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HISTORY and evolution of the Taskgroup
Background
There is worldwide concern about the potentially damaging effects of chemicals in the environment on the health of humans, animals, agriculture and ecosystems. Economic and population growth are increasing rapidly, exacerbating such problems as land degradation and pollution from uncontrolled urbanisation, industrialisation, intensive agricultural practices and over-exploitation of aquifers. These and other problems are having an impact on the geochemistry of the Earth’s surface and the sustainability of its life-support systems from the local to the global scale.
Defining and understanding the current abundance and spatial distribution of chemicals in different environmental compartments (e.g., soils, sediments, surface and ground water, vegetation) are essential first steps in being able to recognise and quantify natural or human-induced changes in the future. Dr. Mary Lou Zoback, former President of the Geological Society of America, stated the issue eloquently: “Documenting and understanding natural variability is a vexing topic in almost every environmental problem: How do we recognise and understand changes in natural systems if we don’t understand the range of baseline levels?” (Zoback, M. L., 2001. Grand Challenges in Earth and Environmental Sciences - Science, Stewardship, and Service for the Twenty-First Century: Geological Society of America Today, v. 11, no. 12, pp. 41-47).
Systematic geochemical mapping is the best method available to assess and provide a basis for monitoring changes in the levels of chemical elements at the Earth’s surface. Geochemical maps have traditionally been valuable in addressing a whole range of environmental problems, as well as for identifying potential mineral resources at the local to national scale. Several decades of geochemical mapping by national geological surveys, and related organisations throughout the world, have resulted in a wealth of valuable information. However, these data cannot readily be applied to broader regional or global studies, because they have been collected using different sampling, analytical and data interpretation methods (Darnley et al., 1995 - “The Blue Book”). Part of the reason behind this is that there are no internationally agreed standards for geochemical surveys.
Such incompatible data could be used if they were normalised to a reference dataset, i.e., data generated from a worldwide suite of geochemical samples collected, prepared, analysed and interpreted using a universally consistent set of protocols. Each of the available geochemical survey datasets could then be normalised to the reference dataset and interpreted across political boundaries in order to identify geochemical features, including both enrichment and depletion of elements, with the potential to affect the health of humans, animals and ecosystems. New areas with potential for undiscovered mineral resources could also be identified.
History and Objectives
The Task Group on ‘Global Geochemical Baselines’ has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements and species in the Earth’s near-surface environment. The database and accompanying element distribution maps can then be used to establish a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognised and measured.
The current Task Group traces its origins to 1988 as Project 259 ‘International Geochemical Mapping’ of UNESCO’s International Geological Correlation Programme (IGCP). This first phase was concluded with the publication of UNESCO Report 19 “A global geochemical database for environmental and resource management” (Darnley et al., 1995 – “The Blue Book”). This detailed the requirements necessary for establishing a global geochemical database through multi-media, low-density sampling on the basis of the Global Geochemical Reference Network (GRN), which covers the Earth’s land surface with about 5000 grid cells of 160 × 160 km (area 25 600 km2). These requirements included:
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commonly available representative sample media, collected in a standardised manner;
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continuity of data across different landscape types;
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adequate quantities of the sample media for future reference and research requirements;
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analytical data for all elements of environmental or economic significance;
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the lowest possible detection limits for all elements; and
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strict quality control at every stage of the process.
From 1993 to 1997, the project continued under the IGCP as Project 360: ‘Global Geochemical Baselines’. The design of the GRN was finalised and sampling sites selected in a statistically random way, based on the 160×160 km grid system. Standardised methods for geochemical sampling, sample preparation, analysis and data management to be used in conducting the global-scale geochemical survey, agreed by the representatives of more than 100 countries, were also prepared during this phase of the project. More detailed methods for sampling in semi-arid, temperate and glaciated terrains were published in the “FOREGS/EuroGeoSurveys Geochemical Mapping Field Manual” (Salminen et al., 1998), which can be downloaded from URL ??.
Following completion of the two IGCP projects, the International Union of Geological Sciences (IUGS), in collaboration with the International Association of GeoChemistry (IAGC), established in 1998 the current Task Group on ‘Global Geochemical Baselines’. The Task Group’s main objective for this phase has been to encourage and facilitate the population of the GRN worldwide through application of the sampling, sample preparation, analytical and data management protocols established in the earlier phases of the project. This has been achieved by making the expertise within the Task
Group available to countries interested in initiating a national geochemical survey.
Summary of project phases
Phase I: IGCP 259 (1988-1992). Assessed the requirements and methods for global geochemical mapping. Recommendations published in "A global geochemical database for environmental and resource management", A.G. Darnley et al. (1995) UNESCO Publication 19. During this period extensive research work was carried out in Europe, China and Canada especially for the development of continental scale geochemical mapping techniques.
Phase II: IGCP 360 (1992-1997). Established a worldwide network of professional applied geochemists. Developed a set of methods for GRN sampling in temperate, glacial and mediterranean climates. Initiated discussion of methods for sampling in other climates. Published the first version of the “FOREGS geochemical mapping field manual” (Salminen, Tarvainen et al., 1998), which is in the process of updating to include sampling instructions in other morphoclimatic terrains “FOREGS/EuroGeoSurveys geochemical mapping field manual” (Salminen, Tarvainen et al., in preparation).
Phase III: IUGS/IAGC Task Group on “Global Geochemical Baselines” (1997 - present). During this phase 26 European countries participated from 1996 to 2006 in a common project under the auspices of the Forum of European Geological Surveys (FOREGS), presently the Association of Geological Surveys of Europe (EuroGeoSurveys or EGS). The results of this project have been published in two printed volumes, which are both freely available for downloading from: http://www.gtk.fi/publ/foregsatlas/
(1) Salminen, R., Batista, M.J., Bidovec, M., Demetriades, A., De Vivo, B., De Vos, W., Duris, M., Gilucis, A., Gregorauskiene, V., Halamic, J., Heitzmann, P., Lima, A., Jordan, G., Klaver, G., Klein, P., Lis, J., Locutura, J., Marsina, K., Mazreku, A., O’Connor, P.J., Olsson, S.Å., Ottesen, R.T., Petersell, V., Plant, J.A., Reeder, S., Salpeteur, I., Sandström, H., Siewers, U., Steenfelt, A. & Tarvainen, T., 2005. FOREGS Geochemical Atlas of Europe, Part 1: Background Information, Methodology and Maps. Geological Survey of Finland, Espoo, 526 pp.
(2) De Vos, W., Tarvainen, T. Salminen, R., Reeder, S., De Vivo, B., Demetriades, A., Pirc, S., Batista, M.J., Marsina, K., Ottesen, R.T., O’Connor, P.J., Bidovec, M., Lima, A., Siewers, U., Smith, B., Taylor, H., Shaw, R., Salpeteur, I., Gregorauskiene, V., Halamic, J., Slaninka, I., Lax, K., Gravesen, P., Birke, M., Breward, N., Ander, E.L., Jordan, G., Duris, M., Klein, P., Locutura, J., Bel-lan, A., Pasieczna, A., Lis, J., Mazreku, A., Gilucis, A., Heitzmann, P., Klaver, G. & Petersell, V., 2006. Geochemical Atlas of Europe. Part 2 - Interpretation of Geochemical Maps, Additional Tables, Figures, Maps, and Related Publications. Geological Survey of Finland, Espoo, 692 pp.
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