Sossio Fabio Graziano

The “Tufo Giallo della Via Tiberina” (Sabatini Volcanic District, Central Italy): a complex system of lithification in a pyroclastic current deposit

The Sabatini Volcanic District belongs to the Roman magmatic province of Central Italy, and the Tufo Giallo della Via Tiberina was one of the most voluminous pyroclastic flow-forming eruptions in this district. Post-depositional processes strongly affected this pyroclastic flow deposit leading to the crystallization of different authigenic phases (chabazite, phillipsite, feldspar). A field volcanological survey, along with a careful mineralogical characterization of a large amount of samples of the lithified facies, allowed us to reconstruct a type section primarily based on the amounts of the main authigenic phases. Chabazite always prevailed over phillipsite throughout the entire section, although in the innermost portions of the deposit, where temperatures remained high, chabazite mostly converted into a more stable phase such as an adularia-like phase. In addition to the zeolitization process, the fairly strong mechanical properties of this tuff can be also ascribed to the diffuse occurrence of microcrystalline calcite, which re-precipitated as a secondary phase after the dissolution of carbonaceous clasts.

Expanded clays in water treatment: some alternative filtration media

Companies from different industrial sectors regularly use biological aerated filters to reduce pollutants resulting from industrial productions. These filters use a bed of inert material for the growth of a microbial colony which has the key role to break down pollutants. The inert bed is usually formed by organic or inorganic material and always more often from natural products such as the commercial Biodagene which is the product of fired shales from France. This research aims to use clayey Italian rock formations for the production of lightweight expanded aggregates and to test physical-mechanical features of fired products, to verify the possibility of manufacturing a viable alternative media to inert products currently traded.