Seismic-to-well correlation at Ocean Drilling Program (ODP) continental slope Sites 902, 903, 904, and 906 identifies 19 Pleistocene-Eocene unconformable surfaces and reflectors. Seismic features on 120-channel, tuned, air-gun seismic data are tied to borehole depths via one-dimensional synthetic seismogram models. Reprocessed migrated seismic profiles along Maurice Ewing Lines 1005 and 1027 reveal clear images of two middle Miocene canyon-cutting surfaces and Pleistocene slump-bounding unconformities. At Site 904, good-quality compressional-wave velocity and density values allow models to match seismic facies. A high-amplitude continuous seismic facies between Miocene unconformities q and w can be attributed to distal toe-of-delta clinoforms containing alternating glauconite-rich and -poor sedimentary facies. A seaward-thinning Oligocene interval downlaps the upper Oligocene/upper Eocene, producing reflectors resolvable only through ties to biostratigraphic and lithologic borehole data. A silica-indurated diagenetic front within the middle Eocene produces reflectors that do not have chronostratigraphic significance and can mislead sequence stratigraphic interpretations.
Date of initial receipt: 6 March 1995
Date of acceptance: 20 December 1995
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