胶东地区地幔捕虏体中黄铁矿含金性及其意义

Study on the gold abundances of pyrites within mantle xenoliths and its significance in Jiaodong peninsula

胶东新生代玄武岩中地幔捕虏体内所发现的硫化物主要为黄铁矿,以两种状态产出,即橄榄石晶粒中的黄铁矿包裹体和橄榄石晶隙中的黄铁矿,此二者成分相当,具有继承性特点。经分析,黄铁矿的金含量很高,比其它地区同类地幔捕虏体中硫化物金含量高十几倍,相当于地壳金丰度值的数十万倍。硫化物中的金比硅酸盐中的金具有强得多的活化能力,因此上地幔中的金易于为上升的幔源C-H-O流体所携带上升至地壳参与成矿作用,从而控制着胶东金矿集中区内金矿的形成与分布。

Most of sulfide found in mantle xenoliths in Jiaodong peninsula is pyrite,which appears in two forms,i, e., disseminated fine inclusions in olivine and filled between olivine grains, The pyrites have similar component, and show the features of inheritance. Electronic microprobe analysis suggests that the pyrites have high gold abundance. It is implied that mantle gold in Jiaodong, being easily activated due to its presence in pyrites, can provide much gold for gold mineralization in the area. And mantle-derived C - H- O fluids could be the main agent transporting gold from mantle to the crust.