9416933 Gehrels One of the fundamental questions in Cordilleran tectonics is the degree of orogen-parallel transport of outboard terranes before final docking and amalgmations to North America. Paleomagnetic data has commonly been used to determine latitude shifts of allochthouous terranes, but the method has many possible sources of error. As a result, geologic data is frequently at adds with paleomagnetic interpretations. This project intends to employ an entirety different technique to detect and quantify orogen-parallel terrane translation. Prior work has assembled a database of the distribution of zircons in source rocks along the western north american craton. This project will examine suites of detrital zircons from outboard terranes and match their age distributions to the North American craton database to estimate the degree of allochthoniety. Successful results will provide an independent test for possible northward translation of several exotic terranes in western Nevada and northern California, thereby helping to resolve the discrepancy between paleomagnetic results and geology analysis. ***
