Abstract
The author surveyd the topographies and volcanic ash in the area surrounding Mt. Daisen, San-in disstrict, western Honshu. Up to present, it has been said that the terraces and uplands are scarcely developed in San-in district, but the author recognized the several series of fluvial, marine terraces and pyroclastic uplands, many of which are covered with volcanic ash several meters thick.
The author's purpose in this survey was to make clear the condition of these terraces, uplands and volcanic ash, and to establish the geomorphic development in the area surrounding Mt. Daisen.
The condition of volcanic ash beds are shown in Figs. 1-3, and distribution of terraces and pyroclastic uplands are in Figs. 5-7. The developing order of terraces and pyroclastic uplands were concluded by t-he correlation of volcanic ash beds covering them, some absolute dates of which were decided by Carbon-14.
The geomorphic development derived from the above data is summarized in Table 1.
