Find in Library

The Muroto Peninsula on the Pacifi c margin of southwest Japan (Fig.1) formed as a result of tectonic events associated with oblique subduction along the Nankai Trough (Sugiyama, 1992, 1994). Late Pliocene forearc basin deposits of the Tonohama Group are exposed on the west coast of the peninsula. Until recently, stratigraphical and paleontological data have been collected only from rather scattered and poorly exposed outcrops (e.g., Yokoyama, 1926; Katto, et al.,1953; Kurihara, 1968; Nishida, 1979; Okumura and Takei, 1993), and no detailed chronological and sequence-stratigraphic framework has been established. The paleoenvironmental changes recorded in the formation thus remain poorly understood.