Heshangpu Fm

Its base marked by yellow thin-medium-bedded fine sandstone is distinguished from conglomerate of the underlying Sanqiao Fm.

Its top marked by dark purple clayey sandstone with quartz sandstone, yellow gray mudstone, shale and marl is bounded by the overlying Liwaxia Fm.

The present formation is distributed in Tongxin, Yaoshan, Xiji and Guyuan of Ningxia, Huating and Zhuanglang of Gansu, and Longxian of Shaanxi. In Ningxia it is most developed in Heshangpu-Liwaxia of the Guyuan County where its lithology is the finest and coarsens and its thickness decreases northward, generally from 38.3 to 762.4 m. Within the boundary of the Gansu Province, it is marked by interbedded sandstone and mudstone and varies greatly in thickness, 1216 m at maximum in the Mengjiatai area of Huating, and eastward it becomes thinner, only about 100 m thick. It is generally of shore facies deposition. In the Guguan area of Longxian of Shaanxi, it varies considerably in lithology, from sandstone with conglomerate in southeast to sandy mudstone and shale in northwest. It ranges from 350 to 571 m in thickness. Sandstone and conglomerate of the formation are commonly cupreous which constitute an important cupreous horizon of the Liupanshan Gr, also with uranium mineralization beds.