西天山博故图金矿床地质特征和找矿预测

Geological Characteristics and Ore Prediction of Bogutu Gold Deposit in Western Tianshan

博故图金矿床位于西天山石炭纪—二叠纪裂谷带中,其矿体赋存于构造破碎带内的大哈拉军山组火山碎屑岩、石英钠长斑岩及辉绿岩中。矿体受东西向基底断裂和北西向次级张扭性断裂带控制,对围岩没有选择性。与金矿化紧密相关的蚀变类型为硅化、黄铁矿化、毒砂矿化、泥化、绿泥石化。依据火试金分析结果圈定金矿体42条,矿体长45~1050 m,斜深34~670 m,平均厚度1.31~9.49 m,最大35.2 m,平均品位1.2~3.46×10-6,最高品位40×10-6,矿床平均品位2.01×10-6,金资源量(控制+探明+推测)达大型,矿床类型为浅成低温热液型金矿。金矿带上发育金、砷、银、钼等元素异常,矿体位于激电高极化率异常梯度带上,物、化探综合勘查成果显示Ⅰ号金矿带及其外围仍有很大找金潜力。

The Bogutu gold deposit is located in a Carboniferous-Permian rift zone,the West Tian Shan of Xinjiang,with orebodies occuring in quartz albite porphyry,Dahalajunshan Formation volcanic clastic rock and diabase within a fracture zone. The ore bodies are controlled by EW trending basement faults and secondary transextensionnal faults without dominant hosting rock. The alteration types closely related to gold mineralzation include silicification,pyritization,arsenopyritization,argillation,and chloritization. Totally 42 gold orebodies are delineated by fire assay results,which are 45- 1050 m long,inclined deep 34- 670 m,with average thickness 1. 44- 35. 2 m,average grade 1. 2- 3. 46 × 10- 6,largest grade 40 × 10- 6,and average grade 2. 01 ×10- 6. The gold reserves and resource( proven + indicated + inferred) of this deposit approach to a large scale( Au > 20 t). It is an epithermal gold deposit,where Au,As,and Mo anomalies are present within the gold mineralization zone,and gold orebodies occur in the gradient belts of high chargeability IP anomalies. The results of comprehensive geochemical- geophysical surveys show that the ore zone No. I and its surroundings have a great potential of gold resources.