Evidence of late Roman glass production in Southern Lusitania (Ossonoba, Faro, Portugal).

The excavation of numbers 32 and 34 on Calle Francisco Barreto, in Faro (Portugal), in 2017, identified some of the remains of a 2nd-century AD fish-salting factory in the industrial area of Ossonoba. Once this factory ceased operating, its structures were given other uses until their final abandonment in the 6th century AD, including the construction of a glass furnace in the central courtyard, found in association with glass-working remains and glass vessels. The typological study of the glass and the related pottery dates the activity of the furnace from the early to the mid-5th century. The results of the chemical analysis (EMPA and LA-ICP-MS) of several glass samples taken from both vessels and glass-working waste are in line with the chronology based on typology, which has made it possible to confirm the dating provided by the typological study and determine the Egyptian and Levantine Mediterranean origin of the glass worked at the furnace. The evidence clearly indicates that glass-working at the complex only began after the fish-salting facility had ceased operating