Zoogenic weathering and formation of the present-day surf ace deposits of eastern Mongolia

Abstract

High percentage of skeleton is typical of soils in Eastern Mongolia which develop on solid rocks eluvium (such as granites, syenites, siltstones). Colluvial, alluvial and lacustrine deposits of piedmonts and valleys also contain coarse material in large quantities. Mammals' activity accounts for so-called zoogenic weathering: animals bring debris to the surface and also enhance common weathering process. Examples from various regions of Eastern Mongolia show conclusive evidences of the skeleton reduction in soils within the areas of burrowing mammals habitation, Lasiopodomys brands Radde, Marmota sibirica Pall., and Meriones unguiculatus Miln.-Edw. in particular. The process rate depends on the degree of the soil reworking by the animals, that is on- the relative age of the holes. In some regions skeletonless soils may result from the burrowing mammals activity.