Recent excavations at Pompeii: new findings and their volcanological implications

S03.06 - Volcanoes and Human History Recent excavations at Pompeii: new findings and their volcanological implications Claudio Scarpati1, Annamaria Perrotta1, Andrea Montanaro1, Domenico Sparice1, Alberta Martellone2, Arianna Spinosa2, Massimo Osanna2 1Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli “Federico II”, Italy 2Parco Archeologico di Pompei, Italy Detailed descriptions of the effects of Plinian explosive eruptions on urban settlements are rare. For this reason, volcanologists spent considerable time studing the destruction of the roman towns around Vesuvius occurred during the 79 AD eruption. At Pompeii, during the eruption accumulated about three metres of pumice lapilli from the eruptive cloud and successively one to three metres of stratified ash aggraded from pyroclastic currents. Both phases caused hundreds of victims. All reconstructions followed the chronology of Pliny the Younger, who witnessed the eruption and wrote two famous epistulae to the historian Tacitus. In these letters the eruption is described as a continuous event that lasted about nineteen hours. New stratigraphic data collected during recent excavations in the Schola Armaturarum, a famous building located in the central part of the Pompeii archaeological site, seems to contradict the never discussed before continuity of the eruption. Inside this building a large quantity of debris from walls and roofs was found lying through the whole pyroclastic sequence. Roofing tiles were found in the lapilli fall deposits, while eastwest trending walls were partly demolished in the ashy deposit accumulated during the flowage of the pyroclastic currents. A relevant observation is the presence of an erosive surface, 55 cm depth and 320 cm wide, covered with a few cm thick lens of reworked material cut into the middle part of the pyroclastic succession. The finding of this structure suggests a time gap in the eruptive phenomena affecting the city of Pompeii; this pause could have pushed the inhabitants, recovered indoor during the fallout phase, to leave their homes trying to reach safer places.