Tracing the Origins of an Anthropic Vitrified Structure with “Pre-Bleached with Blue LED” Thermoluminescence Dating: The Enigmatic Serravuda Hilltop Fortification in Calabria, Italy

Abstract

The Serravuda site on a hill near Acri, Calabria in Italy was discovered in 1970. The site presents a unique vitrified lithoid structure. Early theories speculated on its vitrification, ranging from forest fires to extraterrestrial impacts. The structure consists of vitrified Paleozoic rock fragments forming a 45-m-long wall, possibly once extending further. Analysis suggests that humans transported these fragments for construction, with subsequent partial vitrification occurring due to high temperatures from wood combustion. Thermoluminescence dating, using the innovative “Pre-bleached with Blue LEDs” protocol, indicates origins between the Late Bronze Age and Iron Age, aligning with settlement periods in the region. Fading studies were conducted to correct the error in the age data due to signal loss. The scenario suggests that the vitrification of the structure may have been a consequence of human utilization of timber for construction, with combustion resulting from random events such as forest fires or lightning strikes. This description has remarkable similarities with to those proposed for Iron Age vitrified forts in Northern Europe, suggesting that Serravuda could be seen as a precursor to such forts. Moreover, this prompts intriguing inquiries into the origins and evolution of Nordic engineering techniques focused on fire utilization in construction.

Keywords

• luminescence dating
• thermoluminescence (TL)
• glass material
• fortification
• Mediterranean