Jianmenguan Fm
Type Locality and Naming
Sichuan Basin – north and NW. Hou Defeng and Wang Xianxing erected the Jianmenguan conglomerate in 1939. The type locality for the designation is in Jianmenguan of Jiange county of Sichuan. The reference section is in Jianmenguan of the Jiange County. Lower-middle formation in the Chengqiangyan Gr in northern Sichuan Basin.
Lithology and Thickness
The Jianmenguan Formation is composed of purple red massive quartz conglomerate, purple red sandstone, siltstone and mudstone. It is 542.4 m thick.
Synonym: Jianmenguan Fm.
Relationships and Distribution
Lower contact
Its base marked by the occurrence of massive conglomerate is distinguished from brick-red sandy mudstone of the Lianhuakou Fm. The contact is conformable.
Upper contact
its top is bounded by the appearance of light purple red thick-bedded conglomerate at the base of the Hanyangpu Fm. The contact is conformable.
Regional extent
The formation occurs on the northwest margin of the Sichuan basin. It varies considerably both in lithology and thickness. The basal conglomerate is 240 m thick in Niuxinkou, 200 m in Jianmenguan in Ximiao of Jiange of the west Sichuan basin and thins out eastward to Xinchang, and changes in facies to sandy mudstone with gravel-bearing sandstone around Jijiapo of Qinglinkou of Jiangyou. The formation is the thickest in Jianmenguan.
GeoJSON
Fossils
None listed
Age
Depositional setting
It belongs to piedmont alluvial fan deposition.
Additional Information