Methods of planation surface mapping at mountain areas (a case of Western Transbaikalian Territory)

Abstract

Surfaces with slope less than 5⁰ were outlined along river valleys and at axial zones of mountain ridges using large scale maps. Adjacent fragments of the slightly inclined surfaces were put in groups, topographic steps linked by steeper slopes were noted and relicts of ancient topographyplanation surfaces were traced within certain height intervals. Most clearly they can be seen at the summit planes of ridges. Six surfaces of continuous and intermittent denudational planation have been identified, five of them corresponding to those established earlier during field geomorphological studies (tables 1, 2). Map of planation surfaces allows to show stages of topography and drainage development; it marks shifts, thrusts, grabbers, subsided and uplifted parts of mountains. Depth of erosional cut-off of ore-bearing structures can be defined.