黑龙江宝兴沟金矿床构造叠加晕特征及深部预测

Characteristics of Superimposed Structural Haloes and Deep-Seated Ore Prediction in the Baoxinggou Gold Deposit of Heilongjiang Province

宝兴沟矿区位于黑龙江省塔河县,2002年由1∶10万水系沉积物测量异常圈定,2007年通过1∶1万和1∶2万土壤测量进一步圈定了异常范围,并利用槽探工程进行揭露,首次发现了Au矿体,矿体主要为蚀变砂岩、蚀变闪长岩、蚀变闪长玢岩等,少量为含金石英脉,以中-低温蚀变为主。本文在充分收集矿区已有资料的基础上,结合矿区最新的钻孔采样数据,对矿床地球化学特征进行了研究;分析了矿床构造叠加晕分布特征,矿床前缘晕特征指示元素为Sb、As,近矿晕特征指示元素为Pb、Ag、Au、Zn、Cu,尾晕特征指示元素为W、Mo、Bi,初步确定了宝兴沟金矿床串珠状矿体、不同深部矿体组合的构造叠加晕模式;并依据已知矿体及矿床构造叠加晕,对深部有利成矿部位进行了预测,指出I-1-1号矿体向下应有很大的延伸或I-1-3号矿体深部应有盲矿存在,I-2-1号矿体深部可能有盲矿体存在。

Baoxinggou gold deposit is located in Tahe county Heilongjiang Province,and was originally delineated through 1： 100000 stream sediment survey in 2002,the first ore-body was discovered by 1 ∶ 10000 and 1 ∶ 20000 soil survey and the subsequent trenching in 2007. The ore-bodies are mainly made up by altered sandstones,altered diorites and altered dioritic porphytites,secondly by quartz veins,the alteration of rocks took place at middle-low temperatures. This work collected geological and latest drilling sampling data of the Baoxinggou gold deposit to study its geochemical characteristics and analyze superimposed structural haloes. The results show that front haloes are indicated by elements Sb and As,near-ore haloes by Pb,Ag,Au,Zn,and Cu,and tail haloes by W,Mo,and Bi,respectively. A model was established to characterize these superimposed haloes,by which this work predicted deep-seated orebodies in the deposit. It suggested that the I-1-1 orebody may have a greater downward extension or there may exist blind ore-bodies below the I-1-3 and I-2-1 orebodies,respectively.