A team led by University of Missouri researcher Brandi L. MacDonald has discovered the world’s oldest ochre mine, dating back 40,000 years in Eswatini.
By leveraging advanced facilities at the University of Missouri—including the Mizzou Research Reactor (MURR), Materials Science and Engineering Institute (MSEI), and the Electron Microscopy Core (EMC)—researchers have mapped how ochre from this site was mined and distributed to surrounding communities.
"By comparing the ochre sources with places where people lived, exchanged, and used those ochres between 2,000 and 40,000 years ago, we can see how their choice of raw materials changed over long periods of time," MacDonald explained.
This comparison helped scientists “anchor human activities in time” and understand the development of cognition and social networks in early human communities. Through neutron activation analysis and other high-tech processes at MURR, researchers created a “geochemical signature” to identify the origin and distribution of ochre artifacts, crucial for understanding ancient trade and cultural practices.
Samples from Eswatini's Lion Cavern underwent further examination with advanced Raman spectroscopy at MSEI and imaging tools at the EMC, revealing the unique chemical structures within the ochre.
This meticulous approach revealed new insights into the methods early humans used to mine, transport, and use ochre, deepening our understanding of Stone Age societies and their creative expression.