Field, seismic, structural, and stratigraphic data were used to reconstruct the geologic history of the Arctic in 10-m.y. time slices from the present to mid-Jurassic--the initial opening of the Arctic Ocean. A basic assumption is that Lomonosov Ridge, Alpha Ridge, Mendeleyev Ridge, and Chukchi Plateau are all foundered continental plates.

Opening of the Arctic occurs in two stages: Late Jurassic-Cretaceous for the Canada basin and Neogene for the Eurasian basin. Opening is facilitated by two subparallel transform shears--the Arctic (Kaltag-Porcupine) on the east and the Chukchi on the west. Deformation is essentially tensional on the Barents side of the Arctic and shear-compressional on the Alaska side.

The development of Chutkoya, North Slope, Brooks Range, northwest Canada, Seaward Peninsula, and central Alaska can be sequentially related to Arctic opening, modified by impingement on the northern terrane of allochthonous terranes arriving from the south--the Pacific plates of Tintina, Denali, Orca (Prince William-Chugach-Yakutat), Anadyr, Khatyrka, Kolyman, and other minor terranes.

The North Slope of Alaska, a passive, rifted, subsided margin, is restored to line up with a similar margin on Alpha Ridge. Northeastern Alaska (the Romanzof Mountain area) lines up opposite the north end of the Sverdrup Rim, near Prince Patrick and Borden Islands.

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