GRANITES OF THE LATE PALEOZOIC DIORITE-GRANITE ASSOCIATION ON THE NORTHERN CAUCASUS, RUSSIA - GUIDES FOR TUNGSTEN MINERALIZATION

Late Paleozoic granites compose a considerable part of the Main Range of the Greater Caucasus, and the determination of their metalliferous potential is, therefore, of both scientific and practical importance. The Late Paleozoic granitoids are combined, based on geologic and isot opic geochronological data, into a diorite-granite association, which comprises four successive intrusive phases: diorite-quartz diorite, gr anodiorite, biotite granite, two-mica granite, and their vein derivati ves (leucocratic granite, aplite, alaskite, and pegmatites). This pape r reports the specific petrochemical, mineralogical, geochemical, and Sr-isotope features of the rocks of each of these phases, along with t he isotope features of the accessory scheelite from the igneous rocks and scheelite from a number of ore occurrences and mineral deposits of the skarn, greisen, hydrothermal quartz vein, and magmatic (pegmatiti c) types-all of them spatially related to the granitoids. We thoroughl y examined the following factors, which are usually employed to establ ish genetic links between ore mineralization and magmatism: spatial as sociation of tungsten mineralization with acid igneous rocks; specific petrochemical, geochemical, mineralogical, and petrophysical features of the rocks and minerals of the subsequent intrusive phases; and tem poral relationships between the mineralization and granite intrusions. The data obtained were used to assess the contribution of each of the factors (which are commonly employed to establish genetic relationshi ps between mineralization and magmatism), and led us to conclude that the tungsten mineralization is related to the biotite and two-mica gra nites and pegmatites of the association considered. Each of the granit e types was assessed with respect to its tungsten potential and ore-ge nerating capability.