Latest erosional incision in river valleys of southern East Siberia

摘要

Examples of the geological and geomorphic framework of river valleys in the Tunka rift basin (Baikal rift system) and in the Irkutsk amphitheater (Siberian craton) have been used to show that horizontal and vertical motions of tectonic units in southern East Siberia are superposed with periodic movements. In the latter, the waves of slow uplift are attendant with erosional incision events, whereas during the subsidence cycles the incised valleys become filled with mainly alluvial sediments. The latest incision events in the area occurred in the past 70 kyr.