Geological setting
All MetPro’s project areas are situated in the Scandinavian Caledonides. The Scandinavian Caledonides occupies the majority of Norway. The orogeny is built up by a number of thrust sheets which were emplaced during a continent-continent collision. Figure 1 shows the general geology and figure 2, a cross section over the central part of the Caledonides.
Figure 11). Geology over the Scandinavian Caledonides.
Norway is dominated by the Uppermost, Upper and Middle Allochthon.
Figure 21). Cross section over the central
parts of the Scandinavian Caledonides.
MetPro´s projects mainly consist of Volcanic Massive Sulphides.
A stratabound volcanic massive sulphide (VMS) deposit is formed on the ocean floor where metal bearing hot fluids escape the crust. This occurs exclusively in areas with volcanic and tectonic activity. The hot fluids percolate through the surrounding rocks and sediments, picking up solved metals. The fluids circulate in hydrothermal cells driven by the heat of an underlying magma chamber and are expelled to the ocean floor through conduits. When the hot fluids interact with cold seawater the metals are precipitated in mounds on the ocean floor, or just below it, often with a clear zonation between the different sulphides. The deposition of metals occurs during the waning stages of volcanism. Most often the footwall is composed of a volcanic rock that undergoes intense alteration where the fluids emanate from the crust. The hanging wall can be composed of volcanics or sediments. If additional volcanic cycles occur, the hanging wall will be composed of volcanic rocks and often there is a second ore horizon related to the waning stages of the subsequent volcanism. A sedimentary hanging wall would indicate that a longer period without volcanic activity has occurred and enough time has passed for considerable sedimentary material to accumulate.
Minerals and associated metals in MetPro’s project areas
Arsenopyrite – often indicating gold
Chalcopyrite – containing copper, often indicating gold
Fahlerts – containing copper, gold, silver
Galena – containing lead, often indicating silver
Malachite – containing copper
Sphalerite – containing zinc
1) Gee D.G., Juhlin C., Pascal C. and Robinson P., 2010. Collisional Orogeny in the Scandinavian Caledonides (COSC). GFF, 132, pp. 29-44.
