title: Selection and Use of Manganese Dioxide by Neanderthals.
abstract: 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.
authors.affiliation: Faculty of Archaeology, Leiden University, Einsteinweg 2, 2333CC Leiden The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Heyes
authors.affiliation: 3mE Process and Energy, Delft University of Technology, Leeghwaterstraat 39, 2628CB, Delft, The Netherlands.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Anastasakis
authors.affiliation: 3mE Process and Energy, Delft University of Technology, Leeghwaterstraat 39, 2628CB, Delft, The Netherlands.
authors.forename: Wiebren
authors.initials: W
authors.lastname: de Jong
authors.affiliation: Faculty of Archaeology, Leiden University, Einsteinweg 2, 2333CC Leiden The Netherlands.
authors.forename: Annelies
authors.initials: A
authors.lastname: van Hoesel
authors.affiliation: Faculty of Archaeology, Leiden University, Einsteinweg 2, 2333CC Leiden The Netherlands.
authors.forename: Wil
authors.initials: W
authors.lastname: Roebroeks
authors.affiliation: Faculty of Archaeology, Leiden University, Einsteinweg 2, 2333CC Leiden The Netherlands.
authors.forename: Marie
authors.initials: M
authors.lastname: Soressi