Wanquansi Ag-(Au-Pb-Zn-Cu) deposit, Chicheng Co., Zhangjiakou Prefecture, Hebei Province, China

Polymetallic volcanic-hosted metasomatite, consisting of veins and lensoid orebodies occurring in faults and fracture zones of andesite, trachyandensite and diorite of the Middle Jurassic Houcheng Formation and the Late Jurassic Baiqi Formation. The minerals have xenomorphic granular, metasomatic relics, detachment of solid solution and fracture textures; they occur as veinlets, disseminations, breccia and colloidal formations. Alteration is planar or linear. Planar alteration consists of central sericite, silica, pyrite and kaolinite alteration and by lateral (marginal) prophylitization. No economic veins occur in the altered area except some limonite and quartz veinlets. Linear alteration occurs along faults and in the host rock adjacent to the deposit and is closely related to deposit formation.

Ref.:
- http://wrgis.wr.usgs.gov/open-file/of03-220/DATABASE/lode_deposits.txt