Abstract:

Based on comparison of geological features of the copper and gold deposits related to Emeishan basalt, combining with isotopic geochronologies from individual deposit done by predecessors, the authors established a spatial-temporal framework and a metallogenic model for these deposits. It was shown that the Emeishan basalts erupted and upwelled because of mantle uplifting during Late Caledonian to Early Hercynian. They carried significant Cu and Au, which not only formed Cu-Au mineralization in basalts and tuffs, but also provided important source for post-volcanism stratabound Cu-Au deposits. Copper and gold leached by hydrothermal fluids in the volcanic protores would migrate along faults and fractures, which were driven by structural-thermal driven effects in Indosinian and Yanshanian. They would subsequently precipitate in favorable locations where were abrupt changes of structure and chemical potential. Cu and Au enriched in it, and finally ore bodies formed.

Key words: copper deposit, gold deposit, Emeishan basalt, the border area between Yunnan and , Guizhou