U/TH Dating of Pre-Holocene calcareous tufa deposits in the Umbria-Marche Apennine (Italy)

Cilla G., Dramis F., Fubelli G., Maceroni D., Malocco S., Materazzi M., Remigio M., Soligo M., U/Th dating of pre-Holocene calcareous tufa deposits in the Umbria-Marche Apennine (Italy). (IT ISSN 0391-9838, 2025). This note describes the characteristics of two calcareous tufa (freshwater travertine) deposits found in the Umbria-Marche Apennine. The first has grown in the Laverinello Valley, a tributary of the upper Potenza River, along the road from the village of Poggio Sorifa; the second deposit originated in Val di Sasso (Sasso Valley), a tributary of the upper Esino River, on the edge of a waterfall, currently inactive and disconnected from the present drainage network. The U/Th dating of samples taken from the investigated tufa deposits (55 +/- 6 ka BP-58 +/- 6 ka BP, 65 +/- 8 ka BP-67 +/- 5 ka BP, respectively) places them in the Upper Pleistocene, corresponding to sharp warming peaks within cooling periods. These dates seem to support the genetic model of freshwater travertine deposition proposed by Dramis et al. (1999), based on the control exerted by the formation in the aquifer of a reversed thermal gradient in correspondence with climate warming.