Style and process of the superimposed mineralization in the Sanjiang Tethys
三江特提斯叠加成矿作用样式及过程

The Sanjiang area in China has experienced the multi-episodes of ocean-continent subductions in the Tethys Period and the continent-continent collision in Cenozoic; various ore deposits formed in the ocean growth and subduction environment, and they are also situated in the transition time from the main collision to late collision stages, the Cenozoic collision induce the formation of the porphyry copper-gold belt, the lead-zinc deposits hosed in sedimentary rocks as well as the orogenic belt. The multiple episodes of metallogenesis located in the different time and tectonic background occurred in one orefield or ore deposit, causing various types of superposed deposits. These deposits can be categorized into three types and further into nine subtypes, that is: (Type 1) superposition of magmatic hydrothermal deposit on the previous VMS deposit, including subtype of Himalayan hydrothermal superposing on the Hercynian-Yanshanian VMS deposit, represented by Laochang Pb-Zn-Mo deposit and Luchun Cu-Pb-Zn deposit, that of Indosinian-Yanshanian hydrothermal upon the Hercynian VMS deposit, e.g., Yangla deposit; (Type 2) superposition of magmatic hydrothermal deposit on the previous sedimentary deposit, comprising the subtype of Himalayan hydrothermal superposing on the primary Yanshanian metal-enriched strata, such as Baoyangping Cu-Pb-Zn deposit, that of the Himalayan sedimentary Ge-bearing hydrothermal absorbed by the Miocene coal seam (Dazhai and Zhongzhai Ge deposit), and that of the Yanshanian hydrothermal superposing the Caledonian metamorphic Fe-bearing horizon (Fenshuiling Fe-Cu deposit); (Type 3) superposition of between multiple episodes of magmatic hydrothermal deposit, for instance between Himalayan hydrothermal and the Indosinian one (Laowangzhai gold deposit), between the Yanshanian upon the Indosinian (Pulang-Hongshan Cu deposit) and between the different Himalayan hydrothermal (Jinman Cu deposit). The superstition increased the metal types, reserve quantity, economic value of the deposits, yet it was mainly supported by chronological data and general phenomena in deposit and orefield scale, the detailed formation conditions, spatial orebodies and ore structure and the geochemical and mineralogical evidences are still necessary for further study.