Facts and problems of the evaluation of regional geochemical anomalies

Abstract：Regional geochemical anomaly evaluation is a major problem which exploration geochemistry has faced for a long time. Now, there are mainly eight conventional methods for evaluation, such as the geological-tectonic unit evaluation method and multi-elements quantifying evaluation index method. By using these anomaly evaluation methods, we fail to have a good understanding of the superficial appearance and essence from the development and evolution of the petrogenetic and metallogenic system, and the constraining of anomalies by supergene factors, genetic mechanism of anomalies and geological-geochemical environment produced by anomalies are less studied and only the information of the anomaly itself is extracted and used. Therefore, the study of the phase states of occurrence and relative proportions of ore-forming and mineralized indicator elements in different media of the primary and supergene zones, summing-up of the characteristics of element migration, accumulation and dispersion in different environments, analysis of the genetic mechanism of supergene anomalies on that basis, systematic anatomy of various internal and external factors controlling anomaly development and further selection of indices for regional anomaly evaluation and establishment of a combined qualitative and quantitative regional anomaly evaluation index system are a new concept for evaluating regional geochemical anomalies.