INTERNATIONAL GEOCHEMICAL MAPPING - A NEW GLOBAL PROJECT

There are many types of world synoptic maps, but only within the last few years has serious attention been given to the need for a world geochemical atlas to provide an overview of relative geochemical abundance levels, regional trends and anomalous patterns. Surfical geochemical data are relevant to a wide variety of mineral resource, agricultural, forestry, environmental and health questions as well as geological problems. Systematic maps provide an index and a starting point for detailed studies relating to the many applications of geochemistry. In 1988 a proposal for an International Geochemical Mapping Project was accepted by UNESCO/IUGS, to be administered through the mechanism of the International Geological Correlation Program (IGCP). IGCP Project 259 is intended to create a network of scientists and organizations working towards the goal of preparing systematic geochemical maps of the world. Coordination is provided through a series of Technical and Regional Committees, established to resolve scientific, technical and administrative problems. For example, not all existing data sets are readily accessible; surveys were initiated primarily for mineral exploration purposes using a variety of media and sample densities; samples have been analysed for different groups of elements by a variety of analytical methods, often with uncertain quality control. Nevertheless, from a practical viewpoint there is a large reservoir of data which, despite imperfections, should be utilized to the greatest extent possible. In order to provide control, serve as an international reference framework, and provide preliminary coverage across unsurveyed regions of the world, pilot studies are being undertaken to determine specifications for a new, very low-density sample network, using the minimum number of disparate sample types.