Anji Fm
Type Locality and Naming
It was named by Zhejiang Party of Regional Geological Survey in 1966. The type section is located at north of Xiaofeng, Anji County in northwest Zhejiang Province. The reference section is at Huangshu, Anji, measured by Zhejiang Bureau of Geology and Mineral Resources, 1989.
Synonym: (安吉组) , The Anji Fm and the Xiaxiang Fm established in Anhui are basically similar in lithology and their type sections are closely located. Although we retain the name Anji Fm., it is possible that the Anji Fm is a synonym of the Xiaxiang Fm as Rong Jiayu proposed in 1998 (Lin et al., 1998).
Lithology and Thickness
The formation, about 520 m in thickness, is composed of dark grey, grey green and grey black muddy siltstone and silty mudstone intercalated with fine-grained sandstone.
Relationships and Distribution
Lower contact
Conformable contact is observed with the underlying Yankou Fm of the Ordovician.
Upper contact
Conformable contact is observed with the overlying Dabaidi Fm of the middle Silurian.
Regional extent
It is distributed in northwest Zhejiang and southeast Anhui provinces.
GeoJSON
Fossils
The fossils found mainly in the lower part include graptolites of Normalograptus persculptus zone and the Akidograptus ascensus zone. Since there are no graptolite fossils found so far in the higher levels, the possibility of an age of late Rhuddanian to early Aeronian for the middle and upper parts of the formation cannot be ruled out.
Age
Depositional setting
Additional Information