Nanlong Fm
Type Locality and Naming
The type section is located at the Nanlong Village in the Namu River Valley of Dongfang City, Hainan Province. It was named by the Regional Geological Survey Party of Guangdong Province in 1964.
Lithology and Thickness
Clastics. Composed mainly of a suite of grey-brown, dark-grey and grey-green microclastic rocks, intercalated with carbonate and siliceous rocks. The major rock types are siltstone, siliceous siltstone, fine-grained quartz-sandstone, micro-grained quartz-greywacke, silty calcareous hydromica-bearing siltstone, sandy siltstone, siliceous siltstone and marl. Thickness is about 400 m.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Eding Fm
Upper contact
Uncertain due to incomplete exposure on the surface due to denudation.
Regional extent
Distributed largely in the Changhua River Valley in the Changjiang County of Dongfang City
GeoJSON
Fossils
Its middle and upper parts yield such Plant fossils (phytolites) as Annularia mucronata, Taeniopteris sp., etc., and with the upper part only yielding the Annularia crassiuscula, Pecopteris arborescens, etc. In the Niudiling section the Nanlong Fm is 350-m thick, with its upper part yielding Fusulinida represented by Parafusulina bosei, Parafusulina sp.; brachiopods such as Leptodus nobilis, L. richthofeni, etc.; and bivalves such as Nuculopsis sp., Ensipteria sp., etc., and with its top part yielding Cephalopoda represented by Shouchangoceras shouchangense, Altudoceras orientale, etc.
Age
Depositional setting
It is interpreted as littoral-basin facies and coastal-lagoon facies deposits.
Additional Information