The crystalline rocks of western and southern Dove Bugt, North-East Greenland

Abstract

The land areas around Dove Bugt are dominated by quartzo-feldspathic orthogneisses with a complex history of emplacement and deformation. The oldest rocks recognised are supracrustal units, mainly marbles and rusty-weathering metasedimentary rocks. Locally gabbro-anorthosite units are associated with the supracrustal rocks. These rock units are cut by different phases of the gneisses, of which the most abundant are grey banded orthogneisses. Two different varieties of pink orthogneiss are also recognised. Different types of tabular amphibolitic bodies, relicts of dykes or sills, cut most rock types. The area lies within the East Greenland Caledonian fold belt, but available isotopic data suggest that the crystalline rocks include Archaean and early Proterozoic suites which have undergone uncertain degrees of Caledonian reworking. It is not clear at present how much of the deformation history of at least four periods of deformation and associated mylonitisation is Caledonian, and how much pre-Caledonian.