卡鲁安伟晶岩锂矿的地气场特征及找矿意义

在伟晶岩锂矿勘查中,为了解决常规物探方法由于矿体与围岩差异不显著、应用效果不佳、化探法对隐伏锂矿效果不明显的问题,以新疆卡鲁安伟晶岩锂矿为研究区,布设了两条总长6 605 m的地气研究剖面,完成了191个测点的国内外首例地气测量勘查伟晶岩锂矿研究工作,每个测点获得Li、Rb、Be、Cs、Nb、Y等39种元素的含量,据此研究了卡鲁安研究区伟晶岩锂矿的地气异常特征。结果表明,在伟晶岩锂矿脉的倾斜方向一侧,均能捕获包含Li、Rb、Be、Cs、Nb、Y等多种元素的显著地气异常;在无矿(化)伟晶岩上方,Rb元素的地气异常幅度会增大,其它元素异常幅度则明显变小,Be不出现地气异常;其它岩性上方,没有地气异常出现。研究证实了地气法对寻找伟晶岩锂矿是准确、有效的,对在伟晶岩锂矿勘查中应用地气法找矿提供了理论参考和技术支持。

Geogas field characteristics of the Kalu'an pegmatite lithium deposit and its prospecting significance

In conventional geophysical exploration method for pegmatite lithium mineral exploration, there exist the problems that the difference between the orebody and the surrounding rock is not significant, the application effect is poor, and the geochemical exploration method has no obvious effect on the concealed lithium deposit. In view of such a situation, the authors investigated the technical problems related to the application of geogas method in the exploration of pegmatite lithium deposits. With Kalu''an in Xinjiang as the study area, the authors deployed two geogas research sections with a total length of 6 605 m, and completed the case study of pegmatite lithium deposits with 191 measuring points, which was performed for the first time both in China and abroad. The values of 39 elements such as Li, Rb, Be, Cs, Nb, and Y were determined. On such a basis, the characteristics of geogas anomalies in the Kaluan pegmatite lithium deposit were studied. The results show that significant gas anomalies containing Li, Rb, Be, Cs, Nb, Y, and other elements can be captured on the tilted side of the pegmatite lithium veins, that, above the barren pegmatite, the abnormal amplitude of geogas in Rb element will increase, and the anomaly amplitude of other elements will obviously decrease, with no gas anomaly, and that, in other lithologies, there is no abnormal geogas. It is confirmed that the geogas method is accurate and effective in the search for pegmatite lithium deposits.