Current Work

 IUGS Commission on Global Geochemical Baselines

 

• Completion and publication in 2022 the International Union of Geological Sciences Manual of Standard Methods for Establishing the Global Geochemical Reference Network;

• Organisation of sessions and workshops on the occasion of international conferences and congresses;

• Starting in 2023 the revision of the Darnley et al. (1995) IGCP 259 report;

• Providing advice and assistance to countries planning to participate in the Global Geochemical Baselines project, and 

• Providing advice and assistance to countries planning regional geochemical surveys.

 

 

Africa

 

Contacts:  Keith Shephard, k.shepherd@cgiar.org; Theo Davies, daviestheo@hotmail.com; Marthinus Cloete, mcloete@geoscience.org.za; Buba Turay, turay78@yahoo.co.uk

   

 

Soil Health

 

The Africa Soil Information Service (AfSIS) is developing a practical, timely, and cost-effective soil health surveillance service to map soil conditions, set a baseline for monitoring changes and provide options for improved soil and land management. Because knowledge about the condition and trend of African soils is highly fragmented and dated, there is an urgent need for accurate, up-to-date, and spatially referenced soil information to support agriculture and environmental management in Africa. The system will facilitate the identification of areas at risk of soil degradation and corresponding preventive and rehabilitative soil management interventions.

 

AfSIS is targeting 17.5 million km² of continental sub-Saharan Africa and 591,740 km² of Madagascar giving a total of ~18.1 million km² covering 42 countries. A probability sample of 60 sentinel sites is being characterised stratified (in proportion to size) based on the distribution of the major Köppen-Geiger climate zones. The actual randomised sites (see figure below) cover 21 African countries. Each sentinel site is 10 x 10 km² within which 160 plots of 1000 m² plots are sampled. Soil samples are taken at 0-20 cm and 20-50 cm from all plots, and to 100 cm on every third plot.

 

All samples are being characterised using near and mid-infrared diffuse reflectance spectroscopy in the World Agroforestry Centre's Soil-Plant Spectral Diagnostics Laboratory [http://africasoils.net/services/data/soil-databases/]. A 10% subset of samples will be subjected to a wide range of tests, including extractable nutrients, soil carbon using thermal combustion, total element analysis using total X-ray fluorescence spectroscopy, mineralogy using X-ray diffraction spectroscopy, particle size analysis and soil stability using laser diffraction spectroscopy, water holding capacity, and engineering properties.

   

 

Nigeria

  

The systematic national geochemical mapping of Nigeria, conducted under the terms of a World Bank funded project (NGMTAP), was concluded for two master cells (the 'Minna Cell' and the 'South-western Cell') in 2011, with the submission of an overview report to the Nigerian Government. The two completed cells cover a combined area of 52,000 km². The project was undertaken by the Nigerian Geological Survey Agency (NGSA) with the support of the British Geological Survey (BGS) and the Geological Survey of Finland (GTK). The project consisted of three major components:

 

1. Production of baseline geochemical maps of Nigeria based on a sampling density of 1 sample per 100 km² for 25 complete global geochemical reference network (GRN) cells and 19 incomplete cells;
   
2. Collection of samples (sediment, water, soil, etc.) from 5-8 sampling sites per cell (i.e., 200-300 sampling sites across Nigeria);

 

Production of baseline geochemical maps of cells considered to be the most prospective for specific minerals, based on higher density sampling of 1 sample per 20 km².

 

    

 

Sierra Leone

  

The World Bank, in 2009, approved funding a geochemical mapping project in Sierra Leone based on selected topographic map sheets in the country. The selection of sheets was made using sound geological calculations by staff of the Geological Survey Department. The aim of the World Bank funded geochemical mapping project is to provide baselines geoscientific information for mineral exploration and environmental management through a study of the distribution of gold, coltan, base metals and iron ore in the country. This is a three-year project to conduct geochemical surveys of 9 sheets and geological mapping of 6 sheets. The geochemical sampling program involves stream sediments sampling and soil sampling. A total of 1255 stream sediment and 32 panned concentrates samples were collected by 5 geologists within the first phase of the programme. Multi-element analysis was conducted using a combination of ICP-MS and ICP-AES techniques. However, a special analytical technique was used for the rare earth elements (REEs) and the platinum group elements (PGM). The samples were dried and sieved to 0.180 mm prior to analysis.

 

 

Asia

Contact: Xueqiu Wang,  wangxueqiu@igge.cn 

 

National- and continental-scale geochemical mapping projects have been carried out in China since the late 1970s:

 

1. The Regional Geochemistry – National Reconnaissance (RGNR) Project, which is China’s largest national-scale geochemical mapping project, and has covered more than 6 million km² of the country's hilly and mountainous regions since 1978. Generally, stream-sediment samples were collected at a density of 1 sample per km² and 4 samples were composited into one analytical sample for analysis of 39 elements. Approximately 1000 map sheets at a scale of 1:200000 have been produced by each provincial geological survey. The geochemical atlas of whole China using an average value per 100 km², 400 km² and 1600 km² grid was published in 2012.
2. The Multi-purpose Eco-geochemical Mapping project has been conducted in the quaternary plains of eastern China to provide data for environmental regulation and for improvement of agricultural practices since 1999. Soil samples were collected from the surface (0-20 cm) and a deeper zone (150-200 cm). The sampling density for the surface samples is 1 sample per km² and for the deeper sample is 1 sample per 4 km². Fifty-two elements and organic carbon (Org.C) and pH were determined.
3. Penetrating geochemical mapping project has been conducted in covered terrains, including basins, at a density of 1 sample per 100 km² with analysis of 30-70 elements since 1994. In the past 10 years, an area of approximately 800 000 km² has been covered.
4. 76 Geochemical Element Mapping (76 GEM) project has been carried out since 1999. One composite sample from approximately 100 individual stream sediment samples of the RGNR project original samples were analysed for 76 elements. The geochemical atlas for 76 elements has been edited by Professor Xie Xuejing and published in Chinese by China Geological Publishing in 2008.
5. The Environmental Geochemical Monitoring Networks Project (the EGMON project) was launched in 1993 as a pilot study for the IGCP360 in an attempt to find a suitable sampling medium universally available representing a very large area. For this purpose 500 flood-plain sediment samples were collected in large catchment basins in whole China, and 51 elements were determined according to the IGCP259 recommendations.
6. China is cooperating with Colombia, Brazil, Guyana, Kazakhstan and Mongolia in national- and global-scale geochemical mapping by transferring its expertise in sampling, chemical analysis, and map generation through bilateral and multilateral collaboration.
7. China Geochemical Baselines Project. The China Geochemical Baselines Project (CGB) is a contribution to the IUGS/IAGC Task Group on Global Geochemical Baselines. Its purpose is to document China's nationwide abundance and distribution of all chemical elements. The geochemical data and accompanying maps represent geochemical baselines for understanding the past geochemical evolution and predicting the future chemical changes of the Earth. Each Global Reference Network (GRN) cell is divided into 4 CGB sub-cells. Approximately 1,500 CGB sub-cells cover the whole of China (9.6 million km²). Soil samples for pedosphere and rock samples for lithosphere geochemical baselines will be collected in each CGB sub-cell. Two sampling sites are designed to collect homogeneous samples of soil/overbank/floodplain sediments from each CGB cell for establishing pedosphere geochemical baselines. At each site, two samples are taken: 0-25 cm depth and >100 cm depth. Typical rock samples, representing different geological ages, are simultaneously collected in each CGB cell for establishing lithosphere geochemical baselines to interpret the geogenic sources of secondary geochemical patterns and to explore the evolution of elements with respect to geological time from Archaeozoic to Quaternary. Seventy-six elements are determined by ICP-MS/AES following 4-acid digestion and by XRF following fusion as the backbone methods combined with another 10 methods. Analytical quality is under strict control by using standard reference samples. Internet-based software named Digital Chemical Earth, similar to Google Earth, is being developed, which can manage the geochemical database and allow people to access vast amounts of geochemical data and maps through the Internet. A 5-year term, from 2008 to 2012, is planned for covering the whole of China's mainland. The Atlas will be published in 2019.

 

Australia

Contact: Patrice de Caritat, Patrice.DeCaritat@ga.gov.au

 

The Geochemical Atlas of Australia was completed in 2011 and provides data on 68 mineral elements in sediment samples which were gathered from 1315 sites in 1186 catchment basins across Australia as part of Geoscience Australia's National Geochemical Survey of Australia project.

 

At each site two depth intervals were sampled and two grain size fractions were separated from the samples.  The shallower sample was from up to 10 cm below the surface (Top Outlet Sediment, TOS) and the deeper sample was from 60 to 80 cm below the surface on average (Bottom Outlet Sediment, BOS).  For each depth, the coarse (<2mm) and fine (<75µm) fractions were used for chemical assays.  The samples were prepared and analysed for up to 68 chemical elements using a range of techniques which yielded Total, Aqua Regia soluble and Mobile Metal Ion™ soluble concentrations.  Additionally, a bulk split was used for the determination of bulk soil properties.

 

The Geochemical Atlas of Australia are available for downloading from the website of Geoscience Australia

[http://www.ga.gov.au/about/projects/resources/national-geochemical-survey/atlas]

 

 

Caritat, P. de, Cooper, M., 2011. National Geochemical Survey of Australia: The Geochemical Atlas of Australia. Geoscience Australia Record 2011/20, 557 pp. (2 Volumes);  http://www.ga.gov.au/about/projects/resources/national-geochemical-survey.

 

 

Europe

Contacts: Clemens Reimann, Clemens.Reimann@NGU.NO; Alecos Demetriades, alecos.demetriades@gmail.com

• New analytical data on the samples of the FOREGS/EuroGeoSurveys Geochemical Baselines project are being processed, and the results are in the process of being published in different papers.
• EuroGeoSurveys 'European Ground water Geochemistry' project has been completed and a geochemical atlas published: Reimann, C., Birke, M. (Eds.), 2010. Geochemistry of European Bottled Water. Borntraeger Science Publishers, Stuttgart, 268 pp., 28 figures, 6 tables, 2 appendices, 67 element maps, and a CD-ROM with all the analytical data and maps. Available online at: http://www.schweizerbart.de/publications/detail/artno/001201002
• Papers on national interpretations of bottled water data and specific themes were published in a Special Issue of the Journal of Geochemical Exploration, i.e., Birke, M., Demetriades, A. and De Vivo, B. (Guest Editors), 2010. Mineral Waters of Europe. Journal of Geochemical Exploration, 107(3), 217-422.
• The soil Geochemical Atlas of Cyprus was published in 2011, and the results presented at Symposium organised by the Cyprus Geological Survey Department, Hilton Park Hotel, Lefkosia, Cyprus, 5-7 September 2011, and the presentations are available for downloading at http://www.moa.gov.cy/moa/gsd/gacsymposium2011.nsf/index_en/index_en?OpenDocument, and a geochemical atlas published: Cohen, D.R., Morisseau, E., Rutherford, N. & Zissimos, A.M., 2011. Geochemical atlas of Cyprus. University of New South Wales Press, 144 pp.
• The Geochemical Atlas of European Agricultural and Grazing land Soil (GEMAS) was completed in 2014 with the publication of two volumes: 

 

Reimann, C., Birke, M., Demetriades, A., Filzmoser, P. & O'Connor, P. (Editors), 2014. Chemistry of Europe's agricultural soils – Part B: General background information and further analysis of the GEMAS data set. Geologisches Jahrbuch (Reihe B 103), Schweizerbarth, Hannover, 352 pp.; http://www.schweizerbart.de/publications/detail/isbn/9783510968473/Geologisches_Jahrbuch_Reihe_B_Heft_B103_Chemistry.

 

Russia

Contact: Arkadiyh Golovin, golovin@imgre.ru

Geochemical mapping of the Russian territory at a scale of 1:1000000 (MPGM-1000) is conducted under the guidance and by the efforts of specialists of the Institute of Mineralogy, Geochemistry and Crystal Chemistry (IMGRE), which is a leading Russian institute in the field of applied geochemistry and is affiliated with the Geological Survey of Russia (Federal Agency of Mineral Resources) of the Ministry of Natural Resources and Ecology of the Russian Federation.

From 1992 to 2010, MPGM-1000 was carried out in Russia for 33 map sheets representing a total area of 2694.6 thousand km² square km². For the same period, geochemical maps at a scale 1:1000000 were compiled for 71 sheets (8208 thousand km²) with the use of previously conducted geochemical sampling at scales from 1:1000000 - 1:100000. Thus, the total area covered by low-scale geochemical mapping in Russia is 10,900 thousand km² 63.8% of the country. The total number of samples taken from the various environment compartments is: 179,688 samples of country rock, 614,628 samples of stream sediment, 372,796 samples of soil, 19,966 samples of water, and 1,308 samples of concentrates.

 

Indian subcontinent

Contact: Pradip Govil, govilpk@gmail.com

 

 The National Geophysical Research Institute (NGRI) conducted a soil geochemical survey of India from 2004-2009. Sampling was based on the Global Geochemical Reference Network (GRN). Top soil (544 samples) and bottom soil (469 samples), as defined by the Blue Book (Darnley et al., 1995), were collected from 115 of the 122 GRN cells covering India. The samples were analyzed for 23 elements by X-ray fluorescence spectrometry.

 

 

North America

Contacts: (1) U.S.A.:  David B. Smith, dsmith@usgs.gov; (2) Mexico:  Francisco Moreira Rivera, fmoreira@sgm.gob.mx

 

 

A soil geochemical survey of the conterminous United States and Mexico was initiated in 2007. Sampling at 4857 sites in the conterminous U.S. was completed in 2010 (1 site per 1,600 square kilometres); sampling of ~1,300 sites in Mexico was completed in 2012. The following samples were collected at each site: (1) soil from a depth of 0-5 cm; (2) a composite of the soil A horizon; and (3) a sample from the soil C horizon, or if the top of the C horizon was deeper than 1 metre, a sample was collected from about 80-100 cm. Each sample was air-dried at ambient temperature and sieved to <2 mm.  The <2-mm fraction of each sample was analysed for a suite of 45 major and trace elements by methods that yield the total or near-total elemental content.  The uniqueness of this project is the determination of major mineralogical components in the samples from the soil A and C horizons by a quantitative X-ray diffraction method using Rietveld refinement.  Sampling in the conterminous United States was completed in 2010, with chemical and mineralogical analyses completed in May 2013. The resulting data set provides an estimate of the abundance and spatial distribution of chemical elements and minerals in soil samples of the conterminous United States and represents a baseline for soil geochemistry and mineralogy against which future changes may be recognised and quantified.  This final report by Smith et al. (2014):  (1) describes the sampling, sample preparation, and analytical methods used; (2) gives details of the quality control protocols used to monitor the quality of chemical and mineralogical analyses over approximately six years, and (3) makes available the soil geochemical and mineralogical data in downloadable tables. 

 

• Smith, D.B., Smith S.M., Horton, J.D., 2013.  History and evaluation of national-scale geochemical data sets for the United States. Geoscience Frontiers, 4(2), 167-183; https://doi.org/10.1016/j.gsf.2012.07.002.
• Smith, D.B., Cannon, W.F., Woodruff, L.G., Solano, F., Kilburn, J.E., Fey, D.L., 2013.  Geochemical and mineralogical data for soils of the conterminous United States.  U.S. Geological Survey Data Series 801, 19 pp.;  http://pubs.usgs.gov/ds/801/.
• Smith, D.B., Cannon W.F., Woodruff, L.G., Solano, F., Ellefsen, K.J., 2014.  Geochemical and mineralogical maps for soils of the conterminous United States.  U.S. Geological Survey Open-File Report 2014-1082, 386 pp.;  http://pubs.usgs.gov/of/2014/1082/.

 

Interactive website:  https://pubs.usgs.gov/sir/2017/5118/ 

 

The Mexican results are expected to be available in 2019.

 

South America

Contacts: (1) Brazil:  Carlos Alberto Lins, carlos.lins@cprm.gov.br; João Larizzatti, joao.larizzatti@cprm.gov.br; (2) Colombia:  Gloria Prieto, gprieto@ingeominas.gov.co

  

Brazil

  

The geochemical mapping of Brazil is being conducted by the Geological Survey of Brazil (CPRM, www.cprm.gov.br). High Density Geochemical Mapping is being carried out via a National Geological Mapping Programme (scales 1:250,000 and 1:100,000).  Low-density Geochemical Mapping, covering all Brazilian territory, is being executed in hydrographic basins in Brazilian States.

  

 

Colombia

  

During 2011, the Geological Survey of Colombia (INGEOMINAS) began new geochemical mapping in areas using low and medium density sampling. In eastern Colombia, in a region of geological homogeneity ('Llanos Orientales'), 4200 km². In addition, a sampling programme was conducted in Central Colombia covering 2400 km² by stream sediment at a density of 1 sample per 4-9 km².  A new geochemical sampling programme that will be completed in 2012 was initiated for 71,400 km² using stream sediment at a density of 1 per 4-9 km².

 

 

Send information about current continental-scale projects to:  Anna Ladenberger [E-mail:  anna.ladenberger@sgu.se] or Paula Adánez [E-mail:  p.adanez@igme.es] or Ariadne Argyraki [E-mail:  argyraki@geol.uoa.gr].