Geochemical baselines in relation to analytical methods in the It _ -Uusimaa and Pirkanmaa regions, Finland

摘要

Geochemical baselines of As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, V and Zn concentrations were investigated for two Finnish regions (It_-Uusimaa and Pirkanmaa) using different determinations based on separate analytical methods: (1) total concentrations based on X-ray fluorescence (XRF) spectrometry or strong acid leach; and (2) 'near-total' concentrations determined using aqua regia extraction (ISO 11466) and/or concentrated nitric acid leaching (US EPA 3051A). The geology of the It_-Uusimaa region is dominated by late-orogenic plutonic rocks, while the bedrock in Pirkanmaa contains arc-type volcanic and sedimentary rocks and turbiditic greywackes. Topsoil (0-25 cm) and subsoil samples that were analysed represent the most common mineral soil parent material types of the study regions: sandy soils, glacial till and clayey soils. The normative mineral composition of the samples was estimated using the NORMA model.