The copper deposits of the Birtavarre district, Troms, Northern Norway. Kopperforekomster i Birtavarre-området Troms.

Abstract

The report gives the results of a 4-year (1952-55) programme for the investigation of a former copper-mining area in the north of Norway, carried out by the Geological Survey of Norway (NGU). The stratigraphy and structure of the district have been discribed in a previous NGU publication (Padget 1955). The ore deposits occur in one particular division (Ankerlia Series) of the layered Caledonian schists which underlie the whole area (see Plates 1 and 2). No deposits have been found outside this division. The greatest concentration of deposits occurs in the centre area along the south limb of a major, open E-W anticline (Moskogaissa anticline). In the same area the normally NW-plunging linear structures of the schists show a marked swing to an E-W direction (Plate 2). It is suggested that this area of \"structural anomaly\" has been responsible for the concentration of the sulphides. However, all kinds of control have been relatively weak and nowhere have the orebodies reached significant size by modern standards. It appears that the ore-bearing solutions spread out over large areas along zones of minor shearing within the Ankerlia Series. These zones lie roughly concordant with the schistosity and bedding for the schists and manifest themselves at outcrop as bands of marked rusting which are easy to follow in the field.