ATLANTE GEOCHIMICO-AMBIENTALE D'ITALIA Geochemical Environmental Atlas of Italy

The Geochemical Atlas of Italy addresses the need for a large scale geochemical mapping based on FOREGS procedures. The aim of the Geochemical Atlas of Italy is to define background/baseline chemical element values on a national scale and it will help government decision makers in defining trigger and action limits on a local scale, bearing in mind the complex spatial variability of Italian geology. As regards the Geochemical Atlas of Italy, data of Italian topsoil (T), subsoil (C), stream water (W), stream sediment (S) and floodplain sediment (F), have been extracted from the FOREGS database and supplemented with new sampling data from 8 additional sites. The italian territory has been divided into 27 sampling cells (Fig. 1.1) on the basis of the Global Terrestrial Network (GTN), a sampling grid of 160 km x 160 km cells which covers the entire surface of the Earth, according to the establishments of the Global Geochemical Baseline project (IGCP 360) (Darnley et al., 1995). During field activities and sample preparation, FOREGS procedures (Salminen et al., 1998) were strictly followed. The geochemical data used for the FOREGS project and the new data from subcells of southern Italy have been processed using ArcView GIS™ and a new Multifractal IDW method available in the software GeoDAS™ (Cheng et al., 2003; Lima et al., 2003). Interpolated maps have been overlayed by dots and have been classified by statistic graphs, for a total production of 348 maps. Data show that, even, on a large scale, the distribution of elements reflects the major geo-lithological Italy structures.