Shuiqing Fm
Period:
Silurian
Age Interval:
Homerian-early Ludfordian (S2-S3) (38b)
Province:
Yunnan
Type Locality and Naming
It was proposed by Zhang Yuanzhi (1996) to refer to the lower part of former “Mojiang Group”. The type section is Shuiqingliangzi section, ca. 8 km south of the Mojiang Xian, Yunnan Province. The formation is exposed in Lüchun-Jinping region of southern Yunnan Province with a huge thickness of over 2000 m.
Synonym: (水箐组)
Lithology and Thickness
It is over 551m as measured at the type section, where the top boundary with the overlying strata is not exposed. It consists of dark grey, greyish green, greyish purple shale, siltstone, and fine-grained sandstone.
Lithology Pattern:
Sandy_claystone
Relationships and Distribution
Lower contact
It overlies the Manbo Fm, probably conformably as Zhang et al. (2014) suggested.
Upper contact
And it possibly underlies the Luohong Fm of Early Devonian.
Regional extent
The formation is exposed in Lüchun-Jinping region of southern Yunnan Province.
GeoJSON
null
Fossils
A very diversified graptolite fauna had been found in the formation, two Wenlock and three Ludlow graptolite biozones were recognized by Zhang et Lenz (1999), in ascending order: Colonograptus praedeubeli Biozone, C. ludensis Biozone, Lobograptus progenitor Biozone, L. scanicus Biozone and Saetograptus fritschi linearis Biozone.
Age
The graptolite biozonation indicates that the Shuiqing Fm is younger than the Manbo Fm. The Llandovery is absent in Mojiang area, whereas the Pridoli is probably present, but not yet confirmed due to the poor preservation of the yielded graptolites according to Zhang et Lenz (1999).
Age Span:
Beginning stage:
Homerian
Fraction up in beginning stage:
0
Beginning date (Ma):
430.62
Ending stage:
Ludfordian
Fraction up in the ending stage:
1
Ending date (Ma):
422.73
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Wang Chuanshang and Wang Xiaofeng