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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 66 (1982)

Issue: 7. (July)

First Page: 964

Last Page: 964

Title: Mesozoic-Cenozoic Tectonic Evolution of Western North America--Alternative to the Orocline: ABSTRACT

Author(s): Joe S. Dixon

Article Type: Meeting abstract


A time-lapse sequence for the Lower Jurassic of North America-Siberia positions is used, geared to Mid-Atlantic opening rates and pole of rotation, to show a possible linkage between the Pacific and Arctic Oceans. With a pervasive and long-lasting right lateral movement on all terranes west of the Rocky Mountain Trench (Tintina system), one can perceive Alaska, Yukon, British Columbia, and the western states as a complex of transported microplates joined by transform faults and sutures. The modification of these boundaries and the creation of structural salients in the northern Cordillera are credited to a lower Tertiary collision of the Alaskan Brooks block and Chukotka with the eastward moving Kolyma shield complex. The concept introduces a possible linkage between the xtinct Kula-Farallon Ridge and the Alpha Cordillera and credits spreading within the Arctic to Barents Shelf migration by spreading away from Alaska, between the Nansen fracture zone and the Taymyr trend.

The microplate fabrics of both Alaska and eastern Siberia favor accretionary processes, with all blocks carried out of the Pacific region or along the west edge of the North American craton, rather than rifting away from Arctic Canada.

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Copyright 1997 American Association of Petroleum Geologists