Guanzhuang Fm

The naming section is located in Qiluoguan Township-Pagu Township northwest of Mengyin County, Shandong. Named by Tan Xichou (1923).

Three members may be generally distinguished: Lower member is purplish red, grayish purple and gray mudstone, sandy mudstone and muddy sandstone with purplish red, grayish purple and grayish yellow sandy conglomerate, sandstone or sandstone lenses, the top of which is intercalated with carbonaceous shale. Middle member is grayish black, purplish red and grayish green mudstone with grayish white and purplish red conglomerate and grayish purple, brick-red and yellow sandstone, muddy sandstone, marlstone and limestone, containing coal seams, the base of which is grayish yellow and yellow sandy conglomerate. Upper member is purplish red sandy conglomerate with sandstone. The thickness may be up to 1800 m or so.

According to the records, the mammals and gastropods predominate in the biotas of this formation. Besides turtles and crocodiles (Pritichampsus rallinati), there are at least 15 genera and species of mammals, which have been discovered by different geologists for many years since the 1920s. The main forms are Coryphodon flerowi, Eudinoceras xintaiensis, Kuanchuanius shantunensis, Haplomys sp., Grangeria canica, Hyrachyus metalophus, Helaletes sp., Lophialetes sp., Schlosseria sp., Breviodon minutus and Rhodopagus laiwuensis. Some species in this fauna may probably correlate with the Middle Eocene Bridgerian species in North America. From the natures and characters of the fauna, it is very similar to the middle Eocene Ashantou fauna in Inner Mongolia. The gastropods are mainly the assemblage represented by Ganeselloides marianus, Physa shantungensis and Dimorphoptychia speciosa. There are about 19 genera and 30 species of ostracods, mainly including Canodoniella albicans, Eucypris wutuensis and Metacypris changzhouensis. In the sporopollen assemblage, angiosperms account for ~48%, gymnosperms 28.9% and pteridophytes 23%, of which Tripororicellaesporites, Ephedra, Lycopodiumsporites and Schizaeoisporites are dominant.

The so-called Guanzhuang fauna is a general designation of mammal fossils found at Guanzhuang of Mengyin, Xizhou (or Xigou) of Xintai and Laiwu, and most species of the fauna occur in Xizhou, Xintai; so the fauna is also called the Xizhou fauna (Tong Yongsheng, 1989) or the Xintai fauna (Zhou Mingzhen and Qi Tao, 1982; Qi Tao and Meng Zhenya, 1983).

It is interpreted to fluvial and lacustrine deposists.