Wangguangou Fm
Type Locality and Naming
East end of South Qinling tectonic region. The type section is located at Wangguangou to Baishiyan, about 12 km southwest of Xichuan County, Hunan. It was named by The South of Henan Regional Geological Survey of Beijing Geological College in 1961, and is published by "The Regional Scale of South-central China” in 1974.
Lithology and Thickness
Sandstone, Claystone. The total thickness is 206.5 m . Base of this formation is composed of grayish-purple sandy dolomite intercalated with a few beds of earth-yellow calcareous claystone and clayey banded limestone. Clayey limestone intercalated with syngenetic conglomerate can occur in the base of this formation.
Lower part is dominated by grayish-yellow medium- to thick-bedded feldspathic quartz sandstone, mica-bearing fine-grained sandstone and claystone, with interbeds of reef limestone. Middle part is characterized by grayish-yellow medium- to thick-bedded feldspathic quartz sandstone with interbeds of gray to grayish-purple claystone. Upper part is composed of purple silt-bearing claystone, thin-bedded fine-grained sandstone, shelly limestone and bioclastic limestone. The middle and upper parts have three intercalated beds of thick-bedded reef limestone.
Relationships and Distribution
Lower contact
It conformably overlies on the Baishangou Fm.
Upper contact
Conformably overlies the Hulushan Fm.
Regional extent
Variation of thickness in this formation is similar to that of the underlying Baishangou Fm; the west of Laoguanhe is about 150 m thick, the east could reach to 180 m, and it is 240 m thick in Yongqingshan of Neixiang.
GeoJSON
Fossils
The limestone yields coral, Stromatopora, brachiopods, and bryozoan fossils; and in middle and upper part, it is characterized by coral Peneckiella-Donia assemblage zone.
Age
Depositional setting
It is interpreted as a platform margin bio-reef facies deposit.
Additional Information