Global geochemical mapping

Abstract：The deficiencies in more than 50 national and regional geochemical mapping projects in the world carried out from 1973 to present are all analytical in character. The IGCP259 Project under the aegis of UNESCO＇s IGCP Program carried out from 1988 to 1992 aimed to standardize geochemical mapping methods used in the world. This project advances several analytical requirements for forthcoming geochemical mapping projects, which mainly include the following: 71 elements should be analyzed in the future mapping projects; the detection limits of trace and ultratrace elements must be lower than the corresponding crustal abundances and the Chinese GSD and Canadian STSD standard sample series should be used for the correlation of global data; the aim of the IGCP360 Project (Global Geochemical Mapping Project) is to use 5000 composite samples taken at very low sampling densities to cover the whole Earth＇s land surface. Besides social，political and economic problems, the main bottleneck is the difficulties to meet IGCP259 analytical requirements by many countries. The best way to solve this bottleneck is proposed in the present paper.