Zuogong Fm
Type Locality and Naming
In 1983, Chen Bingwei and Ai Changxing measured the section at Dongda Village, Zuogong County, Tibet. In 1985, Zou Chengjing and Han Zizhang built a Zuogong Fm based on the section.
Synonym: Chengdu Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, and District Investigation Group of Sichuan Bureau of Geology and Mineral Resources (1992) named the Early Late Triassic Norian strata in the area of Zuogong as Jiapira Fm, and compared it with the upper part of the Late Triassic Norian strata in the area of Tuba, which was from the Late Triassic Carnian to the Early Norian.
Lithology and Thickness
Lower clastic member consists of purplish red conglomerate, gray-white quartz sandstone with thin layer marl, calcareous mudstone and reef limestone. Middle limestone member is composed of gray limestone, argillaceous limestone and intermediate basic volcanic interlayer. Upper clastic member is interbedded with lime-black sand shale with a little limestone and coastal coal seam. Its thickness is greater than 1100 m.
Relationships and Distribution
Lower contact
The bottom boundary is marked by the initial occurrence of purplish red conglomerate above the pseudo-conformity surface, which is the pseudo-conformity contact with the underlying Middle Triassic Dongdacun Fm
Upper contact
The top boundary is marked by the final occurrence of grayish-black sand and shale
Regional extent
GeoJSON
Fossils
Montivaltia sp., Thecosmilia sp., Monotis cf. salinaria, Cardita cf. shombodes
Age
Depositional setting
Additional Information