Qingyan Fm

Fossils of bluestone were published as early as 1900 by E. Koken, dating from the Middle Triassic Latinian to the Late Permian Carney. Xu Deyou (1943), Xu Deyou and Chen Kang (1943) named the "Qingyan Layer" and studied the right side of its evolution again, changing its age to the Middle Triassic Anisian stage. The Regional Stratigraphic Table of China (Draft) (1956) was renamed Qingyan Fm and its age was defined as Middle Triassic. The named section is located in Qingyan, about 30 km south of Guiyang, Guizhou.

Synonym: Chingyen Fm

"The lower part is mainly shale, the upper part is mudstone, when the turtle crack. The bottom boundary is marked by the appearance of thin to medium thick gray limestone. It can be divided into two sections: the first section includes the hills hill limestone, shale and limestone, hornet slope camp is mainly composed of gray in a thin layer to thick layers of limestone, calcirudite with the rhythm of clay rock layers: the second paragraph includes ray playing rock slope and fishing marl, mainly by the yellow grey calcareous clay rock, shale and grey, dark grey to thick layers of marl rhythm in each layer." [English text as was provided by the compilers; which obviously had some auto-translate problems.] The thickness is 400 to 1000 m. From northwest to southeast, the content of limestone decreased, and the shale increased, and the thickness decreased gradually to the Xinyuan Formation.

From bottom to top, it can be divided into four ammonoid zones (beds): (1) Leiophyllites- Ussurites zone, (2) Nicomedites yohi zone, (3) Paraceratites binodosus zone, (4) P. trinodosus zone. Brachiopods: top Lissorhynchia ovamaea, Adygella elongate, middle part Lepismatina hsui, Nudispirferina minina, Thecocyrtelloidea tubulosa, Neoretzia fuchsi, Rhaetina angustaeformis and bottom Diholkorh ynchia sinensis, Septaliphorioidea paucicostata, Nudispirferina.

It is interpreted as shallow sea deposit.