Examination of long cores collected by deep-sea drilling shows that, at least during the Cenozoic, oceanic sediments accumulated at rates which varied widely in space and time, and that there are many gaps in the sedimentary record. Locally, sedimentation may be extensively controlled by ocean circulation and chemistry. Comparison of data from different regions, however, reveals broad, globally synchronous fluctuations in rate of sediment accumulation, the oceans apparently oscillating between periods of high (middle Eocene, early Miocene) and low (Oligocene, Paleocene) accumulation. Hiatuses in the record are common during periods of generally low accumulation. Such global changes in the rate of deep-sea sediment accumulation can be related to both sea-level fluctuations and global climatic changes, and their influence on sediment supply and ocean circulation.

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