A petrographic and geochemical study of the Early Proterozoic, Bangenhuk granitoid rocks of Ny Friesland, Svalbard

Old Red Sandstones and younger strata overlie a variety of deformed and metamorphosed Early Paleozoic and Precambrian rocks on Svalbard, referred to as the Hecla Hoek Complex. At least three different terranes are recognized, occurring in eastern, northwestern and southwestern areas. The Eastern Terrane is exposed in the northeastern parts of the Svalbard archipelago in Nordaustlandet and Ny Friesland. In the latter area, c. 1750 Ma old granites and gneissic granites, mostly from the Bangenhuk Formation in the lower part of the Hecla Hoek, have been studied. Petrographical and geochemical data indicate that the rocks can be classified as granites and granodiorites and plot as A-type granites in tectonic discrimination diagrams. They are characterized by high alkali contents, high K2O/Na2O- and Fe2O3*/(Fe2O3*+MgO) ratios and high contents of Zr, Zn, Y, Nb, Ga and REE (except Eu). The geochemical coherence of the rocks suggests that they represent related magmatic events. Deformation and metamorphism have not influenced the element distribution significantly