Aeromagnetic Evidence for Origin of Arctic Ocean Basin: ABSTRACT

Abstract

Approximately 147,000 km of low-level (450 m) aeromagnetic tracks were flown over the Arctic Ocean and adjacent Greenland and Norwegian Seas. From these data inferences could be made about the geologic structure and evolution of the Arctic Ocean basin. The Alpha and Nansen Ridges produce magnetic profiles that show axial symmetry and correlate with profiles in the North Atlantic that cross the Reykjanes Ridge and profiles in the Norwegian Sea that cross Mohns Ridge. A quantitative attempt has been made to verify these correlations, which infer that the Alpha Cordillera became inactive 40 m.y. ago, when the locus of rifting shifted to the Nansen Cordillera. The lack of magnetic disturbances associated with the Lomonosov Ridge is interpreted to be a section of the former Eu asian continental margin that was translated into the Arctic basin by sea-floor spreading along the Nansen Cordillera axis. Within the Canada basin there is a thickening of sediments from the Asia continental margin toward the Canada Arctic Archipelago. Sediment thickness in the Makarov basin is estimated to be 1-1½ km. There appears to be only about ½ km of sediment covering the younger Fram and Nautilus basins. The absence of large magnetic anomalies over these basins can be explained by a 10-km elevation of the Curie isotherm. End_of_Article - Last_Page 2512------------