Shestakov O. Gold and its elements-satellites in the weathering crust of Yuriyivske and Balka Shiroka gold deposits

The dissertation is devoted to the formation problems for the searching signs of the original gold deposits in the hypergenesis zone that may be used to search the latters by the geochemical sampling of the weathering crusts (the region of the exploration is the Ukranian shield). The search signs are considered as the anomalous gold contents (i.e. higher than the geochemical background) and its elements-indicators (silver, arsenic, copper, zinc, lead, bismuth, nickel, molybdenum, wolfram) in the samples. The character of the anomaly complexes for these elements together with the gold anomalies determines the search significance of them and the perspectivity of the anomalous lots for the further exploration of gold original deposits respectively. The factors of mobilization, and precipitation of gold and its elements-satellites in the "crystalline base weathering crust" system are studied. The ways of their migration in this system, the character of complexity for the anomalies and the factors of their forming in the process of migration and precipitation of the elements are found. The significance of the anomalies for the different elements-indicators of gold in the weathering crust zones and their complexity for the prospecting estimation of the suitable anomalous areas are revealed. The gradation of elements-indicators as the searching signs is established. This gradation is the sequence of decreasing significances: copper, zinc, nickel, lead. It designates to the elements-indicators the informative weights in the marks. The simple and applied method for their integral account in order to assess the anomalous lots for the further exploration is developed. The set of anomalies for the satellites of gold gives the types of geochemical barriers in the hypergenesis zone that allows developing the method of their indirect determination (in particular, the alkaline barrier is determined using Ni/Fe ratio, such elements, which are related geochemically). Key words: gold, elements-indicators, crystalline base, weathering crust, migration, concentration, geochemical barriers, informative weight, integral account.