GEOLOGY AND PALEOVОLKANIC CONDITIONS FOR FORMATION OF BARSUCHIY LOG DEPOSIT (SOUTHERN URALS)

Abstract

The article reviews the geological structure and paleovolcanic conditions for the forma-tion of the pyrite-polymetallic deposit Barsuchiy Log, located within the Dzhusinsky ore district. It is shown that four strata participate in the structure of the ore-bearing volca-nogenic complex, the first and third of which are composed mainly of basaltic porphy-rites and their tuffs, and the second and the fourth are effusive and pyroclastic rocks of the dacite and rhyodacite composition. Analysis of the thicknesses and facies of these volcanic complex layers made it possible to reconstruct various palevolcanic elements within the ore field, including: the Karabutak uplift, which is a linear anticlinal structure such as a volcanic ridge; stratovolcano, which is the main element of accumulative structure; a number of paleovolcanic structures of the central type located on the slopes and at the foot of the stratovolcano. It is established that within the area the location of the ore -bearing volcanic complex is completely determined by the boundaries of the Karabutak uplift, the position of the ore field is controlled by the stratovolcano, and its throat determines the structural distribu-tion of the ore bodies of the Barsuchiy Log deposit. The deposit is represented by three stratified ore bodies of lenticular shape, composed mainly of massive ores, which include pyrite, chalcopyrite, sphalerite and galena. Specificity of the mineral composition of ores consists of an increased amount of pale ore in them, a high content of galena and barite. Taking into account the above-listed features, the Barsuchiy Log deposit can be com-pared with the barite-polymetallic objects of the Baimaksky area and referred to the Caucasian type.