Test of Nature and Extent of Continental Drift as Provided by Study of Proterozoic Dike Swarms of Canadian Shield1
Published:January 01, 1973
W. F. Fahrig, E. Irving, G. D. Jackson, 1973. "Test of Nature and Extent of Continental Drift as Provided by Study of Proterozoic Dike Swarms of Canadian Shield", Arctic Geology, Max G. Pitcher
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The Franklin intrusions are an extensive swarm of late Hadrynian (latest Proterozoic) diabase dikes that are present in an arc from Great Bear Lake eastward to Melville Peninsula, Baffin Island, and northern Ungava Bay. They are chemically and petrologically classified as tholeiites and are probably comagmatic. Paleomagnetic pole positions and numerous whole-rock K-Ar age determinations indicate that the dikes were emplaced at low latitudes 650 m.y. ago. They intrude Hadrynian sedimentary sequences that contain features indicative of depositon under warm climatic conditions.
The Baffin dikes are subparallel with the northeast coastline of Baffin Island and with a pronounced northwest-trending fault system. Intermittent, mainly normal movement along these faults persisted from the Helikian to the Quaternary and produced a series of graben structures which may be due to the same regional tension as the dikes. Thus, Baffin Bay and Davis Strait may have begun to form as early as the late Hadrynian, and they may contain Paleozoic strata.
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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.