地物化综合找矿方法在新疆阿尔泰卡鲁安锂辉石矿床中的应用

Application of the Integrated Geological,Geophysical and Geochemical Ore-Search Method to the Kalu an Spodumene Deposit,Altay,Xinjiang

卡鲁安锂辉石矿床位于新疆阿尔泰哈龙-青河稀有金属矿带、柯鲁木特-吉得克伟晶岩矿集区,赋存于中-上志留统库鲁木提群(红柱石、矽线石、堇青石、十字石)黑云母石英片岩中,以650号、807号、806号矿体规模最大,矿体主要有用组分为锂,锂资源量已达大型规模。在矿区内测制的5条土壤(植物)地球化学剖面表明,Li-Nb-Ta-Bi-Cs-Hf异常与伟晶岩脉的套合性好,植物化探显示的局部异常优于土壤化探。矿区岩矿石之间存在较明显的电阻率差异,矿体表现的异常特征是中高电阻率、高极化率,是本次音频大地电磁测深(AMT)工作的物性前提。施工的4条AMT剖面表明,AMT测量对卡鲁安矿区构造、伟晶岩脉的延伸、深部盲脉或覆盖区伟晶岩脉的预测有一定的指示作用,尤其是对已有矿体深部成矿预测效果较好。采用地球化学测量和遥感蚀变信息圈定异常区,通过地质填图、路线调查寻找矿体(脉),物化探剖面测量定位或寻找矿脉、电阻率法预测延深、槽探揭露圈定矿(脉)体和深部工程验证估算资源量等伟晶岩型锂、稀有金属矿综合勘查技术方法体系是新疆稀有金属找矿勘查工作的有效手段,在卡鲁安地区锂找矿工作中应用效果显著,不仅为进一步找矿突破提供技术支持,也对类似矿床的找矿工作具有一定的借鉴意义。

The Kalu an spodumene deposit lies in the Kelumute-Jideke pegmatite ore district,the Halong-Qinghe rare metal metallogenetic belt in Altay,Xinjiang.It is hosted in the(andalusite,sillimanite,cordierite,grenatite)biotite-quartz schist of the Middle-Upper Silurian Kulumuti Group.The No.650,807 and 806 orebodies are the largest in size,with the main useful component of the orebodies as lithium,the resource of which has reached a large scale.The five soil(plant)geochemical profiles measured in the mining area indicate that Li-Nb-Ta-Bi-Cs-Hf anomalies are well integrated with the pegmatite veins,and the local anomalies shown by plant geochemical exploration are superior to those of the soil geochemical exploration.There is a significant difference in resistivity among the ores and rocks,and the anomaly characteristic of the orebodies is expressed by medium to high resistivity and high polarizability,which is the physical premise of audio-frequency magnetotelluric survey.The four audio-frequency magnetotelluric profiles show that the AMT measurement is an indicator for the prediction of the structure,extension of the pegmatite veins,deep blind veins or the pegmatite veins in the covered areas of the Kalu an mining area,especially for the deep parts of the existing orebodies.This work demonstrates that an integrated ore-search method system is effective,which comprises geochemical survey and remote sensing derived alteration information and can be used to delineate the anomalous areas,geological mapping and route survey to find orebodies(veins),geophysical and geochemical(vegetation)profile measurements to locate or find ore veins,resistivity method to predict the extension of ore veins,trench exposure,deep engineering verification and estimation of resources,as evidenced by exploration of pegmatite-type lithium and rare metal deposits in Xinjiang.It provides technical support to further breakthrough in exploration and sheds light on prospecting in other similar deposits.