Xiaozijing Fm
Type Locality and Naming
The type section of the Xiaozijing Formation is the Xiaozijing-Xinwuchang section (112°05’E，25°23’N). The Xiaozijing and Xinwuchang villages are administrated the by Ninyuan and Lanshan counties respectively. The section was measured by the Hunan Regional Geological Survey Team in 1965. The Xiaozijing Formation was first published by Zhang (1997). The name is derived from the Xiaozijing at Zijing Township, Ninyuan County, Yongzhou City, southwestern Hunan Province. The name was originally appeared in a 1988 manuscript by Luo Haiyan and Huang Weipei from Hunan Regional Geological Survey Team.
Synonym: （小紫荆组）
Lithology and Thickness
The Xiaozijing Formation is an epi-metamorphic clastic and carbonate sequence. It consists epi-metamorphic sandstone and slate mainly, intercalated with several limestone and marl interbeds and with a dolomite bed at base, and a muddy limestone at top. The thickness of carbonate interbeds is several meters or a little more than ten meters. In the type section, the formation is 1058.3 m thick.
Relationships and Distribution
Lower contact
The Xiaozijing Fm rests conformably on the Chayuantou Fm.
Upper contact
It is conformably overlain by the epimetamorphic clasctic Jueshangou Fm.
Regional extent
The Xiaozijing Formation is widely exposed in the far southern Hunan Province. In the exposed areas the thickness of formation varies from 650 to 1058.3 m.
GeoJSON
Fossils
The only known fossil from the Xiaozijing Formation is sponge spicules Protospongia sp.
Age
Depositional setting
Additional Information