Neritic deposits of Eocene and Oligocene age, partly underlain by coal measures, occur over large areas of south-west Auckland, west Nelson and north Westland, and north-east Otago (Waitaki). The well described deposits of south-west Auckland and Waitaki consist of sedimentary units bounded by unconformities and each containing distinctive fossils. Each sedimentary unit reflects an increase, each unconformity a decrease, in depth of sea, and the successions represent cycles of deposition and non-deposition or erosion. The succession of cycles in Waitaki matches that in south-west Auckland. The early Tertiary of Nelson and Westland has not been fully described but seems to contain comparable sedimentary cycles.