Decoding Capua’s roof terracotta: A multi-analytical study of the Fondo Patturelli sanctuary and Alveo Marotta furnace (6th century BCE – 1st century BCE)

The main focus of this study was to examine 25 samples of archaeological ceramic materials currently preserved in the Archaeological Museum of the Ancient Capua and Mitreo investigated in the framework of an international project. These samples primarily consist of architectural terracotta from the Fondo Patturelli extra-urban sanctuary, as well as architectural terracotta, pottery and waste material from the nearby Alveo Marotta furnace. To investigate these artifacts, a multi-analytical mineralogical-petrographic approach was performed. Thin section observations revealed that almost all samples exhibit a coarse-grained paste. The fragments were categorized into three petrographic groups based on the type and quantity of temper, which is mostly composed of volcanic grains. They include lithics and juvenile fragments (obsidians and pumices) ascribed to the products of the major Campanian eruptions as detected via FESEM-EDS. Bulk chemical analyses (WD-XRF) show that almost all samples form a homogeneous group made with Ca-rich clayey raw materials, also including three wastes of tiles from the Alveo Marotta. By contrast, other two wastes from Alveo Marotta were produced with Ca-poor clay suggesting the use of a different raw material. From a technological point of view the samples are characterized by a thermal range that varies from 750 to 900 °C, notably different between the earlier and later production periods, with the former fired at lower temperatures.