Mills for the Roman army – geochemical provenance analyses of millstones from the Augustan fortresses Haltern, Oberaden, Anreppen und Barkhausen

Abstract

For the first time a study is published which presents a petrological analysis of all Roman lava quarries in the volcanic Eifel region and which develops recommendations for a provenance analysis of millstones on the basis of the geochemical composition of the raw material. According to these recommendations, in each case two millstone samples from the Roman fortresses Haltern, Oberaden, Anreppen and Barkhausen were analysed geochemically. Affiliation is carried out in three steps: 1. geochemical characterisation checks whether an Eifel provenance can be considered, 2. cluster analysis tests to which quarry or group of quarries the sample can be attributed, and 3. discriminant analysis allocates the sample to its quarry of origin – with a certain probability. Combining these methods, an exact provenance from the Eifel area for the analysed finds can be established.