DSDP Site 519 is located in the central South Atlantic at a water depth of 3769 m. (super 10) Be is carried mainly by non-CaCO (sub 3) phases of the sediments. There is a positive correlation between (super 10) Be and (super 9) Be in the sediments at DSDP Site 519. Three probable hypotheses can explain the glacial to interglacial differences in the beryllium isotope ratio. The stratigraphic position of the (super 10) Be peak is between two tephra layers originating from two volcanic eruptions, Campanian Ignimbrite and Citara. This (super 10) Be peak provides a unique relative time marker. The low mobility of beryllium once it has become attached to mineral surfaces has led to the use of (super 10) Be to study marine sedimentation rates, Mn-nodule growth rates, and subduction pathways in arc volcanism. By measuring the decay of (super 10) Be in deep-sea sediments, it was determined that pelagic sediments were deposited at a rate of several millimeters per 1000 years.