Tree-Ring Chronological Investigation on the Oak Poles of the Prehistoric Settlement of “Gran Carro” in Lake Bolsena, Central Italy: Landscape and Human Occupation

Dendrochronological analysis was carried out at the archaeological settlement of Gran Carro, located in Lake Bolsena (Italy). According to the most recent archaeological evidence, the site dates back to the period spanning from the Middle Bronze Age (15th century BC) to the Early Iron Age (8th century BC). In the excavation of the archaeological area, wooden piles from deciduous oak species ( Quercus section robur and Quercus section cerris ) were found, species still common in the area. The analysed trees, aged 15–50 years, likely came from managed forests, though agamic regeneration is possible. Relative felling dates provide initial insights into the duration of the settlement phases, revealing modifications to the original structure over an interval year ranging from 9 to 23 years. Absolute dating using wiggle matching indicates that most of the analysed piles date between 934 and 810 BC, though calibration curve slope limits precision. Nonetheless, dendrochronological analysis suggests that the settlement associated with an individual dendrogroup can likely be placed more precisely within this time range from 907 to 885 BC. From a broader perspective, the excavated area so far indicates that the settlement can be dated with 95% probability to the period 1054–810 BC and with 68% probability to the period 1017–817 BC. The results represent a significant milestone and may offer valuable insights for future investigations and developments.