The Pacific northwest continental margin was the site of extensive accretion of crustal fragments during the Cretaceous. The suturing of the Alexander and related terranes to the western margin of Stikine and other inboard terranes was accompanied by extensive magmatism that formed the Coast Mountains batholith. However, the presence of isotopically evolved material of possible North American affinity within and adjacent to the batholith raises fundamental questions about the degree of allochthoneity of all accreted terranes. This project will attempt to determine the extent of the possible North American rocks, their relationships to adjacent terranes and the age relations between them. Results will allow interpretation of the geometry of accretion- related structures in the suture zone and will provide constraints on the origin and displacement history of the stikine terrane.
