Jingjingzigou Fm
(6), early-Early Permian
Type Locality and Naming
The type section is located at Jingjingzi trench to the southeast of Urumqi City, Xinjiang, with its reference section being situated at Yushugou trench to the southeast of Urumqi City. It was named by the Regional Geological Survey Party under the Geological Bureau of Xinjiang.
Lithology and Thickness
Volcaniclastics and Clastics. The lower and middle parts of the formation represent uneven interbeds of blue-grey and grey-green tuffaceous sandstones, thick-bedded dense tuffs and yellow-grey and black-grey clayey rocks, while the upper part of the formation consists of dark-grey siltstone, sandy shale, siltstone and fine-grained sandstone. Thickness is 1500 m.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Wulabo Fm.
Upper contact
Conformable contact with the overlying Lucaogou Fm.
Regional extent
Distributed on the northern slope of the Bogeda Mt., and with its exposures being found to occur in the areas of Dongshan Mt., Jingjingzigou and Shirengou, extending easterly to Sangonghe, Ganhezi and Dalongkou. The degree of the development of tuffs varies from place to place. The thickness of the formation is reducing to be of about 300 m to the east of the Ganhezi area.
GeoJSON
Fossils
Spore-pollen fossils as represented by the Hamiopollenites-Striatobatieites-Striatoparvisaccites assemblage; Plant fossils (phytolites) as represented by Calamites sp. and Cordaites sp.; and Ostracoda as represented by Darwinula monitoria, etc.
Age
Depositional setting
It is interpreted as littoral- and delta-facies deposits.
Additional Information