Overthrust model for the Sierra Nevada

The structure of the northern Sierra Nevada, California, is a series of east-directed thrust faults modified by upright and west-directed folds and faults. The highest tectonic unit is a nappe composed of the Smartville ophiolitic complex and related rocks. These structures collectively represent the Middle Jurassic Nevadan orogeny. This overthrust-backfold model resembles Middle Jurassic events in British Columbia and the Cretaceous-Tertiary tectonics of the western European Alpine belt, and it is consistent with the hypothesis that the Nevadan orogeny reflects the collision of an oceanic volcanic arc with North America.