| Abstract |
The seismic stratigraphy of the Blake-Bahama Basin is interesting because of the apparent acoustic blanking of the deeper reflectors.The blanking is caused by shallow high impedance layers, diffractions at shallow hyperbolic reflectors, and velocity inversions. Only recently have high-energy multichannel seismic techniques been employed in the basin to reveal the true configuration of the deeper reflectors and the extent of the blanking (Figure 1). In 1974 a cooperative U.S. Geological Survey-Institut Français du Pétrole cruise aboard R/V Florence collected three profiles, FC I, II, III, using a 24-fold Flexichoc system (Dillon et al., 1976).DSDP Site 391 was selected on the basis of these U.S.G.S.-I.F.P.seismic data. A survey aboard R/V Conrad was made in 1975, after Leg 44 drilling, to collect the 24-fold multichannel lines MC 1 and 2.The survey extended the seismic coverage in the area and provided ties to Sites 390 and 391 (Windisch et al., 1976). [NOT CONTROLLED OCR] |
