Huohong Fm
Type Locality and Naming
The type section is located in the area of Yingpan---Nonghe, Huohong District in Ziyun County, Guizhou Province. It was named by the Fifth Prospecting Team under the Ministry of Geology and was quoted by the Guizhou Team of Stratigraphy and Paleontology in 1977.
Lithology and Thickness
Sandy claystone. It is a set of fine-grained clastic rocks intercalated with siliceous limestone. It is mainly composed of grayish-black thin-bedded mudstone to sandy mudstone intercalated with quartz sandstone, siltstone, calcareous sandstone and siliceous limestone. The formation is 994 m thick.
Relationships and Distribution
Lower contact
It has conformable basal contact with the underlying black thin-bedded calcareous mudstone of the Chehe Fm; and at Pu'an has a conformable contact with the limestone of the Guanziyao Fm.
Upper contact
It is overlain by the siliceous rocks of the Liujiang Fm.
Regional extent
It is distributed in the areas of Ziyun, Luodian and Pu’an counties in south and southwest Guizhou. In Sanglang area, the formation changes facies into quartzose sandstone and clayey siltstone with the thickness decreasing down to 250 m.
GeoJSON
Fossils
It yields abundant tentaculites: Nowakia otomari, Viriatellina, Striatostyliolina; brachiopods: Stringocephalus, Emanuella; and crinoids.
Age
Depositional setting
It is interpreted as a deeper-water intraplatform basin deposit, but the brachiopods indicate a neritic environment
Additional Information