Recent Pedological Approach to Reconstruction of the Quaternary Environment in Japan and East Asia.

Abstract

Pedological studies contributed to the reconstruction of Quaternary environment of Japan and eastern Asia in 1990s. Study of the material in the Red-Yellow soil, a representative relict paleosol in Japan, improved understandings of the soil's genesis. The origin of Japanese Red-Yellow soils confirmed to be aeolian dust from the Asian continent and can be characterized as a transitional soil between a tropical and a warm regime, which has been developed by weathering during 103kyr. Studies of weathered volcanic ash layers improved the understanding of the formation of tephra-soil sequences widely distributed in Japan. The development of tephra-soil has occurred succestively during intervals between volcanic activity by the addition of weathered tephra and aeolian dust. Interpretations of environmental change in Holocene and late Pleistocene by investigations on tephra-soil and loess-soil sequences were supported by these findings.