Lithology and geochemistry of sedimentary rocks in Pavlivsk field in the western part of the Kryviy Rih structure

Abstract

The purpose of the paper is to determine the features of lithology, geochemistry and the possi-bilities of complex use of sedimentary deposits in the western framing of Kryvyi Rih iron ore basin on the example of Pavlivsk deposit.The obtained new data allowed us to establish the significant influence of age, structural and ge-netic factors on the lithological composition and metallogenic specialization of sedimentary formations on the area. A close connection of sedimentary rocks with fault-block tectonic structure of the crystal-line basement of the region is established. The sedimentary cover begins with the Paleozoic-Cenozoic crust weathering of Precambrian plagiogranite-migmatites of the Inguletsk complex. Above the weath-ering crust there are coarse-grained and fine-grained quartz sand of the lower Neogene, in separate layers with kaolinite clays and iron hydroxides. Important influence on the metallogenic specialization of the sedimentary complex rocks was made by accessory minerals: rutile, ilmenite, zircon, apatite and others. Secondary clay minerals are enriched with a large number of heavy minerals, which also occur in Neogene sands. Significant accumulation of a wide range of chemical elements (Zr, Y, Yb, Sc, Pb, La, Au) is found mainly in the lower and upper parts of the section enriched with clay components. Scientific novelty. The performed researches allowed us to divide the rock of a sedimentary cover into three age-old lithologic-geochemical zones: I - Paleozoic-Cenozoic weathering crust; II - Neogene sea sands with accumulation of phosphorus in actuator apatite; ІІІ - eolian deposits of the Quaternary period with Au - metallogenic specialization.Practical relevance of the research. The new data concerning lithology, mineral composition and geochemistry of sedimentary rocks of the western part of Kryviy Rih structure has an important scien-tific significance. An important search value is the concentration of gold (100 mg / t) in Quaternary eolian loam ofthe area.