Study on the Late Quaternary Glaciations in the Hidaka Mountains, Hokkaido, Japan

本研究调查了日本北海道东高山脉冰川地貌、冰川沉积物和冰川标志物的空间分布和地层学。特别关注高山地区目前的地质过程和气候条件，利用其特征重建末次冰期的冰川和冰缘环境。此外，还利用一些关键的标记物，对日达卡山脉冰川的精确年代学进行了研究。讨论了日本高山的冰川和冰缘条件，并与瑞士和加拿大的几个军团进行了比较，并列举了典型的现代例子。结果表明，在上一次冰期冰块之下可能存在一个可变形的松散沉积层和下伏的冻土层。我们还在一年多的时间里首次成功地测量了日达喀山峰顶的现今气温和地温。根据地温状况，确定了该地区活动的多年冻土。这些数据使我们不仅可以讨论北海道高山地区的现状，而且还可以讨论北海道高山地区的气候环境。

This study investigated spatial distribution and stratigraphy of glacial landforms, glacial sediments and marker tephras in the Hidaka Mountains, Hokkaido, Japan. Particularly, the present geological processes and climatological conditions in the alpine regions are paid attention to apply their features to reconstruct glacial and periglacial environments during the last glacial period. In addition, precise chronology of the glaciations in the Hidaka Mountains was investigated using some key marker tephras. The glacial and periglacial conditions in the Japanese high mountains were discussed comparing with several legions in Switzerland and Canada, wheie typical present examples are distributed.Microstructures of glacial sediments obtained from the field were analyzed to reconstruct the former subglacial condition in the Hidaka Mountains. As a result, it is strongly suggested that a deformable unconsolidated sediment layer and an underlying fiozen layer might be existed beneath the ice mass during the last glaciation.We also have successed the first measurement of the present air and ground temperatures at the summit area of the Hidaka Mountains through a year. According to the ground temperature regime, active permafrost is confirmed in this region. These data allow us to discuss not only the present state but also the pareo-environment in the high mountain ranges in Hokkaido.