Quantifying Dextral Shear on the Bristol-Granite Mountains Fault Zone: Successful Geologic Prediction from Kinematic Compatibility of the Eastern California Shear Zone

Abstract

AbstractFor regional kinematic compatibility to be a valid boundary condition for continental tectonic reconstructions, there must be tests that validate or invalidate kinematic model predictions. In several reconstructions of western North America, the displacement history of the Mojave block continues to be unresolved. The magnitude of displacement along the Bristol-Granite mountains fault zone (BGMFZ), which is the eastern margin of the Eastern California Shear Zone (ECSZ) in the Mojave block, is a key example of a long-standing kinematic prediction that has defied a positive field test until now. The ECSZ is a network of late Neogene and Quaternary right-lateral strike-slip faults that extend from the Gulf of California north through the Mojave Desert, linking Pacific–North America plate motion with Basin and Range extension. This network of faults accounts for ∼15% of post-16-Ma plate transform motion. Geologic estimates of net dextral offset along the Mojave portion of the ECSZ (53 ± 6 km) are appro...