One of the remarkable features of the geology of the Chiatura manganese deposit is the presence of different facies of ore-bearing sediments. Of particular interest is the change in these facies in the vertical section of the manganese ore strata, which was well traced both from outcrops and from numerous drill holes. Analysis of the geological structure of the formation of ore-bearing sediments and host rocks led to the conclusion that the vertical change of facies depended on the orogenic movements that took place at the time of formation of the manganese ore strata. A very interesting fact was that within the area of the Chiatura deposit, which occupies an area of about 100 sq. km, the amplitude of these movements in different parts of it was apparently unequal, which affected the mineralogical composition and structure of various facies. The proposed work contains a brief summary of the main provisions relating mainly to this phenomenon, almost unknown in the literature, among sedimentary ore deposits. There is reason to assume that changes in the composition of facies in the vertical section in the Oligocene deposits of the Chiatura region were caused by orogenic movements, which were the last echoes of the pre-Oligocene orogenic phase.

In this article, the author attempts to present in general terms his views, on the one hand, on the methodology for studying chrome deposits in the most general sense, and on the other hand, on the geological nature of these deposits. The author himself has extensively studied primarily the platinum-bearing chromite iron ores of the Urals. For purposes of identification, non-platinum-bearing chromites were also studied alongside this work. The latter were studied in more detail in Transcaucasia (in the area of Lake Gokcha), as well as in the Northern Caucasus (in the area of the Bolshaya Laba River). We can outline the following genetic types of chrome-spinel formations: 1) chrome-spinels formed in the earlier magmatic period; 2) accumulations of chrome-spinels formed in the later magmatic period, when the main mass of the host rocks had already been nearly formed; 3) chrome-spinels formed by hydrothermal processes, mainly during the serpentinization of rocks.