Geochemical gene: A promising concept in discrimination and traceability of geological materials

Geochemical gene is a new technique presented recently and its history is described and classified into three stages up to the present. To construct a geochemical gene, five steps are suggested as selection of elements, determination of reference values, spectral line and codes, calculation of similarity, and sequence of elements. The essence of the geochemical gene is similar to the quantitative description of the spider diagram or REE pattern regardless of the compositional closure effect. According to the construction steps, 7 geochemical genes have been constructed by now as the lithogenes of LG01, LG02, and LG03, the metallogenes of MGAu and MGW, and the rare earth elemental genes of REEGO1 and REEG02. Lots of weathering profiles developed on different lithological rocks in China have been studied to test the gene properties of heredity and inheritance and the results indicate that the geochemical genes can keep steady during rocks' weathering according to the similar gene criterion of >= 80% on gene similarity. Moreover, the LG01 and LG03 are more stable than LG02, the LG03 may be steadier than LG01, and the REEG01 is more stable than REEG02 during rocks' weathering. The gene similarity between a sample and the ideal acidic rock is called the sample's acidic similarity which can be used as a tool to classify samples and discriminate their provenances compositionally on the LG01 and LG03 lithogenes. The gene similarity between a sample and the ideal ore is called the sample's mineralization similarity which can be viewed as an integrated index to determine a sample with or without mineralization on the field of geochemical exploration. Based on the geochemical gene database constructed from the regional geochemical survey data, the gene similarity can be used to trace a geological material where it is from. To code geochemical genes and calculate gene similarities between samples, a software named as GGC (Geochemical Gene Coding) is developed non-commercially.