Map of the natural background at 1:250,000 scale of the Emilia-Romagna plain - Cr, Cu, Ni, Pb, V, Zn

It represents the area distribution in the subsoil (90-140 cm deep) of the content of 6 metals (Cr, Cu, Ni, Pb, V, Zn) in soils for agricultural use. This depth is considered representative of the natural background content ('pedo-geochemical content' according to ISO/DIS 19258, 2005). The cartographic units are represented by groups of polygons belonging to the same concentration classes. Factors that regulate the natural content of metals in soils are: origin of the sediment in which the soil was formed, texture, and evolutionary degree. For chromium as well as nickel the dominant factor is the origin of the sediments that originate the soil. The map has an original setting as it uses genetic-environmental interpretation for the evaluation and geographical extension of the geochemical data, associating groups of soils with geochemical affinity with the same natural background values. The point data are obtained with the XRF (X-ray Fluorescence Spectrometry) analytical method in order to determine the total content to perform a thorough and correct geochemical analysis.本数据集涵盖农用土壤亚表层（深度90~140cm）中6种金属（铬Cr、铜Cu、镍Ni、铅Pb、钒V、锌Zn）含量的面积分布特征。该深度被视作土壤自然背景含量的典型代表区间，依据ISO/DIS 19258:2005标准，该类含量亦被称为土壤地球化学含量（pedo-geochemical content）。制图单元由归属同一浓度等级的多边形群组组成。调控土壤金属自然含量的关键因素包括：成土母质成因、土壤质地与土壤发育程度。其中，铬与镍的自然含量主导影响因素为成土母质的成因。本幅地图采用创新性编制思路：通过遗传-环境解译方法开展地球化学数据的评估与地理延展，将具有地球化学亲缘性的土壤群组归为同一自然背景值范畴。点位数据采用X射线荧光光谱法（X-ray Fluorescence Spectrometry）获取，用于测定金属全量，以开展全面且规范的地球化学分析。