Vol 61, No 4 (2019)

The data presented in the article consistently outlines the methodology for studying the orientation and morphogenetic characteristics of fracture systems of four scale levels including kilometers, meters, centimeters and millimeters. The Urtuisky granite massif, located in the South-Eastern Transbaikalia to the west of the Streltsovsky caldera, containing uranium deposits unique in their reserves was chosen as the object of the research. The massif is composed of Late Riphean granites and granite-gneisses, affected by dynamometamorphic and hydrothermal-metasomatic transformations in various degrees, and dissected by numerous faults with traces of fluid activity of various tectogenesis episodes. The interrelation between such geometrical parameters of fractures systems as specific density and specific length was established. It is shown that such geostructural data should be used for conceptual and numerical modeling of fluid filtration and radionuclides transport processes occurring in a three-dimensional fractured-pore space of crystalline rocks, as applied to the reconstruction and modeling of uranium ore formation and use of geological space for radioactive materials isolation.

An analysis of the regional gravitational field of the north-east of China, Korea and Western Primorye was carried out. The distribution of gold deposits was compared with the development of Mesozoic magmatism and negative anomalies of the gravitational field. Based on the analysis of geological, mineragenic, petrophysical and geophysical materials, geological and geophysical zoning of the western part of the Khanka massif was performed, and a scheme for interpreting geological and geophysical data with elements of minerageny was drawn up. A connection was established between the anomalies of the magnetic and gravitational fields and the position of the supposed gold-bearing ore regions and nodes located in the zone of joints of the North China Triassic-Jurassic volcanic-plutonic belt with the Proterozoic substrates of the Khanka massif. According to geophysical data, Early Jurassic intrusions were identified as, controlling the location of the gold nodes. It was concluded that the gold mineralization is related to the Jurassic magmatism, which increases the prospects for the discovery of gold mineralization in the Khanka district of the Western Primorye.

Slepaya Zalezh is the largest ore body of the Tyrnyauz Mo-W deposit. It is the priority object on the renewal of its operation. A dissemination of molibdoscheelite, scheelite and molibdenite, controling ore concentrations, is confined to metasomatic rocks of the productive stage, laid on skarns, near-skarn rocks, hornfelses and marbles. The types of the ores are divided accordingly of ratio in them of different facies of ore-bearing metasomatic and initial rocks, which is a working out mass of ore. 7 types of the ores are divided and maped on the ore body vertical projection. Aposkarn ores predominate clearly in the I and II types, accordingly laid over endo- (substituting hornfelses) or exo- (apomarble) skarns. In the III type there are ores laid over endo-skarns and near-skarn rocks in equal parts. Relative to it the type IV contain less of of near-skarn rocks, but more of hornfelses. Ores replacing exo-skarns and to a lesser degree (up to 25%) – marbles dominate in the V type. The type VI is an intermediate one between the types III and IV. In the type VII all initial rocks are presented. Every of the types has a stable mineral and chemical composition inherited from the initial rocks. The ores of the specific type have convenient simple distinguishing features for a hand sorting of specimens, samples, and a preliminary ore separation. The types of ores have narrow change limits in size and form of ore mineral grains and their intergrowthes, percentage of minerals harmful for the flotation. Minor differences in contents of the useful components of each ore type offer possibilities of their selective working off and burdening. Mapping results contain data of the distribution of accompany sorts of mineral resources: garnet and wollastonite in the skarns and productive metasomatic rocks, pyroxene-plagioclase near-skarn rocks and hydrothermal alterated rocks with Cu, Au and other mineralization.