These become concentrated in the surface film and in marine sediment, especially estuarine mud.

During the 1970s and 1980s he developed an important technique of marine sediment dating through the measurement of the racemisation rates of amino acids.

The melting of large icebergs deposits sediment of various sizes, usually referred to as glacial marine sediment, onto the shelf and deeper marine areas.

Subsequent studies showed that there are more than a thousand viral species in human stool and possibly a million different viruses per kilogram of marine sediment, including many bacteriophages.

The data are derived from pollen and foraminifera (plankton) remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate; these are called proxies.