Guandi Fm

It was named by Ding Wenjiang and Wang Yuelun in 1937. The type section is located in the areas from Yilong to Guandijian and from Canglangpu to hainiushan in Yilong County, eastern Yunnan Province. The reference section is at Yuejiashan Mt., southwest of the Qujing County seat in eastern Yunnan.

Synonym: （关底组） ; Kuanti Fm. The Mientian Fm (Grabau, 1924) is also a synonym of the Guandi Fm and had long ago been abolished by Ding and Wang (1937). The Shangcun Fm (proposed by Bian Zhaoxiang in 1924), resting in between the Tangchi Fm of the Ordovician System and the Devonian System and consisting of violet and green shale intercalated with minor sandstone, is probably also be a synonym of the Guandi Fm. The Malung Limestone (Grabau, 1926, p. 10) is equivalent to the dark grey crystalline limestone horizon in the lower part of the Guandi Fm, i.e., the sixth horizon in the Yilung-Guandi section classified by Ding and Wang (1937).

The Guandi Fm is subdivided into two parts. Lower part ("the Yuejiashan Member"), approximately 220 m in thickness, consists of yellow green, grey green shale and pelitic siltstone very often intercalated with thin-bedded marl and sandstone, and occasionally with purplish red pelite. Upper part ("the Guandi Member"), about 560 m thick, is composed of purplish red, yellow, yellow green siltstone, shale and pelite.

The fossils can mainly be seen in the lower part and a few are from the upper part. The formation is rich with brachiopoda Striispirifer yunnanensis, Atrypoidea foxi, Retziella uniplicata, Nikiforovaena sinensis, Morinorhynchus; trilobite Acanthopyge; corals Squameofavosites, Favosites, Parastriatopora, Ketophyllum, Zelophyllum, Cystiphyllum, Mucophyllum, Holmophyllum; nautiloid Heyuncunoceras, Platydiscoceras; bivalves Grammyasioides, Leiopteris; conodont Ozarkodina crispa (collected from the upper part), and gastropod, etc.