Approaching the study of rock "monuments". The archaeological site of Pietralba (Upper Tiber Valley, Arezzo, Italy)

A multidisciplinary investigation of some open-air manufactured rocky blocks (both of Proto-historic and Medieval Age) found in the archaeological site of Pietralba (Arezzo, Italy) was performed. The Pietralba blocks display different typologies: a rectangular tub, an L-shaped tub, a throne, and a pyramid. Their study has been approached from the geo-morphologic, mineralogical and chemical standpoint with the threefold purpose of selecting how to better preserve the exposed surfaces from the atmospheric agents, of shedding light on their enigmatic use and, as a consequence, of developing a study-method never applied so far in this field. Even though rock Bmonuments^ are largely widespread and constitute a very intriguing issue, just few studies have been carried out on such artefacts and they have never produced univocal and definitive outcomes regarding their use and age. Samples collected from the tubs were analysed in order to identify the mineralogical and chemical inorganic composition, as well as the possible presence of organic components.