In this paper, internal structure of slump beds distributed in Oshiba Jima Island, Higashi-hiroshima were described from a viewpoint of their form, and were considered in the context of teaching materials. The Oshiba Jima Island consists mainly of the H7 Rhyolite Member of Haigamine Formation of Cretaceous Takada Rhyolites. The slump beds were found out from the mudstone and tufaceous sandstone intercalated with welded tuff beds of the H7 Rhyolite Member. The form of asymmetric slump folds and thrusts on an outcrop are not difficult to describe. When used in combination of some analogue experiments, morphological characteristics of the slump beds have the potential to be a learning tool to improve the understanding of geologic structures.

本研究の一部に科学研究費補助金基盤研究（A）課題番号25242015および同基盤研究（C）課題番号26350235を使用した。