Gaotan Fm
Type Locality and Naming
The type section of the Gaotan Formation is the Gaotan-Yangmeitan section Gaotan, Chongyi, Jiangxi Province (114°16’E, 25°45’N). It is the same section with the overlying Shuishi Formation, the interval spanned by the formation lies about 5 km west of the seat of Chongyi County and was remeasured by Jiangxi Regional Geological Survey Team in 1966. In the type section, the formation is 864.95 m thick. The Gaotan Formation was first published by Compiling Group for Jiangxi Regional Stratigraphic Scale (1980). The name is derived from Gatan Village in Guobu Township, Chongyi County, Ganzhou City, southwestern Jiangxi Province, and was originally appeared in a 1966 manuscript by Wei Xiuzhe from Jiangxi Regional Geological Survey Team who called the formation as Gaotan Group, subsequently it was lowered in rank to Gaotan Formation in a 1988 manuscript by Liu Bangxiu from the Jiangxi Bureau of Geology and Mineral Resources, and the term of formation was finally published by Liu (1997)
Synonym: （高滩组）
Lithology and Thickness
The Gaotan Formation is a clastic sequence, dominated by greyish green, grey, and dark grey, thick- to mega-thick-bedded, medium- to fine-grained blasto-arkose and blasto-feldspathic quartzose sandstone in part, with greyish green slate, silty slate, greyish black carbonaceous slate in part, and minor tuffaceous slate, and with greyish black lenticular limestone at the top part. The lenticular limestone is intercalated with purplish red and light brown, thin-bedded calcareous slate. Laminated bedding is developed in slate, which usually demonstrates black- and white-banded structure. This formation comprises a suite of alternated flysch sandstone and slate with turbidity marks (primary sedimentary structure).
Relationships and Distribution
Lower contact
The Gaotan Fm is in conformable contact with the underling Niujiaohe Fm. The lower boundary of the formation is defined by the lithological change from the carbonaceous slate of the Niujiaohe Formation to the thick-bedded sandstone at the basal part of Gaotan Fm
Upper contact
The Gaotan Fm is in conformable contact with the overlying Shuishi Fm. Its upper boundary is marked by disappearance of the lenticular limestone at the top part of Gaotan Fm.
Regional extent
The Gaotan Formation is exposed in the Cathaysia Area of South China Region, distributed in central and southern Jiangxi Province (Chongyi, Yudu, Xingguo, Taihe, Suichuan, Yongxin, and Longnan counties) and northern and western Guangdong Province (Yingde, Enping, Huiji, Yunan, Heshan, Qujiang, Taishan, Longmen and Nanxion counties). The formation usually has huge thickness, varying from 865 to 4000 m.
GeoJSON
Fossils
The slate of the Gaotan Formation yields inarticulate brachiopods Achrothele chinensis, A. chinchiensis, A. rara, Homotreta lisani, H. shangtungensis, H. orientalis, H. pacifica, Lingullela sp., Obolus luanhsiensis, Palaeobolus discus, and Paterina sp.; and sponge spicule Protospongia sp.
Age
Depositional setting
This formation comprises a suite of flysch deposits of continent-marginal sea-basin setting.
Additional Information