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The early Palaeogene deposits of the Central North Sea have been divided by Stewart into ten depositional units, on the basis of seismic stratigraphy. These are interpreted as the products of variations in relative sea level. The units may be traced from the shelf into the basin using wireline log markers correlated within a biostratigraphic framework. These are interpreted as the signature of transgressive maxima when basinal clastic supply was at a minimum. The attitude of coal or lignite beds within the shelfal areas can be used to demonstrate a period of Palaeogene net uplift, followed by tilting and sinking of the shelf-edge and basinal areas during the later depositional episodes. Other than by a mechanism of load-induced differential compaction around buried or partially buried Mesozoic features no significiant rejuvenation of Mesozoic faults can be demonstrated. The area of uplift extended at least as far as the western limit of the Beauly Formation. The products of Stewart’s depositional episodes vary depending on the tectonic activity. During the uplift phase, thick massive basinal fans were deposited and little or no shelfal deposits are preserved. During the tilting/sinking phase thick progradational wedges were deposited, and basinal deposition was largely confined to shales with relatively small local sand systems.

T h e structural evolution of a basin cannot be reconstructed from sedimentary thicknesses alone without data on palaeobathymetry. T w o classes of geological horizons, are defined, profiles and traces. Profiles are time-lines and bound depositional units. Traces were formed at a known water depth and contain implicit palaeobathymetric data. such units are controlled directly by subsidence, while the thicknesses; of profile-bounded units may be unaffected by the subsidence or even the palaeotopography ofthe basin. prior knowledge of the palaeobathymetry, and it is impossible to distinguish between synsedimentary fault movement and onlap to a pre-existing fault scarp from thickness alone. Reconstruction of the basin history of the North Sea is difficult due to the lack of tracebounded units in the post-Jurassic. T h e validity of previously published studies depends largely on the quality and quantity of palaeobathymetric data included. An alternative basin history is proposed based on the few trace-bounded units in the North Viking Graben. This includes rifting episodes in the Triassic and Late Jurassic, and a period of uplift in the Palaeocene. Rock units bounded by traces are diachronous lithostratigraphic units, and the thicknesses of Dating fault movement from thickness variations in profile-bounded units is difficult without

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