Geochemical indices and regression tree models for estimation of ambient background concentrations of copper, chromium, nickel and zinc in soil

摘要: Abstract Geochemical ratios between elements of environmental concern and Fe have been recommended for estimation “background” concentrations Cr, Cu, Ni Zn in soil. However, little research has occurred to assess the consistency geochemical across soils developed different environments. Broad application generic could result under or over anthropogenic impacts soil subsequent inaccurate assessment risk environment. A survey was undertaken Victoria, Australia, including collection samples (n = 622) from surface (0–0.1 m below ground level) sub-surface (0.3–0.6 m soils, overlying Tertiary-Quaternary basalt, Tertiary sediments Silurian siltstones sandstones. Samples were analyzed metals physical chemical properties (particle size, cation exchange capacity, organic matter pH). correlations parent materials environments compared against relationships reported Australia internationally. Ratios Cr relatively consistent materials, comparable published models background Cr. Conversely, Ni, with Fe, variable weathering and/or depths. Alternative regression equations rule based tree as an improved means prediction ambient Ambient predictable depths, allowing these be extended potentially