Lithoprobe crustal reflection cross section of the southern Canadian Cordillera, 1, Foreland thrust and fold belt to Fraser River Fault

摘要: Seismic reflection data from the south central Canadian Cordillera covering interval easternmost metamorphic core complexes near Arrow Lakes to Fraser River fault system along reveal a highly reflective and complex crust. The base of crustal reflectivity, interpreted as Moho, is clearly delineated by continuous sharp boundary that essentially planar slopes uniformly over distance 250 km about 12.0 s in east 10.5 west. This virtual lack relief at crust contrasts sharply with surface structures involve 25 or more structural relief. Some these can be readily correlated are outlined followed into middle lower Even though part this area was subjected large amounts Eocene extension, not divisible transparent upper layers it parts U.S. Cordillera. Three culminations, Monashee complex, Vernon antiform, Central Nicola horst, on basis configuration geological relationships have formed initially during Jurassic compression then been modified exposed early extension. An example compressional structure observed profiles decollement, which traced westward Extension manifested variety normal faults, including regionally extensive low angle Okanagan Valley-Eagle system, moderately dipping faults such Columbia Slocan Lake high-angle Quilchena Creek Coldwater faults. Both shear zones extensional listric Moho under Intermontane belt.