The tectonostratigraphic units in NAML’s area of interest belong to the Upper Allochthon of the Central Scandinavian Caledonides. The Røros copper–zinc district extends 40–50km north to south, containing volcano-sediment hosted massive sulphide deposits of Cambrian to Silurian age. The main ore-hosting formations are: the Røsjø Formation consisting of metasediments with thin volcanogenic units, generally stratabound and hosting the Kongens–Rødalen, Fjellsjø, and Lergruvbakken deposits; and the Hersjø Formation consisting of hornblende schists (greenstones), interbanded with quartz-albite schists, typically more exhalative, hosting the 5.55Mt Hersjø deposit. The sulphide bodies are lensoidal, consisting of chalcopyrite and sphalerite in massive pyrite and/or pyrrhotite bodies.
COPPER-ZINC DEPOSITS IN THE TRONDHEIM NAPPE COMPLEX
SIMPLIFIED GEOLOGY & LICENCE MAP OF THE RØROS DISTRICT