Fig. (3) Core photos demonstrating sedimentary characteristics of rocks. (a) HH105 well, Chang 8₁², 2262 meters, fine sandstone of parallel bedding, high-angle fracture. (b) HH49 well, Chang 8₁², 2283 meters, mud gravel at the bottom of the sandstone, erosion surface. (c) HH105 well, Chang 8₁², 2259 meters, fine sandstone with coal line.