EAST GREENLAND GEOSYNCLINE

a linear trough in the Earth's crust in which a fragmentary belt of rocks of late Precambrian and early and middle Paleozoic age (about 650 to 350 million years ago) were deposited along a portion of the eastern coast of Greenland. Deformation of the geosyncline occurred during several phases of the Caledonian orogeny (mountain-building episode) between Late Silurian and Late Devonian times (roughly 421 to 360 million years ago). The deformation resulted in folding, westward thrusting, and development of angular unconformities beneath and within Devonian sedimentary rocks and was accompanied by the intrusion of Silurian and Devonian granites. The East Greenland Geosyncline may represent the west flank of the Caledonian Geosyncline, the remainder of which is now exposed along the northwest coast of Norway, prior to continental rifting in Paleozoic time.