Ore and Accessory Mineralization in the Sediments of the Southern Part of Urinsky Anticlinorium

Abstract

Within the southern part of Urinsky anticlinorium the stratigraphic sections, presented by outcrops of sedi- mentary rocks of the Upper Riphean, Vendian and Lower Cambrian on the left bank of the river Lena between the mouths of creeks Terbyas and Trehverstny, 4.5 km above the village Nohtuysk, form a unique, well-studied geological entity called Nohtuyskiy reference section. Uniqueness of the section is in the fact that a number of stratigraphic units of the Upper Riphean, Vendian and Lower Cambrian are fully exposed and easily accessible for study. In this report the results of detection of trace elements concentration level and of the presence of ore and accessory mineralization in rocks of the described section are given. The study has shown ore mineraliza- tion, representing the greatest practical interest, made by chalcopyrite, Ni-containing pyrite, galena, bismite and native silver. Accessory minerals are represented by baddeleyite, zircon, zirconolite, apatite, ilmenite and Mn-ilmenite, hematite, a rare mineral - bismoсlite. Few significant concentrations of gold in limestone (up to 4.47 g / t) and altered carbonate-sulphide-Fe-oxide ores (2.25 g / t) are revealed. Concentration of ore genetic elements is higher in dolerite. The ores belong to Cu-Fe-Ni mineralogical and geochemical type.