Archaeologists say they have discovered the oldest known evidence for intensive ochre mining worldwide, at least 48,000 years ago, in Lion Cavern at Ngwenya in Eswatini, a landlocked country in southern Africa.
Selected hand specimens of samples from sources included in the study: Ngwenya high grade (A-C), Ngwenya low grade (D-F), Kubuta (G), Bulembu (H-J), Lupholo Dam (K, L), Mnyongane (M, N), Maloma (O). Scale bar – 1 cm. Image credit: MacDonald et al., doi: 10.1038/s41467-024-53050-6.
Ochre is widely recognized as a red, yellow, or violet pigmentaceous earth mineral, often conflated with manganese oxide (black ochre), and its importance throughout human history is indisputable.
It survives deep time records, was extracted by intensive mining practices, transported great distances, used in symbolic and mortuary expression, underwent processing to enhance its properties and performance in complex paint mixtures.
It continues to retain widespread cultural importance in many descendant communities today.
Yet, the differences between ochres are not always obvious, and pigments that appear the same in color and texture often have distinct physicochemical properties.
“We can say that ochre is the earliest known pigment used by humans to depict our world,” said Dr. Gregor Bader, an archaeologist with the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen.
“Our species and other hominins have been using the red, yellow, or sometimes purple earth mineral for at least 500,000 years — and possibly even longer.”
In the most comprehensive study to date on the use of ochre in Africa, Dr. Bader and his colleagues investigated how this mineral was used south of the Sahara.
Based on 173 samples from 15 Stone Age sites, the researchers reconstructed the regional networks of mineral selection, extraction, transportation, and the use of ochre.
“We were interested in the entire ochre processing chain: From the selection of the mineral from various geological formations, its extraction, the admixture of other substances such as milk, fat, blood, and plant resins as binding agents, to its transportation to the archaeological sites,” Dr. Bader said.
“How was the knowledge of ochre extraction passed on? Was there an exchange between different hunter-gatherer groups? And are there regional or temporal differences?”
The study shows that there existed both local strategies for procuring ochre as well as long-distance transportation of the important mineral via a network of different mineral deposits.
The archaeometric investigations at 15 sites suggest the presence of a long-standing cultural continuity in the intergenerational transmission of knowledge about ochre extraction and use, including geological conditions or desired physicochemical properties of mineral pigments.
These communities of practice did not develop in isolation but were part of a broader system of relationships influenced and mediated by social interactions such as technological learning, seasonal migrations, the exchange of material culture, and symbolic expression.
“Our data support the assumption that hunter-gatherers were very mobile in Eswatini during the Stone Age and sometimes traveled long distances to transport ochre pigments,” Dr. Bader said.
“It is remarkable that such traditions continue in Eswatini to the present day. It is known from ethnographic studies, for example, that plant healers travel to collect mineral earth pigments for painting and healing ceremonies.”
“Ochre is also considered an important part of wedding ceremonies — the bride is painted with red ochre and animal fat on the morning of the wedding to signal her new status in the community.”
“Our current work impressively demonstrates that researchers from Eswatini take a leading position in the study of Stone Age ochre sources, and that the country holds an immense wealth of this important pigment.”
“Besides breaking down the ochre exchange chain, we also used optically stimulated luminescence dating to confirm that the Lion Cavern in Ngwenya constitutes the oldest known evidence of intensive ochre mining in the world, dating back some 48,000 years.”
“In addition, we can see here some of the oldest evidence of humans actively changing the shape of their environment.”
The findings were published in the journal Nature Communications.
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B.L. MacDonald et al. 2024. Ochre communities of practice in Stone Age Eswatini. Nat Commun 15, 9201; doi: 10.1038/s41467-024-53050-6
