. We studied the internal gold structures of modern placers and conglomerates of the Early Permian age in the north-east of the Siberian Platform. The purpose of the work: to identify the features of the internal structure of placer gold, depending on the chemical composition and the degree of its transformations, as well as the possibility of their use as a prospecting indicator. Structural etching of native gold was performed using the reagent: HCl + HNO3 + FeCl3 × 6H2O + CrO3 + thiurea + water. As a result of the research, it was found that the well-rounded high-grade gold of modern placers has undergone repeated redeposition through intermediate sources. The discovery of slightly rounded gold with an internal structure without signs of exogenous transformation indicates that it entered the modern alluvium from a nearby primary source. This was a prerequisite for setting up ore gold exploration, resulting in identification of apocarbonate hydrothermal-metasomatic formations with disseminated gold-sulfide mineralization were identified. Thus, the features of the internal structures of placer gold in combination with other typomorphic features are additional indications of determining the sources of formation of gold-bearing placers.

Sign in / Sign up

Export Citation Format

Share Document