HR: 11:20h
AN: T12C-05    [Abstracts]
TI: The Lomonosov, Alpha, and Mendeleev Ridges: Tectonic Scenarios in the Arctic Ocean and the Test of Appurtenance in UNCLOS Article 76
AU: Srivastava, S P
EM: ShiriSrivastava@eastlink.ca
AF: Geological Survey of Canada (Retired), Bedford Institute of Oceanography, PO Box 1006, Dartmouth, NS B2Y 4A2 Canada
AU: Varma, H
EM: varmah@mar.dfo-mpo.gc.ca
AF: Canadian Hydrographic Service, Bedford Institute of Oceanography, PO Box 1006, Dartmouth, NS B2Y 4A2 Canada
AU: * Macnab, R
EM: ron.macnab@ns.sympatico.ca
AF: Geological Survey of Canada (Retired), 11 Lyngby Avenue, Dartmouth, NS B3A 3T6 Canada
AB: The land masses surrounding the Arctic Ocean feature several submerged prolongations into the deep central basin. These range in size from enormous i.e. the broad continental shelves off northern Russia and Scandinavia, to small i.e. the Yermak Plateau and the Morris Jesup Rise which flank Fram Strait. Lying between these extremes on the size scale are the Chukchi Borderlands and the Lomonosov, Alpha, and Mendeleev Ridges. At either end of the scale, the prolongations appear to satisfy the Test of Appurtenance in UNCLOS Article 76, where they qualify as components of outer continental shelves. In the middle of the scale, it is generally agreed that the Chukchi Borderlands satisfy the Test of Appurtenance, but the Lomonosov, Alpha, and Mendeleev Ridges are perceived by some as problematic. While the continental composition of the Lomonosov Ridge is generally acknowledged, the structural and tectonic relationships between its extremities and the adjacent continental margins are poorly understood. Meanwhile, the origin and history of the Alpha and Mendeleev Ridges remain shrouded because of the difficulty of undertaking systematic mapping and sampling that would reveal their ages and geological makeups, and shed light on their marginal junctions. There can be little doubt that the nature and emplacement of the Lomonosov, Alpha, and Mendeleev Ridges are related to the tectonic processes that accompanied the creation of the Arctic Ocean. An understanding of those processes would help establish a geological and historic framework for interpreting the sparse knowledge that is available for the three Ridges. This presentation will consider tectonic scenarios that could account for early stages in the development of the Lomonosov, Alpha, and Mendeleev Ridges, and in the process seek to dispel uncertainties concerning their linkages to the adjacent continental margins. Until further research leads to broad general agreement concerning the answers to such questions, it would seem premature to apply the Test of Appurtenance to these features.
DE: 3037 Oceanic hotspots and intraplate volcanism
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 8157 Plate motions: past (3040)
DE: 8169 Sedimentary basin processes
DE: 9315 Arctic region (0718, 4207)
SC: Tectonophysics [T]
MN: Fall Meeting 2005