КОВБАНЬ –ДЕТАЛЬНО СТРАТИФІКОВАНИЙ ЛЕСОВО-ҐРУНТОВИЙ РОЗРІЗ ВОЛИНСЬКОЇ ВИСОЧИНИ

Abstract

The loess-soil section of Kovban` includes all the stratigraphical units of the Upper Pleistocene, as well as pedosediments and alluvial facies of the Middle Pleistocene pre- and early Dnieper times. On the basis of the field pedolithomorphological description and grain-size analysis, it is proved that the majority of the main stratigraphic units show smaller subdivisions. The Prychernomorsk unit includes two loesses (pc1, pc3) and a Luvisol (pc2). The Dofinivka unit consists of three subunits: two incipient soils are divided by a thin loess subunit (df2). The Bug unit is represented in this section by hillwash and solifluction deposits. The Vytachiv unit is a pedocomplex made up of three well-developed soils, separated by loesses. The soils are a Molic Cambisol (vt3), a Cambisol (vt1b2) and a humic gleysol (vt1b1). The Uday unit consists of two subunits: the lower comprises solifluction deposits, whereas the upper is a loess-like bed. The soil succession of the Pryluky unit is well developed. It consists of three soils – a Molic Cambisol (pl3), a Mollisol (pl1b2) and a sod-podzolic soil (pl1b1). On slopes, the lower soil (pl1b1) is formed on the sands of Tyasmyn unit. The Kaydaky unit is represented by polygenetic sod-podzolic soil. Brown forest soil pedosediments of the last warm period of the Middle Pleistocene overlie Middle Pleistocene alluvial facies. These pedosediments were deformed by syngenetic cryogenic processes and dissected by ground wedges during the Dnieper cryogenic stage. The data obtained indicate that at the end of the Mid Pleistocene, the study area was subjected to uplift that controlled intense river incision and denudation processes. Five phases of cryogenesis have been revealed in the section: dn, ts, pl1b1-b2, ud, bg.