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Gold Mineralization in the Eastern Tannu‐Ola Ore District of the Altai‐Sayan Folded Area (Russia)
Author(s) -
Chernykh A.I.
Publication year - 2014
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12375_1
Subject(s) - citation , library science , history , computer science
The Eastern Tannu-Ola ore district is confined to the large tectonic block of the Upper-Yenisei folded system and is composed mainly of Vendian(?)–Ordovician rocks. They are represented by Vendian(?)-Early Cambrian island-arc volcanogenic-sedimentary complexes, metamorphosed at the level of the greenschist facies and contorted into folds of various orders (Mongush et.al., 2011). A characteristic feature of the Eastern Tannu-Ola district is a wide development of massifs of the intrusive rocks, intruded volcanogenic-sedimentary rocks. Such massifs are constituted by the Late Cambrian diorites, granodiorites, granites and plagiogranits. Intrusions of the Ordovician granite-leucogranite composition and of Early Devonian granite composition (Rudnev, 2013) are less common. Occurrences of iron, gold and copper are known within the Eastern Tannu-Ola ore district. Gold mineralization belongs to gold-skarn and gold-sulphide-quartz types. Its formation is connected with granitoid massifs of Late Cambrian age. Indications of gold-containing polymetallic mineralization, associated with the Early Cambrian vulcanites are revealed in the western part of the district. Besides, there are identified features of molybdenumcopper-porphyry mineralization with gold within the district. This mineralization formation is concerned with the Ordovician and Early Devonian granites and leucogranites. Gold mineralization is controlled by fractured zones in near-contact and over roof parts of granitoid massifs, intruded Early Cambrian volcanogenicsedimentary rocks. According to the information available, direct and indirect indicators of gold mineralization are concentrated in south and north-eastern ore district, where the Despenskiy and Elegest-Mezhegeiskiy iron-coppergold ore clusters are allocated. These clusters are characterized by similar geological structure and combination of ore control and ore parent minerogenetic factors. Besides, the Irbiteiskiy gold-containing polymetallic cluster is distinguished by the author in the western part of the region. Despenskiy and Elegest-Mezhegeiskiy gold ore clusters are stretched in sublatitudinal direction and confined to the South Tannu-Ola and Bai-Dagskiy faults respectively. A characteristic feature of geology of both clusters is the presence of numerous, various rank, differently directed and uneven-aged faults. Crushing and fractured zones in igneous-sedimentary rocks and granitoids provided a favorable environment for unloading of hydrothermal solutions and generation of large vein-veinlet and stockwork gold-sulfide-quartz zones. Numerous zones of skarnization, sulfidization, epidotization, silicification, sulphide-quartz veins and veinlets with gold, copper, plumbum, sulphosalt, and silver mineralization are observed in endomorphosed and exomorphozed zones.