A new lake in Italy (Southwestern Sardinia): a maar?

Abstract

This study of a small lake basin located near the southwestern coast of Sardinia has allowed individualisation of this morphology as this lake is linked to the volcanic outcrops of the Oligo-Miocene that constitute the basement of this territory. The historical, physical and geological characteristics of this lake, known as «Stagno’e Forru» («stagno» means «pond», so it has always been considered as such), allow us to hypothesise to a possible origin as a maar formed during the final activity of the calc-alkaline cycle in the Oligo-Miocene span. The possible genesis is examined and discussed within the recent evolution of the landscape. Its age, in accordance with the ancient shorelines individualised in the sea base and in the cords of the beach, cannot be established, making drilling of the lacustrine deposits necessary for further investigation. However, knowledge of this lake is significant because it is the confirmation of another lake existence in Sardinia; until now, Sardinia is known to have only one natural lake, which was formed by an aeolian obstruction.