Lungwangmiao Fm
Type Locality and Naming
The type section of the Lungwangmiao Formation, the Lungwangmiao section, is located on the northwest shore of Dianchi Lake, at the foot of the Xishan (West Hills). The section lies about 14 km southwest of Kunming, or about 23 km northwest of the seat of Kunming City (in Chengong District) (102°38’E, 24°56’N) and was measured by Lu (1941). The Lungwangmiao Formation is incomplete exposed in the type section due to disconformable contact with overlying Devonian Haikou Formation. In the type section, the Lungwangmiao Formation is 181.6 m (the thickness of beds 23‒49 of Lu’s 1941 section). The Lungwangmiao Formation was named by Lu (1941). The name is derived from Lungwangmiao (spelled Longwangmiao in Hanyu Pinyin) Temple in Xishan District, Kunming City, eastern Yunnan Province. Afterwards, this unit was adopted as a Chinese standard Cambrian chronostratigraphic unit, the Lungwangmiaoan Stage (Xiang et al., 1981; Zhang, 1985; Compiling Committee for Chinese Stratigraphic Lexicon et al., 1999), and had been used for a long time until a new four-fold chronostratigraphic subdivision was introduced (Peng, 2000a, b).
Synonym: （龙王庙组）; In central Sichuan Province the formation is also called the Shihlungtong Fm (Gu and Liu, 1997),
Lithology and Thickness
The Lungwangmiao Formation is basically a carbonate sequence, consisting of grey to dark grey, medium- to thick-bedded limestone, argillaceous limestone, dolomitic limestone and argillaceous dolomite, intercalated with minor sandy shale. In central Sichuan Province the formation, which is also called the Shihlungtong Fm (Gu and Liu, 1997), is dominated by grey to dark grey, thin- to medium-bedded dolomite and dolomitic limestone with minor interbeds of sandy mudstone, gypsum or halite.
Relationships and Distribution
Lower contact
The Lungwangmiao Fm rests conformably on the underlying Tsanglangpu Fm. Its lower boundary is defined by the appearance of limestone at its base.
Upper contact
It is overlain either conformably by the Toupossu Fm or disconformably by Devonian Haikou Fm. The upper boundary, as revealed by other sections in eastern Yunnan, is defined by the appearance of sandstone, shale or marlstone of the Toupossu Fm.
Regional extent
The Lungwangmiao Formation is exposed in the western part of Yangtze Area of South China Region, distributed widely in eastern and northeastern Yunnan and central Sichuan Province. In Yunnan, the formation is completely exposed in the areas to east and north of Kunming, with thickness ranging between 161 and 206 m, and decreases thickness westward with no deposit of top part of the formation in Xishan area. In Sichuan, the formation is usually about 100 m thick.
GeoJSON
Fossils
The Lungwangmiao Formation is poorly fossiliferous, yielding trilobites Redlichia murakamii, R. nobilis, R. sinensis, Antagmus mernus, Eoptychoparia yunnanensis, Hoffetella elongata, Poulsenia shenjiayinensis, and Xiaomajiella planimaginis; brachiopod Kutorgina cingulata; bradoiid Houlongdongella sp.; and hyolithid Allatheca sp.
Age
Depositional setting
The formation represents mainly deposits in a more or less enclosed subtidal flat environment.
Additional Information