Heritage Cases

MOTIVATION FOR THE CHEMICAL ANALYSIS The 8 backed tools from Sibhudu, listed in the table below, were originally analysed by Dr Marlize Lombard using microscopy. They have also been analysed for their mineral components, using FTIR and Raman analyses (and some SEM-EDS), by Drs Luc Bordes and Linda Prinsloo in Wollongong, Australia. Mineral components such as hematite, goethite, graphite and several minor elements were identified, in addition to a few organic components like bone. The Australian study provided useful data on the loading agents mixed into products that we interpreted as adhesives for hafting the stone tools to handles or shafts. Unfortunately, the organic resins or gums that were probably the main original components of the adhesives have not yet been characterised. Dr Guilhem Mauran was employed at Wits to carry out GC-MS on the tools in 2020, but his arrival from France as a post-doctoral fellow coincided with the start of Covid-19 and all the university laboratories were closed for the duration of his South African stay, so the work was not done. Dr Patrick Schmidt of Tübingen University, Germany, has started a project to characterise Podocarpus (yellowwood) resin. This would seem to be the most likely resin used for hafting adhesives on many of the Sibhudu tools as well as on tools from other sites where Podocarpus is known to have grown. Podocarpus is part of the vegetation record at Sibhudu until the end of the Howiesons Poort at this site, around 62,000 years ago, but the resin has not yet been securely identified on the tools. Two backed tools from Sibhudu that were studied in Pisa by Dr Ilaria Degana were found to have coniferous resin, but no further identification was made. The tools listed in this application have mineral residues visible on their hafting edges and these imply that mineral components were part of compound adhesives used at the site. The minerals would have needed a moist component to bind them and create a fixative. We think the most likely component is yellowwood resin. Although the most urgent need is to characterise the organic (specifically plant resins if they preserve) component of the adhesives using GC-MS, the other chemical analyses will also be undertaken. While these tests have been conducted elsewhere, one must point out that the instrument probes are tiny and small points on the tools have been chemically identified. It will therefore be valuable to repeat some of the FTIR, Raman and SEM-EDS procedures. ADDRESS WHERE SAMPLES WILL BE ANALYSED Dr Schmidt will travel to Germany with the 8 tools in his hand luggage so that the tools do not have to be sent by courier. Eberhard Karls University of Tübingen Department of Prehistory and Quaternary Ecology Schloss Hohentübingen Burgsteige 11 72070 Tübingen, Germany Dr P. Schmidt office telephone number is: +49 7071 29 74390 Email address: for Patrick Schmidt is patrick.schmidt@uni-tuebingen.de Institute telephone (answered by secretary) is: +49 7071 29 76457 LOCATION DETAILS Sibhudu Cave 29° 31' 21.2736" S, 31° 5' 8.2608" E PORTION 10 OF THE FARM SINEMBE NO 16902-FU Site ID: 10487 Sibhudu-001 Map: 2931CA Verulum Nearest town: Verulum District: KwaDukuza Municipality, Kwazulu-Natal Age of materials: 65,000 – 60,000 years old PARTICIPATING RESEARCHERS L. Wadley (PhD) – excavator of Sibhudu to 2011. (Wits University) P. Schmidt (PhD) – (University of Tuebingen). CURATION OF MATERIALS University of the Witwatersrand, Archaeology Curator: Dr Thembi Russell Contact: thembiwe.russell@wits.ac.za University of the Witwatersrand, PO Wits 2050 The material is temporarily stored at Wits University. The table listing tools is attached as a pdf.