Cave of Hearths Breccia_OSL

The Cave of Hearths (CoH), located in the Makapan Valley in the Limpopo Province close to the modern town of Mokopane, has long been an influential site to trace the evolution of hominins in southern Africa (Mason 1969; 1988, McNabb and Sinclair 2009). Besides some earlier investigations, excavations were initiated in the 1940s and continued into the 1950s (Mason 1969). The CoH yielded in situ Acheulian (Early Stone Age; ESA) occupation in Beds 1 to 3. The ESA beds have been dated to between 780,000 and 390 000 years ago using palaeo-magnetism dating (Herries and Latham 2009). The CoH also has an extensive Middle Stone Age (MSA) occupation in Beds 4 to 9. The presence of lithics from the Pietersburg Industry places the MSA at the CoH in the MSA I and II, dating to between 128,000 and 75,000 (Wurz 2013). The site also has Later Stone Age (LSA), Iron Age and historical occupations in Beds 10 and 11. The presence of Oakhurst-style lithics in the LSA bed suggests an age between 12,000 and 7000 years ago (Lombard et al. 2012), and the ceramic style may suggest an occupation during the Early Iron Age (AD 400 – 900, Huffman 2007). The material from the surface likely relates to the siege of 1854 (Mason 1969, 1988).

Few archaeological sites in South Africa have such extensive and successive occupations by hominins over millennia. The earlier radiocarbon dates (Mason 1969) vastly underestimated the time depth of the occupations, and these dates are no longer accepted (cf. Wadley 2015). The imprecise dating of the CoH beds remains a serious constraint. Despite the site’s importance in earlier discussions on the evolution of hominins in South Africa, it has largely been excluded from archaeological debates on the ESA and MSA in particular due to the imprecise dating (Wadley 2015). At many other sites, each period show variation in terms of material culture, and without more precise dates, the artefacts (fauna, lithics, human remains, ceramics, bone tools, etc) from the CoH remain limited in their study potential.

For an ongoing permit (4168), I was given permission to sample six blocks of breccia for OSL dating at the University of the Witwatersrand. For this current application, I am requesting permission to extract, using a microdrill, a total of 30 grams of quartz from three of these breccia blocks (that are used for OSL dating). The extracted quartz is to be taken to France, per hand, where the suitability of the quartz will be investigated for future ESR dating (so 10 grams from 3 blocks, thus totaling 30 grams). I am therefore requesting a permanent export permit, as the samples will not be returned. Preliminary investigations of the quartz by Dr. Mary Evans have shown that the quartz will be suitable for future ESR dating.

Methodology (short):
ESR dating measures the amount of unpaired electrons in crystalline structures that were previously exposed to natural radiation. The age of a substance can be determined by measuring the dosage of radiation since the time of its formation. For this application, the quartz will be extracted using a microdrill at the University of the Witwatersrand, then it will be taken to France in person, where the suitability of the materials will be determined for future ESR dating.