Origin of Arctic and North Atlantic Oceans1
Published:January 01, 1973
Late Proterozoic through Early Permian evaporite deposits are widespread in northern Canada, Greenland, and northern Eurasia. All of these evaporites are found today on the Atlantic Ocean, Eurasia, and Canada sides of the Lomonosov Ridge and its extensions into northern Siberia and northern Canada. No evaporites are known to be present on the Pacific side of the Lomonosov Ridge or north of its extensions into Siberia and Canada. This fact alone suggests that the Atlantic Ocean has been open into the Arctic since middle to late Proterozoic time; it further suggests that the Lomonosov Ridge and its continental extensions were in existence by late Proterozoic time. Hence, the distribution pattern indicates that the evaporites were brought in by, and precipitated from, marine waters entering via the present location of the Atlantic Ocean and the Lena Trough. Geologic data from Iceland, new geophysical data from the North Atlantic Ocean, and physical continuity of the Proterozoic Lomono-sovides around the Canadian basin of the Arctic Ocean lend strong support to the interpretation given here.
Post-Devonian evaporite deposits in the Arctic are scarce, and their depocenters generally are farther south than those of Devonian and pre-Devonian times. The locations of the post-Devonian evaporite depocenters appear to be related to the formation of two sills across the present North Atlantic: the Franz Josef sill between Novaya Zemlya and Spitsbergen, separating the Arctic from the North Atlantic, and the Faeroe-Greenland sill extending from Scotland to southeastern Greenland.
Because the known evaporite-distribution patterns show such close relations among the present North Atlantic and Arctic Oceans; the present continental positions; and the existing sites of the Lomonosov Ridge, the Franz Josef sill, and the Faeroe-Greenland sill, postulation of plate-tectonic models for the formation of the North Atlantic and Arctic is unnecessary. In fact, no plate-tectonic or polar-wandering mechanism yet proposed explains the orderly geometric relations between the evaporite deposits and the observed geographic-topographic features. Hence, sea-floor spreading, plate motions, and polar wandering—if they ever took place in the North Atlantic-Arctic region—were pre-late Proterozoic events.
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Following the discovery of Prudhoe Bay oil field in 1968, much attention was turned to the Arctic in the search for giant hydrocarbon accumulations. The Soviets had already proved giant reserves in their West Siberian Basin, and exploration was moving ahead quickly in the Canadian Arctic. Plans were drawn up for an AAPG Symposium on Arctic Geology and held in February 1971. Papers were selected from the Symposium for this publication and cover seven topical groupings: Regional Arctic Geology of Canada, Regional Arctic Geology of the Nordic Countries, Regional Arctic Geology of the USSR, Regional Arctic Geology of Alaska, Comparisons in the North Atlantic Borders, Evolution of the Arctic Ocean Basin, and Economics of Petroleum Exploration and Production in the Arctic.