Organic-walled dinoflagellate cyst data of sediment core GeoB20628-1

To better understand palaeoceanographic and palaeoenvironmental changes and their driving mechanisms offshore the southern coast of South Africa since the last deglaciation, we present organic-walled dinoflagellate cysts (dinocysts) data of 36 samples from marine sediment core GeoB20628-1 which was retrieved from the southern coast of South Africa, east of the Breede River mouth, during RV METEOR cruise M123 (34°33.880′ S, 21°05.670′ E) in 71 m water depth. The results indicate a distinctive depositional environment from lagoonal to shallow marine conditions clearly reflected in the composition of different dinocyst groups. The markedly distinct changes in the depositional environment over the last 14 ka driven by the interplay of marine transgression, fluvial input, upwelling intensity and their interactions with regional vegetation and climate changes.