Abstract:

The genetic types of Au-(Ag)-Te-Se metallogenic systems can be classified according to the characteristics of occurrence and degrees of tellurium and selenium enrichment in gold deposits as (1) epithermal Au-Ag deposits, (2) orogenic gold deposits, (3) Carlin and Carlinlike gold deposits, (4) alkaline and subalkaline intrusionrelated gold deposits, (5) Cu-Au porphyry deposits, (6) Cu-Au skarn deposits, and (7) goldpolymetallic volcanogenic massive sulphide (VMS) deposits. Tellurium and selenium preferentially partition in the mantle while intrusive and volcanic rocks are important sources of Te and Se in the Au-(Ag)-Te-Se metallogenic system. Moreover, black rock series are important sources of Se, whilst temperature, pH and oxygen fugacity are important controllers of TeSe transport and enrichment. The oreforming mechanisms of the Au-(Ag)-Te-Se metallogenic systems are closely related to magmatic degassing, fluidmelt separation, waterrock interactions, fluid boiling and mixing, and organic processes. Among them, magmatic degassing, fluidmelt separation, fluid boiling and mixing are important mechanisms in the formation of telluriderich gold deposits, while waterrock interactions, fluid mixing and organic processes are important mechanisms in the formation of seleniderich gold deposits. During ore formation, some metastable or unstable minerals precipitated in early stages usually experience solid solution separation, and minerals in contact with unsaturated fluids often trigger coupled dissolutionreprecipitation reactions; both processes result in the formation of various mineral assemblages and ore textures.

Key words:  gold deposit, Au-(Ag)-Te-Se metallogenic system, genetic types of deposits, metallogenesis