The Pleistocene Crustal Movements and the Inclination of Coastal Terraces on the Southeastern Kyûsyû

Abstract

In his previous papers, the writer has shown a peculiar contrast of the geoglogic structures of the lower Pliocene strata inn the Fossa Magna and in the outer zone of southwest Japan. And' he has concluded that. the structural lines of the.. lower Pliocene deposits do not conform with the general trend lines of the Honsyu arc or with the main structural lines of the outer zone of southwest Japan, but with the trend of the contour lines of the summit level in the outer zone of southwest Japan, and that the attitude of the lower Pliocene strata wasere made by the Pliocene crustal movements. From the above conclusions, . he has called in question that the crust deformation of the similar tendency as in the Pliocene crustal movements may have been continued during the later geologic period. In this paper he takes note of attitude of the. lower Pleistocene deposits and the inclinations of 4 coastal terraces arranged in step. on the southeastern coast of Kyusyu. And he points out that the dips of strata and the inclinations of the terraces are the older, the steeper they incline towards E. or EES., and the crustal movements of the similar tendency have been continued or repeated in these districts since the early Pliocene age. And he inclines to conclude that the recent structural features of the lower Pliocene deposits in the outer zone of southwest Japan may represent the total result of the crust deformations accumulated slowly since the early Pliocene age.