Metallogenic Dynamics of Zhashui Ag-Pb Polymetallic Ore Deposit in Shaanxi, China

摘要

Zhashui Ag-Pb polymetallic ore deposit is located in northern Qinling geosyncline. In this paper, its geological features and metallogenic background are introduced. The volcanic dynamics, physical-chemical conditions of metallogeny and ore-forming experimental simulation are discussed in detail. Based on the existence of paleovolcanic activity, the protolith characters and geochemistry of ore-bearing rock series, the authors study the law of volcanic activity in Middle Devonian period. The physical-chemical conditions of metallogeny, including temperature, pressure, pH and Eh of mineralizing solution, are also determined. The evolution of salinity, f(O_2). pH, M (H_2S), M(SO_4~(2-)) (M is mole fraction of certain component), t (temperature) and a (ionic activity) of mineralizing solution suggests that the mineralization was a long-term dynamic process. Finally , the metallogenic pattern is established.