The Neogene fluvial terrace scarp downwearing at the Lena River during the Holocene

Abstract

Comparative analysis of three sections of fluvial sandy terrace at Central Yakutia revealed changes in the slope's structure during the Holocene. At the east-facing slope the defluction is the prevailing process; the slope inclination decreased from 42 to 28^o, a 10-5^o deluvial apron being formed at the slope base. At the north-facing slope defluction goes with cryosolifluction; at first the upper part of the slope was flattened (to 28^o), and then retreated as the lower part decreased in steepness to 15^o and deluvial-solifluctional apron was formed (the latter being 9 to 3-4^o steep).