Heishan Fm
Type Locality and Naming
Central-north Yunnan (border with southernmost Sichuan). The Heishan Fm was named by Meng, H. M. (Meng Xianmin), Hsu, S. C. (Xu he) et al. in 1944. The type locality is situated at Heishangou, Yinmin, Dongchuan City, Yunnan. It is the upper-middle formation of the Dongchuan Gr.
[Figure: The Heishan Fm of the Dongchuan Gr in Yunnan Province]
Synonym: （黑山组）
Lithology and Thickness
In the type locality, the Heishan Fm consists of black organic-rich slate within both the lower and upper parts. The organic-rich slate in the lower part is sandwiched with blue-grey clayey slate; and the dark-grey thin- to medium-bedded muddy limestone and dolomite with thin-bedded slate are sandwiched between the upper slate and lower slate. The basic-volcanic-sedimentary conglomerate and tuffaceous sandstone are often intercalated between upper slate and middle limestone. Layered copper ore deposits often occur in the basal part. The thickness varies greatly from 250 to 1786 m.
Relationships and Distribution
Lower contact
The Heishan Fm is in conformable contact with the underlying Luoxue Fm.
Upper contact
The top is overlain by the Qinglongshan Fm (Luzhijiang Fm), which is the uppermost formation in the Dongchuan Gr.
Regional extent
Central-north Yunnan (border with southernmost Sichuan). The formation is distributed only around Dongchuan, Yunnan. The Etouchang Fm in central Yunnan Province is roughly synchronous with Heishan Fm and both of them are copper-bearing horizons, but there are some lithologic differences. The thickness varies from 1000 to 3500 m.
GeoJSON
Fossils
The slate yields microplants: Trachysphaeridium, Sicyomipha, Pseudozonosphaera, Asperatopsophosphaera, Scaphite etc.
Age
Depositional setting
Additional Information