Cretaceous to Paleogene accretion was the main cause of the accretionary complex of the Shimanto Belt. Contemporaneous accretionary wedges occur also in Indonesia (Wakita, 2000b). The accretionary complex of the Shimanto belt is characterized by tectonically stacked turbidites. Mélanges, including radiolarian chert, are less dominant than those containing turbidites. The Cretaceous– Paleogene accretionary complex of the Shimanto Belt is dominant in turbidite and contains less chert and limestone. This difference was caused by the position of the decollement, which developed at the toe of accretionary wedge. In the present Barbados accretionary wedge the décollement was developed mainly within the hemipelagic sediment, because the porosity of the sediments, including radiolarian remains, is very low, compared with the other stratigraphic units (Shipley et al., 1997).