Albitised gneisses in the area between Paakitsoq and Kangerluarsuk, north-east Disko Bugt, West Greenland

Abstract

Fine-grained rutile-bearing albite-rich rocks (> 95% albite) locally replace Archaean granodioritic orthogneisses in the area between Paakitsoq and Kangerluarsuk, eastern Disko Bugt. They occur as anastomosing networks within albite-rich gneiss and as replacements along linear fracture zones. Albitisation resulted from pervasive metasomatism, but the origin and nature of the albitising fluids are uncertain. A tentative comparison is made with rutile-rich albitites (‘kragerøites’) in southern Norway.