Tectonic model explaining divergent contraction directions along the Cascadia subduction margin, Washington

Differential motion across the central Cascadia subduction boundary in Washington results in a complex pattern of folds and faults within the shelf and onshore parts of the accretionary margin, Faults and folds above a coastal, north-northwest-trending thrust system provide evidence of ongoing subduction-related contraction, South of this coastal thrust system many fold axes and thrust faults trend east-northeast, in the direction of convergence, These structures are not consistent with a simple subduction system undergoing northeastward convergence. This deformation, adjacent to the boundary between the subduction complex and the Siletz terrane, may be driven by relative convergence between the northward-translating Siletz terrane and the subduction complex, The regional pattern of modern uplift rates is consistent with ongoing north-south contraction across this boundary and the north-south compressional stress held in the area.