The paleo-lacustrine diatomaceous deposits of Monte Amiata volcano (Tuscany, Italy) and the Ezio Tongiorgi paleontological collection in the Museum of Natural History of the University of Pisa

At the foothill of Monte Amiata volcano (southern Tuscany, Italy), small extinct lake basins of latePleistocene age are documented. These lake basins were characterized by the deposition of twovery different types of sediment: a) derived from the authigenic precipitation of iron oxides(goethite) and exploited as earth pigments; b) biogenic siliceous sediment composed of fossildiatoms and named diatomaceous earth or diatomite. The lacustrine sediments of Mount Amiatavolcano were widely exploited for various applications since ancient times. Literary documentsbegin in the 16th century, with the descriptions of Cesalpino, Gesner, Agricola, and Imperato.Specific references to the diatomites of Monte Amiata are quoted in the 17th century by Bocconeand Bonanno. The quarrying activity was described by Micheli in 1733. During the 18th and 19thcenturies, the diatomaceous earths of Monte Amiata are part of the important geologicalcollections of Micheli, Targioni Tozzetti, Baldassarri, Campani, and Tommi. A particularsignificance has the collection of botanic and ichthyologic fossils collected by Ezio Tongiorgi,and now preserved in the Museum of Natural History of the University of Pisa sited at theCharterhouse of Pisa in the Calci village. These paleontological samples preserve the biologicaland physical testimonies of the environmental and climatic changes of the late Pleistocene andare now particularly valuable because they are the only remaining evidence of the diatomaceouslacustrine deposits of the paleo-lakes of Monte Amiata. For these reasons, they representgeological materials with a fundamental cultural value.