Upper Palaeozoic (Permian and possibly Carboniferous) basal sandstones and carbonate rocks rest with angular unconformity on Hecla Hoek rocks in the south-western part of the island of Nordaustlandet, Spitsbergen. Upper Palaeozoic rocks are in turn disconformably overlain by lower Mesozoic (Triassic and possibly lowermost Jurassic) shales, siltstones, and minor sandstones. The upper Palaeozoic-lower Mesozoic sequence thins by sedimentary convergence north-eastward from more basinal areas in Vestspitsbergen to a stable shelf in Nordaustlandet.