Research

PhD (October 2019-March 2024) - Provenance of Southern Cape Rivers: Links to Hydroclimate and Early Humans

My PhD research focused on investigating if past climate changes in South Africa contributed to the cultural evolution of Homo sapiens. This work involved reconstructing the palaeoclimate of South Africa during the time intervals of 100 to 50 thousand years ago (ka).

I mainly focused on the use of marine sediment cores as a climate archive. You can imagine sediment cores as time capsules, they hold all the secrets of the past, in the sediment itself and in the 'palaeo' organisms which are trapped within. Marine sediments are a palaeoclimatologists' friend (and sometimes foe...) which can provide us with past records of temperature, salinity, CO2, provenance, sea level, flow speed, to the time interval which the sediment dates back to.

I analysed the geochemistry of river sediment material deposited from major rivers in South Africa (between Durban and Cape Town). This provided me with the geochemical source region fingerprints which I could then apply in the marine realm to understand where the sediments originated.

Simply put, reconstructing where sediment originated during the time interval of 100 to 50 ka helps to further our understanding of the regional climate variability. If we know where the sediment has come from, and during which specific time intervals, we can infer that either more sediment was being supplied from a region during that time, or that there was a stronger transport regime, and/or it was a mixture of both processes.

Our main findings conclude that during intervals when sea level was lower, we see an increase in river discharge from South Africa. During this time, the climate and landscape provided an ideal habitat for large mammals as the freshwater river reserve was higher, the coastal plant biome and ecosystem were richer and this likely ensured early H.sapiens populations had a diverse diet and developed their hunting skills.

Publications

Pryor, E. J., Tangunan, D., van der Lubbe, H. J. L., Simon, M. H. and Hall, I. R. 2024. Recommended centrifuge method: specific grain size separation in the <63 µm fraction of marine sediments. MethodsX 12, article number: 102718. (10.1016/j.mex.2024.102718)