SMALL FAULTS AND KINK BANDS IN THE NANKAI ACCRETIONARY COMPLEX - TEXTURAL OBSERVATIONS FROM SITE-808 OF ODP LEG-131

We present backscattered scanning electron microscope and petrographic microscope observations of deformed sediments from Ocean Drilling Pro gram (ODP) Site 808 in order to better understand the dewatering and d eformation history of the Nankai accretionary complex. This synthesis of deformation textures has three implications. First, the early struc tures that dominate the Nankai prism, small faults and kink bands, hav e very different electron microscope versus optical microscopic expres sions. This observation is important to investigations of fine-grained sediment in both stable and active tectonic settings, in part, becaus e these materials have often been studied almost exclusively by electr on microscope methods. In sediments of this type, investigators often forego petrographic analysis because of the relative opacity of sample s at normal (i.e. 30 mu m) thin section thicknesses. Second, the textu ral observations we have compiled suggest that these deformation struc tures acted as 'single-event' pathways that contributed to diffusive d ewatering of the prism. Third, our observations serve as a reference f rame for the early tectonic structures that are important to the dewat ering history of a 'sandy' accretionary prism.