The late Miocene to Pleistocene ice-rafting history of southeast Greenland

• Published in: Boreas Vol. 31; no. 1; pp. 28 - 35
• Main Authors: John, Kristen E. K. St, Krissek, Lawrence A.
• Format: Journal Article
• Language: English
• Published: 01.03.2002
• Subjects: Marine; ANW, Greenland, Vestgroenland; Northern Hemisphere; PN, Greenland, Greenland Ice Sheet; ANE, Atlantic, Irminger Basin; Greenland; ANE, Greenland, Oestgroenland
• ISSN: 0300-9483
• DOI: 10.1080/03009480210651

Analysis of a Miocene-Pleistocene ice-rafted debris (IRD) record from the western Irminger Basin provides evidence for the initiation and long-term behavior of the SE portion of the Greenland Ice Sheet. In the late Miocene ( similar to 7.3 Ma), IRD supply to Ocean Drilling Program site 918 increased significantly indicating that glaciers large enough to reach sea level were present in SE Greenland long before the onset of widespread Northern Hemisphere glaciation. IRD accumulated at this site throughout the Pliocene and Pleistocene, supporting the hypothesis that SE Greenland was a key nucleation area for the formation of the Greenland Ice Sheet. Since glacial onset, the western Irminger Basin IRD record is characterized by a succession of episodes with high IRD mass accumulation rates (MARs). The site 918 IRD record indicates that greatest iceberg production in SE Greenland occurred during major climatic transitions (e.g. widespread Northern Hemisphere glacial expansion at 2.7 Ma and the mid-Pleistocene climate shift at 0.9 Ma), and that SE Greenland sometimes also led the northern North Atlantic region in glacial response to climatic forcing (e.g. glacial intensification at similar to 4.8 and, along with NE Greenland, at similar to 3.5 Ma).