Sediment Deformation in the Shallow Levels of an Accretionary Prism: Evidence from Miura and Boso Peninsulas

Abstract

The Izu Collision Zone (ICZ) encompasses the region of the Neogene to Recent arc-arc collision between the main island of Japan, or Honshu Island arc, and the Izu-Ogasawara (Bonin) Island arc immediately southwest of the Boso Peninsula (Figure 2). This area represents the junction between three active plate convergence zones: the Japan Trench to the northeast, the Izu Trench to the southeast and the Nankai Trough to the southwest. This juncture therefore represents one of the few active trench-trench-trench triple junctions in the world. The present collisional boundary runs west to east through the Suruga Trough and under Mt. Fuji to the Sagami Trough and to the triple junction area to the east (Figure 2).