PCA-KM联合分析方法在鹿井地区综合放射性异常识别中的应用

Application of PCA-KM Joint Analysis Method in Comprehensive Radioactive Anomaly Identification in Lujing Area

鹿井地区是我国重要的花岗岩型铀矿基地,相关研究表明该地区仍然存在很大的找矿前景。文章以鹿井东部地区为例,采用地面伽马能谱、地气、天然土壤热释光和土壤210Po等联合测量方法进行铀矿找矿勘查,运用PCA-KM联合分析方法进行综合异常识别,并结合地质资料对区内综合异常的分布特征、控制因素展开研究。结果表明,PCA-KM提取的综合异常可以有效反映已知铀矿化分布,降低综合解释多解性,能够将深部铀矿化、浅部铀矿化以及碱交代作用导致的放射性异常进行分离。区内综合异常与断裂构造、地层接触带以及碱交代作用关系密切;经综合分析,最终圈定了界坑东南部、黄峰岭东部、蛇坑东南部、鹿井-金鸡岭一带为成矿有利区。

Lujing area is a famous granite-type uranium base in China.Relevant studies show that there is still a great prospecting prospect.In this paper,eastern Lujing uranium ore field was studied with the combined measurement methods of ground gamma-ray spectrometry,geogas,natural soil thermoluminescence and soil 210Po for the uranium ore prospecting and exploration,PCA-KM combined analysis method was used to identify the comprehensive anomalies,and the distribution characteristics and control factors of comprehensive anomalies were analyzed by combining the geological data.The results showed that the comprehensive anomaly extracted by PCA-KM can effectively reflect the distribution of known uranium mineralization,reduce the ambiguity of comprehensive interpretation,and separate the radioactive anomalies caused by deep uranium mineralization,shallow uranium mineralization and alkali metasomatism.The comprehensive anomalies in the area are mainly related to fault structure,stratigraphic contact zone and alkali metasomatism.The southeast of Jiekeng,the east of Huangfengling,the southeast of Shekeng and Lujing-Jinjiling area were finally delineated as favorable metallogenic prospects.