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the intended application and the individual rock’s
hardness, which varies widely.
One of the obstacles to resolving how and
why the rocks were used is in their very nature.
“Ochre use by definition is destructive,” Zipkin
says. “Generally what we find are the remnants.
Whatever the application was is gone. The vast
majority of ochre used is no longer part of the
archaeological record.”WHAT REMAINS
The remnants archaeologists are left with can still
be impressive. In Ethiopia’s Porc-Epic Cave, for
example, Rosso and her colleagues have studied
the largest ochre assemblage ever collected:
more than 4,000 pieces weighing nearly 90
pounds in total.
The material was excavated in the 1970s, but in
2016 Rosso and her team performed a high-tech
analysis on the pieces, which are about 40,000
years old. “In Porc-Epic, we see the complexity of
how the ochre was used by the different tools they
needed to work with it,” says Rosso.
Among their findings: assorted tools for
processing ochre, such as grindstones, and aExcavations
in South Africa’s
Blombos Cave (above)
have found artifacts
up to 100,000 years
old. In the 1970s,
researchers dug up
the largest collection
of ochre-related tools
(right) in Ethiopia’s
Porc-Epic Cave,
dating back about
40,000 years.
2 inches