Underwood, Michael B. (2002): Strike-parallel variations in clay minerals and fault vergence in the Cascadia subduction zone. Geological Society of America (GSA), Boulder, CO, United States, Geology (Boulder), 30 (2), 155-158, georefid:2002-014646
Abstract:
Clay minerals probably affect the zonation of mechanical properties within a thick unit of abyssal-plain deposits as they enter the Cascadia subduction zone. Landward-vergent thrust faults develop above a deeper decollement because smectite-rich mudrocks within that corridor release more water during clay dehydration, which in turn elevates pore pressure and reduces basal shear stress relative to wedge strength. Conversely, dilution of smectite by illite and chlorite increases the frictional coefficient, and fluid overpressure should drop where smectite dehydration is volumetrically reduced. Thus, thrust faults within chlorite-rich segments of the margin are seaward vergent.
Coverage:
West: -126.2048 East: -125.0705 North: 44.5330 South: 44.4026
Relations:
Data access: