In the Tokachi plain of the south-eastern Hokkaido, some buried periglacial phenomena, that is, earth mounds, patterned grounds and involutions were found in places by the studies of the Tokachi Research Group, including the authors themselves. By ascertaining the stratigraphical relation among, several pumice falls, loam and gravel deposits in which those phenomena come into existence, six perigalcial phases have been detected, one of which is in the post glacial age and the other five are in the last glacial age. In this area, detected were two phases of buried sand dunes, constructed by some reworked pyroclastic deposits under the cold and arid conditions having poor vegetation, by M. Kimura et al. Considering these buried sand dunes, the phenomena suggesting the epochs of cold climate in this plain are analysed stratigraphically as follows.
In this paper the authors intended to classify the older tephra, so-called Tama tephra and the middle or lower Pleistocene marine sediments in Oiso and Yokohama areas, southern Kanto district. The results are summarized as follows: (1) The older tephra in Oiso area is devided into four members, that is, Tsuchiya, Soda, Fujisawa and Zoshiki tephra. Each tephra covers conformably on the marine sediments, Nanakuni-toge, Soda, Fujisawa and Zoshiki formations respectively. (2) Tsuchiya tephra, the uppermost member (30m in thickness) is correlated with Tsuchihashi tephra (13-8m in thickness) in Yokohama area and the Tama hills. Soda tephra (25m in thickness) is correlated with Sannodai tephra (10m in thickness) in Yokohama area. (3) Tsuchiya tephra is covered unconformably by Kissawa formation which was deposited in the Shimosueyoshi transgression age. Soda tephra may be covered unconformably by Nanakuni-toge formation. Zoshiki tephra are probably older than Soda formation. (4) In Yokohama area, the marine sediment which is covered conformably by Tsuchihashi tephra may exist. However, the relation between this sediment and Totsuka formation, which is proposed by the Kanto Quaternary Research Group as the marine deposit of the post-Byobugaura and pre-Shimosueyoshi age, could not be sufficiently clarified yet.
This thesis was written of the topography and volcanic ash layers (the so-called Kanto Loam) of the Musashino upland extending over the western region of Tokyo Metropolis. The results are summarized as follows: 1) The geomorphic surfaces of the Musashino upland may be divided into Yodobashi, Narimasu, Akabane, Nakadai and Tachikawa terraces from older to younger in order. These terraces are covered with the volcanic ash layers. It was found that the older terraces are covered with the thicker volcanic ash layers, compared with the younger terraces. 2) In classifying Yodobashi and Narimasu terraces, two pumice beds, namely SIP and Pm-1 found in the volcanic ash layers are used as key beds. In the case of Akabane and Nakadai terraces, TP would be used as key bed. 3) Beneath the sediments of Yodobashi and Akabane terraces, observed are drowned valley features. Those valleys are filled up with marine sediments representing each of the transgression periods. The amounts of transgression are estimated several ten meters with Yodobashi terrace, and several meters with Akabane.