The Occurrence Of Some Distinct Areas In The N. W. Mediterranean Sea Based On The Elemental Properties Of The Sediment (Horizontal And Vertical Distribution)

Abstract

As pan of the EROS-2000 project (European River Ocean Systems),sediment samples were collected in the North Western basin of the Mediterranean Sea in May 1990. In these samples trace and/or majorelements were determined to advance the knowledge about theconcentration, sources and cycles of natural and anthropogenicconstituents in coastal areas. Three fractions were determined: the porewater fraction whichcontains all dissolved elements the leachable fraction which containsall easily available elements and the residual fraction which containsthe strongly bound elements in the sediments. The results show thatthe investigated area can be separated into five "sub-areas" which aredifferent in element concentration, leachable fraction andsedimentary composition. Highest concentrations of trace elementsare found in sediments closest to the Rh6ne delta. In this area severaldiagenetic processes are observable. In summary the Rhone is probably the major source for several(trace-) elements to the Gulf of Lions which is located close to theriver mouth of the Rhone. The influence of the Ebro on (trace-)element concentrations in the sediments close to theriver mouth isprobably minimal.