Precambrian gneisses and intrusive anorthosite of Smithson Bjerge, Thule district, North-West Greenland

Abstract

Smithson Bjerge is part of the Precambrian crystalline complex of North-West Greenland. The area comprises the Qaqujârssuaq anorthosite, the Heilprin Gletscher complex, paragneisses, multiphase orthogneisses and diverse minor granitic and basic intrusions. The Heilprin Gletscher complex comprises intimately associated granite, ferrogabbro and ferrodiorite. The Heilprin Gletscher complex and the Qaqujârssuaq anorthosite were intruded into the paragneisses and the multiphase orthogneisses, and may form an anorthosite-granite-ferrodiorite association. All lithological groups apart from the minor intrusions have been affected by large-scale overtumed folding and regional medium-pressure granulite facies metamorphism.