The nature and timing of tectonism in the western facies terrane of Nevada and California; an outline of evidence and interpretations derived from geologic maps of key areas

Along the outer miogeocline of Nevada and Southern California, lower Paleozoic siliceous sediments and basalt flows, the western facies terrane emerged in Late Devonian time and were deeply eroded; but structural evidence that this event, the Antler Orogeny, involved intense folding and thrust faulting is notably scarce. Almost all the intense folding and thrust faulting of Proterozoic to Permian strata dates from the Jurassic to Eocene interval. If this tectonic history is valid, then the genesis of the Antler Orogeny is reduced to a question of vertical tectonics. Pre-Jurassic contraction involving subduction and collision with island arcs is not indicated or required, but the ultimate origin of Paleozoic tectonism remains unclear.