Scheelite occurrences in granulite facies metamorphosed supracrustals, West Greenland

Abstract

In 1982 the first traces of scheelite in heavy mineral concentrates from stream sediments were found in the Godthåbsfjord area. Subsequently a quite extensive scheelite mineralisation has been found in the Malene supracrustal rocks (Appel, 1986a). During 1985 a regional stream-sediment sampling programme was carried out covering an area of about 30 000 km2 within the Godthåb area. As aresult of this programme scheelite was found in most of the streams draining Malene supracrustal rocks (Appel, 1986b). One of the areas which appeared to be interesting is the Sermilik area c. 75 km south of Nuuk. In this area several streams with high contents of scheelite were found. The area has been subject to granulite facies metamorphism and a major granitic intrusion emplaced. Both events might have caused extensive mobilisation and subsequent upgrading of stratabound scheelite mineralisation. The supracrustals are situated at the shore of a smal! fjord, where ice rarely causes problems for shipping. The alpine topography, with near vertical cliffs, poses an obstacle for prospecting. The present paper describes only field observations. Laboratory work is confined to X-ray identification of scheelite in some of the heavy mineral concentrates and in a few rock samples.