New outcrop of the thrust fault at the lower boundary of the Oeyama Ophiolite Nappe (Sekinomiya peridotite body)

Abstract

A new outcrop of the thrust fault at the lower boundary of the Oeyama Ophiolite Nappe in SE Japan was found at the southeastern part of Todoroki, Sekinomiya area, Hyogo Prefecture. The Oeyama Ophiolite Nappe is an oldest nappe in Southwest Japan. The thrust was developed between the underlying metagabbro of the Yakuno Ophiolite Nappe and the overlying serpentinized mantle peridotite of the Oeyama Ophiolite Nappe. The composite planar fabric consisting of the main thrust and the shear zones in metagabbro suggests the movement of the overlying Oeyama Ophiolite Nappe towards SE to ESE at the present direction.