常规次生晕法在广西资源县云头界钨钼矿找矿中的成果及意义

Result of applying routine secondary halo method to tungsten-molybdenum prospecting work in Yuntoujie area of Ziyuan County, Guangxi, and its significance

广西资源县云头界钨矿异常区多被表土覆盖,局部出露钨矿化。据钨重砂矿物化学性质较稳定,风化剥蚀后迁移距离较近,而异常区表土覆盖不厚的特点,采用次生晕化探方法对云头界钨矿异常区1.4km2开展化探扫面找矿。根据8条化探剖面线共575个样品分析结果,圈出了6个钨异常区,在其中4个钨异常区施工槽探工程,都发现对应的石英脉型钨矿体。这揭示了该区矿体与次生晕异常的分布具有非常一致的对应关系。次生晕化探异常表明,该矿主矿脉沿走向长度超过1km,矿床规模可望达到中型。常规次生晕法在云头界钨矿异常区找矿效果明显,这对华南风化土层覆盖区钨矿找矿工作有重要的启示。

The tungsten anomaly area in the Yuntoujie is mostly covered by surface soil 1～3 m in thickness, and hence tungsten mineralization can only be seen locally. It is well known that tungsten minerals cannot not be transported far away from their original localities during later weathering and denudation. In view of such a feature of tungsten minerals and on account of the fact that the tungsten anomaly area is covered by relatively thin layer of surface soil, the authors used the secondary halo method to locate blind tungsten ore bodies in an area of 1.4 km^2 in Yuntoujie. W, Cu, Pb, Ag, and Zn in 575 samples from eight geochemical prospecting lines were analyzed. According to the concentrations of trace elements, six secondary halo anomaly districts of tungsten were delineated, and four of them have been proved to accord with tungsten vein mineralization, suggesting that the delineated secondary geochemical anomalies of tungsten in the Yuntoujie area are caused by tungsten mineralization beneath the surface soil. On such a basis together with trenching and pitting observation, the authors hold that the main ore vein is more than 1 km in length along its strike and that the Yuntoujie W-Mo deposit is likely to reach middle to large size in tungsten reserves. The successful locating of blind ore bodies by secondary geochemical halo method in the Yuntoujie area suggests that the secondary halo anomaly method is effective and can be employed in search for tungsten bodies in surface soil covered areas in south China.