Genetic-age categories of planation surfaces

Abstract

Four genetic-age categories of planation surfaces correspond to large stages of geological and geomorphological development. 1) Protopeneplains are original surfaces forming during the transitional period from preplatformian development to platforms. 2) Pre-geomorphological surfaces formed during the period of platformian sedimentary cover accumulation. 3) Initial watershed surfaces which formed the present topography through endogenous and exogenous deformation. 4) Neogene-Quaternary surfaces of incomplete planation, adjacent to valleys. Distribution and age of the distinguished categories are analysed at different continents and under different morphostructural conditions.