Three-dimensional geometry of sedimentary basins and Moho beneath Western Canada from ambient seismic noise tomography

We study the characteristics, geometry, and provenance of major sedimentary basins and their host tectonic belts in western Canada based on a comprehensive 3D shear wave velocity ( Vs) model derived from ambient seismic noise tomography. Within the Insular belt, the offshore Queen Charlotte (QCB) and Georgia Basins (GB) have a maximum depth exceeding 10 and 7 km, respectively, with variable Moho depths underneath. Within the Intermontane belt, the maximum basin depth is 7.5 and 7 km for Nechako and Bowser/Sustut Basins, respectively. The Moho is 34–48 and 33 km in the northern and southern parts of the Intermontane belt, respectively, but is obscured in other areas by shallow high- Vs structures associated with relatively high uncertainty estimates. The high- Vs structure is likely related to structural complexity at the edge of an underthrust craton. Within the Western Canada Sedimentary Basin, the deepest part of the Alberta Basin is located between the Montney and Duvernay Basins, with a maximum depth >6 km. At greater depths, the Moho is observed to dip slightly toward the southwest, but some local variations exist beneath the Montney Basin. The deepest basins estimated in this study are found beneath the QCB (>10 km), Williston Basin (>10 km), and the Alberta Deep Basin (>6 km), while the deepest Moho underlies the Williston Basin (∼46 km), parts of the QCB (∼44 km), Alberta Deep Basin (>45 km), and northern British Columbia (∼46 km).