The thesis is devoted to the study of the lithological features and mineralogical substantiation of the complex use of sedimentary rocks in the central part of Kryvyi Rih. The main results of work are obtained on the basis of processing of primary materials of geological observations of sedimentary rocks in the open pits and natural outcrops of the Kryvyi Rih basin.
The author studies the feature of the geological structure and material composition of the Paleozoic-Cenozoic sediments in the central part of the Kryvyi Rih iron ore basin, their origin and directions of integrated use. New data on the mineral composition of sedimentary rocks in the natural occurrence and accumulated in the dumps are obtained.
The geologic-lithological section, the stratigraphic column of the district, and the correlation of the sections of sedimentary rocks between the deposits have been constructed. Dependence of power and composition of sedimentary rocks on the nature of the Precambrian basement lay is established. It is determined that on its elevated sites a powerful layer of weathering crust was formed, while in the lower part formed a variety of lithological shifts of coastal-marine and continental sedimentary rocks. The influence of accessory minerals on the metallogenic specialization of rocks of the sedimentary complex is established. The distribution of chemical elements in the sedimentary section, which has a pronounced logical character, is investigated. Significant accumulation of a wide range of chemical elements exceeding the value of Clark (Zr, Y, Yb, Sc, Pb, La, Au) is found predominantly in the lower and upper parts of the section. Importance is the concentration of gold (100 mg / ton) in the Quaternary eolian soils of the area. The performed studies allowed to divide the rock of the sedimentary cover into four age-old lithologic-geochemical zones: I - Paleozoic-Cenozoic weathering crust; II –Paleogene- Neogene sea sand; ІІІ - deposits of the Quaternary period, IV –modern sediments (travertines).
The author analyzes the ecological situation that has developed in the city of Kryvyi Rih in general and in particular in its central part, which is an urgent problem for the city and for preservation of the environment. The general description of the objects of modern technogenic loading in the territory of the central part of Kryvyi Rih is presented.
The scale of the influence of man-made objects on the geological environment of the studied territory is determined. The collected information on the history of the study of the sedimentary cover of the region, which is the basis for further analysis of changes occurring in the geological environment under the influence of man-made mining activities of the mining enterprises.
According to the results of research, the influence on the accumulation of heavy metals in the geological environment, not only mining and processing enterprises, but also ordinary, domestic waste and municipal wastewater, was confirmed. In addition, the weight of the wind rose in combination with the relief is emphasized as an additional factor for the distribution of heavy metals in soils. Also, the tendency to active adsorption of plants by a certain percentage of heavy metals has been confirmed, which in combination with periodic reclamation works significantly reduces the concentration of the studied elements, keeping them in most cases within the limits of permissible concentrations. Exceptions include the areas directly adjacent to the mining and extraction facilities.
The analysis of the 3D model of the distribution of sedimentary layers of the Paleogene-Quaternary age range indicates the decisive influence of the geological structure of the Precambrian crystal Foundation, tectonic faults active from the Precambrian to the modern geological period. The regularities of the distribution of sedimentary rocks are established and can be used in the construction of complex geological and geochemical models and various tectonic and geodynamic schemes, as well as in solving practical problems of Geology and mineral prospecting.
The results of lithologic and technological studies of sedimentary rocks indicate the possibility of profitable enrichment and the complex use of neogene rocks and weathering crust of Precambrian granites and migmatites with the production of kaolinite, quartz, zirconium and other industrial concentrates.
Key words: sedimentary rocks, Kryvyi Rih basin, Precambrian granites and migmatites, weathering crust, mineral composition, geological environment, travertine, tailings storage, complex use.
