Structural geometry and kinematic evolution of the central Canadian Rocky Mountain Foothills fold-and-thrust belt: Complex kinematic relationships controlled by detachment utilization

Balanced regional cross sections based on surface, seismic, and subsurface data show that the thin-skinned fold-and-thrust belt in Rocky Mountain Foothills of Kakwa area central Canadian Rockies consists a lower buried thrust developed Paleozoic Triassic strata an upper exposed faulted fold Jurassic to Cretaceous strata. Changes wavelength, amplitude, geometry with stratigraphic level indicate multiple detachments were utilized belt. Exposed folds are chevron or box shaped. Most appear be detachment fault propagation formed by fault-to-fold displacement transfer. Geometric kinematic relationships vary from faults congruently folded underlying (early fault) abruptly truncated (late fault). In contrast, folding sheets is consistent in-sequence deformation for all except one. A sequential restoration balanced section shows variable observed can explained changes successive as they climbed out Chevron-folded younger associated transfer footwall older fault. These thrusts faulting utilization successively higher levels. Late truncate preexisting required out-of-sequence (hinterlandward) level, illustrate another mechanism which critical taper maintained