Seismoacoustic Study of the Shallow Gas Transport and ... - E-LIB

Chapter 3
3.5. Interpretation and Discussion
3.5.1. Chronostratigraphy
Although for our study area published information on deep penetration drill sites is
rare, age estimates for seismic units can be derived from some published seismic studies
in adjacent areas. Tari (2011) showed an interpreted seismic line (Fig. 14) which clearly
indicated an erosional unconformity between the Miocene and Pliocene sediments. The
line is located in the Southwest of our study area. Meisner (2011) presented an
interpreted seismic section through Tuapse Trough in the Eastern Black Sea basin, which
showed the boundary between the Quaternary and Pliocene at 1.2 s TWT in the deep
basin. Drill site Subbotina-403 from the mouth of the Kerch Strait, which is in the
Northeast of our study area, and three seismic lines close to our study area are published
by Stovba et al. (2009), providing a crude stratigraphic framework. All the abovementioned
seismic studies provide a reference to estimate the age of seismic units in the
study area. The age correlation is simple and limited in accuracy, and main results are
summarized in Table 2.
Figure 14 Left figure (a) indicates
“Deepwater play types in the area
south of the Crimea and the Kerch
Peninsula” from Tari (2011), the
erosional truncation boundary
between the Miocene and Pliocene
is marked by black arrows. The
location of the interpreted seismic
line is shown in the figure (b),
which is closely located in the
southwest area of our study area.
Black point shows the Drill site
Subbotina-403
Based on these age assignments, we interpreted H5 as the boundary between the
Miocene and Pliocene, which may coincide with the Messinian erosional truncation
surface (5.3 Ma BP) (Tari, 2011; Stovba et al., 2009). The Messinian erosional truncation
surface is a major unconformity between Miocene and Pliocene deposits, which is
associated with a substantial drop of sea level during the Messinian Salinity Crisis (less
than 6 Ma ago). It has been confirmed by several boreholes (Ryan and Cita, 1978; Hsü
and Giovanoli, 1979; Gillet et al., 2007) and seismic data (Finetti et al., 1988; Robinson
et al., 1996) from offshore areas in the Mediterranean Sea and the Black Sea. H3 is the
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