Dapingzi Fm
Type Locality and Naming
The type section is at Dapingzi in Tongchang of Jinping County, Yunnan. The Dapingzi Fm was named by Yunnan Party of Regional Geological Survey in 1975, and was published by Yunnan Bureau of Geology and Mineral Resources (1990).
Synonym: (大坪子组）
Lithology and Thickness
The formation is characterized by basal lime-dolomite, lower and middle parts of dark gray, gray limestone and sandy limestone with flint nodules, and upper part of silty mudstone. In the type section, the Dapingzi Fm is 250 m thick.
Relationships and Distribution
Lower contact
The formation rests conformably on the quartz siltstone intercalated with argillaceous limestone of the Nanbanhe Fm
Upper contact
It is disconformably overlain by the Middle Silurian (Posongchong Fm ?)
Regional extent
The Dapingzi Fm is restricted to Luogetang and Baimazhai of Jinping County, Yunnan, with a slightly variable lithology and thickness. In Luogetang, it contains sandy sediments in the lower part and dolomitic sediments at the top, and recorded a thickness of 32 m; in Pingbahe, it is composed of siliceous dolomite in the lower part and siliceous banded dolomitic limestone intercalated with limestone in the upper, with a thickness of 92 m; in Tongchang, it is 250 m thick, and 158 m thick in Baimazhai.
GeoJSON
Fossils
This stratigraphic unit can be divided into two coral zones, Ningnanophyllum zone in the lower part and Agetolites oculiporoides zone in the upper.
Age
Depositional setting
Additional Information