Selection and Use of Manganese Dioxide by Neanderthals

Summary

Several Mousterian sites in France have yielded large numbers of small black blocs. The usual
interpretation is that these ‘manganese oxides’ were collected for their colouring properties and used
in body decoration, potentially for symbolic expression. Neanderthals habitually used fire and if they
needed black material for decoration, soot and charcoal were readily available, whereas obtaining
manganese oxides would have incurred considerably higher costs. Compositional analyses lead us
to infer that late Neanderthals at Pech-de-l’Azé I were deliberately selecting manganese dioxide.
Combustion experiments and thermo-gravimetric measurements demonstrate that manganese dioxide
reduces wood’s auto-ignition temperature and substantially increases the rate of char combustion,
leading us to conclude that the most beneficial use for manganese dioxide was in fire-making. With
archaeological evidence for fire places and the conversion of the manganese dioxide to powder, we
argue that Neanderthals at Pech-de-l’Azé I used manganese dioxide in fire-making and produced fire on
demand.

Details

Project number

036.003.967

Main applicant

Prof. dr. J.W.M. Roebroeks

Affiliated with

Onderzoekschool ARCHON

Duration

07/04/2016 to 08/04/2016