Fi g. 4.5. Coset of planar cross-bedding (lithofacies Sp) showing first-order bounding surfaces. Cretaceous, Banks
Is land, Arctic Canada
Fi g. 4.6. Two second-order surfaces (arrows) enclose a bed of plane-lam in ated sandstone (lithofacies Sh), which shows
gradational contacts above and below with ripple cross-laminat ion (Sr}. Eocene, Axel Hei berg Island, Arctic Canada