Yinggehai Fm

Hainan-offshore SW. The named section is located at NO.6 drill of Ying in the sea, 69 km southwest of Sanya, Hainan. The Yinggehai Formation spans the 453 to 1188m part of NO.6 drill of Ying as the reference section. The South China Sea Branch of China National Petroleum Corporation was named in 1981 by Hu Zhongping and Su Houxi.

It is shallow to semi-deep marine gray mudstone with gray-white siltstone and glutenite, rich in organisms and shell fossils. The lithology is fine at the bottom and coarse at the top. It can be divided into upper and lower sections. Lower section is dominated by gray and green-gray mudstone with thin layers of siltstone. Upper section is gray mudstone with the white sandy conglomerate, lime sandstone, and siltstone. The upper part of this Formation is mainly composed of mudstone in NO.2 et 6 drills of Ying, while NO.9 drill of Ying contains glutenite. The regional total thickness is 576 to 1455m.

This group contains abundant fossils species. Planktonic Foraminifera species include Globoquadrina altispira, Globoratalia acostaensis, G.menardii (dextrorotation), Globigerinoides extremus, Sphaeroidinellopsis dehiscens, etc., and benthos Foraminifera include Pseudorotalia spp., Asterorotalia spp., Uvigerina fliniti, etc., including zones N17—N21; calcareous nannofossils include Discoaster brouweri, D.pentaradiatus, Reticulofenestra pseudoumbilica, Ceratolithus rugosus, Amaurolithus tricorniculatus, etc., including zones NN16—NN18; pollen is the combination of Quercidites-Polypolysporois -Chenopodipollis combination; ostracods are Neomonoceratina delicata-Ambocythere elliptica combination. In addition, this group still produces fossils such as bryozoans, gastropods, and bivalves.

Shallow-semi-deep ocean