Geochemical Genes Related To Granite Weathering In The Yunmengshan Area Of Beijing,China

Since the 1980 s,the Regional Geochemistry-National Reconnaissance Program(RGNR Program)and the National Multi-Purpose Regional Geochemical Survey Project(NMPRGS Project)have covered more than 7 million square kilometers of land areas.During this period,a large number of river sediment samples have been collected.The samples that have locations had been tested and analyzed to form a huge database of river sediment.There are some immobile elements in the 39 elements analyzed by the RGNR Program and 54 elements and indicators analyzed by the NMPRGS Project.The stability of immobile elements and the ratio of two adjacent immobile elements are commonly used for the identification of environment,compositional classification,and geochemical tracing.Geochemical tracing is an important application among them.Geochemical gene technology is a new technology proposed in recent years.This technology includes LG01,LG02,LG03 lithogenes and MGAu,MGW metallogenes and REEG01,REEG02 rare earth element(REE)geochemical genes.In order to carry out the research on the weathering process and sample traceability method in the Yunmeng Mountain area of Huairou district,Beijing,two adjacent weathering profiles were selected in this article in the largest granite body in this area to collect samples,and the data are obtained after testing and analysis to analyze the rock and soil and river sediment samples.The weathering behavior of elements and the stability of geochemical genes in the process of weathering.After observing that geochemical genes have good heredity,inheritance,and similarity in this area,we began to verify the representativeness between rock samples,soil samples,and among rock samples and soil samples,and among rock samples and soil samples and river sediment samples.The representativeness of the average value of the geochemical genes in multiple samples among rock and soil and sediment samples,and it was found that the geochemical genes of the average value of in the multiple samples have good representativeness.We use geochemical genes to actualize compositional classification,mineralization recognizing and sample traceability in this area.This area is classified based on the acid similarity of LG01,LG02,and LG03 lithogenes,and the result is similar to the lithology classification result by single index silica.The mineralization similarity of the two metallogenes of MGAu and MGW is used for mineralization recognizing.The mineralization recognizing results are the same as the gold and iron ore areas in this area,and the area between two adjacent gold mines shows extremely high mineralization similarity.Using river sediment samples of the RGNR Program and the NMPRGS Project in the Yunmeng Mountain area of Beijing,We find that the similarity of the 7 genes relative to the element average value of multi-samples can be used to trace the sample in this area,and the results most locate in the Yunmengshan granite,and locate around the sampling points of the weathering profile in this article.