Correlation of SCS data and ODP core lithologies recovered at Sites 998, 1000, and 1001 was accomplished by creating synthetic seismograms from velocity and density measurements. At all three sites, many of the major reflectors in the SCS data correlate with high-amplitude events in the synthetic seismograms. Furthermore, vertical changes in SCS facies can be related to downhole variations in core lithologies.
The synthetic seismogram generated for Site 998 permits correlation of the Site 998 core with SCS data over the site. Several of the units identified in the lithostratigraphic descriptions from Site 998 (Sigurdsson, Leckie, Acton, et al., 1997) correlate quite well with seismic intervals having distinctive seismic character. Zones of low-continuity, low-amplitude seismic facies correlate with several turbidite-rich core intervals. Several chert layers correlate with moderate- to high-amplitude, moderate- to high-continuity reflections. However, some intervals of chert layers cause no seismic response.
The synthetic seismogram results from Site 1000 also provide excellent visual correlation with SCS data from Line CH9204-30. The correlation with the biostratigraphy from the core permits age determination of interpreted seismic horizons. The synthetic seismogram also correlates several seismic characteristics with lithologies from Site 1000. Several planktonic foraminifer turbidites correlate with zones of low continuity seismic reflectors. An interval of coarse-grained, neritic sand turbidites correlates with high-amplitude, moderately continuous reflectors. Finally, the chalk-limestone transition is correlated with a high-amplitude reflection, below which there are no high-frequency reflections.
The synthetic seismogram created for Site 1001 facilitates correlation between the SCS data and the core recovered from Site 1001. The most significant correlation links the 30-Ma middle Miocene to early Eocene unconformity in the core with the A" seismic reflector and the sediment-basement interface with the B" seismic reflector. Several chert layers identified in the ODP core do not correlate with SCS reflectors.