Counterclockwise Rotation of the Arctic Alaska Plate: Best Available Model or Untenable Hypothesis for the Opening of the Amerasia Basin

Summary: For the past thirty years the most widely aeeepted model for theopening of Amerasia Basin of the Aretie Oeean has been that the basin openeclby eountereloekwise rotation of northern Alaska and acljaeent Russia (AretieAlaska plate) away frorn the Canadian Aretie Arehipelago about a pole in theMaekenzie Delta region. Reeently LANE (1997) has ealled this modcl into ques­tion. Thus it is worth reviewing the main data and arguments for and against themodel to determine if indeed it is untenable as claimed by Lane, 01' is still thebest available model.The main evidenee in favour of the modcl includes the alignment of diversegeologieal lineaments ancl the eoineiclenee of Alaskan, Valanginian paleo­magnetie poles with the eratonie one following plate restoration employing therotation model. The odds of such restored matches oeeurring by chance are as­tronornic and thus sueh data provide very eonvineing evidenee for the rotationhypothesis. Reeent gravity and acromagnetic data have allowed the interpreta­tion of a former spreading centrc with flanking anornalies. The orienration ofthese features is compatiblc with the rotation hypothesis, thus adding furthersupport to the model.A review of the various points raised by