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Figure 1
 
Figure 1.

Schematic terrane map (A), paleogeographic map (B), and cross section (C) showing our preferred tectonic model of the northwestern Cordillera ca. 130 Ma with east-dipping subduction beneath Chugach subduction complex (CT) and Wrangellia composite terrane (WCT [also referred to as the Insular terrane] is outlined in red, and includes AT, PT, and WT), east-dipping subduction beneath inboard terranes, and a marine basin of indeterminate width separating the WCT from inboard terranes. Terrane abbreviations: AT—Alexander; CT—Chugach; PT—Peninsular; ST—Stikine; WT—Wrangellia; YTT—Yukon-Tanana. Abbreviations in A are G—Gravina basin; K—Kahiltna basin; M—Methow basin; N—Nutzotin basin. Spatial extent of volcanism and Insular terrane is schematic. (A) modified from Kapp and Gehrels (1998); (B) digital elevation map © 2013 Colorado Plateau Geosystems Inc.; (C) modified from Trop and Ridgway (2007).

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