Determination of Radium, Thorium, and Protactinium in sediment cores of the Indian Ocean

Instead of the isotopes Jo, Th, and Pa the radioactive daughter products Rn, Tn, and An were measured. It was possible to date four cores and to calculate the sedimentation rates. A rough estimation of the sedimentation in the northern part of the Indian Ocean can be given. In the middle part, the sedimentation rate is s = 0.32 cm/10**3 years, and near Africa and near India this rate increases to values of about2 cm/10**3 years.