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Brilli, Mauro
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- PublicationRestrictedDetermining the origin of carbon dioxide and methane in the gaseous emissions of the San Vittorino plain (Central Italy) by means of stable isotopes and noble gas analysis(2013-03-06)
; ; ; ; ; ; ;Giustini, F.; CNR ;Blessing, M.; BRGM ;Brilli, M.; CNR ;Lombardi, S.; Università Roma La Sapienza ;Voltattorni, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Widory, D.; UQAM/GEOTOP; ; ; ; ; The chemistry and isotope ratios of He, C (d13C) and H (dD) of free gases collected in the San Vittorino plain, an intramontane depression of tectonic origin, were determined to shed light on mantle degassing in central Italy. The C isotopic composition of CO2 (d13C–CO2 2.0‰to 3.8‰) and He isotope ratios (R/RA 0.12–0.27) were used to calculate the fraction of CO2 originating from mantle degassing vs. sedimentary sources. The results show that CO2 predominantly (average of 75%) derives from the thermo-metamorphic reaction of limestone. Between 6% and 22% of the CO2 in the samples derives from organic-rich sedimentary sources. The mantle source accounts for 0–6% of the total CO2; however, in two samples, located in proximity to the most important faults of the plain, the mantle accounts for 24% and 42%. The presence of faults and fractures allows upward gas migration from a deep source to the Earth’s surface, not only in the peri-Tyrrhenian sector, as generally reported by studies on natural gas emissions in central Italy, but also in the pre-Apennine and Apennine belts. Isotope ratios of CH4 (d13C–CH4 6.1‰ to 22.7‰; dD–CH4 9‰ to 129‰) show that CH4 does not appear to be related to mantle or magma degassing, but it is the product of thermal degradation of organic matter (i.e. thermogenic origin) and/or the reduction of CO2 (i.e. geothermal origin). Most of the samples appear to be affected by secondary microbial oxidation processes.421 35 - PublicationOpen AccessMapping oxygen stable isotopes of precipitation in ItalytStudy region: Italy.Study focus: The oxygen isotope composition from 266 pluviometers was used to study thespatial variability of 18O and its relationship with Italian orography. The local meteoricwater lines (LMWLs) of northern, southern and central Italy and Sicily are reformulatedand a new definition of isotopic variations with elevation is provided.New hydrological insights for the region: Altitude and, to a lesser extent, latitude are themain geographical factors affecting the isotopic signature of precipitation in Italy. A high-resolution map of the spatial distribution of18O content in precipitation was created usingthe identified relationship between 18O/Latitude-Altitude and the spatial distribution ofthe residuals. The general features of the 18O distribution map may be summarised asfollows: 18O distribution over the Alps clearly depends on latitude and altitude, whereasover the Apennines, which run down the whole peninsula from north-west to south-east,it is more affected by altitude, the contour lines roughly following the axis of the chain. Theisotope compositions on the western side of the peninsula are generally higher than thoseof the east at the same elevation and latitude; they are more or less uniform in the northernplain of Italy.
159 147 - PublicationOpen AccessExploring mobility in Italian Neolithic and Copper Age communities(2021-01-29)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ; ; ; ;As a means for investigating human mobility during late the Neolithic to the Copper Age in central and southern Italy, this study presents a novel dataset of enamel oxygen and carbon isotope values (δ18Oca and δ13Cca) from the carbonate fraction of biogenic apatite for one hundred and twenty-six individual teeth coming from two Neolithic and eight Copper Age communities. The measured δ18Oca values suggest a significant role of local sources in the water inputs to the body water, whereas δ13Cca values indicate food resources, principally based on C3 plants. Both δ13Cca and δ18Oca ranges vary substantially when samples are broken down into local populations. Statistically defined thresholds, accounting for intra-site variability, allow the identification of only a few outliers in the eight Copper Age communities, suggesting that sedentary lifestyle rather than extensive mobility characterized the investigated populations. This seems to be also typical of the two studied Neolithic communities. Overall, this research shows that the investigated periods in peninsular Italy differed in mobility pattern from the following Bronze Age communities from more northern areas.135 19 - PublicationRestrictedH2O and CO2 in minerals of the hauyne-sodalite group: an FTIR spectroscopy study(2009-07-06)
; ; ; ; ; ;Bellatreccia, F.; Università Roma Tre ;Della Ventura, G.; Università Roma Tre ;Piccinini, M.; Università Roma Tre ;Cavallo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Brilli, M.; I.N.F.N.; ; ; ; This paper reports an infrared spectroscopic study of a set of sodalite-group minerals. The specimens have been identified using a combination of X-ray diffraction and microchemical analysis. As expected, the Si/Al ratio is ~1; the extra framework cation content is characterized by a well-defined Na -(Ca+K) substitution. The lattice parameters of the studied samples range from sodalite (sample LM11) with a = 8.889(2) A , to hauyne (sample HR3S) with a = 9.1265(2) A. The specimens, having the SO4-- group as a dominant anion, show a clear correlation between the a cell edge and the K content. Single-crystal FTIR spectroscopy shows that hauyne and nosean typically contain enclathrated CO2 molecules,in addition to H2O and minor carbonate, while sodalite is virtually CO2-free. Detailed microspectrometric mappings show a non-homogeneous distribution of volatile constituents across the crystals, which may be related to the presence of fractures in the crystals. Because of such zoning, a relatively wide variation is observed when calibrating extinction coefficients on the basis of a bulk analytical method such as CHN elemental analysis.210 48 - PublicationOpen AccessGeophysical and geochemical multi-method investigations for reconstructing subsurfaces, alluvial sedimentology, and structural geology (Tiber valley, Rome)Geophysical and geochemical methods were applied to detect the subsurface setting of an Upper Pleistocene-Holocene fluvial incised-valley where a travertine body intercalates between alluvial deposits of the Tiber river (central Italy), at Prima Porta (close to Rome). This study allowed us to provide more information regarding the local stratigraphic architecture and structural features, as a reference analogue to similar settings: i.e., hard (stiff) lithic travertines buried below fine and loose alluvial plain covers. Two Electrical Resistivity Tomography (ERT) profiles, interpreted and calibrated using previously collected litho-stratigraphic data from a borehole, identified a massive body, with a relatively high resistivity that correlates with the 21 travertine deposit of Prima Porta. In addition to ERT, ambient noise measurements, processed with the HVSR technique and 2D array, and seismic refraction tomography were carried out; HVSR data were highly consistent with ERT results and allowed to discriminate between the travertine body and the silty-sand channels and overbank deposits, which were attributed to the Tiber river’s evolution during Upper Pleistocene-Holocene. Finally, the presence of cracks/fractures could be inferred, as suggested by slight polarisation effects recorded in the HVSR results and soil-gas anomalies.
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