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 t he 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 m atter and resuspended sediment in the collected matter. Considerable v ariations within and between years, seasons, and nearby stations were found for gross sedimentation rate and for the ratio between primary s ettling matter and resuspended sediment. This pattern also applied to organic C. A predominance of primary settling matter was recorded main ly in spring. Resuspended matter was a large component in the annual b udget for all years and stations. In fact, the resuspended portion com monly exceeded 50%, and periods without resuspension seem to occur rar ely or never in the investigated area.