Stratigraphy, structure and igneous features of the Angnertussoq layer of the Fiskenæsset complex

Abstract

A prominent layer of the Fiskenæsset complex (Kalsbeek & Myers, 1973) extends for at least 10 km eastwards from Angnertussoq mountain which is situated about 14 km south-east of Fiskenæsset. Its stratigraphy is broadly similar to that of the Qeqertarssuatsiaq layer to the north (Windley, Herd & Bowden, 1973), and to those parts of the Fiskenæsset complex in the Majorqap qava area (Myers, 1973) and in the region north of Bjørnesund (Walton, 1973). Igneous textures and grading are extremely well preserved in the Angnertussoq layer, the grading providing a confirmation of the way-up of the stratigraphic succession indicated by the whole-rock chemistry (Windley et al., 1973). Five weeks were spent mapping the stratigraphy and structure of the Angnertussoq layer on approximately 1:20000 aerial photographs. At its narrowest it is less than l m thick and at its widest, 2 km. It is bordered conformably by biotite/hornblende-bearing granitic gneisses. The complex in this area was recrystallised by at least an amphibolitegrade metamorphism and deformed by thrusting and two major phases of folding.