Crustal structure and lithology of the northern Canadian Cordillera: alternative interpretations of SNORCLE seismic reflection lines 2a and 2b
Seismic reflectors at shallow crustal levels recorded in SNORCLE (Slave  Northern Cordillera Lithospheric Evolution) lines 2a and 2b in the northern Canadian Cordillera can be reconciled with many stratigraphic and structural elements known from geological mapping. Clearly evident examples are the crustal penetrating, Northern Rocky Mountain Trench (NRMT) Fault, the several kilometres thin slices of Slide Mountain (Sylvester Allochthon) and Cache Creek terranes, and the northward dipping Hotailuh Fault. Interpretations of lithological successions and structures at deeper crustal levels are more speculative. Of fundamental significance is a southwesterly tapering wedge of continental crust overlain in its distal part by the allochthonous terrane Stikinia and, northeast of Thibert Fault, by a thick, probably structurally thickened sequence of sedimentary rocks and the extensive granitic Cassiar batholith. The top of the wedge is interpreted to be a tectonic accretion surface resulting from collision of Sti...