Eustatic sea level changes interpreted from seismic stratigraphy; a critique of the methodology with particular reference to the North Sea Jurassic record

Seismic stratigraphic methods for interpreting eustatic sea level change are based on generalized stratigraphic models and chronostratigraphic interpretations that have not been substantiated by publication of the necessary basic supportive data. Chronostratigraphic correlations of sea level change curves between basins are based partly on circular reasoning. Onlap and offlap seismic models may not indicate sea level change but flexural subsidence, facies shifts, or changes in sea level in the opposite direction to that proposed. Resolution of some of these problems may be achieved by publication of basic data now in confidential industry files. The widely acclaimed "Vail curves" should not be used as templates for basin correlation until such data have been provided, and such use should be supported by appropriate conventional lithostratigraphic and biostratigraphic documentation from each new basin. Where such data have been made available, as with the North Sea Jurassic, serious questions of interpretation are raised.