Chapter 2. Sequence stratigraphic concepts and methodologies

Abstract

Abstract This chapter reviews sequence stratigraphic concepts and methodologies and presents an approach that is most applicable to the North Sea Jurassic, based on the concept of genetic sequence stratigraphy. The concept of depositional sequences, comprising rock units bounded by unconformities, has been developed from the late nineteenth century up to the present day. Many different studies have been carried out on North Sea Jurassic sequence stratigraphy, from the early 1980s to the present day and involving a range of different approaches. Many authors have adopted the J sequence approach that was first published in the early 1990s; however, a number of alternative North Sea Jurassic sequence schemes have also been described. A close relationship existed between tectonics and sequence boundary development, particularly during the Middle–Late Jurassic in the North Sea region. Several of the major unconformities that are known to be of regional extent can be directly related to significant tectonic phases. Other sequence boundaries, for which a tectonic control is not evident, for example, particularly in the Early Jurassic, were potentially driven by glacio-eustatic cycles, which may have been controlled by orbital forcing cycles.