地壳全元素探测——构建“化学地球”

地壳物质探测是地壳探测工程的重要组成部分。化学元素是地球物质组成的最基本单位,被称为地球的基因。矿产资源是由化学元素组成的,环境是受化学元素行为制约的,因此,对地壳中所有元素精确含量和分布的探测,对解决人类所面临的资源和环境问题具有重大意义。地壳全元素探测项目拟发展4种地球化学探测技术,包括地壳中所有天然元素的精确分析技术,中下地壳物质成分识别技术,穿透性地球化学探测技术,海量地球化学数据和图形显示技术。建立1个覆盖全国的地球化学基准网,系统采集代表性岩石样品10000件,疏松物样品6000件,按标准化的方法分析其主量元素和微量元素含量(包含78种元素),建立中国大陆地球化学基准值,为研究化学元素的分布、演化和成矿物质背景提供基准参考数据。进行总长度3300km的3条地球化学走廊带的实验与示范,采集各类代表性岩石样品5000件,进行元素和同位素测定,构建走廊带地壳地球化学模型、跨越不同大地构造单元的元素空间变化和大型矿集区成矿物质背景。为开展全国地壳探测工程奠定基础,并为最终建立"化学地球"进行技术准备和先导性实验。

China Geochemical Probe: Making "Geochemical Earth"

China Geochemical Probe (CGP), as part of the China Earth Crust Probe (SinoProbe), is an Earth science project to provide geochemical baselines, distribution and evolution of all elements, and finally to establish a holistic digital "Geochemical Earth" in China. The goals of the project are (1) to develop 4 geochemical methodologies: analytical methods for all-elements, deep-penetrating geochemical methods, the earth crust geochemical model and global geochemical data visualizing software, (2) to establish China nationwide geochemical baselines for rocks and soils, (3) to make the crust geochemical models by pilot study on 3 geochemical transects to display element distribution in upper, middle and lower crust, (4) to explore evolution of elements in different tectonic plate of China with geologic times from Archeozoic to Quaternary, (5) to identify areas of interest for mineral resources and environments. Total 15000 typical rock and 6000 soil samples were collected in the China Geochemical Baselines Networks covering the whole mainland and 6000 samples were collected along the 3 transects, 78 elements have been determined. The project includes the following five programs: China Geochemical Baselines, China Continental Earth Crust Geochemical Reference Model, Deep-penetrating Geochemistry through Cover and Basin, Geochemical Earth Software, and Geochemical Evolution with Geologic Times along Transects.