Geological and statistical validation of a gold-prediction model based on low-density surface geochemistry and other geoscientific data, Nuuk region, West Greenland

Statistical prediction models for gold occurrences in the Nuuk region, West Greenland, based on low-density stream sediment geochemistry, regional aeromagnetic and aeroradiometric data have outlined favourable areas and provided multi-parameter signatures for them. The results have been validated during field studies of geological settings, lithology and lithochemistry. The favourable areas occur in mafic metavolcanic members of Archaean supracrustal belts that are characterized in the data by elevated Ni/Mg ratios and elevated Cs and Rb. The most promising gold mineralization has a distinct signature with high As, Al, U and Th. The chemical features identified by the statistical analysis have been verified as originating from properties of rocks within the areas of known and predicted gold mineralization. The study has shown that the regional data reliably identify chemical features that may be caused by extensive hydrothermal alteration in the environments where gold mineralization occurs. Furthermore, the regional data have drawn the attention to important differences in the setting of known gold mineralized sites but owing to limited data resolution the statistical prediction is unable to pinpoint the mineralized structures themselves.