The post-Tyrrhenian evolution in Sardinia: evidence from Ebidozzi palaeovalley (Argentiera, North-Western Sardinia, Italy).

Analyses of selected samples coming from a well exposed plio-pleistocenic stratigraphic section located along the coastline of northwestern Sardinia, allow us to evaluate the recent geomorphological evolution of a sector belonging to an ancient valley infilled by sedimentary deposits, mainly of continental environment. The palaeovalley filling has been favored by erosional processes in post-Tyrrhenian regression times under climate exchange recorded during Holocene. The occurrence of halite mineral phase in the studied stratigraphic sequence, suggests the prolonged occurrence of salt environments during the early phase of post- Tyrrhenian regression before the begin of an aeolian regime. Assuming a uniform erosive process for the last 80 Ka, we evaluate its the efficiency on the basis of the volume of deposits infilling the investigated palaeovalley. The obtained deposition rate is about 0.5 m3/year.