Daquan Fm
Type Locality and Naming
The type section is located at Daquan area 10 km to the north of the Hexibao Railway Station of the Lanzhou-Xinjiang Railway in Gansu Province. It was named by Liang Jiande in 1977, and was cited officially by the Compiling Group on the Regional Stratigraphic Chart of Gansu Province in 1980.
Lithology and Thickness
Conglomerate and clastics. Grey-green and yellow-green conglomerate and pebble-bearing coarse-grained sandstone, intercalated with grey-green sandstone, siltstone and a small amount of black shale. The basal part of the formation composed of grey-green conglomerate. Its top part possesses a 3-m-thick grey-black thin-bedded clayey fine-grained sandstone. Thickness is 57 m.
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Hongquan Fm
Upper contact
Overlain by Lugou Fm (early Triassic)
Regional extent
Distributed in a restricted area, being found to occur only in the Daquan region.
GeoJSON
Fossils
Plant fossils (Phytolites) represented by the Zamiopteris glossopteroides-Lobatannularia lingulata-Peltaspermum buevichae assemblage. Bivalves and ostracods.
Age
Depositional setting
It is interpreted as alluvial deposits.
Additional Information