Features of searching for the diamond deposits by mineralogical methods in different landscape and geological conditions

Abstract

This article has a methodical orientation. There are discussed the features of the use of silt mineralogical methods in the search for native and placer deposits of diamonds. The key points of the theory of the forming sedimentary reservoirs, which contain the scattering aureoles of satellite minerals and the placers of diamonds, are considered. In connection with the cyclicity of sedimentogenesis, during the formation of aureoles in diamond-bearing regions redeposition of kimberlite mineral associations occurs (often repeated). That is why they are not so common in the primary deposit. An indication of re-deposition is a discrepancy between the typomorphic features of minerals and the nature of the deposits that contain them. The main feature that makes it possible to distinguish redeposited associations is the discrepancy between the degree of the indicator minerals wearing and the facies appearance of the deposits. The alternation of the sedimentogenesis cycles and repeated deposition of minerals from earlier reservoirs into newly formed deposits leads to the accumulation of material from different eras of kimberlite erosion in aureoles and placers. The ratio and absolute contents of different generations of minerals in aureoles can be completely different. These parameters determine the degree of contrast of a particular aureole, which means the level of search efficiency. There are also considered the prospecting situations in various diamond-bearing provinces – Angola, Brazil, Sakha-Yakutia, Ukraine. The features of the heavy concentrate mineralogical analysis in these regions are discussed also. There are given the general principles of using mineralogical methods in different landscape and geological conditions of the territories; the recommendations for carrying out a complex of works that must be performed to prepare the mineralogical and paleogeological basis for the forecast map. It is necessary for this to carry out a complex of studies, which includes the study of the typomorphism of indicator minerals, lithologic-facies and material features of the terrigenous deposits that contain them, and conducting paleogeological and paleogeographical reconstructions. The probability of the forecast and the effectiveness of searches using mineralogical methods depends on the consideration degree of the search conditions specifics in the structural-facies zones, the landscape-geological search conditions and the quality of paleoreconstructions.

Keywords

• diamonds
• search
• scattering aureoles
• mineralogical methods
• ukraine