First discovered by Pierre Teilhard de Chardin and Henry de Monfreid in 1929 and excavated in 1933, the Porc-Epic cave is a Middle Stone Age dwelling that was used to process ochre—a pigment commonly employed in ancient cave paintings—for 4,500 years.
More than 4,000 pieces of ochre were discovered on-site, weighing in at nearly 90 pounds, which archaeologists subsequently determined to be “the largest such collection ever discovered at a prehistoric site in East Africa,” artnet news reported.
A new paper published in the PLOS ONE research journal hypothesizes that prehistoric visitors likely processed ochre by grinding, flaking, notching, and scraping the iron-rich stones to yield brightly-colored, “fine-grained” powders. The researchers even likened a selection of sharpened ochre fragments to crayons.
While it may have also been used for its medicinal qualities in small doses, “the production of small amounts of ochre powder is usually considered more consistent with symbolic activities,” the paper continues, “such as body painting, the production of patterns on different media, or for signalling.” Depending upon their individual properties, the stones could have been used to produce mostly warm-colored shades of red, orange, yellow, and brown.
Written by university researchers Daniela Eugenia Rosso, Francesco d’Errico and Alain Queffelec, the paper proposes that the cave was a shared community centerpiece that played a valuable role in the cultivation of early art.