METALLOGENY OF ENDOGENOUS GOLD IN TUVA
I.V. Gas'kov1, S.G. Prudnikov2
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Tuva Institute for the Integrated Development of Natural Resources, Siberian Branch of the Russian Academy of Sciences, ul. Internatsional’naya 117a, Kyzyl, 667007, Russia
Keywords: Gold metallogeny, deposits, ore gold, age dating, Tuva
Abstract
Analysis shows that the occurrences of ore gold of different formational types and ages widespread in the Republic of Tyva are related to the intricate and long geologic history of this region. The Tyva region is of polycyclic development; in the period from the Precambrian to the Cenozoic, there were stages of subduction, accretion-collision, and rifting processes accompanied by volcanism of different types and a wide manifestation of granitoid magmatism. Gold metallogeny was discretely developed throughout the geologic history of the region and was most widely manifested at the island arc stage (570-510 Ma), in connection with the formation of gold-bearing pyrite-polymetallic deposits. The late Cambrian-Ordovician period of granitoid magmatism was also productive for gold mineralization: It was marked by the formation of porphyry Au-Cu-Mo deposits, proper gold deposits, and gold-skarn, gold-quartz, and gold-beresite ore occurrences. Several gold-bearing clusters confined to different structure-formational zones are distinguished in the Tuva area. To date, gold contents of commercial interest have been identified in the Tardanskoe gold deposit with Au reserves of 7371.8 kg, in the gold-bearing Kyzyl-Tashtyg pyrite-polymetallic deposit with estimated Au reserves of 15.08 tons and Ag reserves of ~700 tons, and in the gold-bearing Ak-Sug porphyry Cu-Mo deposit with C2 gold reserves of 83 tons and silver reserves of 368 tons. In the course of prospecting and revision performed at many gold ore clusters in recent years, additional information about the high endogenous-gold potential of the Republic of Tyva has been obtained. There are a number of objects promising for commercial reserves of endogenous gold, such as The Kara-Bel’dir gold ore cluster with C1 and C2 gold reserves of 22.8 tons, the Aldan-Maadyr gold ore cluster with predicted P2 gold resources of 38 tons and Р3 gold resources of 80 tons, the Eiligkhem ore cluster with predicted P3 gold resources of 36 tons, the Kyzyk-Chadr ore cluster with predicted Р1 + Р2 gold resources of 39.7 tons and silver resources of 198 tons at the Kyzyk-Chadr deposit, and the East Tannu-Ola ore district with Au resources of 68.3 tons. Thus, the intricate geologic development of the Tyva area and various geologic events, including large-scale magmatic processes, led to the formation of both gold and gold-bearing deposits and ore occurrences, which give reason to anticipate revealing of large commercial reserves of endogenous gold and the development of gold mining industry in the republic.
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