The Argentario coast towers: geomaterials, history and conservatiojn state

Known by the Etruscans for its safe docks in their maritime trade, the Argentario peninsula was inhabited by the Romans, as evidenced by the ruins of Cosa (273 BC) on the hill of Ansedonia, and by the luxurious residence of the Domitii Enobarbi family, "argentarii as profession", i.e. bankers, in Santa Liberata. After the fall of Roman Empire, the Argentario history became confused with that of the surrounding areas, controlled by Barbarians, Byzantines, Lombards until the coming of Carlo Magno. Later on Argentario became, during the XII century, property of the Aldobrandeschi family, important noble family whose domains centered on Colle di Val d' Elsa, Fiora and Sovana. In 1414, Argentario passed with Orbetello and other territories under the control of the Republic of Siena. In the Senese period, the first systematic fortification of the peninsula, against the barbarian invasions that became more frequent and devastating, was realized. In 1557, following a military defeat, all the Senese territories passed in 1557 under the rule of Cosimo I de' Medici and Philip II of Spain reserved for himself a small coastal strip comprising Orbetello, Talamone, Argentario, Capalbio and subsequently part of the Elba island, that formed the State of Presidi. Philip II increased the military connotation of the territory upgrading the network of existing coastal towers and with the constructions of numerous and mighty fortresses: from 1563 to 1571, under the impulse of the Spanish viceroy of Naples Pedro Afan de Ribera, 17 coastal towers were realized in the territories of Orbetello and Argentario. The Spanish rule ended in 1707, leaving a deep urban and architectural traces. In this contribution, within an historical and architectonic context, the study of the geomaterials and state of conservation of three selected towers is presented. Stones ashlars and raw materials used for the preparation of bedding mortars were investigated with mineralogical and petrographic methodologies (optical and electronic microscope, X-ray diffraction) in order to enlighten the relationship with local geological outcrops. Furthermore, a survey about the restoration interventions was performed in order to verify the compatibility of used materials and their durability.