新疆吉拉拜金矿床地质特征及成因

吉拉拜金矿位于新疆布尔津县北约 40km处的哈巴河黑云母斜长花岗岩体内北西向断裂带中 ,研究表明该金矿为石英脉型金矿 ,稀土元素研究表明 ,矿化蚀变岩石与黑云母斜长花岗岩具有相似的变化特征 ,流体包裹体均一测温表明成矿温度为 12 0～ 36 0℃ ,有两个峰值 ,一个峰值位于 2 70～ 30 0℃范围 ,另一峰值位于 15 0～ 2 30℃范围内 ,表明岩浆期后热液和断裂活动对成矿均起作用。含金脉石英的氢氧同位素组成研究表明 ,矿化早阶段 ,成矿热液中以变质热液及岩浆热液为主 ,随着矿化作用的后移 ,成矿溶液中自然会加入越来越多的大气降水 ,导致其氢氧同位素组成向大气降水线方向漂移。研究结果显示 ,哈巴河岩体为该金矿提供成矿物质 ,成矿流体是由哈巴河岩体的岩浆期后热液、动力变质热液及大气降水共同组成 ,北西向断裂带是这些成矿热液的运移通道。该北西向断裂带为逆冲压扭性质。该逆冲压扭断裂中的局部弱应力部位是成矿物质有利的沉淀富集场所。吉拉拜金矿床含金石英脉就是沿北西向逆冲压扭性断层中局部张性部位产出。哈巴河岩体中北西向断裂带及其中的石英脉都很发育 ,具有很好的找矿前景

Geological characteristics and genesis of the Jilabai gold deposit in Altay, Xinjiang

The Jilabai gold deposit is located in the NW stretch fault of Habahe biotite granite body. Based on the study analyses, the gold deposit is regarded as the one of quartz vein types. The chara cteristic of H-O isotope and the rare earth elements shows that the ore-formin g materials mainly came from the Habahe biotite granite, and the part from the metamorphic rocks such as amphibole-schist. The projection points of δD 、 δOH2O inδD～δO H2O drawing between lines of ma gma water, metam orphic water and atmospheric water show that the ore-forming fluids were compo sed of magma-late hydrothermalism, dynamometamorphic hydrothermalism and meteoric water. The study of rare earth elements display that the metallogenesic and non - metallogenesic rocks show the same characteristics of curve. The average temper ature of fluid inclusion shows that the mineralization temperature is about 120 ℃～360℃ and there are 2 peak values of 270～300℃ and 150～230℃. The NW faul tis the path of the ore-forming hydrothermalism.