Present interactions (subduction, translation, rifting) between the Pacific oceanic plates (PP) and the North American craton (NAC) are similar to earlier events and represent a continuation of the tectonic evolution of the Cordilleran orogen. The formation and breakup of Pangea also influenced Cordilleran evolution. Based on these observations, it is possible to model the tectonic evolution of Alaska without accreting "exotic microplates."

In early Phanerozoic time, a passive marine shelf was present along the western margin of NAC, which was the depositional site of a miogeoclinal clastic-carbonate sequence. Subduction of PP beneath NAC, coincident with the formation of Pangea, began in early Paleozoic time and generated an island-arc/back-arc rift. Miogeoclinal fragments were incorporated in the back-arc rift. A middle Paleozoic orogeny collapsed the back-arc rift and obducted the arc onto NAC.

The Tethys Rift split Pangea into Laurasia and Gondwana in the Triassic. As Laurasia moved northward, a continental margin rift with 1,000-km left-lateral offset developed along the NAC's western margin. In the Late Jurassic, Laurasia rifted apart, and NAC moved westward relative to PP. Subduction collapsed the lower Mesozoic continental margin rift, generated a continental arc, and culminated as a major orogeny in the Late Cretaceous.

Cenozoic subduction of ocean-spreading ridges shifted the relative movement between PP and NAC. Northwest subduction of PP generated the Aleutian arc, and a translational boundary was established in southeastern Alaska. NAC's obducted outboard terrains were offset northwestward by the Tintina and related faults.

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