Age determination of sediment core MD99-2201

The aragonite dominated core MD992201 comprises the past 7230 years in a decadal time resolution and shows sedimentation rates of up to 13.8 m/kyr. Aragonite mass accumulation rates, age differences between planktonic foraminifera and aragonite sediments, and temperature distribution are used to deduce changes in aragonite production rates and paleocurrent strengths.

Aragonite precipitation rates on GBB are controlled by exchange of carbonate ions and CO2 loss due to temperature-salinity conditions and biological activity, and these are dependent on the current strength. Paleocurrent strengths on GBB show high current velocities during the periods 6000–5100 years BP, 3500–2700 years BP, and 1600–700 years BP; lower current speeds existed during the time intervals 5100–3500 years BP, 2700–1600 years BP, and 700–100 years BP.