Typomorphic Features and Source of Native Gold from the Sykhoi Log Area Placer Deposits, Bodaibo Gold-Bearing District, Siberia, Russia

Abstract

The Bodaibo gold-bearing district in the Lena gold province of Siberia is one of the largest and oldest placer gold-bearing provinces in the world. Approximately 1650 tons of gold has been extracted from the region. Precise studies on the source of these unique placer deposits are lacking and still controversial. Native gold from four different locations was gathered to investigate its morphology, chemical signatures, structure and inclusions. Some data on primary bedrock mineralization were obtained from the published literature. The linear weathering crusts developed along the zones of disjunctive dislocations near the Sukhoi Log gold deposit were researched. If they coincided with zones of low-grade veinlet-disseminated gold–quartz–sulphide mineralization with small gold grain sizes, a supergene replacement of primary mineralization was known to have occurred, accompanied by the formation of gold-rich rims and an increase in the size, content and purity of gold. Such mineralization associated with linear weathering crusts can be a source of local eluvial–proluvial placers, while placers of large valleys are formed due to low-sulphide gold–quartz lodes.

Mineralogical Method as an Effective Way to Predict Gold Ore Types of Deposits in Platform Areas (East of the Siberian Platform)

“…Identified patterns made it possible to develop a method for predicting minerogenic types of gold deposits based on the indicators of placer gold and features of their distribution and to link them with various geological structures for the first time [15]. Similar studies on the mineralogy of placer gold, in order to identify the types of ore sources and the genesis of placers, have been successfully conducted and continue to be developed by Russian scientists [16][17][18][19][20][21][22] and also by foreign researchers [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The study of the typomorphic features of placer gold (morphology, chemical composition, micro-inclusions, internal structure) in order to identify minerogenic types of ore sources was carried out using well-known mineralogical and geochemical methods. All analyses were performed in the laboratory of physical-chemical methods of analysis of the Diamond and Precious Metal Geology Institute, SB RAS (DPMGI SB RAS), Yakutsk (Russia).…”

Compositional Signatures of Gold from Different Deposit Types in British Columbia, Canada

“…The continuation of this work will without doubt involve the characterization of gold from deposit types where compositional data are relatively scarce. In addition, researchers interested in developing regional compositional templates should be aware of other gold signatures specific to specific deposit types, for example, those associated with relatively unusual hydrothermal systems [31] or those associated with a specific sub-class of a broader category [64].…”

Palladian Gold: Chemical Composition, Minerals in Association, and Physicochemical Conditions of Formation at Different Types of Gold Deposits

“…Native gold often contains microinclusions of ore minerals, silicates, oxides, carbonates, etc. Special attention during recent years has been paid to the study of the impurities and minerals in paragenesis with native gold, since these characteristics are important informative signs of deposits with different types of mineralization [8,[13][14][15][16][17][18]. Effective criteria for forecasting and searching for gold deposits can be provided by a study of the mineralogical-geochemical composition of native gold.…”