LITHOLOGICAL FEATURES OF THE CONTAINING ROCKS AND SPATIAL DISTRIBUTION OF LATE CRETACEOUS EXOTIC IN SECTIONS OF THE STRIYA WORLD OF THE SKIBOVA ZONE OF THE CARPATHIANS

Abstract

Based on lithological and petrographic studies of the Late Cretaceous formations of the Skybova zone of the Ukrainian Carpathians, the main lithological types of rocks containing coal fragments have been characterized and the nature of their distribution has been established. Coal-bearing rocks were studied from a number of outcrops on the banks of the Dniester River (Strilki village), the Yablunka River (Strilbychi village) and the Svyatoslav quarry (Korostiv village, Skole district). The work reveals the genetic nature of the processes and factors of sedimentation and transformation of rocks, establishing a connection between lithological features and forms of occurrence of Upper Cretaceous deposits. The sections were studied in detail methodologically and the composition of host rocks from the Late Cretaceous deposits of the Stryi Formation was described. In the natural outcrops we studied, the lithological composition of the rocks is mainly coarsemedium- grained sandstones, dark gray, gray, on fresh chips with a brownish or greenish tint, strongly carbonate, in some places there are scales of muscovite and biotite. In the lower parts of the section, there are gravelites of yellowish color, massive with single small (up to 2×4 mm) inclusions of black coal and inorganic rock of white, gray and dark gray colors. In gravelites (cement) is carbonate, and its inorganic inclusions do not react with acid. Coal fragments discovered and studied by us occur in outcrops among strata of coarseand medium-grained quartz carbonate sandstones, in the Stryan world of the Late Cretaceous on the banks of the river. Dniester (with. Arrows), r. Apple tree (with. Shooting) and career «Svyatoslav» (p. Korostiv, Skoliv district). Their distribution in the section is uneven. In some places these are single fragments of different sizes, in others – mass clusters of pieces of different sizes, cemented by sandstone into a kind of coal breccias and conglomerates. The amount of coal fragments in gravelites is much smaller than in sandstones. Their sizes vary from units of millimeters to tens of centimete rs. The degree of rolling of coal fragments is directly proportional to their size. This is due to their location on the transfer path from the denudation region to the sedimentation region, the distance between them and the mass of coal fragments. Small weakly mineralized pieces are quite light and therefore were carried mainly in a suspended state by the surface or middle layers of the water flow and had little contact with its bottom, were not rolled. Large ones rolled along the bottom of the transport medium (water flow) and were transferred together with coal to the sedimentation basin, that is, with grains of quartz and carbonates.