R. Salminen1, A. Demetriades2, and S. Reeder3
1Geological Survey of Finland, Espoo, Finland
The FOREGS Geochemical Baseline Mapping Programme's main aim is to provide high quality, multi-purpose environmental geochemical baseline data for Europe. The need for this type of data was justified by the first Working Group on Regional Geochemical Mapping immediately after the Chernobyl accident in 1986, when it was realised that a baseline for radioactive and other polluting elements could not be defined (Bølviken et al. 1990, 1993, 1996). Subsequent compilation of inventories of existing regional geochemical databases in Europe revealed the existence of some 120 separate geochemical databases based on up to seven different sample media. Although a wide range of element concentrations were determined by 13 different analytical methods, many environmentally essential elements were, however, not measured. (Plant and Ridgeway, 1990; Plant et al. 1996, 1997). Because it was impossible to compile a homogeneous data set for the whole of Europe from these data, it was clear that the establishment of a harmonised European wide geochemical database was essential. This database could then be used for levelling older national geochemical databases in order to produce more detailed European wide maps to satisfy the needs of present day national and European Union legislation. Plant et al. (1997) made the case thus:
The IUGS/IAGC Global Geochemical Baselines Programme aims to establish a global geochemical reference baseline for >60 determinants in a range of media for environmental and other applications. The European contribution to the programme has been carried out by government institutions from 26 countries under the auspices of the former Forum of European Geological Surveys (FOREGS). This activity is now transferred to EuroGeoSurveys, the Association of the European Geological Surveys in which FOREGS is merged. The main objectives of this European survey were: 1) to apply standardised methods of sampling, chemical analysis and data management to prepare a geochemical baseline across Europe; and 2) to use this reference network to level national baseline datasets.
Data on geochemical baselines are urgently needed in Europe, because environmental authorities in most countries are defining limits for contaminants in soils for different land use purposes. At the same time, the Commission of the European Union (EU) is preparing the Soil Protection Directive. As geochemists know, the natural concentrations of elements are different in the different constituents of overburden, and vary zmarkedly between geologically disparate areas. State authorities, however, are not always aware of these significant natural variations, which should be taken into account in defining action limits. There are already examples of action limits that are lower than natural concentrations.
The data produced by the FOREGS Geochemical Baseline Mapping programme should make a significant contribution to the EU Soil Protection Directive, especially as a basis for defining action limits. Older national geochemical data sets in Europe, as it has already been pointed out (Plant and Ridgeway 1990; Plant et al. 1996, 1997), are not in a form that can be readily used for this purpose. It is not possible to define the present day European geochemical baseline for a single element on the basis of old geochemical data.
Systematic baseline environmental geochemical data are necessary to inform policy makers and to provide a sound basis for legislation. According to Plant et al. (1996), for this purpose such data are required to be:
The report by Plant et al. (1996) also gives reasons why Geological Surveys, or equivalent governmental institutions, are particularly well suited to provide the data needed to establish systematic environmental geochemical baseline databases for Europe.
In Europe, the geochemical results of the Global Terrestrial Network sampling (GTN) - also called the Global Reference Network (GRN) - as recommended by the UNESCO International Geological Correlation Programmes IGCP 259, "International Geochemical Mapping", and its successor, IGCP 360, "Global Geochemical Baselines" (Darnley et al. 1995), will be used as a reference to normalise national baseline datasets in Europe.
The FOREGS programme is also the European contribution, and a practical example, to the International Union of Geological Sciences (IUGS) - International Association of Geochemistry and Cosmochemistry (IAGC) Working Group on "Global Geochemical Baselines".
The FOREGS Geochemical Baseline Mapping Programme was approved in 1996 by the Forum of European Geological Surveys' Directors (FOREGS). In 1996, the Working Group representatives were nominated by each country and by the end of 1997 the principles of field and analytical methodologies were agreed. The field methodology was subsequently tested and modified during a practical field course in the Slovak Republic in June 1997, and the "FOREGS Geochemical Field Manual" was published in 1998 (Salminen, Tarvainen et al. 1998).
The geochemical data are based on the analysis of samples of stream water, stream sediment, floodplain sediment (or alluvial soil), residual soil, and humus collected from 26 European countries. High quality and consistency of the data were ensured by using standardised sampling methods (Salminen, Tarvainen et al. 1998), and by applying rigorous, harmonised quality assurance measures during chemical analysis and subsequent data handling stages.
The choice of sampling media has been made in accordance with the recommendations of the IUGS/IAGC Working Group on Global Geochemical Baselines (Darnley et al. 1995). These media, described below, are considered to be the most representative of the Earth's surface environment, and are the most commonly used in past and current environmental geochemical investigations:
Stream and floodplain sediment samples generally reflect the average geogenic composition of a catchment basin for most elements, although they are sensitive to pollution. Since most national Geological Surveys have undertaken national stream sediment studies, the FOREGS stream sediment baseline data will be used to level these more detailed national datasets, and to link the results across Europe.
Stream waters reflect the interplay between geosphere/hydrosphere and pollution. At the same time, they can be a major source of drinking water. Many surveys have completed local studies, so the FOREGS data can be used to link results across Europe.
Soil samples reflect variations in the geogenic composition of the uppermost layers of the Earth's crust. Because of this, it was important to avoid soil sampling at locations that had visible or known contamination. Priority for site selection was given to:
Comparison of topsoil and subsoil data gives information about enrichment or depletion processes between the layers. One such process is anthropogenic contamination of the top layer. The <2 mm fraction was taken according to environmental standards. The <0.18 mm and finer fractions have been widely used in mineral exploration programmes, and the FOREGS data will be used to create a link between environmental and mineral exploration databases.
Humus samples can be used to determine the atmospheric (anthropogenic) input of elements to the ecosystem. To reach this aim, samples were collected in forested areas as near as possible to the residual soil sampling sites. To reflect the atmospheric input, the uppermost few centimetres of the organic layer were collected immediately under the green vegetation and litter (max. 3 cm).
GTN sampling locations were totally randomised, and are not designed to show the lowest natural background concentrations in the European environment, but to demonstrate the geochemistry of the surface environment at the end of the 20th century.
Organisation and Time Frame of the Programme
The work was carried out by the FOREGS Geochemistry Working Group. To this group belonged representatives of the following 26 European countries (see table at end of chapter). An executive group was nominated to lead different activities as described below:
Work started with the preparation of the Field Manual (Salminen, Tarvainen et al 1998), which was accepted by each participating country. The sampling was carried out as national projects by the geological institutions of the FOREGS countries. Sampling started in 1998 and was completed in November 2001.
Nine laboratories from participating Geological Surveys were selected to carry out the analysis. In order to ensure the homogeneity of the data and to avoid any bias between laboratories or analytical methods, each laboratory was nominated to take responsibility for carrying out analysis by a particular analytical technique or techniques on all samples of a certain type. Analytical work was carried out from 1999 to 2003. All applied methods are described in detail in the analytical manual (see chapter on Analysis). A sample archive was established in the Slovak Republic and samples will be available for future analysis at the discretion of the FOREGS Geochemistry working group.
The Geological Survey of Finland (GTK) coordinated the sampling, analytical work and data management. GTK provided detailed sampling instructions (also on web pages), sent all maps of random sampling sites within GTN cells, created the project database, and gave further information whenever needed.
Bølviken, B., Demetriades, A., Hindel, R., Locutura, J., O'Connor, P., Ottesen, R.T., Plant, J. Ridgeway, J., Salminen, R., Salpeteur, I., Schermann, O. & Volden, T. (eds.), 1990. Geochemical Mapping of Western Europe towards the Year 2000. Project proposal. NGU Report 90-106, 12 pp. and 9 app.
Bølviken B., Bogen J., De Vos W., Ebbing J., Hindel R., Ottesen R.T., Salminen R., Schermann O., & Swennen R., 1993. Final report of the Working Group on Regional Geochemical Mapping 1986-1993. Forum of European Geological Surveys (FORGES). Geological Survey of Norway (NGU) Open File Report 93.092.
Bölviken, B. Bogen, J., Demetriades, A., De Vos, W., Ebbing, J., Hindel, R., Langedal, M., Locutura, J., O'Connor, P., Ottesen, R.T., Pulkkinen, E., Salminen, R., Scherman, O., Swennen, R., Van der Sluys, J. & Volden, T., 1996. Regional geochemical mapping of Western Europe towards the year 2000. Journal of Geochemical Exploration 56, 141-166. Elsevier Science Publishers, Amsterdam.
Darnley, A.G., Björklund, A., Bölviken, B., Gustavsson, N., Koval, P.V., Plant, J.A., Steenfelt, A., Tauchid, M., & Xie Xuejing,, 1995. A Global geochemical database for environmental and resource management. Final report of IGCP Project 259. Earth Scinences 19, UNESCO publishing, 122 pp.
Plant J.A. & Ridgeway, J.M., 1990. Inventory of geochemical surveys of western Europe; appendix report 10: In: Western European Geological Surveys, Working Group on Regional Geochemical Mapping; Geochemical Mapping of Europe towards the Year 2000, pilot project report. Norwegian Geological survey, NGU report 90/105. 20 pp.
Plant, J.A., Klaver, G., Locutura, J., Salminen, R., Vrana, K. & Fordyce, F.M., 1996. Forum of European Geological Surveys (FOREGS) Geochemistry Task Group 1994-1996 Report. British Geological Survey (BGS) Technical Report WP/95/14. 52 pp.
Plant, J.A., Klaver, G., Locutura, J., Salminen, R., Vrana, K. & Fordyce, F., 1997. The Forum of European Geological Surveys Geochemistry Task Group inventory 1994-1996. Journal of Geochemical Exploration 59, 123-146.
Salminen, R., Tarvainen, T., Demetriades, A., Duris, M., Fordyce, F. M., Gregorauskiene, V., Kahelin, H., Kivisilla, J., Klaver, G., Klein, P., Larson, J. O., Lis, J., Locutura, J., Marsina, K., Mjartanova, H., Mouvet, C., O'Connor, P., Odor, L., Ottonello, G., Paukola, T., Plant, J. A., Reimann, C., Schermann, O., Siewers, U., Steenfelt, A., Van der Sluys, J., Vivo, B. de, & Williams, L., 1998. FOREGS geochemical mapping field manual. Geological Survey of Finland, Guide 47, 36 pp.
The work was carried out by the FOREGS Geochemistry Working Group. To this group belonged representatives of the following 26 European countries:
In addition to the country representatives listed above, the following persons have participated in the activities of the programme in its different phases:
Prof. Simon Pirc
Dr Otmar Sherman
Prof. Manuel Pinto
Dr David Smith
Dr Arthur Darnley
M. Birke, W. Kantor
B. De Vivo
E. Kallio and
A. Bartha and
E. van Vilsteren,
P. Paslawski and
Data processing teams:Finland:
A. Lima and
M. Vetuschi Zuccolini
A. Bel-Ian and
S. Reeder and