Chapter 7. Alternative North Sea Jurassic sequence stratigraphic schemes

Abstract

Abstract This chapter reviews previously published North Sea Jurassic sequence stratigraphy schemes. Some of these works have applied the originally published J sequence schemes, while 18 have established new schemes. The most significant of these are discussed and compared to the newly defined J sequences. Most of these additional documented schemes have been defined for the Upper Jurassic interval, with a more limited number of schemes for the Lower and Middle Jurassic. Different authors have adopted a wide range of sequence notation methods while none of the publications describing the new sequence schemes has offered detailed sequence definitions. Due to the ensuing confusion, it is recommended that a more formal method of sequence definition is adopted in future sequence stratigraphic studies. In intervals in which reservoir successions are developed, such as the Fulmar Sandstone Member in the J56–J63 sequences, particularly in fields in which extensive coring has taken place, authors have usually been able to recognize additional sequences, which are probably at fourth-order scale, at a higher resolution than the defined third-order J sequences.