OSTRACODS IN A COLD-TEMPERATE COASTAL ENVIRONMENT, WESTERN TROMS, NORTHERN NORWAY - SEDIMENTARY ASPECTS AND ASSEMBLAGES

This study presents sedimentological and micropaleontological data on ostracods from a cold-temperate inner shelf setting in the Troms Distr ict, northern Norway. The coarse fraction analyses carried out on sedi ment surface samples from coastal platforms and adjacent outer fjord t roughs reveal a considerable contribution from ostracods to the accumu lation of skeletal carbonates in distinct depositional settings. Ostra cod accumulation is highest along wave-sheltered areas of coastal plat forms where fleshy seaweed and coralline algal communities thrive in 1 0 to 30 m water depth. Current-exposed slopes of outer fjord troughs s how a highly mixed ostracod assemblage consisting of imported species from the shallow coastal platform which is mixed with the trough assem blage. The hydrodynamic transport of ostracods into deeper areas resul ts from the strong tidal current regime. Because of this mixing proces s, only the end members, the coastal platform and the fjord trough ass emblages can be defined. The former is characterized by Baffinicythere emarginata, Cythere lutea, Finmarchinella angulata, Hemicytherura cla thrata, Robertsonites tuberculatus, Sclerochilus rudjakovi, Semicyther ura undata and Xestoleberis cf. depressa. The outer fjord trough assem blage is characterized by Cluthia cluthae, Cytherella abyssorum, Cythe ropteron alatum, Krithe cf. adelspergi, Muellerina abyssicola, Cythere lla cf. vulgatella and Cytheropteron testudo. Members of the northern Norwegian trough assemblage are known to occur in deeper open shelf en vironments of the NE-Atlantic.