Flem-New_geochem_maps_Norway_2021.jpg

<p>Newly compiled data from four mineral soil surveys covering the mid- and northern part of Norway will be presented. </p> <p>The Geological Survey of Norway (NGU) has re-analysed stored soil C-horizon samples, which were collected during two low-density soil surveys in the 1980s in Northern Norway (1 sample/36 km2). Recently, two new soil surveys covering all of Trøndelag, the county in the prolonging southern direction, have been carried out using the same sample density. All analyses were carried out in the same laboratory. Compared to the analyses from the 1980s, lower detection limits were obtained and results for many more elements than previously were reported. Quality control demonstrated that the analytical results from Trøndelag are, for most elements, directly comparable with the results from Northern Norway. It was thus possible to produce uniform geochemical maps covering Norway from Mid-Norway to the coast of the Barents Sea and the Russian/Norwegian border for many chemical elements.</p> <p>Although, the occurrence of base and precious metal and rare earth elements (REE) anomalies indicating mineralized areas are obscured by the low-density sampling, bedrock geology and many mineral districts are generally well reflected in the element maps. Examples include Caledonian and Proterozoic sediments at the coast of the Barents Sea marked by prominent Ag, As, Bi, REE, Cs, Fe, Mn, Pb and Sb anomalies and the two geochemically quite distinctly different greenstone belts in Finnmark (Kautokeino and Karasjok) prominently visible on the Co, Cr, Cu, Mg, Ni and V maps. Especially on the Ag, As, Bi, Co, Cu and Sb maps, many of the known mineralisations and mineral belts like Nussir/Repparfjord copper or the Joma/Skorovas Cu/Zn district and possible extensions thereof are highlighted. Despite the low sampling density, the new geochemical maps provide useful first order criteria to identify areas with potential for mineral exploration in northern Norway.</p>