Descriptive text to Geological map of Greenland, 1:500 000, Dove Bugt, Sheet 10

Abstract

The Dove Bugt 1:500 000 scale geological map sheet covers a segment of the East Greenland Caledonian orogen extending between latitudes 75°–78°N and longitudes 16°–29°W. The region was mapped in the summers of 1988–1990 as part of a regional Survey mapping programme, and the map sheet was printed in 1997.

The region covered by the Dove Bugt map sheet is dominated by Palaeoproterozoic gneiss complexes, with smaller amounts of Mesoproterozoic and Neoproterozoic metasedimentary rocks, and isolated strips of Palaeoproterozoic and Lower Palaeozoic sedimentary rocks. All these rock units have been reworked to a varying degree during the Caledonian orogeny. Post-Caledonian sedimentary rocks occur in the south-east corner of the map sheet area and as narrow, fault-bounded enclaves elsewhere, while Palaeogene basaltic lavas and sills crop out on the island of Shannon.

The rocks of the Caledonian orogen form a number of major thrust domains. The most extensive and structurally lowest is the Nørreland thrust sheet which is characterised by lenses and layers of medium-temperature, high-pressure eclogites. The Western thrust belt occupies a broad zone of eastern Dronning Louise Land that comprises Palaeoproterozoic gneiss complexes interleaved with Palaeoproterozoic and Palaeozoic metasedimentary rocks. This thrust domain is separated from the foreland rocks of western Dronning Louise Land by the Imbricate thrust zone. In the south-west part of the map sheet the highest structural domain, the Hagar Bjerg thrust sheet comprises three rock sequences: crystalline gneisses, the Mesoproterozoic Smallefjord sequence and the Neoproterozoic Eleonore Bay Supergroup.

The crystalline gneiss complexes that dominate the map sheet area and make up a significant proportion of the different Caledonian thrust domains have all yielded protolith ages of c. 2 Ga. They are attributed to a major period of crust formation in the Palaeoproterozoic. The gneisses have been variably affected by Caledonian deformation and metamorphism.