SPATIOTEMPORAL DISTRIBUTION OF PARTICULAT E FE, AL, MN, CA, MG, TI AND V IN THE DOVER STRAIT

Within the framework of the European Fluxmanche programme, 92 sampling s of suspended particulate matter were collected during eight cruises through the Dover Strait. The mean concentrations obtained for Al (44. 3 mg/g), Fe (27.4 mg/g) and Ca (110 mg/g) are comparable to those obta ined by Nolting and Eisma in January 1980. However, the concentrations of Mn (0.585 mg/g) Ti (3.14 mg/g) and V (0.225 mg/g) are twice as lar ge. An important gradient of concentration is observed between the coa stal and offshore waters, reflecting coastal erosion and human activit ies. Detailed examination of the contents of the major elements indica tes that these remain practically constant in the particulate matter d uring a tidal cycle. On the other hand, the concentrations of heavy me tals (Mn, V, etc.) vary notably and the use of models simulating the d ispersion of the contaminants confirms these observations. The study o f the Fe/Al ratio permits a distinction between the two surveys: that carried out in November 1990, where high values are obtained because o f the presence of a low-density alumino silicate phase and of diatoms; and that carried out in May 1991, to which the influence is added of a planktonic bloom, together with a fluvial contribution along the Eng lish coast and the effects of coastal erosion along the French coast.