Geochemical atlas of agricultural and grazing land soil of Italy (The GEMAS project in Italy)

GEochemical Mapping of Agricultural Soils (GEMAS) is a cooperation project between the Geochemistry Expert Group of EuroGeoSurveys (EGS) and Eurometaux. The GEMAS project aim was to produce soil geochemical data at the continental-scale consistent with the EU regulation REACH (Registration, Evaluation and Authorisation of Chemicals). All GEMAS project samples were analysed by variety of methods, including ICP-AES and ICP-MS following an aqua regia extraction, XRF and an MMI leach. The Italian Atlas contains colour surface maps displaying interpolated data and graduated dots, maps for regional variability of factor scores of elemental associations, and 15 baseline maps of selected elements following the Italian statutory intervention criteria. The maps in the Italian Geochemical Atlas show that the spatial distribution of chemical elements in the agricultural and grazing land soil is governed mostly by geogenic factors, even though the concentration levels of many of the investigated elements are well above the intervention limits set by the Italian environmental law (dl 152/2006). Regional-scale maps show that the element distribution patterns reflect the geochemistry of the major lithological units and structural lineaments, even using a very low sampling density grid of 1 sample site/2500 km2. Areas, such as the Roman-Neapolitan Alkaline Province, the Iglesiente-Sulcis mining district in Sardinia, the Ligurian ophiolites and the evaporites formation in Sicily, are easily detectable on the produced maps. An important outcome is that the Geochemical Atlas of Italian agricultural and grazing land soil facilitates the popularisation of the background/baseline variation for chemical elements at the country-wide scale.