Taoshan Fm
Type Locality and Naming
The name was proposed by the Party of Regional Geological Survey, Jilin Bureau of Geology in 1977 and published by Liu Weizhou et al (1982). The type section is situated at Xishan, Mengjiagou, Jinjiatai Township, Yitong County, Jilin Province. The reference section is at Nanshan, Dazigou, northwest of Taoshan, Jinjiatai Township, Yitong County, Jilin Province.
Synonym: (桃山组)
Lithology and Thickness
Lower part is dominated by interbeds of light-colored acidic lava with light-colored silty slate. Upper part consists of black, grayish black slate, silty slate intercalated with tuffaceous siltstone and micritic sandstone.
Relationships and Distribution
Lower contact
Both lower and upper boundaries are yet unclear.
Upper contact
Both lower and upper boundaries are yet unclear. Regionally, the next younger unit is the Zhangjiatun Fm of uppermost Silurian.
Regional extent
The formation, 400 m odds in thickness, is, as so far known, exposed only in areas of the type section and reference section localities. The strata there are overturned.
GeoJSON
Fossils
It yields rich graptolite and seven graptolite zones can be listed in ascending order as follows: 7. an unnamed zone; 6. Stomatograptus grandis zone; 5. Oktavites spiralis zone; 4. Monoclimacis vomerinus-M. cf. griestoniensis zone; 3. Streptograptus exiguus-S. cf. crispus zone; 2. Spirograptus turriculatus zone; 1. Streptograptus runcinatus-Rastrites cf. linnaei zone. In addition, according to information from the floaters picked up near the type section, there are still elements from the Monograptus sedgwickii zone and the Diplograptus modestus zone.
Age
Depositional setting
Additional Information