We thank Gilbert Boillot for providing copies of the Lusigal seismic lines and Karl Hinz for copies of the Sonne lines. The constructive comments of Doug Masson, Sarah Prosser, and an anonymous reviewer are gratefully acknowledged. The preparation of this paper was aided greatly by Denise Swann (word processing) and Andrew Lloyd and John Taylor (cartography). We thank the Leg 149 Shipboard Scientific Party and the ship and drilling crews for enabling lithostratigraphic and biostratigraphic data to be collected to "calibrate" the seismic interpretations presented in the paper.