No.16

Located at the entrance of Majia Valley, this formation belongs to the Upper Triassic Xinduqiao Formation (T3xd), consisting of a set of semi-deep marine flysch. The lower part has more sandstone, with rhythmic interbeds of sandstone and shale, while the upper part is mainly shale. There are two basic sequence combinations: evenly thick interbeds of sandstone and shale, and unevenly thick interbeds of shale with sandstone.