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[sup.29]Si nuclear magnetic resonance (NMR), electron spin resonance (ESR) and Mossbauer spectroscopy reveal some influences of magma dynamics on the structure of natural volcanic glasses. Our study concerns three carefully selected pumice samples collected from the Cretaio Tephra, deposited during a small-volume eruption that occurred in Roman times at the Island of Ischia, in the Phlegraean Volcanic District. We analysed glass separated from fragments of these pumice samples, which represent three different stratigraphic members of the Cretaio pyroclastic succession. Erupted during distinct phases of the eruption, these sampled members formed by either magmatic fragmentation or phreatomagmatic processes. Previous geochemical studies showed a homogeneous trachytic composition throughout the Cretaio sequence and a slight variation of the Sr-isotope ratio. The results of microprobe analyses confirm the homogeneous trachytic composition of the glass at the 20 [micro]m scale. The curve-fittings of the [sup.29]Si MAS NMR spectra show variable relative proportions of [Q.sup.4] and [Q.sup.3] species in the glass structure. The glass/melt extruded during the first phase of the eruption contains a larger amount of [Q.sup.4] than glass from the later phase, and it has negligible quantities of [Q.sup.2] species. This finding could indicate that disproportionation reactions such as 2[Q.sup.3] [??] [Q.sup.2] + [Q.sup.4] might not be applied to describe the Q-speciation in highly polymerized natural trachytic melts, and the first erupted glass with the highest amount of [Q.sup.4] is interpreted as representative of a more polymerized melt, even if chemically indistinguishable from the others. Also Mossbauer spectra show that this glass differs from those extruded during the later phases of the eruption because it contains [Fe.sup.3+] in network-forming tetrahedral coordination. [sup.29]Si cross-polarization-magic angle spinning (CP-MAS) experiments do not reveal a significant contribution of water speciation to silicon depolymerization in glass from surge deposits indicating that the magma probably interacted with water after the melt-glass transition temperature interval was crossed. We suggest that the detected structural variations reflect variable time-temperature paths during rise of different melt batches possibly caused by ascension in a segmented dyke prior to or during the Cretaio eruption.

The Campi Flegrei caldera in southern Italy is one of the greatest geohazard areas on Earth. Evidence of an active magmatic and geothermal system is provided by ongoing ground uplift, with volcano-tectonic and long-period (LP) seismicity, the persistent degassing of ~1500 tonnes of CO per day, the presence of hot fumaroles at temperatures of 90-150 °C, brine-rich aquifers (with total dissolved solids up to 33 g l) and high thermal gradients in the crust (with temperatures reaching 420 °C at 3,050 m b.s.l.). Since the 1940s, more than 100 exploratory boreholes have been drilled in the area to depths of 80-3,100 m by the Azienda Geologica Italiana Petroli (AGIP) and the Società Anonima Forze Endogene Napoletane (SAFEN). To date, however, no systematic reanalysis of the drilling data has been carried out, and the buried volcanic structure has not been updated using the most recent scientific results and previous findings. By integrating unpublished data from the AGIP and SAFEN reports with published information from geological, volcanological, petrological, petrophysical and geophysical studies, this paper presents an improved picture of the Campi Flegrei caldera that will be useful for volcanic hazard assessment and mitigation in the Naples area and for future research planning. The results suggest that intra-caldera activity has been influenced by how the magmatic system at depths greater than about 4 km has determined the transfer of magma, volatiles, and heat to the overlying geothermal system and, ultimately, to the surface. In particular, intriguing is that the most volcanically active central-eastern sector of the caldera, which is subject to intense bradyseismic ground movement and gas emission, coincides with a structurally delimited subsurface rock volume characterized by an uprising of the 100 °C isotherm, a deep water supply to the shallower aquifer, the early disappearance of secondary calcite, LP seismicity and high seismic S-wave attenuation. In this area, we also document evidence of repeated injection at depths of c. 1.5-3.0 km of isolated and small-volume batches of magma, where occurred their crystallization and degassing. Shallow intrusions and degassing of magma are thus identified as two of the key processes that drive unrest in Campi Flegrei. [ABSTRACT FROM AUTHOR]

Abstract: We present a study of olivine-hosted glass/melt inclusions (MIs) in the most primitive rocks erupted at Procida Island, within the Phlegraean Volcanic District (PVD), Southern Italy. MIs were analyzed by combined Scanning Electron Microscopy coupled with Energy Dispersive X-ray-detectors, Wavelength Dispersive X-ray-equipped Electron Microprobe and Fourier Transform Infrared (FT-IR) Spectroscopy; notably, the novel Focal-Plane-Array mode provided high-resolution FT-IR images evidencing the distribution of the C–H–O species across samples. Olivines range in composition from Fo85 to Fo90, do not show chemical zoning and are totally anhydrous. The majority of the MIs are glassy, while only few are completely crystallized. Some MIs, however, show the occurrence of crystal nuclei, i.e., nano- to micro-sized pyroxenes and oxides, and appear as low-crystallized MIs. The glass of crystal-free and low-crystallized MIs shows K-affinity and a compositional range along the basalt, trachy-basalt, shoshonite, tephrite basanite and phono-tephrite array. H2O and CO2 contents up to 2.69wt.% and 2653ppm, respectively, define a major degassing trend with small isobaric deviations. The collected data allow recalculating entrapment pressures from ~350MPa to <50MPa and suggest that the magma ascent was dominated by degassing. Crystallization was a minor process, likely also consequent to local CO2-fluxing. Mingling occurred between variable degassed and crystallized magma portions during decompression. The geochemical and isotopic data of Procida glasses and rocks, and the compositional relationship between our MIs and those from slightly more evolved and radiogenic Phlegraean products, indicate that Procida basalts are an adequate parental end-member for the PVD. Our data suggest that a CO2-rich magma source was stored at depths of at least 13–14km (i.e., 350MPa) beneath the PVD. Fast ascent of magma batches directly started from this depth shortly before PVD trachy-basaltic to shoshonitic eruptions. Such results have implication on volcanic hazard assessment in the PVD area. [Copyright &y& Elsevier]

In this paper we describe recent applications of micro-infrared imaging in the Earth sciences. We address, in particular, the use of Fourier-transform infrared (FTIR) spectroscopy in characterizing the zoning and speciation of H and C in a variety of geological materials, including microporous minerals, nominally anhydrous volcanic minerals (NAMs), and crystal inclusions. These investigations show that use of the modern techniques of FTIR imaging enables detection of the zoning of volatile species across the studied samples, and possible configuration changes of structurally-bound carbon molecular species (e.g., CO2 vs CO3) during crystal growth. Such features, which are not accessible with other micro-analytical techniques, may provide information about the physicochemical properties which act as constraints in the genesis of the samples, and important information about the evolution of the geological system. Tests performed with focal-plane-array detectors (FPA) show that resolution close to the diffraction limit can be achieved if the amounts of the target molecules in the sample are substantially different. We also point out the possibility of using FTIR imaging for investigations under non-ambient conditions. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

• Individuals greatly vary in fungiform papillae pattern (density and size) on the tongue. • The FP density decreases in all diameter sizes with aging. • Limited gender effects were found on FP density for specific diameter sizes. • No association was found between PROP status and FP densities in different diameter sizes. • Uniform and small size FP were associated with increased responsiveness to oral stimuli. The association of fungiform papillae (FP) density with responsiveness to oral sensations is controversial. It has been speculated that FP size is a relevant feature for oral responsiveness, thus partially accounting for inconsistencies between FP density and oral responsiveness. This study aims to evaluate factors affecting the number of FP with different diameter sizes (age, gender, PROP status) and to explore the relevant associations with responsiveness to oral sensations in water solutions and food products. Three-hundred-fifty subjects participating in the Italian Taste project were involved, balanced for gender (53% females) and age class (18–30, 35%; 31–45, 35%; 46–60, 30%). The automated image analysis of tongue pictures was used to detect FP and count their frequencies, distinguishing 11 diameter size classes (range from 0.3 to 1.05 mm). Frequencies were converted into FP densities (FP/cm2) for each size. Taste responsiveness in water solutions (sour, bitter, salty, umami, sweet, astringent, pungent) and in three food products with varied intensity of target sensations (pear juice for sourness; bean purée for saltiness; tomato juice for pungency) was measured. Density of FP from all size classes decreased with age. Females showed higher FP density in size of 0.78–0.84 mm diameter, and males in the size of 0.44–0.49 mm. PROP status did not significantly affect the density of FP in any size class. Principal Component Analysis on individual FP density values of the 11 classes allowed identifying four subject groups with different FP patterns: high density and large diameter (HighLarge), high density and small diameter (HighSmall), low density and large diameter (LowLarge), low density and small diameter (LowSmall). FP pattern groups significantly affected oral responsiveness, the highest responsiveness was associated to the uniform pattern characterized by low density and small size FP. [ABSTRACT FROM AUTHOR]

Despite the growing interest in the sensory and healthy properties of extra virgin olive oil (EVOO), the topic of oil-food pairing is practically unexplored. This study systematically explores sensory effects on the flavor and harmony obtained by combining two ingredients (EVOOs and vegetables) and aims to provide practical indications for harmonic oil-vegetable combinations. The approach considered an optimal pairing of five EVOOs combined with five typical raw Italian vegetables characterized by different degrees of bitterness (Artichoke, Late Treviso radicchio, Chioggia radicchio, rocket, Early Treviso radicchio). An Index of Disharmony was computed for each pairing, using intensity ratings given by a trained panel that described EVOOs, vegetables and pairings. The results suggested a flavor congruency principle to enhance the oil-pairing harmony. EVOOs with intense green and bitter flavor maximise harmony when combined with very bitter or very pungent vegetables. EVOOs with moderate green flavor and bitterness seemed best paired with vegetables with low/intermediate bitterness. [ABSTRACT FROM AUTHOR]