Yingyangguan Gr
Type Locality and Naming
Junction of Guangxi, Guangdong, and Hunan. The Yingyangguan Gr was named by Li Zihui (1979). The type section is located at near Xialong, Yingyangguan, Hexian County, Guangxi Zhuangzhu Zizhiqu (Guangxi Zhuang Autonomous Region) (about 6 km southwest of Yingyangguan).
Synonym: （鹰阳关群）
Lithology and Thickness
The whole Yingyangguan Gr is dark gray to black and mainly argillaceous with rare sandstone. The whole group is slightly metamorphosed and with minor phosphorus and many layers of iron ore. The group can be subdivided into four members. First member is volcanic member, which consists of metamorphosed volcanic rocks, spilite-keratophyre, keratophyre with limestone, dolomite, schist and chert. Second member is calcareous phyllite, argillaceous limestone with minor phyllite, volcanic clastic rocks. Third member is sericite phyllite, which shows horizontal lamination and phosphatic quartzite in the bottom. Fourth member is phyllite and slate with minor dolomite locally and there is a layer of magnetite-hematite about 20 m thick in its bottom. The total thickness of Group is 2090 m.
Relationships and Distribution
Lower contact
The Yingyangguan Gr is conformable with the underlying Lijiapo Fm
Upper contact
The Yingyangguan Gr is conformable with the overlying Changan Fm. Next younger regional unit is the Lechangxia Gr (Sinian/Ediacaran) on schematic stratigraphic column.
Regional extent
Widely distributed in the junction area of the Hunan, Guangdong and Guangxi Provinces
GeoJSON
Fossils
Age
Depositional setting
Additional Information
The Yingyangguan Group is similar to “Chang'an Formation” in North Guangxi, It is over 2750 m thick (exposed), and subdivided into five members: (1) glaciomarine sedimentary clastic rocks, (2) volcanic rocks , (3) phosphatic calcareous rocks, (4) sericite schist, (5) clastic rocks with banded magnetite ore.