Modern foraminiferal distribution in the subarctic Malangen fjord and adjoining shelf, northern Norway

摘要

Living (stained) and dead (unstained) foraminifera have been investigated along a NW-SE transect from the inner fjord head to the adjoining shelf of the subarctic Malangen fjord, northern Norway. The outer sill of the fjord is deep and allows good exchange with water masses from the Norwegian Coastal and Norwegian Atlantic currents. The aim of this study is to elucidate the recent foraminiferal fauna and its relation to sediment properties and water mass characteristics.Three benthic foraminiferal assemblages have been distinguished on the basis of the dominating living and dead benthic species. The Bulimina marginata-Cassidulina reniforme assemblage is found in the inner fjord basin, where it is correlated with relatively cold (6-6.9degreesC) and slightly less saline water masses (34-34.75parts per thousand) compared to the Norwegian Atlantic Water masses. The Brizalina skagerrakensis assemblage is found in the outer fjord basin, an area influenced by relatively stable temperate (6-7.9degreesC) and saline (34-35.1parts per thousand) basin water caused by inflows of Norwegian Atlantic Water. The Cassidulina obtusa assemblage is found outside the outer sill on the shelf and reflects a higher temperature (5.7-9.8degreesC) on the shelf compared to the outer fjord. Two planktic foraminiferal assemblages have also been distinguished. The Globigerinata uvula assemblage is found in the outer fjord basin and on the inner shelf. The Neo-globoquadrina pachyderma (dextral) assemblage is found on the outer shelf, where the influence of Norwegian Atlantic Current is the largest.