Pedogenic studies in eastern Nepal—new aspects about the last glaciation

Abstract

Soil development of high mountain soils was studied in eastern Nepal with regard to new aspects about the Quaternary history of landscape and climate. The soils were developed in Quaternary glacial deposits, i.e. the lowest clearly identified terminal and lateral moraines of 5 high valleys of the Khumbu and Solu region, all located between 3800 and 4300 m asl. Particle size analysis, pedogenic iron oxides and weathering indices were used to obtain information on soil development of the different sites. Except for one site no significant differences were found in the extent of soil development indicating that all soils and their corresponding glacial deposits are of similar relative age. In combination with recently published numerical datings of the terminal moraines in one of the high valleys, the age of the deposits could be narrowed down partly correcting former findings. The maximum extent of the last glaciation, if accepted as more or less synchronous to the global Last Glacial Maximum, was less pronounced than previously assumed. However, morphological and pedological findings give evidence of an early phase of Late Pleistocene glaciation further down valley corresponding to new results from High Asia, the Japanese Alps, North Siberia, and the Kamchatka peninsula.