The Macquenoise sandstone (Devonian-Lochkovian), a suitable raw material for ancient querns and millstones: quarries, properties, manufacture and distribution in France and Belgium

For some years, a French-Belgian team of archaeologists and geologists is investigating the provenance of ancient quern-stones and millstones. Their study revealed the frequent occurrence of particular coarse sandstones derived from Lower Devonian strata in the Ardenne region, known as either the Arkose of Haybes by geologists or the Arkose of Macquenoise by archaeologists. Material for Late Iron Age and Roman quern-stones and millstones was quarried from open pits located west of the border between France and Belgium, between the Belgian village of Macquenoise (Commune of Momignies, Province of Hainaut) and the French town of Hirson ( Aisne Department, Hauts-de-France region). This paper describes the raw materials, presents thedifferent types of grindstones produced through historical times and provides a detailed diffusion map of the millstones.