Shimagou Fm

Kumkoi Basin, SE corner Xinjiang. In 1965, the Altun Joint Survey Team of the Xinjiang Petroleum Management Bureau and the Xinjiang Production and Construction Corps firstly used this name in their unpublished manuscript, but they didn’t assign its type section. Gao et al. (2014b) assigned a lectostratotype for this formation, which is located at the Daobeiliang (=Huatiaoshan) section (E88°22′, N37°18′), north of the Ayakkum Lake in the Kumkol Basin, Ruoqiang County, Xinjiang. This formation was formally published by the Regional Stratigraphic Chart Editorial Group of Xinjiang Uygur Autonomous Region (RSCEGXUAR) (1981).

Synonym: Gao et al. (2014b) treated the Huatiaoshan Fm used in the 1:1000000 Regional Geological Survey Reports by the Xinjiang Regional Survey Team is a synonym of the Hongliang Fm.

It is mainly characterized by the greyish-brown, reddish-brown, and dark red conglomerates, with interlayers of red, purple, and greyish-white sandstones and earthy yellow mudstones. Its lower part is formed by greyish-green mudstones and greyish-black mudstones and shales. Stellar copper deposits are deposited in its sandstones and gravels. In the Baiquan River drainage, its top contains fossil mammals and sporopollens, which are deposited in the lacustrine deposits (Li et al., 2019). Its thickness is in range of 1000~2057 m.

Mammals: Erinaceus cf. E. mongolicus, Eptesicus sp., Spermophilinus kumkolensis, Myomimus maritsensis, Dipus nanus, Democricetodon lindsayi, Ochotonidae gen. et sp. indet.. Sporopollens: Picea, Pinus, Ephedra, Quercus. E (evergreen), Quercus. D (deciduous), Corylus, Hippophae, Fraxinus, Betula, Rosaceae, Asteraceae, Artemisia, Poaceae, Chenopodiaceae. (Li et al., 2019)

It is interpreted as a set of detrital deposits in basin environment.