PAGEAbstract1Part 1. Preparation of the Physiographic Diagram3Part 2. Physiographic Provinces11Introduction11Nomenclature and classification of deep-sea relief11Units of depth and slope12Continent and ocean16Continental margin17Definition and general categories17General categories17Category I provinces17Category II provinces18Category III provinces19Regional description of continental margin21Benches and terraces of the continental margin41Geology and geophysics of continental-margin physiographic provinces51Seismicity of the continental-margin provinces51Magnetic anomalies and continental-margin physiographic provinces51Crustal structures and continental-margin provinces52Sediment distribution and physiographic provinces of the continental margin53Past, present, and future of the continental-margin provinces53Ocean-basin floor55General description55Abyssal plains55General discussion55Regional description57Abyssal hills61Definition and distribution61Regional description63Origin of abyssal-hills topography65Other major features of the abyssal floor66Abyssal gaps66Mid-ocean canyons66Regional description66Origin of abyssal-floor topography74Oceanic rises74Definition and distribution74Regional description74Seamounts of the ocean-basin floor78Seismicity of the ocean-basin floor80Ocean-basin floor provinces and crustal structure80Mid-oceanic ridges83Definition83Mid-Atlantic Ridge83Provinces of the Mid-Atlantic Ridge84General statement84Crest provinces84Flank provinces95Azores Plateau97Azores-Gibraltar Ridge98Atlantis-Plato-Cruiser-Great Meteor Seamount Chain98Geology and geophysics of Mid-Atlantic Ridge physiographic provinces98Seismicity of the Mid-Atlantic Ridge98Sediments and physiographic provinces of the Mid-Atlantic Ridge99Rocks of the Mid-Atlantic Ridge99Crustal structure of the Mid-Atlantic Ridge provinces100Origin of the Mid-Atlantic Ridge103Sub-bottom reflections recorded on PDR records and physiographic provinces105Summary of province characteristics107Bibliography109Index115