Radiocarbon ages measured on different sample types from the marine sediment core OR1-1218-C2-BC which was retrieved from the southern South China Sea using a box corer. Onboard the ship, the core was separated into several sub-cores of which nine sub-core were analysed. Bulk samples contain 1/3 of 200 individual foraminifera (~800 µg) picked from the nine sub-cores at discrete depths (0 - 2, 6 - 8, 10 - 12, 16 - 18, 22 - 24, 28 - 30 and 32 - 34 cm.). Additional small number samples are based on 5 specimens with ten replications for two depths (6 - 8 and 36 - 37 cm) from sub-core 1. The data are used to estimate the sediment accumulation rate and the vertical extent of the sediment mixing. Additionally, the data are used to assess the intensity of the sediment mixing and the three-dimensional age-heterogeneity within the core.