Preliminary results on the distribution of uranium in drill cores from Kvanefjeld, Ilimaussaq intrusion

As part of the uranium extraction research programme carried out at the Risoe National Laboratory, geochemical and mineralogical investigations of the Kvanefjeld area were conducted at the Geological Survey of Greenland. Principal conclusions on the distribution of uranium and the mineralogy of the potential uranium ore from Kvanefjeld are summarised: Uranium is primarily distributed in the lujavrite varieties and in deformed lavas. The radioactive grains may show homogeneous, layer- (vein-) like, nest-like or single-crystal, coarse-grained types of distribution in the rocks. Steenstrupine of two types (generations), A and B, represents the main uranium-bearing mineral. It is generally metamictized or altered into secondary in situ phases. The metamictization and alteration of steenstrupine are primarily dependent on its U-Th content and not on the rock type or on the degree of hydration of the primary felsic minerals. (author)