Latest Cretaceous to early Tertiary dextral strike-slip faulting on the southeastern Yalakom fault system, southeastern Coast Belt, British Columbia

The Yalakom fault system cuts the Cadwallader, Bridge River, and Methow terranes for 300 km along the northeast side of the Coast Belt in southwestern British Columbia. The fault system had major dextral slip after middle Cretaceous contractional deformation and early Late Cretaceous volcanism, which ceased by latest Eocene time. At discrete times, the Yalakom fault system had major changes in the configuration of active faulting, which resulted in four stages of faulting over ≃ 40 m.y. An estimate of 115 km dextral, strike-slip displacement on the Yalakom fault is based on offset of a unique three-part structural succession of the Methow, Cadwallader, and Bridge River terranes. The presented interpretations preclude the Yalakom fault from being a major contributor to large-scale northward translation of the northwestern Cordillera interpreted from paleomagnetic data to have occurred largely before Eocene time. The Yalakom fault system probably was linked to the Hozameen and Ross Lake faults.