The National Geographic Society's grant covers research in the Nama Karoo (area in purple), a desert that stretches across the interior of South Africa. Map from Wikimedia Commons.

Stretching across the interior of South Africa, south of the Kalahari, is a vast desert biome called the Nama Karoo. There is only fragmentary data on the roughly 2 million years of human history in the region. Likewise, little is known about the area’s environmental history. Brian Stewart, assistant curator of paleolithic archaeology at the University of Michigan Museum of Anthropological Archaeology, aims to change that. With the help of a research grant from the National Geographic Society, he will study the desert’s paleoclimate and its record of human settlement.

With a multidisciplinary team of geomorphologists and paleoclimate scientists from the Universities of Leicester (UK), Montpelier (France), Johannesburg and the Free State (both South Africa), Stewart is surveying, mapping, and dating ancient lakebeds in the Nama Karoo. The team plans to create the region’s first detailed record of the availability of surface water in the Pleistocene. This information will aid them in answering key questions related to climate change and human occupation in the area.

Five questions the team hopes to answer:

1.     When did lake inundations occur and were they consistent in timing?

2.     What drove positive hydrological budgets?

3.     How reliable were these water sources and how variable were lake conditions (e.g., salinity)?

4.     How did the wider landscape evolve, and what drove the emplacement of adjacent Aeolian-fluvial landforms?

5.     What is the antiquity and behavioral significance of archaeological material associated with these locales?

Stewart and his team hypothesize that large-scale fluctuations of surface water are key to understanding the likely complex process of ancient human occupation/abandonment of this region, perhaps analogous to the “greening” and re-desertification of the Sahara at various times in the past. As with Stewart's work in other parts of the southern African interior, this project will provide a fuller picture of early human adaptations across the breadth of southern Africa’s diverse ecosystems.