Wanshan Fm
Type Locality and Naming
Pearl River Mouth Basin (offshore). The named section is located in No.1 of Guang Dong Xinjiang basin; the reference section is located in HZ13-1-1 in Huizhou section. Named in 1981 by Zhong Shuixian and others.
Lithology and Thickness
The formation is composed of the gray mudstone, silty mudstone and off-white fine sandstone, sandstone. The bottom of the formation is coarse and the top is fine, and it can be divided into two sections: Lower section is dominated by gray and dark gray silty mudstone with thin layers of gray sandstone; Upper section is dominated by gray and white fine conglomerate and sandstone, with thin layers of gray silty mudstone. The clayey siltstone has increased downward. Clayey interbeds, and the clayey matter generally contains ash, with fine horizontal bedding and poor diagenesis. 335 m thick.
Relationships and Distribution
Lower contact
False integration contact with the underlying Upper Miocene Yuehai Fm.
Upper contact
Conformably overlain by upper Quaternary – Qionghai Fm of bathyal silty mudstone
Regional extent
It is widely distributed in the Zhujiangzui Basin (Pearl River Mouth Basin). Its thickness varies greatly, from north to south, from east to west, and the thickness varies from place to place, with a total thickness of 0-541m.
GeoJSON
Fossils
This Formation has a rich fossil record. Foraminifera planktonic species belong to the N18 to N21 zone, mainly including Globorotalia margaritae, G. tosaensis, G. miocenica, Globoquadrina altispira, G. globosa, Globigerinoides extremus, Globigerina crassireticulata, Sphaeroidinellopsis seminula, etc. Asterorotalia spp., etc.; Calcareous nannofossils belong to the NN12-NN18 zone, and its characteristic elements include Amaurolithus tricorniculatus, Ceratolithus rugosus, Discoaster asymmetricus, D. pentaradiatus, D. tamalis, Reticulofenestra pseudoumbilica, Sluithus asusbies, Triquetrorhabdulus rugosus, etc.; The palynological record is a combination of Cupuliferoipollenites-Liquidambarpollenites
Age
Depositional setting
Neritic regression sediments
Additional Information