DETRITAL BEDROCK ELEMENTS AS TRACERS OF SETTLING RESUSPENDED PARTICULATE MATTER IN A COASTAL AREA OF THE BALTIC SEA

Particulate matter settling out of the trophogenic layer was collected in sediment traps at five stations during 5 yr in a coastal area of the Baltic Sea. Al, Fe, and Ti in the intercepted matter were inferred to be due mainly to the presence of fine-grained bedrock detritus and were used as markers to calculate the proportion of primary settling matter and resuspended sediment in the collected matter. Considerable variations within and between years, seasons, and nearby stations were found for gross sedimentation rate and for the ratio between primary settling matter and resuspended sediment. This pattern also applied to organic C. A predominance of primary settling matter was recorded mainly in spring. Resuspended matter was a large component in the annual budget for all years and stations. In fact, the resuspended portion commonly exceeded 50%, and periods without resuspension seem to occur rarely or never in the investigated area.