In search of the optimum Raman/IR signatures of potential ingredients used in San/Bushman rock art paint

Vibrational spectroscopy (Raman and FTIR) has played an important role in identifying pigments, substrata and deterioration products in rock art studies worldwide: in the laboratory and on-site. However, the detection of organic binders and carrying agents has so far been scarce and the quality of many spectra recorded on-site inadequate. In this study, possible pigments (charcoal, ochre, raptor faeces, thermally treated ostrich egg shell, etc.), binders (fat, egg, blood) and carrying agents (saliva, gall, egg, water) were selected based on artistic considerations and analysed with FTIR and Raman (514.6 and 785 nm excitation, both available in mobile instruments) spectroscopy in order to determine usable marker bands for each ingredient. The resultant marker bands were then used to analyse five ten year old San replica paints. It was found that FTIR spectroscopy is very efficient to identify organic compounds as there is no fluorescence but the broadness of the bands inhibits the exact assignment of many ingredients. A high fluorescence background experienced for many natural products prevented the recording of Raman spectra for all ingredients, in many instances though the sharp peaks usually associated with Raman spectra make identification easier than with FTIR spectroscopy. Most of the ingredients in the paints could be identified, but it is clear that better results are obtained when more that one technique is used.     

Responses of South African Agate and Chalcedony When Heated Experimentally,and the Broader Implications for Heated Archaeological Minerals

Here we present a database of responses by South African agate and chalcedony to heat treatment. This will assist analyses of heated stone tools not only in South African archaeological sites, but wherever heated agate and chalcedony pieces were knapped. The minerals are abundant worldwide. To replicate potential heating methods during the Stone Age we placed some minerals in a wood fire, some under coals, and others were buried in sediments beneath fires. Thermal responses include lustrous flaked surfaces, pot lid fractures, semi-circular internal fractures, rough internal surfaces, and crazing. Aerobic heating is implied by pot lid fractures. To explain the thermal responses we analyzed the minerals using X-ray fluorescence, Raman spectroscopy, and carbon and sulfur analyses. Our chalcedony contains more water and impurities than agate, making it more vulnerable to thermal damage. Our method of combining field experiments with chemical analyses has global applications even though we expect that mineral components of agate and chalcedony will vary slightly in different parts of the world.     

Dr. H.F. Verwoerd en die Ossewa-Brandwag 1938–1952

Abstract

South Africa's railway and harbours operator (SAR&;H) was the arch promoter of overseas tourism to South Africa for thirty years after Union in 1910. To its package tours for independent inbound tourists, the SAR&;H added exclusive port-to-port rail trips across South Africa by partnering with overseas cruise ship operators. Whereas the European market was a mainstay, the more distant North American market only became accessible in relation to lengthy round-the-world cruises. Between 1926 and 1939 approximately fifty long-distance luxury trains met thirty-one cruise liners to transport some 5,000 wealthy tourists through various inland scenic, cultural and wildlife attractions in southern Africa. Port calls by visiting cruise liners created their own spectacle and stir. Eventually more cruise passengers elected to stay on board ship at the end of long ocean voyages, elite visitors took cross-country flights to increase the novelty of travel, and this first period of South African sea-rail tourism came to a close.     

Record-Making,Research, and Removal: Mitigating Impacts on Rock Art in a CRM Context in Southern Africa—the Case of the Metolong Dam,Lesotho

African Archaeological Review - This paper reports on the steps taken to mitigate the impact of the Metolong Dam (Lesotho) on the rock art present within the catchment of its associated reservoir....     

Removal of Rock Art Affected by the Raising of the Clanwilliam Dam Wall,Western Cape Province,South Africa: Techniques and Procedures

The commissioning by South Africa’s Department of Water and Sanitation of a new and higher wall for the Clanwilliam Dam will increase dam storage and provide additional water for emerging and existing commercial farmers. But there is a cost to South African heritage. The raising of the wall will flood 27 rock art sites as well as other archaeological and historical resources. In partial mitigation of this impact on heritage the removal of particular pieces of rock art was approved by Heritage Western Cape, the provincial heritage agency. This report focuses on the removal process and techniques used to cut out three pieces of rock art under the management of PGS Heritage between 18 April 2016 and 7 May 2016 from the sites designated CDE02 and CDW10. Publication of the techniques used and the procedures followed will add to the sparse literature on rock art removal and increase the accessibility and availability of information about the removed stones.     

A Raman spectroscopic study of glass trade beads excavated at Mapungubwe hill and K2, two archaeological sites in southern Africa,raises questions about the last occupation date of the hill

Thousands of glass trade beads were excavated over a 75 year period on Mapungubwe Hill and at K2, two archaeological sites in the Limpopo valley, South Africa. An assemblage of 175 beads that appeared to be different in shape, size and colour (red, yellow, green, blue, white, black, pink, plum) was studied with Raman scattering. At least seven different chromophores or pigments (lazurite, lead tin yellow type II, Ca/Pb arsenate, chromate, calcium antimonate, Fe–S “amber” and a spinel) have been identified. Pigment identification allows the recognition of specific productions and indicated that many of the pigments colouring the beads excavated on Mapungubwe hill were manufactured after the 13th century, confirming the presence of modern beads in the archaeological record, some dating from the 19th century. This date is in agreement with the last occupation date for the hill suggested by the earlier excavators and raises questions about the revision of this date to 1290 AD by archaeologists in the 1970’s.