The isotope geochemical characteristics of the precambrian iron-bearing formation gold deposit in Dongfengshan, Heilongjiang Province

Dongfengshan gold deposit is occurred in hornstone of Dongfengshan group under iron-bearing stratum. Ore-bearing stratum contain richly pyrrhotite, pyrite, spessartine and dannemorite. Additionally, there are smaller arsenopyrite and cobaltite. The δ34S values of pyrrhotite and pyrite are -1.54%∼0.98% and -0.27%∼0.61%, respectively. Sulfur of sulfide occurrence mainly from plutonic source. The δ18O values of different rocks and minerals show following: marble 1.31%∼2.39%, magnetite 0.41%∼1.05%, quarts 1.37%∼2.09%, grunerite 1.09%∼1.68%, garnet 0.99%∼1.75%. These δ18O values reflect thermal contact metamorphic character of gold deposit. The δ18O values of the Paleozoic granite obviously are of two groups: one is terrene granite in southern ore area, its δ18O values are 0.87%∼1.14%; the other is drill hole plutonic granite in northern ore area, its δ18O values are 0.05%∼0.11%. The granite from drill hole was strongly sericitized. Dongfengshan group was formed in early Proterozoic. Dongfengshan gold deposit is a high temperature thermal contact metamorphic syngenetic deposit