The Nagssugtoqidian boundary and the deformation of the Kângamiut dyke swarm in the Søndre Strømfjord area

Abstract

The season's objective was the reconnaissance mapping of a c. 7000 km² area lying between Søndre Strømfjord, the Inland Ice and the Sukkertoppen ice capo. An important feature of this region was known to be the progressive northward deformation of the Kangamiut dyke swarm and an associated amphibolite facies metamorphism of both the dykes and their granulite facies country rocks (Noe-Nygaard & Ramberg, 1961). These changes have been regarded as marking the southern limit of Nagssugtoqidian orogenic activity. In order to make a more comprehensive study of this boundary, the reconnaissance was extended to include the c. 3000 km² area southwest of the Sukkertoppen ice cap, bounded by Søndre Strømfjord and Evigheds Fjord.