Fifty-one chemical elements in till from the Oppdal region, Mid-Norway: relation to mineralization, Quaternary and bedrock geology

The study presents data from a geochemical till survey conducted in the Oppdal/Berkåk area of Central Norway. Using a 1 x 2.5 km grid, 877 samples were taken to cover a 2000 km² survey area (one site per 2.2 km²). The samples were air dried, sieved to <2 mm and analysed for 51 elements following an aqua regia extraction. A number of geochemical anomalies, related to lithology, a prominent fault zone, mineralization or environmental processes, are delineated for a large number of elements. Four main anomalies are outlined. A large, elongated (40 km long) multi-element anomaly is associated with normal faults and adjacent rhyolitic-andesitic rocks occurring in the area. Elements associated with gold (As, Sb) form an anomaly on the central high-altitude area just to the east of the fault related anomaly. Two further areas that display high concentrations for many elements are located around Orkelsjøen and Soknedal. Climatic/topographic conditions have a strong influence on the Hg and Se distribution. Several areas that display geochemical anomalies, where more detailed studies could be conducted were also identified.