Testing Of Geochemical Lithogene

Geochemical Lithogene is a geochemical gene constructed to characterize the geochemical characteristics of rocks and their weathering products.Eleven immobile elements are selected during weathering to code the lithological geochemical gene,and the sequence of these immobile elements is Al₂O₃?SiO₂?P?Ti?La?Fe₂O₃?Th?Zr?Nb?Y?U.The proximity between different geochemical genes can be expressed by similarity of gene.In this paper,three scales of samples,rock-soil weathering crust,residual slope sediment-stream sediment profile and 1?200 000regional geochemical prospecting sediment in the granite body of Huayuangong area,Anhui Province,are selected to test and preliminarily apply the geochemical lithogene.Based on 80%genetic similarity criteria,in the process of granite weathering,the geochemical lithogenes show good heredity in the products from the bottom bedrock to the surface weathered soil,and good inheritance in the samples from the surface soil to the bottom bedrock.It is found that soil and sediment samples from the same parent rock had similar geochemical lithogenes.In order to study the stability of geochemical lithogenes in particle size difference of samples,three samples?soil,slope and pond?are selected for particle size seven-stage screening,and the genetic similarity of different particle size samples with original samples is calculated.The results show that the screened samples are similar to the original samples.These results indicate that geochemical genes exhibit stable heredity,inheritance and similarity in weathering products from rocks to residual slope soils to stream sediments.This characteristic can be used to trace the samples of soil and stream sediments by geochemical lithogenes,and to infer the possible source of the samples.The results of geochemical lithogenes test on 1?200 000 regional geochemical river sediments show that,based on 80%similarity criteria,geochemical lithogenes can circle the sampling sites of soil and river sediment samples on horizontal profiles,and the source of soil and river sediment samples can be traced by using geochemical lithogenes.Geochemical gene databases can be established based on regional geochemical survey of river sediments in China.Geochemical lithogenes have broad potential applications in geology and forensic science.