A few km far from the confluence of the Fioi valley into the Carsoli basin, some hundreds m2 wide and ca. 1.5 m thick carbonatic deposit is present, embedded within late Middle Pleistocene alluvial gravel. The deposit formation might be related to sub-aerial deposition of CaCO3 (tufa) from emerging groundwater. A U/Th dating to 46 ± 6 ka BP constrains the deposit within the MIS 3, corresponding to a phase of warming between the MIS 4 and 2
