Gaojingchao Fm
(68), lower to middle Kungurian Stage (late Cisuralian Epoch; late-Early Permian)
Type Locality and Naming
The type section is located at Gaojingchao (102°08′, 22°44′), Lu Chun County, Yunnan Province. It was named by the Bureau of Geology and Mineral Resources of Yunnan Province in 1990.
Lithology and Thickness
Clastics and Volcanics. Composed mainly of clastic rocks, intercalated with carbonate rocks and acidic, intermediate-basic volcanic rocks. Lower part is composed of grey quartz-sandstone, feldspar-quartz-sandstone, silty shale and clayey shale, intercalated with a small amount of limestone and many layers of grey dacitic porphyry, altered trachytic basalt, andesitic porphyrite, volcanic breccia and tuff. Upper part of the formation consists of grey quartz-sandstone, silty shale, clayey siltstone and layered tuff. Thickness 350 to as much as 2800 m.
Relationships and Distribution
Lower contact
Unconformable contact with the underlying Xiamidi Fm of the Upper Carboniferous Series (Not in Carboniferous Lexicon).
Upper contact
Uncertain contact with the overlying strata. Next younger regional unit might be the Lazhuhe Fm or Bahiu Fm.
Regional extent
Distributed in the Gaojingchuo area of Luchun County and the Dadiehe area of Jiangcheng County in a NW-trend, and in a small scale. It is getting thinning from southeast to northwest, with its thickness reaching as great as 2851.4 m at the Gaojingchao. Northwesterly to the Luchun County the Lujiao Volcanics disappeared, and being replaced by the occurrence of grey micritic and cryptocrystalline limestones and lime-conglomerate, intercalated with calcareous sandstone and clayey shale, with a thickness of 350.7 m.
GeoJSON
Fossils
Fusulinida such as Misellina claudiae, M. aliciae and Parafusulina visseri; as well as brachiopods and bryozoa.
Age
Depositional setting
It is interpreted as littoral-shallow-sea deposits.
Additional Information