Geophysical modelling of aeromagnetic anomalies in Altemark, northern Norway

Abstract

In connection with investigations of the talc deposit \"Nakkan\" in Altermark, surrounding magnetic anomalies have been modelled and interpreted. The goal of this work is to get more knowledge about the possibility of finding addi- tional resources of talc in the vicinity of the Nakken deposit. Two magnetic profiles have been modelled; the first crosses the exposed ultramafic termed \"Lille Esjeklumpen\", while the second crosses a very weak positive magnetic anomaly west of the Nakkan deposit. The modelling of the Lille Esjeklumpen ultramafite indicates that it extends no more than 150 metres below surface. The modelling of the weak anoamaly to the west indicates that it is caused by a relatively low magnetic rock which is exposed at the surface-most likely a granet-mica schist.