High-resolution paleomagnetic dating of sediments deposited in the centralBaltic Sea during the last 3000 years

Sediment cores from the main sedimentary basin in the Baltic Sea, the Gotla nd Deep, provide a high-resolution record of changes in the Holocene paleo- environment and paleoclimate. Due to the inherent inaccuracy (reservoir eff ect, redeposited material) of the C-14 dating method in dating marine sedim ents, the known changes in the Earth's magnetic field recorded in three sed iment cores from the Gotland Deep were used to produce a more detailed and accurate timescale. The variations in the inclination and declination were compared to the paleosecular variations over the last 3000 years recorded i n annually laminated lake sediments from Finland. This correlation made it possible to construct, for the late Holocene Gotland Deep sediments, a high -resolution time-scale with an estimated absolute accuracy of better than /-50 years. This new timescale made it possible to determine the mean annua l rates of sedimentation with an unprecedented accuracy. The sedimentation rates were found to have varied considerably both in time (from 0.2 up to 4 .3 mm/year) and space, indicative of the patchy nature of accumulation in t he Gotland Deep during the past 3000 years. (C) 2000 Elsevier Science B.V. All rights reserved.