Loess-like deposits of the diamond-bearing placer Yuzhnaya Rassolnaya (Perm region)

Abstract

The article describes the loess-like deposits of the northwestern blocks of the South Rassolnaya deposit, where the industrial diamond content of the Silurian intermediate reservoir was previously established. In these proposals of field geologists, «cranes» (loess pupae, loess nodules, dutiki) are noted. The article studied: 1) the granulometric composition of loess-like deposits using two methods: sieve analysis and laser diffraction analyzer Analysette 22 MicroTec plus; 2) the mineral composition of the heavy fraction of loess-like and underlying sediments - using quantitative mineralogical analysis; 3) quantitative gross mineral composition and the ratio of clay minerals in the pelitic fraction - using a D2 Phaser X-ray powder diffractometer (Bruker, Germany).  Some features were noted in the process of sample preparation for the scientific study of loess-like deposits (obligatory dispersion), as well as peculiar mineral aggregates consisting of light fraction minerals (quartz, feldspars) and similar to «rolling stones», which also include heavy allothigenic ones minerals that are transported by wind and, apparently, over considerable distances in the absence of terrestrial vegetation or water barriers. As a result of the study, it was concluded that the described loess-like deposits in the study area do not have a direct connection with diamond potential. Key words: Perm region, Silurian, granulometry, mineralogy, X-ray phase analysis, loess, crane grass, diamond-bearing placers.