9628515 Mahoney A key controversy in the US and Canadian Cordillera concerns the amount and timing of northward translation of allochthouous terranes. Paleomagnetic data imply large-scale translation of both Insular and Intermontane terranes between late Cretaceous and Eocene times, but geologic data apparently limits the total margin-parallel displacement to much smaller amounts since late Cretaceous time. This investigation will attempt to resolve the controversy by testing a specific prediction of the large-scale translation hypothesis, namely a large (2000 km) relative displacement between the 80-55 ma, by use of upper Cretaceous strata, and an examination stratigraphic linkages between the rocks of this age that are found on both superterranes. Results are expected to provide robust data to resolve this controversy, which should also be useful in providing insight into the record of large-scale displacements in other orogenic systems.
