8 - Sequence stratigraphy

Summary

This chapter deals with sequence stratigraphy. It contains a section on Foraminifera in sequence stratigraphy.

Sequence stratigraphy

Sequence stratigraphy attempts to subdivide the rock record into genetically related – commonly unconformity-bounded – rock units or sequences (Jones et al., in Jenkins, 1993; Jones, 1996, 2006, 2011a; and additional references cited therein; see also the further reading list at the end of the chapter). The unconformities that form the basis of sequence stratigraphy are generated by base-level fall, in turn driven by glaciation or glacio-eustasy, and/or by structuration or tectonism (see also the comments on ‘General and clastic sequence stratigraphy’ below).

Definitions

Sequences and sequence boundaries A Vailian sequence is defined as a ‘stratigraphic unit composed of a relatively conformable succession of genetically related strata bounded at its top and base by unconformities or their correlative conformities’. Vailian sequence boundaries (SBs) (bounding unconformities) are readily recognisable on seismic stratigraphic criteria (erosional truncation below, and transgressive onlap above). They are also recognisable on palaeontological, sedimentological and petrophysical criteria (see also Section 8.2).