Mortar-type identification for the purpose of Reconstructing fragmented Roman wall paintings (Celje, Slovenia)

Abstract

Archaeological excavations of Roman Celeia (present-day Celje, Slovenia) carried out about 30 years ago revealed the remains of a Roman residential building where more than 9000 fragments of wall paintings were found. The past manual reassembling of fragments proved to be time consuming, limiting the amount of the material that can be examined and reconstructed. However, recently work has been resumed using a software application specifically developed for fragment reassembly. Information on mortar types can provide additional data about the fragments and thus help in the reconstruction process. Fragments of the wall paintings consist of up to three preserved mortar layers, differing in their thicknesses, aggregate compositions and binder colours. Based on the mineralogical/petrographic analyses of the mortars, the investigated fragments of the wall paintings were divided into several groups. The results revealed that the first-mortar-layer aggregates of all the fragments consist of carbonate grains, while the other-mortar-layer aggregates consist of carbonate, silicate/carbonate, silicate or silicate/ceramic grains.