Capraia Island: morpology and geology of a complex volcanic activity during the Miocene and Pliocene.

This paper presents preliminary geologica1 results of a multidisciplinar study on the volcanic succession outcropping at Capraia Island, one of the northernmost islands of the Tuscan Archipelago. The basis of this study has been the field survey at 1:5000 scale, which allows the reconstruction of the volcanic succession and the completion of the 1:10,000 geological map. Morphological, petrographic, geochemical, and radiometric studies have been integated. During the fieldwork we recognised severa1 unconformity surfaces useful to define UBSU. The most important unconformity, benveen Capraia Supersynthem and Punta dello Zenobito Synthem, may identify two volcanic successions that differ in age, eruptive style, petrography, and geochemistry. The bulk of the island formed between 7.55 and 7.16 Ma during separate stages, with calc-alkaline lava flows and dome products. After a period of quiescence benveen 7.16 and 4.63 Ma, activity resumed at 4.63 Ma, with the eruption of shoshonites from a monogenetic centre in the southern part of the island.