Lago di Bolsena: Datazione con il Carbonio-14 di reperti sommersi e fluttuazioni oloceniche del livello delle acque

Abstract

Twenty ¹⁴C age determinations on wood samples from the piles of a Villanovian pile-dwelling settlement, which protrude from the bottom of Bolsena lake at various depth, have been carried out. Studied sites are Gran Carro, Punta Gran Carro, Tempietto, Ragnatoro I, Ragnatoro Sud and Fosso Maltempo on the Lake of Bolsena in central Italy. On the basis of the obtained results, it has been concluded that: 1) The Gran Carro pile-dwelling settlement of Villanovian culture, which is ~4 m below present lake level, had probably been inhabited by Man for a time interval of several hundred years; 2) From the first half of 1200 to the beginning of 800 B.C. (about 3000 years ago), for a time interval of 400 years the lake level had been approximately 3.5 m lower than present level; 3) ¹⁴C determinations on wood samples from trunks at Fosso Maltempo have yielded the age of 1495 ± 65 years B.P.; at that time, the lake level was approx. 6 m lower than present level; 4) The age of handmade piles protruding from the lake bottom at a depth of 7.5 to 9.6 m from the surface at Tempietto, Punta Gran Carro, Ragnatoro I and Ragnatoro Sud, show that the lake level was about 8 m lower than present one in the period from 1300 to the beginning of 1600 AD. Results on Bolsena lake level fluctuations in recent Holocene times are in good agreement with literature data on level fluctuations of the nearby lakes of Martignano and Mezzano, and also on level changes of Fucino lake.