A 58,000 year-old site at the Sibudu rock shelter in KwaZulu-Natal near Durban (South Africa) has revealed innovative, cemented stone hearths that may have been used for the mass production of ochre. The discovery was made by a team lead by Lyn Wadley, a professor at the University of Witwatersrand, and will appear in the Journal of Archaeological Science.
     Ochre was used as a pigment, perservative, and medicinal compound, and was mixed with plant materials and animal fat to create adhesive. Its color ranges from yellows, reds, and oranges to browns and derives from mineral oxides in the clay. Red ochre is formed from yellow and brown by heating to at least 250 Celsius. Ochre residues have been found on ancient stone awls believed to have been used for producing leather clothing. It may indicate that ancient humans wore colorful garments, the fashion that continues today. Adhesive from ochre was probably used to attach stone arrowheads to wooden shafts and stone axheads to handles.
     Wadley excavated four hearths with cemented stones. The hearths contained ochre powder and may have held grindstones or as storage receptacles. 8,000 pieces of ochre were also recovered. She theorized that the raw clay was collected nearby and brought to the site to be heated and ground.
     Previous to this find, not much was known about the processing and use of ochre. Francesco d'Errico, the director of research at the National Center of Scientific Research at the University of Bordeaux (France), said that pieces of pigment are common at early sites. He believes that ochre played such an important part in Middle Stone Age culture that groups would dedicate several members to its production.
     
Source: Discovery News (June 3, 2010)