Banmandaodi Fm

The type section is situated 0.7 m north of the village Alengchu, about 15 km east of Mingyin Town, Lijiang Zangzu Zizhixian (GPS: 100^o30’34.1’’-27^o17’6.6’’ N)., Yunnan Province. It was named by by Duan Yanxue, Li Dingrong and Leng Chonglin in 1974, and published by Yu Changmin, Liao Weihua in 1978.

Conglomerate, Limestone. It is characterized by dark-gray limestone, shale, chert intercalated with sandstone and conglomerate. It can be roughly divided into two parts: Lower part is dominated by dark-gray thick-bedded breccia, conglomerate, fine-grained sandstone, few shale and limestone. The clasts of conglomerate are usually rounded to semi-angular, consisting of quartz, chert, rare limestone and other lithoclasts. Upper part consists of alternation of unequal thick limestone and thin-bedded shale, intercalated with fine conglomerate and siliceous rocks. Flysch cycle, Bouma sequence, flute and groove casts are commonly observed. The total thickness is about 141 m.

It contains abundant tentaculites, ammonoids and a few coral fossils, including tentaculites Nowakia zlichovensis zone and N. barrandei zone, and ammonoids Anetoceras- Erbenoceras zone. Rugose corals include Tryplasma devoniana, Siphonophrentis alengchuensis, Pseudoblothrophyllum elegans, Fasciphyllum minor, etc.

The thin shale and siliceous rocks bearing-tentaculites represent the background sedimentary environment of deep-water basin with allochthonous intervening siliciclastics. A submarine-fan environment is also suggested.