Changping Fm

The Changping Fm is in disconformable contact with the underlying Pre-Cambrian Chingeryu Fm. The base of the formation, by appearance of the micritic dolomite or thick-bedded leopard dolomitic limestone at base, is differentiated from the underlying vary-colored, thin- or platy-bedded argillaceous limestone of the Chingeryu Fm.

The Changping Fm is in disconformable contact with the overlying Manto Fm. The top is bounded by the occurrence of the purplish red brecciated mudstone of the Manto Fm.

The Changping Formation is exposed in the Xuzhou-Huaibei and Northern Hebei-Western Liaoning areas of North China Region, distributed in northwestern Beijing and western Tianjin municipalities and eastern and western Hebei, western Liaoning, southern Jilin, northern Anhui, and northern Jiangsu provinces. In the Xinglon and Pingquan counties of eastern Hebei, in Yixian County of western Hebei, the formation usually consists of thick limestone with brecciated dolomite (eastern part of the province) or quartzitic sandy breccia (western part of the province) at the base in the lower part and dolomite in the upper part. In Hebei, the formation decreases thickness westward, ranging between 13 and 108 m. In Liaoning, the formation is exposed only in the western part of the province (Lingyuan, Jingxi and Jianchang counties), dominated by grey, massive and medium- to thick-bedded leopard dolomitic limestone with brecciated dolomite or striped limestone bearing cherty nodules or cherty bands at base. In Liaoning, the thickness of the formation is thicker in eastern and western areas and thinner in the central area, varying between 7.6 to 115 m. In southern Jilin the formation is exposed in Tonghua and Liuhe counties, and the both sides of Hunjiang River, where the formation consists mainly of black leopard asphaltic limestone with black and yellowish grey, thick-bedded limestone breccia and thick- to thin-bedded limestone. The formation there yields Redlichia spp. In Tianjin, the formation is only exposed around the area of Fujinshan Hill, northwest of Jixian County, where it yields Palaeolenus. In Beijing, the formation is mainly occurred at Mentougou, Fangshan, and Changping districts, dominated by thick-bedded grey and dark grey leopard limestone, dolomitic limestone, calcareous dolomite and micritic dolomite with the thickness ranging between 13 to 95 m. In the border area between Jiangsu (Tongshan and Jiangwang counties) and Anhui (Huaibei City), the formation consists mainly of dolomitic, fine-crystalline algal limestone, striped sandy argillaceous limestone, and dolomitic limestone, containing rich trilobites Palaeolenus fengyangensis and Redlichia sp.