SEDIMENTARY PROCESSES AND THE CREATION OF THE STRATIGRAPHIC RECORD INTHE LATE QUATERNARY NORTH-ATLANTIC OCEAN

The primary difficulty in the interpretation of the stratigraphic reco rd is that a multiplicity of sedimentary processes, some producing sim ilar effects, are responsible for it. We seek to unravel the effects o f the more important processes through analysis of sedimentary propert ies. The effects to be unravelled are those relating to pelagic input (vertical flux) due to organic productivity, wind-blown dust, ice-raft ing and volcanic ash; to horizontal flux in turbidity currents, debris flows, and nepheloid layers caused by the reworking of sea-bed sedime nts by internal waves and bottom currents; and to degradation of the r ecord by dissolution, oxidation and mixing of components. Contrasting regions of the North Atlantic are used to show the effects of bottom c urrents, ice-rafting, wind and productivity on sediments. Applications to estimates of changes in bottom currents, productivity and carbon s equestration in the N.E. Atlantic over the past 30 ka are given.