Topographic levels in mounatin ridges at the Western Okhotsk region

Abstract

A number of methods are proposed to identify topographic levels in mountains, some of the methods are used for the purpose for the first time. Analysis of summit surfaces morphology of the Jugjur and Pribrezhny ridges (Western Okhotsk region), their vertical and lateral distribution and correlation of different watersheds types revealed up to six topographic steps in the region, which can be united into 3 levels. The topographic levels mostly resulted from denudational planation and active block tectonics. Planated watersheds of the 3rd and 2nd levels were formed during Paleogene (and later distorted by neotectonic movements), the 1st level formation took place in Pliocene. Topographic steps system was modified and complicated by river erosion, altiplanation and rocks lithology and structure.