Discovery of a medium-temperature eclogite province in the Caledonides of North-East Greenland

Basic and acid-intermediate bodies containing eclogite-facies parageneses were discovered during recent mapping in North-East Greenland. Scattered throughout an orthogneiss complex, eclogitic pods extend from approximately lat 76 degrees 40'N to the northern limit of the area mapped (78 degrees N), a province comparable in size to the eclogite-bearing Western Gneiss region of Norway. The eclogites are the medium-temperature type typically formed in overthickened continental crust during continent-continent collision. An early Proterozoic event cannot be ruled out, but field relations and regional correlations suggest that the high-pressure metamorphism may be Caledonian. Paleozoic eclogites in Greenland would negate current tectonic models for Caledonian collision that envision simple subduction of Baltica beneath Laurentia, while early Proterozoic eclogites would be the oldest bona fide eclogites known.