Geochemical, mineralogical, stable isotope, geochronological and grain size data of sediment core GRV13-2 from coastal lake Groenvlei, southern Cape coast, South Africa

However, the record also indicates the occurrence of short humid phases during this time, which were probably associated with heavy rainfall events. A transition layer was deposited between 2710 and 1210 cal BP, probably as a result of reworking of sediment. During this time, the lake passed through a major change finally turning into a freshwater system from at least 1210 cal BP until the present.

Our data indicate that the marine influence on the lake decreased due to a lower sea level and climate became generally more humid after 1210 cal BP probably resulting in a greater lake-internal and -external bioproductivity. Based on a comparison with other palaeoenvironmental studies from South Africa, our record suggests a prevailing winter rainfall seasonality at the southern Cape coast between 4210 and 2710 cal BP and a stronger influence of summer rainfall from 1210 cal BP onwards.