Quaternary Geology of the Ice-Free Areas and Adjacent Shelves of Greenland
Greenland, the largest island in the world, has a general bowl shape with peripheral mountainous areas surrounding a central basin that extends below sea level. The Greenland Ice Sheet occupies the central bowl, covers much of the fringing mountains, and in places pushes to the coast where it calves into the sea. Ice-free regions at the fringes of the ice sheet are in most areas mountainous, cut by fiords and contain scattered thin deposits of till and local thick deposits of Quaternary nonglacial sediments of a variety of different ages.
Evidence from shelf areas indicates that an early glaciation of Greenland, which was more extensive than any succeeding one, occurred near the end of the Pliocene (about 2.4 Ma). A younger phase of glaciation (about 1.8 Ma) is recorded near the base of the Kap Kϕbenhavn Formation and in the Lodin Elv Formation. Sediments above deposits related to this glaciation were deposited under cool temperate conditions. Tree remnants included in these sediments suggest a climate incompatible with existence of an inland ice sheet.
Several areas contain a record of a glaciation that occurred prior to the last interglaciation. This has been referred to as Fiskebanke, Scoresby Sund, and Bliss Bugt glaciations in West, East, and North Greenland, respectively. On the basis of intensity of weathering it is suggested that these three are correlative. The glaciation is tentatively referred to Illinoian. This glaciation was more extensive than subsequent glaciations, and distribution of erratics indicates that ice in coastal areas was thick enough to move independent of the underlying topography.