Xiacaowan Fm
Type Locality and Naming
Its type section is located at Xiacaowan (E118°13′, N33°29′), near the town of Shuanggou, Sihong County, Jiangsu Province. The hypostratotype section is located at Xiaowangzhuang (E118°05′, N33°12′), near Fengshan town, Sihong County, Jiangsu Province. Its name is derived from the “Xiacaowan Series” named by Young and Chow (1955).
Synonym: According to Zheng et al. (1999) and Gao et al. (2014b), the Sihong, Fengshan, Huaguoshan, Mingguang, Douchong, Zhengyangguang formations are all synonyms of the Xiacaowan Fm.
Lithology and Thickness
Lower member of is characterized by brownish-yellow and yellowish-brown gravels interbedded with conglomerates containing silty mudstones. Upper member consists of greyish-green, light-grey, and pink mudstones, calcareous mudstones containing greyish-white attapulgite clay, greyish-yellow sand and gravels, and partially containing basalts. It contains mammalian, amphibian, reptile, avian, bivalve, gastropod, plant, sporopollen, ostracod, and charophyte fossils. Its thickness is in range of 8.4~382 m.
Relationships and Distribution
Lower contact
In the type section, the Xiaocaowan Fm disconformably contacts with the underlying Lower Miocene Fengshan Fm (abandoned). In Xuyi area, this formation unconformably contacts with the underlying Upper Oligocene Sanduo Fm. Next older regional unit is the Shanghuangliexi Fm.
Upper contact
Regional extent
This formation is widely distributed to Xiacaown-Guanzhen area in Sihong, and Huagguoshan-Heqiao area in Xuyi of Jiangsu Province, and Mingguang-Nvshan area in Mingguang of Anhui Province.
GeoJSON
Fossils
Mammals: Sinoperadectes clandestinus, Lanthanotherium sp., Crocidosorex sp., Myotis sp., Vespertilionidae gen. et sp. indet., Sayimys sp., Tachyoryctoides sp., Neocometes sinensis, Ansomys orientalis, Eutamias sihongensis, Sciurus lii, Plesiosciurus sinensis, Shuanggouia lui, Palaeosciurus jiangi, Heterotamias sihongensis, Parapetaurista tenurugosa, Sciurinae gen. et sp. indet., Microdyromys orientalis, Apeomys sp., Youngofiber sinensis, Diatomys cf. D. shantungensis, Alloeumyarion sihongensis, Cricetodon wanhei, Democricetodon suensis, Primus pusillus, Megacricetodon sinensis, Neocometes sp., Alloptox sihongensis, Amphicyon sp., Ursidae gen. et sp. indet., Proputorius sp., Mustela sp., Protictitherium sp., Semigenetta huaiheensis, Pseudaelurus (Schizailurus) cf. P. lorteti, Stegolophodon hueiheensis, Delphinus sp., Anchitherium sp., Plesiaceratherium gracile, Suidae gen. et sp. indet., Pecarichoerus sp., Dorcatherium orientale, Palaeotragus sp., Micromeryx sp., Dicrocerus sp., Amphimoschus sp., Stephanocemas sp., Lagomeryx sp., Dionysopithecus shuangouensis, Platodontopithecus jianhuaiensis. (Qiu and Qiu, 2013 in Wang et al., 2013; Qiu, 2015; Qiu and Jin, 2019).
Aves: Mioaegypius gui, Ardeidae gen. et sp. indet., Paltalea tiangangensis, Aquilinae gen. et sp. indet., Palaeoalectoris songlinensis, Phasianus sp., Strigidae gen. et sp. indet.. (Hou, 1984, 1987)
Age
Depositional setting
It is interpreted as a river-lake environment.
Additional Information