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The Late Quaternary stratigraphy and sedimentary processes are interpreted for an area of continental shelf and slope on the eastern side of the South Island, New Zealand, between latitudes 43°00's and 44°50's. Two formations are recognised in the Late Quaternary stratigraphy of the shelf: the Canterbury Bight Formation of mainly Last Glacia1 age and, locally overlying it, the Pegasus Formation of mainly Holocene age. The formations are distinguished by shelf-wide unconformities (visib1e in seismic profiles), by geomorphology, by grain-size modes, and by macrofauna. Ridge-and-swa1e topography occurs on two scales on the shelf. Very large ridges and troughs are interpreted from microbathymetry, stratigraphy, sediments and macrofauna to be the remains of Pleistocene barrier/lagoon complexes. With the aid of radiocarbon dates, four well developed shorelines between 28,000 yr and 15,000 yr old are recognised. The smaller ridges are submarine features, formed by strong currents. Those ridges that are in a zone of constricted and accelerated currents near Banks Peninsula are active, while those well removed from the peninsula constriction are fossil and date from times of lower sea level. Sedimentation on the continental shelf has reached a state of equilibrium with the modern hydraulic regime. Relict sediments of the deglacial transgressive sand/gravel sheet are being reworked in zones of high energy, principally in the region of constricted flow around Banks Peninsula. Modern-input sand (distinguished by its grain-size mode) is restricted by currents mainly to an active belt near shore, but locally it has replaced palimpsest sand on the middle shelf. The modern mud facies, being confined by zones of higher energy, has reached its maximum areal extent; its greatest thickness is in Pegasus Bay. Sea-bed drifter studies, and studies of sediment texture and provenance show that net sediment movement on the shelf and along shore during both Pleistocene and modern times has be