Abstract:

Locating in the center of the Jiamusi block，the Shuanyashan gold mine is a typical skarn deposit．Geologic data from exploration and mining demonstrated that the distribution of deposit bodies is strongly controlled by skamization and fracturing．Gold—content analyses of the country rocks indicated that the gold element resourced from migmatization of basic—andesitic volcanic rocks．The migmatic fluid，which contained higher Au—complex—compound，flows along fractures or bedding faces．When contacted with carbonatite，skarnization occulted decreasing the pH value of
the Au—bearing fluid，leading the gold depositing from the Au—complex．The major Au—bearing mineral is Al~enopyrite(FeAsS)with minor other sulfides，suggesting the complex anion of the Au—complex may be[AsS3]．

Key words: Skarn, Gold deposit, Migmatic fluid, As—S complex anion, Jiamusi block．