Lower Triassic river-dominated deltaic successions from the Sverdrup Basin, Canadian Arctic

Beyond the gross braided stream characteristics of the three river-dominated deltaic successions, the lower two provide a compelling comparison of depositional environments because they formed in the same basin within only a few millions years and thereby were probably subject to similar boundary conditions. The Latest Permian Mass Extinction occurred near the base of the lower sequence containing flood-dominated deltaic facies. We propose that the lower, Induan, sequence is dominated by upper-flow regime plane beds due to the effect of the Latest Permian Mass Extinction on vegetative cover, whereas the middle sequence is dominated by dune-scale cross-stratification formed by lower magnitude, less flood-type flows during the Olenekian.