Gelaohe Fm
Type Locality and Naming
The type section is located at Jialaohe Village, 11 km south of the Dushan county seat, Guizhou Province. The original definition includes the present Zhewang Fm. The lectotype is at the eastern slope of Baihupo Hill, 3 km northwest of the Dushan county seat. It was named by V. K. Ting in 1931.
Lithology and Thickness
Limestone. The Formation is characterized by dark-gray medium- to thick-bedded micritic limestone intercalated with thin clayey limestone and purplish-red shale, marls and siltstones, yielding diverse fossils. A bed bearing-rugose coral occurs in the top of the formation. It is 55 m thick.
Relationships and Distribution
Lower contact
The formation rests conformably on the Zhewang Fm.
Upper contact
The formation underlies disconformably the Tangbagou Fm of lowest Carboniferous. The contact being placed at the change from siltstone and shale below to thick-bedded peloidal limestone of Tangbagou Fm
[Figure Cross section showing the DC boundary between the siliciclastics of Gelaohe Fm of uppermost Famennian (right of black stone tablet) and thick bedded peloidal limestone of Tangbagou Fm (tablet left) ]
Regional extent
It is widely distributed in the southern Guizhou with homogenous lithology with a maximum thickness up to 150 m.
GeoJSON
Fossils
It yields abundant index rugose coral Cystophrentis kolaoohensis, a number of brachiopods Ptychomaletoechia kinlingensis, Schuchertella gelaohoensi, Composita ovata, Cleiothyridina media, Yanguania dushanensis., Cyrtospirifer sp., and foraminifera Quasiendithyra kobeitusana, Q. konensis. The Cystophrentis kolaoohensis represents the highest coral zone of the Devonian in south China.
Age
Depositional setting
The lithology and fossils indicate an open marine condition and a relatively quiet depositional environment.
Additional Information