[Objective]The correct processing and interpretation of geochemical exploration data are critical for re-gional mineral exploration.High backgrounds may be misjudged as anomalies or low and weak geochemical anoma-lies may be ignored,if a unified anomaly threshold is adopted for geochemical exploration data in lithologically com-plex regions due to different elemental abundances in different lithologies.Therefore,it is essential to identify geo-chemical backgrounds and anomalies in lithologically complex regions based on lithologic classification.[Meth-ods]Here,we propose a method for delineating geochemical anomalies based on a Gaussian mixture model of fac-tor scores.The geochemical exploration data are subjected to factor analysis after a log-ratio transformation,and then the lithologic classification is completed by the Gaussian mixture model with factor scores.Subsequently,the standardization is performed to eliminate the lithologic background,and geochemical exploration anomalies are de-lineated with the processed data.This method is used to the geochemical exploration data of 1:200 000 stream sediments in Xupu,Hunan Province.[Results]The results show that the contents of the metallogenic elements in various lithologies of the study area are partly different,and consequently,it would be unreasonable to adopt a uni-form anomaly threshold.In contrast,the method advanced in this paper can accurately classify lithology,eliminate the background of different lithologies,and enhance low and weak anomalies,with the location of the anomalies corresponding to known deposits.[Conclusion]Hence,the Gaussian mixture model enables effective delineation of geochemical exploration anomalies in lithologically complex regions and provides certain information for further mineral prospecting in this region.
关键词
水系沉积物/岩性背景/化探异常/因子分析/高斯混合模型/湖南溆浦
Key words
stream sediments/lithologic background/geochemical exploration anomaly/factor analysis/Gaussian mixture model/Xupu,Hunan Province
维普
万方数据