GEMAS – Chemistry of Europe’s Agricultural soils, Parameters and indices, CIA (Chemical Index of Alteration)

GEMAS (Geochemical Mapping of Agricultural and Grazing Land Soil in Europe) is a cooperative project between the Geochemistry Expert Group of EuroGeoSurveys and Eurometeaux. In total, more than 60 international organisations and institutions worldwide were involved in the implementation of the project. During 2008 and 2009, a total of 2219 samples of agricultural (arable land soils, 0 – 20 cm, Ap samples) and 2127 samples of grazing land (pasture land soils, 0 – 10 cm, Gr samples) soil were collected at a density of 1 site/2 500 km² each from 33 European countries, covering an area of 5,600,000 km². In addition to the chemical element contents, soil properties and soil parameters such as pH, particle size distribution, effective cation exchange capacity (CEC), MIR spectra and magnetic susceptibility were investigated in the samples and some coefficients were calculated. The downloadable files present the areal distribution of the calculated CIA (Chemical Index of Alteration) in the shape of colour shaded contour maps.