The second Palaeo Affad field season came to an end in early March 2013, and was immediately deemed a huge success by everyone involved (see our pictures). During this season’s fieldwork there were some very important – and intriguing – discoveries…
First and foremost, the presence of a well-preserved, stratified open-air site (or series of sites) has now been confirmed in the Middle Nile Valley, dated to the Late Pleistocene on the basis of lithic typology (and soon to be dated by OSL). Beautifully preserved in-situ Palaeolithic artifacts were found in discrete concentrations, sealed below natural alluvial sediments. These scatters of archaeological material were most abundant and well preserved in areas where sedimentation had taken place in localised depressions in the alluvial landscape, surviving subsequent erosion and deflation of the surrounding ground surface. A program of geoarchaeological work has commenced at the site in order to reconstruct the landscape and climatic context of the finds, and this will be allied with a robust OSL dating framework to anchor these changes in time, allowing us to place the hominins making these tools in a broader environmental context.
Despite a long (c. 100 year) tradition of studying lithic assemblages in the Nile Valley lithic, it still remains very difficult to determine the exact typological and chronological position of the lithic assemblages collected in this area below the 3rd cataract. In terms of the lithics at Affad 23, the assemblages are dominated by tools of the flake-oriented Levallois technological tradition, manufactured on chert pebbles most likely collected from the river channel and its margins. Interestingly, there are no microliths present in the assemblage, with the exception of a single early Holocene tool recorded on the present day landsurface. There are also no bifacial tools being recovered from Affad 23 that would be diagnostic of early Middle Palaeolithic populations present in this part of the Nile Valley. However, a single bifacial point was found on the surface of another site located a few hundred meters away from Affad 23, and having no defined relationship to the sequence at this site. Among the known lithic typologies of Nubia, the most similar technological features can be found in the ‘Khormusan’ industry, known from a few locations close to the 2nd cataract and dated to c.65-45kya. But looking for formal analogies across distances of hundreds of kilometers is a rather risky endeavour, and the discovery of a new regional cultural tradition should not to be excluded at this stage.
The occupation levels recorded at Affad 23 also contain a unique and diagnostic collection of mineralized faunal remains. The species present in the assemblage allows us not only to identify the ecosystem in which they could exist, but also sheds light on the hunting practices employed by the Palaeolithic occupants of Affad 23. The identified faunal elements belong to animals that live in a very different ecosystem than we see in the area today. Most of the species found at Affad are hunted today by native populations inahabiting the marshland provinces of Southern Sudan, and therefore marshes such as these must have existed at Affad 23 when hominins were crafting tools and butchering these animals. Preliminary analyses of the animal remains indicate that the carcasses were butchered on-site, suggesting that the animals were brought back to the camp complete. It is important to note that previous late Pleistocene fauna remains in the Nile Valley (mostly unstratified and undiagnostic) did not generate similar data, again supporting the theory that Affad 23 is set to be a very important site and will likely yield more important discoveries over the coming years.
The most surprising discovery this year was a large number (> 100) of small, circular to sub-circular cut features, recorded within the occupation level, cut into the natural silt below, and sealed by upper occupation horizons. These features exhibited all of the qualities of postholes or small pits, and were distributed in circular or linear alignments. Similar features were also identified in 2012, when we provisionally interpreted them as evidence for insubstantial structures for the drying of meat, hide-working or as wind breaks. However, the features found in the 2013 season were much more numerous and substantial to be the bi-product of such light installations, therefore implying much more sophisticated structures. Some of these cut features were found in the area where the sediments have infilled a depression in the landscape (possibly the edge of a palaeochannel), and in this location they are sealed by artifact-bearing alluvial sands and silts. Another spread of these features was recorded in the upper part of the excavated area, directly below a thin sandy level containing a rich lithic assemblage, indicating a variety of subsistence activities being carried out in this area of the Palaeolithic camp.
Complimentary programs of geoarchaeological and geochronological analyses were initiated at the site this year. This work will provide palaeoenvironmental data and tie changes in the environment of the site and its surroundings to a firm chronological framework. Sediment samples were taken from all stratigraphic units recorded at the site and in the immediate surroundings, and a total of 16 OSL samples were taken for absolute dating. A number of micromorphological samples were also taken from selected postholes in order to try and establish the nature and origin of these features. By the end of this year the preliminary results of this work will be known, but until that time we can only speculate on the nature and timing of the site, and the full implications of the archaeological and faunal remains found within it. As it stands, we can be certain that we have evidence for periodically occupied camps, with hominin groups manufacturing stone tools in the Levallois tradition, hunting exclusively for marshland animals, and possibly constructing semi-circular shelters and some other simple constructions in a well-organised camp.