## 2 Geological Framework of the Investigated Samples
The current fault configuration in the Bay of Naples includes E-W-trending strike slip (left-lateral) faults, NE-trending extensional faults, and NW-oriented transtensional structures--likely the result of block rotation within a transtensional environment along an E-W fault zone [55]. With regard to Comiso stone, it originates from the lower portion of the Leonardo Member (Upper Oligocene) within the Ragusa Formation, which spans from the Upper Oligocene to the Miocene in the Hyblean Plateau. This formation is characterized by alternating calcareous and marly layers. The stone itself is a well-lithified, fine-grained calcarenite, predominantly composed of calcite. It exhibits a white to cream color, a compact and tenacious texture, and a uniform structure. Quarried in southeastern Sicily, Comiso stone was extensively used in the construction of monuments in the Baroque towns of the \"Val di Noto\", which are now recognized as UNESCO World Heritage sites [52]. These cities were largely rebuilt using this stone after being devastated by the catastrophic 1693 earthquake. The outcrop of Comiso stone is located near the Comiso-Chiaramonte fault system, which extends toward the village of Monterosso Almo. This system delineates a raised southeastern sector characterized by the presence of Oligo-Moicene limestone formations. The structural framework is defined by three main SW-NE-trending, left-stepping en-echelon dextral strike-slip faults--namely, the Comiso, Chiaramonte, and Monterosso faults. These faults together form a shear zone oriented SSW-NNE [56]. Going on, the Mendicino stone is part of the Tortonian-Messinian sedimentary sequence that filled the basins formed during the early Tortonian in the western portion of the Calabrian Arc. This unit consists of a clastic marine sequence that lies unconformably on top of the Paleozoic basement and dips outward relative to the massif [57]. These deposits are subsequently overlain, again unconformably, by marine sediments deposited during the Upper Pliocene to Lower Pleistocene transgression. In the western sector of the Calabrian Arc--within the forearc region associated with the active subduction of the Ionian Basin--these Tortonian-aged basins were infilled with sediments. In half-graphen structures such as the Craci Valley and along the western slopes of the Coastal Range (Catena Costiera), remnants of the Tortonian-Messinian succession are preserved and, in some locations, uplifted to elevations reaching 900 m above sea level. The age of the Mendicino stone has been determined using planktonic foraminiferal assemblages found in the overlying and underlying clay-rich layers. Four principal lithost stratigraphic units have been identified within the succession, which can be laterally correlated across a broad area [58]. Finally, the \"red tuff and black scoria\" deposit--commonly referred to as Viterbo tuff--is a zeolite-rich volcanic rock belonging to the Sutri Formation. This unit was generated by eruptions from the Vico Volcano, located within the Roman Comagmatic Province (RCP), a north-west to south-east trending belt of ultrapotassic, mostly explosive volcanic districts and minor eruptive centers along the Tyrrhenian margin of central Italy [59]. Geological interpretations increasingly associate the volcanism in this region, particularly in the northern central Tyrrhenian Basin, with back-arc extension processes. According to this view, the Quaternary volcanism along the Tyrrhenian margin resulted from northeast-southwest extensional tectonics that occurred behind the Apennine orogenic front. This extensional regime is thought to have been driven by the northeastward rollback of a subducting slab, which also explains the eastward migration of volcanic activity in the region between approximately 8 and 0.8 million years ago. Within the RCP, the main volcanic centers include Vulsini, Vico, the Sabatini Mountains, and Colli Albani [60].