Longwangzhang Gr
Type Locality and Naming
E. Heilongjiang – Wandashan. The Longzhaogou Group was named by Chen Guangya (1963) in Longzhaogou of the Hulin County, Heilongjiang.
Lithology and Thickness
The Longzhaogou Group is a group of coal-bearing strata of marine and non-marine interbedding facies. The formation consists of the upward succession of the Peide Fm, Qihulin Fm, YunshanCret Fm and Zhushan Fm. "In general, the lower part of the Longzhaogou Group (the Peido Fm) is a volcanic sedimentary formation with some coal intercalations. In contrast, the middle part (the Qihulin Fm and lower part of the Yunshan-Cret Fm) is interbedded fossiliferous marine-littoral deposit sand nonmarine coal-bearing beds intercalated with volcanic clastics. The upper part (upper YunshanCret Fm and the Zhushan Fm} is mainly nonmarine coal-bearing sediments with littoral intercalations". The Group is about 4300 m in total thickness.
Relationships and Distribution
Lower contact
It overlies the base rocks or the Yangshugang Fm unconformably. " This group unconformably overlies the Permian System containing the plant fossil such as Noegerathiopsis, Calamites, Comia, Zamiopteris and others, or lies on Palaeozolc granites."
Upper contact
"It is conformably overlain by the Cretaceous Dongshan Fm of the Huashan Gr, or partly unconformably overlain by the Tertiary formations."
Regional extent
The Longzhaogou Group is distributed in the Hulin, Mishan and Baoqing areas in eastern Heilongjiang.
GeoJSON
Fossils
None listed
Age
Depositional setting
Additional Information
Descriptions copied from Futakami, M., et al. (1995) "Barremian ammonites from the Longzhaogou Group in eastern Heilongjiang, northeast China", Jour. Geol. Soc. Japan, 101: 79-85. Age span from D.P. Xi, X.Q. Wan et al. (2019; Cretaceous chapter of China Integrated Stratigraphy and Timescale).