Geochemical and Engineering Geological Properties of the Volcanic Tuffs Used in the Etruscan Tombs of Norchia (Northern Latium, Italy) and a Study of the Factors Responsible for Their Rapid Surface and Structural Decay

Abstract

The geochemical and engineering geological properties of the tuffs used in the rock-cut cliff tombs of the Etruscan necropolis of Norchia were investigated to evaluate their susceptibility to different weathering agents and confirm their origin. For the first time, materials were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analyses (TGA, DGA and DTG), scanning electron microscopy (SEM-EDS) and energy-dispersive X-ray fluorescence (ED-XRF), and their different origins confirmed. Tests of material properties indicate that both tuffs are poorly durable, but one of them is less susceptible to weathering. Although tombs made with the more resistant material show limited surface weathering, they undergo severe structural damage because of stress release and plant root infiltration. This, combined with the microclimatic conditions established inside river canyons, can trigger rock falls, leading ultimately to the complete destruction of these tombs.a rcm_464 229..251

A case study of zeolitization process: “Tufo Rosso a Scorie Nere” (Vico volcano, Italy): inferences for a general model

“…Mineralogical investigations and chemical analyses show that zeolitization processes greatly affect TRS, both rock matrix and scoria fragments. The main zeolitic phase occurring in the TRS is chabazite and secondarily phillipsite, the former mainly distributed inside the rock matrix, the latter more concentrated inside scoriae, as previously reported by de Gennaro and Langella (1996), Giampaolo et al (2008), and Ciccioli et al (2010). Figure 5a-b represent a reconstruction of mineralogical changes occurring inside a single scoriaceous element.…”

“…In the last 40 years research on Italian quaternary pyroclastic deposits as sources of zeolitic minerals has greatly developed. Most studies focused on the possible mechanisms of zeolite formation, and several genetic hypotheses were proposed (Langella et al, 2013;Cappelletti et al, 2015;Colella et al, 2017). The purpose of this work is the study of zeolitization processes occurring at Vico volcano, with particular attention to the identification of the type of zeolites, genetic mechanisms, and factors that influenced/conveyed the volcanic alteration process.…”

Tree ring ecological signal is consistent with floristic composition and plant indicator values in Mediterranean Fagus sylvatica forests

“…a deep gorge at BAR and a lake caldera at VEN) (Scoppola & Caporali ), maintaining high levels of atmospheric and soil moisture at the biotope scale during the dry season (in a gorge near BAR, air relative humidity was found to be constantly > 85% during the dry season, while outside values were < 65%: Ciccioli et al . ). Moreover, although many studies found that EIVM was among the best‐performing EIVs (references in Loreto et al .…”

“…In this elevation belt, they grow only as extrazonal communities in sites characterized by special geo-morphological features (e.g. a deep gorge at BAR and a lake caldera at VEN) (Scoppola & Caporali 1998), maintaining high levels of atmospheric and soil moisture at the biotope scale during the dry season (in a gorge near BAR, air relative humidity was found to be constantly > 85% during the dry season, while outside values were < 65%: Ciccioli et al 2010). Moreover, although many studies found that EIVM was among the best-performing EIVs (references in Loreto et al 2014), two recent papers have recorded poor performances of EIVM even when compared with measurement of ground water level (Carpenter & Goodenough 2014;Szymura, Szymura & Macioł 2014).…”

Surface Weathering of Tuffs: Compositional and Microstructural Changes in the Building Stones of the Medieval Castles of Hungary

“…Although their durability can be inferred from relevant petrophysical and mechanical properties [6][7][8][9][10][11], only one study has documented the weathering of the monumental stone: the most recurring decay patterns, i.e., differential erosion, crust formation, crumbling, and other detachment morphologies, are dependent on mineralogy, pore-size distribution, and proportions of matrix, lithics, and pumice [7]. Indeed, the literature about tuffs in cultural heritage generally gives much broader consideration to technical characterization, and relatively few works deal with weathering-related mineralogical and geochemical changes of the stone in historical sites and buildings, this being a matter traditionally focused on carbonate rocks (the known case studies, from Europe, Asia, and Central America, are in [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]). The studies mentioned report tuff weathering in terms of surface enrichment in clay minerals and gypsum typically.…”