Abstract:Based on observation of drilling cores and study of tectonic setting, seismite was recognized in the Cretaceous strata of the Tamuchage depression. Seismite is mainly characterized by various soft-sediment deformation structures such as synsedimentary faulting and microfractures, liquefaction vein, pillow structure, and accompanying structures, etc. Based on observation of drilling cores from Ta 219 and Ta 1943 wells, a vertical succession of seismites was established, which is in ascending order, liquefied veins, hydroplastic deformation, axeformed, slump, laddershaped microfracture, and shatter fissure, and so on, which correspond to a change process of earthquake with an intensity from strong to weak. The discovery of seismites is of great significance and will be conducive to understanding of intense action period of basincontrolling boundary fault.