Falkovich О. Geochemical Criteria of Gold Prospecting in the Central Part of the Ukrainian Shield (on the example of Klintsovske deposit).

The thesis is dedicated to development of geochemical criteria of gold prospecting in the central part of the Ukrainian Shield (on the example of the Klintsovskoe deposit). Brief data on the history of investigations of gold ore occurrences in the territory of the Ukrainian Shield and information on geologic-genetic types of gold ore deposits all over the world are presented in the work. Geological structure, geotectonic peculiarities and minero-petrographic characteristic of ore-enclosing rocks and ore bodies of the Klintsovskoe deposit have been considered. Three basic parageneses of ore minerals: loellingite-arsenopyrite, arsenopyrite-pyrrhotine and pyrite-chalcopyrite - were established. An analysis of distribution of chemical elements and their associations in the primary aureoles of the Klintsovskoe deposit permitted establishing the major rows of their zonality in the subore (Mo-W-Cu-Ag), ore (Au-Bi-As-Mo-W-Cu) and over-ore (Au-Mo-W-Cu-Bi-Ag) horizons. Availability of highly contrast anomalies of these elements and their associations may be direct prospecting geochemical criteria of revealing the gold-ore mineralization of Klintsovskoe type. It is expedient to use multiplicative coefficient Au х As х Bi х Mo х W х Cu х Ag for the local prediction of gold prospecting. To find out the dependence of mineralization productivity with geochemical indices, the author has proposed the coefficient of specific ore content (Кпр): Кпр = [Еmc] Крп, where Кпр - coefficient of specific ore content in the profile; Еmc - sum of productivity of ore intersections in the profile; m - thickness of ore intersection (g/t), Крп = Np / N - ratio of the number of holes with ore intersections (Np) of total number of holes to profiles (N). When calculating the coefficient of specific ore content in prospecting-profiles by experiments the author has determined the index 7.32 owing to which one can distinguish the blocks of rich gold-bearing ores. This index determines that the average ore content is 7 g/t at the ore body thickness 1.04 m. The author has proposed to find territories promising for the search of gold in the central part of USh by the presence of gneissic series of Lower-Proterozoic granitoid-metaterrigenous complex in the loops of tectono-metasomatic zones inherent in the deep fractures. In the framework of these series the author has established absolutely new Klintsovskoe type of deposits which may be concentrated in the found ore fields (Yurievskoe, Nadezhdivkoe, Klintsovskoe, Voloshkovskoe, Verkhneingulskoe and Gaevskoe fields) of Kirovograd metallogenic region. Key words: gold mineralization, Klintsovskoe deposit, elements-indicators, geochemical criteria, gold search.