Abstract
In order to clarify the generation mechanism of slickenside, we observe the microstructures of faulted chert, which is composed of the Jurassic accretionary complex in eastern Yamaguchi Prefecture. The chert is a pale blue to white color itself, but the surface of slickenside shows up as black. The observation by a stereo microscope indicates the surface of slickenside is covered by transparent-Si-material. On the thin section parallel and perpendicular to striation and slickenside, respectively, the elongated quartz grains containing many inclusions are oriented obliquely to the slickenside with 20-30 degree. These quartz grains show strong undulose extinction and bulging-recrystallization. TEM observation indicates the amorphous layer with several ten nanometers in width distributes along the slickenside. These results suggest the slickenside was generated by the frictional melting of quartz grains on slip plane.
