Pollen indications of Holocene palaeoenvironments at Florisbad spring in the central Free State, South Africa

Abstract

Mid- to late-Holocene pollen data from Florisbad in the central Free State, South Africa, reveal a number of moisture fluctuations. Commencing at c. 6500 BP the pollen sequence indicates an arid climate but shows more availability of moisture under grassy conditions from summer rain at c. 6300 BP and again at c. 4420 BP. The interval between these dates is characterized by a dry episode with karroid shrubs some time between 5500 and 4500 BP, possibly as a result of less marked summer seasonality. After 4220 BP, moisture conditions gradually fluctuated in intensity or seasonal availability until c. 2100-1700 BP when strong summer evaporation is indicated at the upper end of the sequence. The data are complemented by previously published results on environmental change from the nearby Deelpan site to the west. Although some distinct events correlate regionally over South Africa, summer rains appear to have been significant at Florisbad at an earlier stage in the mid-Holocene than in the Karoo to the south.