尾瀬ケ原古期泥炭層
晩氷期 (Spätglazialzeit) の堆積物
1959 年 1 巻 5 号 p. 155-164
詳細
1959 年 1 巻 5 号 p. 155-164
The Ozegahara Basin is a typical sphagnum-moor, which is situated in Central Japan about 1400 meters above the sea level. Among plants growing in the moor are found many species which are inferred the relic of the last ice age. This basin was born in younger Pleistocene because of damming up the ancient valley of the River Tadami by the lavas from the Hiuchidake Volcano (2346m). At the northeastern corner of the moor are found the peat layers alternating detritus overlaid the deposits of mudflow from Hiuchidake. Stratigraphically these peat layers are correlated to uppermost Pleistocene. According to the pollen analytical data, pollen grains of conifer are predominant through the layers and reversely Fagus pollen grain is very few or partly not in the samples, while the present moor is surrounded by Fagus forest and pollen spectrum from the surface sample of the moor reflects this state. From these results it may be concluded that the temperature of this area at that time was 1-2°C lower than the present day.
