Miaoling Fm
(21), mid-Middle Permian
Type Locality and Naming
The type section is located at the Miaoling Quarry of the Wangqing area, Yanbian Region, Jilin Province, and the reference section is situated in the Houdi Cave of the Kaishantun Village. It was named by Klivolusky in 1959 in an internal report “On the Palaeozoic Stratigraphy in the Southeastern Part of the Songhua River and Wusuli River Region”, and was cited officially by Sheng Jinzhang in 1962.
Lithology and Thickness
Sandstone and Limestone. It is divisible into the Lower and Upper parts: The Lower part is composed largely of black-grey tuffaceous sandstone, intercalated with grey-black and grey-white medium-, and thick-bedded limestones, yielding abundant Fusulinida, corals and brachiopods, with a thickness of over 298 m. The Upper part is composed of variegated tuffaceous sandstone and tuff, intercalated with altered rhyolite and thin-bedded limestone, yielding Fusulinida and brachiopods, with a thickness of over 480 m. Thickness ranges 175-3500 m.
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Shanxiuling Fm in the the Shanxiu Ridge area. Uncertain in type section due to no base exposed at fault contact with the underlying Shanxiuling Fm.
Upper contact
Uncertain in type section due to no top exposed at fault contact with the overlying Kedao Fm
Regional extent
In the Kedao and Shanxiuling areas of the Kaishantun Village the formation is composed mainly of coarse clastic rocks, intercalated with many layers of tuffs, among which the limestone intercalated beds are relatively stable, with a thickness of 175-800 m. In the area of the Miaoling Ridge in the Wangqing County the formation is composed largely of lenticular limestones and clastic rocks, with a thickness of 800-1000 m, with an obvious rhythm. In the area of the Renhe Cave of Hunchun City the formation is composed of clastic rocks, intercalated with limestone, with a remarkable increase in the amount of siltstone; and in the Dongning region the formation is composed chiefly of siltstones, with no obvious cyclicity, with a thickness of 3500 m.
GeoJSON
Fossils
Lower part of the formation yields Fusulinida such as Parafusulina, Schwagerina pseudocompacta; Corals such as Yatsengia, Waagenophyllum indicum kueichowense; Brachiopods such as Neospirifer and Leptodus. The Upper part of the formation yields Fusulinida such as Yabeina cf. hayasakai, Neoschwagerina cf. douvillei; Brachiopods such as Leptodus tenuis. In the Miaoling and Taoyuan areas it yields also the Codonofusiella of Fusulinida; and Marginifera himalayaensis, Spiriferella and Yakovlevia of Brachiopoda. The Fusulinida in the formation belongs to the Neoschwagerina zone, and only the members of the Yabeina multiseptata subzone have been found, without the members of the Yabeina globosa subzone.
Age
Depositional setting
It is interpreted as an island arc-marginal sea-facies.
Additional Information