日本の Neoglaciation について

Abstract

In this paper, the writer discussed on the Neoglaciation in the Japanese Islands.One information is derived from the writer's own glacial-geologic field work in bothCentral Japanese Mountains (Hida, Kiso and Akaishi) and Hidaka Mountains; the otherinformation is based on the paleolimnological evidence in the core sample of Lake Biwa-ko.There are two groups of moraines (Moraine V and Moraine VI) which areextremelyfresh in morphology, only in the Central Japanese Mountains in which climate is warmerand wetter than Hidaka Mountains. Accordingly, the writer owed their origin mainlyto the increase of the precipitation. Regarding age of them, the writer inferred tenta-tively 1, 500 years B. P. and 500 years B. P. Basis of that inference is the paleolimno-logical data indicating wetter climate by ignition loss and residue ratio and by pollendiagram (AP: NAP) and also cooler climate by the low amount of calcium carbonate.In addition, wood found in the outwash deposits of Shirouma Kitamata gave data of520+80 years B.P.Although the existence of pluvial climate in the age of several thousands years agois also shown in the diagram of Biwa-ko, advance of glaciers in that time must bereexamined since the amounts of calcium carbonate suggest considerably high temperatureduring the Hypsithermal Interval in the Japanese Islands.