Reciprocal architecture of Bearpaw and post-Bearpaw sequences, Late Cretaceous - early Tertiary, Western Canada Basin

Campanian-Paleocene nonmarine deposition in the Western Interior Basin was characterized by three marine incursions of 10;The Bearpaw second-order cyclothem consists of a succession of third- and lower-order sequences, with a more complex sequence architecture in the foreland basin syncline (up to the sixth-order) than in the peripheral forebulge sector (only third- and fourth-order sequences). The hierarchy of sequence-bounding surfaces is based primarily on their regional significance (areal extent) and only secondarily on the span of time on the corresponding sequence, allowing a better interpretation of their controlling factors.;The sequence-bounding surfaces are time-transgressive, younger cratonward, as they cross the time-lines represented by bentonite horizons and biozone limits, with a diachronieity rate of 0.5 Ma/625 km. This temporal offset between proximal and distal correlative surfaces is interpreted as a result of a gradual propagation of the basin flexural shape as an aseismic tectonic wave due to the lateral motion of the asthenospheric flow generated by episodes of thrust-sheet loading in the fold-thrust belt.