Yingshuiquan Fm

Wen Shixuan named it in 1979. The named section is located from Shuanghu Office in Shuanghu County to Shuishuquan 1 km south of Shuanghu County in northern Xizang (Tibet). The original Shuishuiquan Fm represents a Marine sedimentary stratum mainly composed of interbedded marl and fine clastic rocks in the late Early Triassic in the Shuanghu area of northern Xizang. In 1985, Wang Ruizhong et al. established the Xishuanhu Fm above the Shushuiquan Fm and below the Kangnan Fm of the Middle Triassic, thus changing the age of the Shushuiquan Fm (Yingshuiquan Fm usage in this Lexicon) to the middle and late Early Triassic.

Synonym: Shuishuiquan Fm

It is characterized by thin gray marl, interbedded fine clastic rocks, oolitic limestone and shell. Lower part is light gray thin layer of pebble marl, calcareous shale, shell argillaceous limestone; Middle part is light yellow, yellowish green with gray mudstone and shale, and the upward limestone is more and more with shale. Upper part is gray, light gray and thin to middle oolitic limestone interbedded with shale. The thickness is about 830 m

Bivalves: Eumorphotis inaequicostata-Pteria cf. murchisoni zone.