The Great Alaskan Terrane Wreck: reconciliation of paleomagnetic and geological data in the northern Cordillera

摘要: Abstract Paleomagnetic studies place much of the Cordilleran orogen ≥3000 km south, relative to autochthonous North America at 85 Ma. This conflicts with geological which have been interpreted indicate minor displacement. The inability reconcile these interpretations has precluded understanding tectonic development Cordillera, and cast doubt on global paleogeographic reconstructions rely upon paleomagnetic studies. I demonstrate that Alaska Yukon are divisible into a series belts, including northerly east–west-trending Arctic Alaska, central southwest-trending Ruby, southerly east-trending Dillinger southeast-trending Yukon–Tanana belts. Each belt is characterized by four regularly arranged rock sequences; (1) Paleozoic continental margin strata, (2) Devonian–Mississippian arc assemblage, (3) an ophiolite, (4) Early mid-Cretaceous arc. These correlations greatly simplify terrane nomenclature northern Cordillera provide basis for new palinspastic reconstruction Cordillera. Continuity belts can be demonstrated through connecting oroclines, facing structural vergence directions vary in consistent predictable fashion indicating previously formed part linear ribbon continent. continent, referred here as SAYBIA, originally extended south from eastern Siberia was ∼8000 long. Northward translation response coupling Kula plate accommodated buckling (oroclinal orogeny) like derailing train, scissored ‘cars’ forming Alaska. Oroclinal orogeny makes available data provides means rapid construction may important process involved ancient nuclei.