Denudation rate and ancient topography relicts conservation at the SE Russian Plain

Abstract

Character and rate of denudation at platformian plains are discussed. Geological and geomorphological methods are used to estimate the annual denudation rate which varied from 0.001 to 0.01 mm during Middle Miocene-Quaternary. Primary sedimentary marine and deltaic plains which are composed of permeable rocks remain practically unchanged by erosion. The plains are spread between the Dnieper and Don rivers and covered mostly with Poltavian and Sarmatian sands. The erosion rate within the limits of erosional surfaces (which form low topographic levels) is about one order of magnitude higher and amounts to 0.01 to 0.02 mm per year. A scheme of denudation rate is compiled, erosional gaps within formations being taken into account. Among the denudation -factors most active are processes of marine abrasion. Stadial character of the denudation processes action is emphasized, and a possibility is considered to use to orographic levels for morphostructural studies.