Geological Survey of Denmark and Greenland Map Series 4
Descriptive text to Geological map of Greenland, 1:500000, Dove Bugt, Sheet 10
Niels Henriksen & A.K. Higgins
The Dove Bugt map sheet, printed in 1997, displays the central region of the Caledonian fold belt in North-East Greenland, and includes small areas of post-Caledonian sedimentary rocks and Palaeogene basalts exposed in the south-east corner of the map area. The rocks in the Caledonian orogenic belt are divided into several westwards-directed thrust sheets displaced against the foreland that occurs at the rim of the Inland Ice. The thrust sheets comprise units of composite pre-Caledonian and Caledonian origin, including Palaeoproterozoic gneisses, Mesoproterozoic supracrustal schists and gneisses, and in the south a succession of Neoproterozoic metasedimentary rocks of the Eleonore Bay Supergroup.
Since the map was compiled, geological mapping of adjacent regions in East Greenland has led to a new understanding of the general structure of the Caledonian orogen. The map sheet description has therefore been presented in a form which is in agreement with modern interpretations, with extensive reference to the newer literature.
Post-Caledonian sedimentary and igneous units comprise Carboniferous sandstones preserved in small down-faulted outcrops, Jurassic–Cretaceous sedimentary rocks outcropping in coastal regions, and Palaeogene basaltic flows and sills found in the south-eastern corner of the map area.
Download the entire paper Map4_p1-32.pdf (pdf-fil ~4.9 Mb)
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.
Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
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