Youhe Fm

Xue (1981) didn’t assign the type section. Zheng et al. (1999) proposed a reference section located at Zhangjiapo-Lujiahao section near the You River, Weinan City, Shaanxi Province. We recommend a lectostratotype for this formation, which is located at the Songjia Gully section (E109°30′, N34°25′), west of the Youhe Reservoir, about 7 km south of Weinan City. This formation was named by Xue (1981). However, it has not been widely accepted. BGMRS(Shaanxi)P (1989, 1998) didn’t employ this formation.

Synonym: This formation is equal to the original “Green Sanmen” (Chinese Association for Quaternary Research, 1959). Zheng et al. (1999) considered that the unpublished “Zhangjiapo Fm” is a synonym of the Youhe Fm. Wang et al. (2013) suggested that both the “Zhangjiapo Fm” and the Youhe Fm are essentially parts of the Sanmen Fm and should be incorporated into the Sanmen Fm.

It is mainly characterized by greyish-green or cyanic grey sandy mudstones and muddy sandstones with interlayers of marlstones. It contains fossil mammals, reptiles, fishes, bivalves, gastropods, ostracods, and sporopollens. Its thickness is about 36 m.

Mammals: Mimomys youhenicus (including M. orientalis), Criectulus sp., Epimys sp., Chardinomys sp. (pro. Mus sp.), Spermophilus sp., Ochotonoides cf. O. complicidens, Nyctereutes sinensis, Elephas youheensis, Proboscidipparion pater (pro. Hipparion houfenense), Rhinocerotidae, Sus sp., Sus subtriquetra, Cervaitus sp., Cervus sp. Fishes: Cyprinus sp., Ctenopharyngodon sp., Mylopharyngodon sp. (Xue, 1981)

It is interpreted as river-lake environment.