Teresa Steele is an Associate Professor in Department of Anthropology at the University of California, Davis, currently on sabbatical in the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. She is a member of the Editorial Board for Open Quaternary. She has research interests in modern human origins and zooarchaeology and field projects in France, Morocco, and South Africa. In this week’s post, she provides insights into her archaeological fieldwork in South Africa in 2014. This is her first ever blog post.
The ancestors of everyone living today came from Africa, but “Africa” is a big place, over 30 million square kilometers, so where did these ancestral populations live? How did they make their living? When did some of them leave Africa to populate the rest of the world? How did they support this expansion? And most importantly, WHY? These are the questions that keep me up at night – me and other paleoanthropologists studying modern human origins.
I am leading the Southern Namaqualand Archaeological Project (SNAP) with Dr. Alex Mackay (University of Wollongong) in the Western Cape of South Africa. The project is based along the Varsche River in the Knersvlakte [map], the quartz-gravel desert (whose name translates to gnashing, or grinding) is so named (as the story goes) because of the crunching sound carriage wheels made going over it (Figure 1). The region is part of the Succulent Karoo ecoregion, after its tiny succulent plants, but it also preserves records of the past. Patches of the landscape are littered with stone artifacts, providing evidence of human activity deep in the past, when stone was the primary source of our technology and when the Knersvlakte provided more resources than today.
South Africa has benefited from a long history of archaeological research, and the southern and western coasts are well-known for their Late Pleistocene archaeological deposits including Klasies River, Blombos Cave, and Pinnacle Point. These sites have provided key data and fueled discussions about modern human origins. The sites include early evidence for advanced technology and symbolism in the form of beads and engraved ochre, some of which is well documented by the TRACSYMBOLS project. Researchers, including Curtis Marean of Arizona State University, have argued that this region provided just the right mix of rich marine resources along with nutritious plant resources (in the form of geophytes) to promote the evolution of modern humans. Others, including Richard Klein of Stanford University, have argued that the record of human behavior from 250,000-50,000 (the Middle Stone Age) is less complex than the more recent Later Stone Age and Upper Paleolithic (which began 50,000–40,000 years ago). To better address these issues, we need a better understanding of the range of variation in Middle Stone Age behavior and especially how technology, subsistence, and demography varied with environmental context. In short, we need more sites from difference environmental contexts so that we can test these models of modern human origins.
One of the most common questions I am asked as an archaeologist is: “How do you know where to dig?” The decision about where to dig is influenced by research design, local contacts, and luck. Around 2008, I was looking for a new project – ideally, a Middle Stone Age site with faunal preservation outside of the well-studied coastal regions. My colleague Jayson Orton (ASHA Consulting; University of Cape Town; and University of South Africa) from my then current South African project (Ysterfontein 1, map from Klein et al. 2004) was targeting Namaqualand Later Stone Age sites for his dissertation research. A few years earlier another mutual colleague (Royden Yates) had shown Jayson some shelters along the Varsche River which he had seen while surveying rock art sites.
In 2008, Jayson and I went to visit the Varshe sites, where it was possible to see Middle Stone Age artifacts scattered on the landscape (Figure 2). In addition to the scattered lithics and surface material, there were three unexplored rock shelters. No matter what, someone was likely to be happy, and we would learn something from a project in the region. In 2009, Jayson, Alex, my graduate student Steve Schwortz, and I spent three weeks in the area testing the three rock shelters and collecting data on surface material. Two of the shelters yielded only Later Stone Age material, Reception Shelter (VR001) and Buzz Shelter (VR005), and the third site, VR003, yielded primarily Middle Stone Age material. We were all happy. Jayson continued to excavate Reception and Buzz, which formed the foundation of his PhD thesis. Alex and I have focused on VR003 with a four-week field season in 2011 (with my one-year-old in tow – fodder for another blog post!) and then again in 2014 (with my four-year-old staying home with daddy).
We targeted this region because it is currently located in a winter-rainfall zone desert. Despite the challenging environment today (the region receives only about 150 mm of rain per year), it was likely much wetter during past glacials, which increases the chances of finding traces of human behavior from MIS 6, 4 and/or 2. Human activity is especially poorly documented southern Africa during MIS 6 and 2, which is unfortunate because these stages encompass the establishment of Later Stone Age and early Middle Stone Age behavior, key periods for understanding modern human origins. MIS 4 is particularly interesting because two variants of the Middle Stone Age, the Still Bay and Howiesons Poort, are associated with it and may have been influenced by the changing environmental conditions leading up to MIS 4 and during MIS 4. Unique aspects of these two industries have played leading roles in discussions of modern human origins, because they are associated with early beads, engravings, and complex stone tool technologies.
At VR003, we have found both the Still Bay (Figure 4a) and Howiesons Poort (Figure 4b) variants within a sequence that extends earlier and later. The stone artifacts show signatures of the region – quartz is the dominant material, which is not surprising given its abundance on the landscape. We find hints of other pre-Still Bay variant, which may link our site to others further south, and as well as some pieces that are unique (Figure 5).
VR003 also preserves vertebrate remains, unlike too many other Middle Stone Age sites. Zebra, wildebeest and hippopotamus support the interpretation of wetter, and therefore grassier conditions during the cooler Late Pleistocene. One of the most surprising finds in the faunal assemblage is a few marine mollusks, particularly limpets; the site is ~45 km from the current coastline, which would have been even further during glacial times. Transport of marine shells over this distance hasn’t previously been documented during the Middle Stone Age, but it common during the Later Stone Age, including at VR001 and VR005.
We are very happy about one thing that we didn’t find this past season – bedrock, which means that VR003 is likely to continue to reveal clues about human evolution into the deeper past. We look forward to returning in 2015.
Chase BM and ME Meadows. 2007. Late Quaternary dynamics of southern Africa’s winter rainfall zone. Earth-Science Reviews 84:103-138. [link]
Chase BM. 2010. South African palaeoenvironments during marine oxygen isotope stage 4: a context for the Howiesons Poort and Still Bay industries. Journal of Archaeological Science 37:1359-1366. [link]
Jacobs Z and RG Roberts. 2009. Human History Written in Stone and Blood. American Scientist 97:302-309. [link]
Jacobs Z, RG Roberts, RF Galbraith, HJ Deacon, R Grün, A Mackay, P Mitchell, R Vogelsang and L Wadley. 2008. Ages for the Middle Stone Age of southern Africa: Implications for human behavior and dispersal. Science 322:733-735. [link]
Mackay A, J Orton, S Schwortz and TE Steele. 2010. Soutfontein (SFT)-001: Preliminary report on an open-air site rich in bifacial points, southern Namaqualand, South Africa. South African Archaeological Bulletin 65:84-95. [link]
Orton J, A Mackay, S Schwortz and TE Steele. 2011. Two Holocene rock shelter deposits from the Knersvlakte, southern Namaqualand, South Africa. Southern African Humanities 23:109-150. [link]
Steele TE, A Mackay, J Orton and S Schwortz. 2012. Varsche Rivier 003, a new Middle Stone Age site in southern Namaqualand, South Africa. South African Archaeological Bulletin 67:108-119. [link]