In February 1992 there was a two day meeting of the Marine Studies Group dealing with pelagic fluxes and sedimentation. Day 1 covered several topics while Day 2 focused on BOFS (Biogeochemical Ocean Flux Study). The BOFS work is being published elsewhere and so the present thematic set and the meeting summary below concentrates on the topics covered during Day 1.
The floor of the ocean is the site of deposition for particles from any source that are transported down through the water column. The sediments record both about past activities in the overlying waters and about past inputs to those waters. Present-day oceanographic processes are analogues for the past, but the data must be interpreted correctly. To do that some idea is needed of what happens to particles on their way down, and what modifications to the record take place upon sedimentation.
Amongst the main themes of the meeting were the variability of the fluxes, and the coupling of the surface waters with the bottom sediments. Although the story that can be gained from isotopes provides extra details, there is still a great deal of information to be gleaned from detailed examination of the trace-metal content of particulates. R. Chester showed how the trace-metal composition of particulate material undergoes modification during its journey from the sea surface to the sea-floor. What is essentially a ‘fingerprint’ of solid-state speciation can be determined by looking at which carrier phase contains which trace element. It was shown that organically bound copper in