Cores from two stations in the Tampen area, in the Norwegian Trench west of Florø, have been analysed (geochemistry, sedimentology, physical properties) and dated (210Pb-dating). One station was located 1000 m downstream, northeast of the Snorre Field, while the other (reference) station was located 9 km to the east-northeast of the Snorre field. The downstream station was clearly influenced by drilling mud discharges, with elevated levels of Ba and Pb in the top sediments. Discrepanices between reported discharges and contaminant contents at dated sediment intervals indicated that resuspension or changing oceanographic conditions may influence the sedimentary record of contaminant discharges. Elevated levels of Ba and Pb in the reference station indicate spreading of drilling-related contaminants over considerable areas. Comparatively high levels of trace metals in old sediments not influenced by anthropogenic inputs demonstrates the importance of geological control in environmental monitoring.