Insights on the Origin of Vitrified Rocks from Serravuda, Acri (Italy): Rock Fulgurite or Anthropogenic Activity?

In this study, twenty five partially vitrified rocks and four samples of collected on the top hill called Serravuda (Acri, Calabria, Italy) are analyzed. The goal is to shed light origin these enigmatic materials. analyzed a breccia cemented rock fragments (gneiss, granitoid, amphibolite fragments) which extends for more than 10 m, forming continuous mass along northern north-west border flat hill. Surrounded by accumulation, exposed Paleozoic granitoid substrate show limited melting or heat-alteration processes. By mapping minerals embedded in glass matrix via X-ray powder diffraction (XRPD) scanning electron microscopy (SEM), an interpretation source material, reactions, thermometric indications form materials Serravuda, Acri (Italy), provided. mineralogical composition heated heterogeneous owing effects heating events, but it mostly recalls parent amphibolite). presence quartz, cristobalite, tridymite, mullite, plagioclase, hercynite, cordierite, olivine glasses suggests that were subjected pyrometamorphism temperature range at formed was about 1000–1100 °C hydrous gas, burning organic material (e.g., wood), assuming thermodynamic equilibrium. Lithologies mixture not outcropping such as gneiss amphibolite. Data suggest most likely result anthropic activities could represent remnants fort walls. mineral assemblage walls made slabs derived from local metamorphic with addition improve strength insulation