Longdongshui Fm
Type Locality and Naming
The type section is located in a gully about 300 m east of Longdongshui Village, 10 km east of Dushan County, Guizhou Province. It was named by Wang Yu et al. in 1964.
Lithology and Thickness
Dolomitic limestone It is mainly a set of carbonate rocks. The lower and middle parts are dominated by dolomitic limestone intercalated with limestone, and the upper part is limestone and clayey limestone with mudstone at top. It is 59.2 m in thickness.
Relationships and Distribution
Lower contact
It is conformably onto the underlying Shujiaping Fm
Upper contact
No overlying rocks in the type section, but elsewhere the next unit is the Banzhai Fm.
Regional extent
It is restricted in Houershan mountains area in Dushan County.
GeoJSON
Fossils
The formation contains abundant corals, brachiopods and a few trilobites, bryozoan, stromatopora, gastropods and bivalves.
Brachiopods can be divided into a Xenospirifer fongi assemblage zone below and an Acrospirifer houershanensis assemblage zone above.
Corals are represented in the lower part by Lyrielasma qiannanense, Grypophyllum diluvianum, Tabularia devoniana, Dushanophrentis cystotabulata, etc., and in the upper part by Utaratuia sinensis, Sociophyllum minor, Breviseptopgyllum kochanense.
Age
Depositional setting
It is interpreted as a shallow open-marine facies. [Previous version had "lagoon"]
Additional Information