Il vulcanismo monogenico medio-pleistocenico della conca di Carsoli (L’Aquila).

The volcanic field is comprised of several Upper Pleistocene small tuff cones, tuff rings and maars (531 ka), aligned along a NNW-SSE normal fault of regional meaning. Most of the deposits are directly related to vent structures and preserve signs of primary proximal origin consisting of high-energy structures, welded lapilli and ballistic impacts. Characteristic sequences of vent coring eterolithic breccias, dry lapilli-ash surges of high-temperature and wet surges of ash-lapilli tuff are exposed and found in well coring. Juvenile fragments consist of plastically moulded lapilli, essentially composed of diopside, phlogopite, leucite, K-feldspar, apatite and immersed in a turbid micro-cryptocrystalline matrix of Ca-carbonate. Lapilli shape indicates that they agglutinated and quenched when still hot plastic. Silicate glass shards are present and have typical cuspate wedges produced by bubbles expansion and disruption during magmatic activity sustained by juvenile gases. A late phreato-strombolian phase builted several tuff-rings and cones. At Oricola - Carsoli - Rocca di Botte - Camerata Nuova volcanic field, juvenile fragments and tuffs range from phonolitic-foidite to foiditic-carbonatitic to carbonatite s.s. The latter forms small pyroclastic flows and surge deposits. Geological context, age, mineralogy and petrology are germane with the near Grotta del Cervo occurrence and are consistent with the carbonatitic-kamafugitic suite of Italy. This new carbonatitic outcrop, that joins the increasing number of Italian carbonatites, puts Italy in a relevant place for what concerns carbon-rich mantle magmatism occurrences. Actually, the six extrusive carbonatites and the intrusive one so far reported, represent one of the largest concentrations of such a kind of rocks all over the world.