全球地球化学填图

作指出了1973年至今世界上50余项地球化学填图计划中普遍存在的缺陷大都涉及分析问题。1988－1992年实施的国际地质对比计划IGCP259项目旨在使全世界地球化学填图方法标准化。在此项目中对分析问题提出了若干规定，主要是要求今后的填图计划应统一分析71种元素，痕量及超痕量元素的检出限必须低于相应的地壳丰度值及采用中国的GSD和加拿大的STSD标样系列，以使全球数据可以对比，在其后开始延续至今的全球地球化学填图计划IGCP360，旨在用极低密度采样早日覆盖全球大陆，讨论了正在实行的两种极低密度采样方案，并提出通过极低密度采集地极少量样品示范性实现IGCP259项目对分析要求的具体建议。

Global geochemical mapping

The deficiencies in more than50national and regional geochemical mapping projects in the world carried out from1973to present are all analytical in character.The IGCP259Project under the aegis of UNESCO ' s IGCP Program carried out from1988to1992aimed 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:71elements 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 IGCP360Project(Global Geochemical Mapping Project)is to use5000composite 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 IGCP259analytical requirements by many countries.The best way to solve this bottleneck is proposed in the present paper.