Tracing the human movements of three thousand years ago by volcanic grinding tools in the Final Bronze Age settlement of Monte Croce Guardia (Arcevia-Marche Region, central Italy).

Volcanic rocks were among the most sought-after materials to produce grinding tools in antiquity because lavas lithologies, either mafic or felsic, ensured good wear resistance and grinding capacity with respect to many other kinds of rocks. The interest in findings made of vesciculated lavas, referable to parts of querns, mortars, and/or pestles of the Final Bronze Age site of Monte Croce Guardia (Arcevia) lies in the fact that this settlement was built upon limestones belonging to the sedimentary sequence of the Marche-Umbria Apennines (central Italy) and far away from potential raw materials of volcanic rocks. A petrologic study of 23 grinding tool fragments clearly indicates a provenance from the volcanic provinces of central Italy: Latium and Tuscany Regions. Few leucite tephrites (5) and one leucite phonolite lavas have a clear magmatic affinity with the high-K series of the Roman Volcanic Province (Latium) whereas the most abundant volcanic lithotype (17 samples) is represented by shoshonites (K-series) whose thin section texture, modal mineralogy and major-trace elements contents closely match with the shoshonite lavas from the Radicofani volcanic centre in the Tuscan Magmatic Province. At Radicofani (a volcanic neck in the eastern sector of Tuscany) a Final Bronze Age site coeval to that of Arcevia is present and a potential pathway corridor from that site towards Arcevia (air-line distance of ca. 115 km) is dotted with many settlements of the same age. Through analytical algorithms based on the slope and the different human-dependent cost-functions which can be applied to determine non-isotropic accumulated cost surface, least-cost paths and least-cost corridors, the best route from Radicofani to Monte Croce Guardia, approximately 140 km long, was simulated, with a walking time of 25-30 h, possibly using pack animals and wheel chariots. Three thousand years ago the Apennine Mountains did not thus constitute a barrier for human movements. This study also shed light on some other possible patterns of interactions between Final Bronze Age communities of central Italy through the present-day regions of Tuscany, Umbria and Marche, aimed towards the best performance of strategic economic activities at that time such as that of the transformation of cereals, and accompanied to cultural and social reasons.

Geoarchaeological Evidence of Middle-Age Tsunamis at Stromboli and Consequences for the Tsunami Hazard in the Southern Tyrrhenian Sea.

Large-scale landslides at volcanic islands are one of the most dangerous geological phenomena, able to generate tsunamis whose effects can propagate far from the source. However, related deposits are scarcely preserved on-land in the geologic records, and are often difficult to be interpreted. Here we show the discovery of three unprecedented well-preserved tsunami deposits related to repeated flank collapses of the volcanic island of Stromboli (Southern Italy) occurred during the Late Middle Ages. Based on carbon datings, on stratigraphic, volcanological and archaeological evidence, we link the oldest, highest-magnitude investigated tsunami to the following rapid abandonment of the island which was inhabited at that time, contrary than previously thought. The destructive power of this event is also possibly related to a huge marine storm that devastated the ports of Naples in 1343 (200 km north of Stromboli) described by the famous writer Petrarch. The portrayed devastation can be potentially attributed to the arrival of multiple tsunami waves generated by a major landslide in Stromboli island, confirming the hypothetical hazard of these phenomena at a regional scale.