Kesur Fm
Type Locality and Naming
Eastern Qinghai-SE Gansu border region. The Kesur Fm was named by the Regional Geological Survey Team, Qinghai Province. Comprehensive Geological Party, Northwest Bureau of Geology, Ministry of Geology in 1964. The type section is in Beimenxia, Huangzhong County, Qinghai Province. Lower formation in Huashishan Gr.
Synonym: （克素尔组）
Lithology and Thickness
In the type section, the Kesur Fm is dominated by dolomitic carbonate rock and characterized by its oolitic dolomite. The base is of brecciated limestone of 5 m thick. The dolomite and limestone distributed in Malaode Mt., Gangcha County, are rich in stromatolites. The Kesur Fm 1600 m thick
Relationships and Distribution
Lower contact
It is in disconformable contact with underlying Qingshipo Fm, Huangzhong Gr, of the Changcheng System
Upper contact
It is in conformable contact with the overlying Beimenxia Fm.
Regional extent
Eastern Qinghai-SE Gansu border region. The Kesur Fm is rather stable laterally both in lithological character and thickness. However, the basal conglomerate is changeable both in thickness and the size of pebbles involved in it. For example, in Beimenxia, Huangzhong County, it consists of brecciated limestone, 5 m thick; in Kesur, Huangyuan County, it is sandy conglomerate, 17 m thick; but on the east side of Chala River, Haiyan County, it consists of quartz conglomerate; at Malaode mountain, Gangcha County, the medium-coarse pebble conglomerate is about 5 m thick; at Huajiu Mountain, Zanbao County, coarse to boulder conglomerate is 140 m thick. These trends show that the basal conglomerate is thickening from east to west and from south to north, with the pebble size increasing in the same direction.
GeoJSON
Fossils
Stromatolites: Anabaria f., Scopulimorpha f., Tungussia f., Baicalia f., Kussiella f., Tielingella f.). microplants (Asperatopsophosphaera sp., Trachysphaeridium sp.)
Age
Depositional setting
Additional Information