An Erosional Trough on the Remnant of an Elevated Peneplain at Mt. Kenashimori, Kitakami Mountains

Abstract

A “Frying-pan” type erosion is observed on the flat top of Mt. Kenashimori (941.5 m) Kitakami Mountains, Iwate Prefecture. The flat of the mountain covered with sod is a small remnant of the uplifted peneplain. A “Frying-pan” type erosion area is the upper part of a shallow-and-wide small valley. The minute cliff at the NE edge of the pan is 15-20 cm high and the bottom is 30 cm lower than the flat top. The author thinks that the mechanism of the erosion is a sheet-flood erosion due to a heavy rain, in which the soil under sod, loosened from solifluction in winter, is washed out by the flood.