Seismic techniques can provide some predictability to the

Seismic
data provide lateral continuity and 3D insights for sequence stratigraphic
interpretations. Seismic stratigraphic analysis techniques can provide some
predictability to the distribution of facies through the application of
sequence stratigraphic concepts (Vail, 1987). The fundamental unit of sequence
stratigraphy is the sequence, which is a relatively conformable succession of
genetically related strata enveloped by unconformities and their correlative
conformities (Mitchum et al., 1977). A sequence is
divided into systems tracts, which are defined by their position within
the sequence and by the stacking pattern of parasequence sets.

Seismic
sequence analysis defines seismic sequences and systems tracts by identifying
discontinuities recorded in reflection
termination patterns. The analysis starts with establishing geometric relationships
of seismic reflections on seismic profiles. Aggradation,
progradation, and retrogradation are the three general stacking patterns used
to distinguish between different depositional systems (Figure 21). Sequence boundaries
and other major surfaces are identified based on seismic reflection
terminations such as onlap, downlap, toplap, and truncation (Figure 22). According
to the reflection termination patterns, seismic reflections can be subdivided into systems tracts.

Well logs provide high resolution vertical stratigraphic data. Integration
of seismic and well log data provides more accurate stratigraphic models of the
sedimentary fill (Van Wagoner, 1991). The well log sequence analysis performed
in this study is based on GR logs
response from available wells. GR logs measure the radioactivity of rocks and are commonly used as a good proxy for grain
size in siliciclatic systems (Van Wagoner, 1991). Abrupt changes in GR

logs responses are commonly related to
sharp lithological breaks associated with unconformities

and sequence boundaries (Krassay, 1998). Variation
patterns of GR logs indicate changes in the