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Aluminotaipingite-(CeCa), (Ce6Ca3)Al(SiO4)3[SiO3(OH)]4F3 , is a new member of the cerite-supergroup minerals, whose general chemical formula is A 9 XM [ T O3Ø]7 Z 3, (A = REE, Ca, Sr, Na and □; X = □, Ca, Na and Fe2+; M = Mg, Fe2+, Fe3+, Al and Mn; T = Si and P; Ø = O and OH; Z = □, OH and F). It was found in cavities of a leucogranitic orthogneiss at the Casette quarry, Montoso, Bagnolo Piemonte, Cuneo Province, Piedmont, Italy. Crystals of aluminotaipingite-(CeCa) are light pink to pink, transparent or semi-transparent, with a vitreous lustre. It forms pyramidal crystals up to 0.07 mm in size and observed forms are {0 0 1}, {1 0 $\bar{2}$ }. The tenacity is brittle, no distinct cleavage is observed and the fracture is uneven. The mineral does not fluoresce in long- or short-wave ultraviolet light. The streak is white. Hardness (Mohs) = 5. The calculated density is 4.476 g cm–3. The mineral is trigonal, space group R 3 c , with a = 10.658(3), c = 37.865(9) Å, V = 3725(2) Å3 and Z = 6. The eight strongest powder X-ray diffraction lines are [ d obs, Å (I, %) (h k l)]: 8.38(29)(0 1 2), 4.499(28)(2 0 2), 3.282(41)(2 1 4), 2.936(100)(0 2 10), 2.816(51)(1 2 8), 2.669(37)(2 2 0), 2.207 (29)(3 0 12) and 1.935(35)(2 3 8). The structure was refined to R =0.0306 for 2297 reflections with I >2σ(I). The crystal structure of aluminotaipingite-(CeCa) contains two nine-fold coordinated sites (A 1 and A 2), which are occupied mainly by lanthanides, and a third nine-fold coordinated A 3 site containing almost equal amounts of lanthanides and Ca. The X site is vacant and at the octahedral M site aluminium prevails over Fe3+. Among the three independent T sites, T 2 belongs to a (SiO4)4– anion, whereas T 1 and T 3 belong to (SiO3OH)3– anions. Fluorine is involved in coordination with the A 1 and A 3 sites. [ABSTRACT FROM AUTHOR]

Groundwater chemistry data play an essential role to identify the water quality status and assess the exposure to human health. Therefore, in the present research, combined approaches used to assess the geochemistry, sources of ions and human health risk in the groundwater of the Tronzano Vercellese. Moreover, a geographic information system (GIS) technique was applied to identify locations have the most risk to human health. The results of the present study show that the groundwater samples had sequence of Ca2+>Mg2+>Na+>K+ in cationic, HCO3−>SO42−>NO3−>Cl−>F− in anionic and Zn > Fe > Ba > Ni > Mn > Cu > Cr > As in metals abundance. The hydrogeochemical approaches indicate that the major ions chemistry was mainly controlled by the weathering of carbonate and silicate minerals, and ion-exchange reactions. Furthermore, statistical analysis reveals that the non-lithogenic origin was the primary sources of some elements (Mn, Zn, Ba, NO3− and K+) in the water samples. The hazard quotient (HQ) and hazard index (HI) were estimated to assess the risk to human health using the United States Environmental Protection Agency (USEPA) methods. Estimated HQ and HI values were higher for the child as compared to the adult and suggesting that the elements posed little hazard individually in the case of the child. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evaluation of activating solution influence on high temperature resistance in AAMs. • Higher availability of silicon and aluminum and better feasibility of the pastes. • Monitoring formation of Si-O-Si and Si-O-Ca networks. • Positive influence of the new crystallizations on mechanical resistance after 1000 °C. • Densification behavior of K sample contrary to the melting of that Na. Thermal performances at 1000 °C of volcanic ash-based alkali-activated materials by both sodium or potassium solutions have been tested. Once defined the feasibility for the potassium set, a multidisciplinary characterization including spectroscopic, thermal, mechanical, diffractometric before and after treatment and dilatometric analyses was applied. The formation kinetics of different networks was evaluated. A correlation between the high mechanical properties and the least amount of water was observed in non-treated samples. Treated samples at 1000 °C showed higher compressive strengths due to the crystallization of wollastonite, leucite and nepheline. Thermal stability was observed increased with the solid content in the potassium-based formulations. [ABSTRACT FROM AUTHOR]

The trace-element geochemistry of speleothems is becoming increasingly used for reconstructing palaeoclimate, with a particular emphasis on elements whose concentrations vary according to hydrological conditions at the cave site (e.g. Mg, Sr, Ba and U). An important step in interpreting trace-element abundances is understanding the underlying processes of their incorporation. This includes quantifying the fractionation between the solution and speleothem carbonate via partition coefficients (where the partitioning (D) of element X (D X) is the molar ratio [X/Ca] in the calcite divided by the molar ratio [X/Ca] in the parent water) and evaluating the degree of spatial variability across time-constant speleothem layers. Previous studies of how these elements are incorporated into speleothems have focused primarily on stalagmites and their source waters in natural cave settings, or have used synthetic solutions under cave-analogue laboratory conditions to produce similar dripstones. However, dripstones are not the only speleothem types capable of yielding useful palaeoclimate information. In this study, we investigate the incorporation of Mg, Sr, Ba and U into a subaqueous calcite speleothem (CD3) growing in a natural cave pool in Italy. Pool-water measurements extending back 15 years reveal a remarkably stable geochemical environment owing to the deep cave setting, enabling the calculation of precise solution [X/Ca]. We determine the trace element variability of 'modern' subaqueous calcite from a drill core taken through CD3 to derive D Mg , D Sr , D Ba and D U then compare these with published cave, cave-analogue and seawater-analogue studies. The D Mg for CD3 is anomalously high (0.042 ± 0.002) compared to previous estimates at similar temperatures (∼8 °C). The D Sr (0.100 ± 0.007) is similar to previously reported values, but data from this study as well as those from Tremaine and Froelich (2013) and Day and Henderson (2013) suggest that [Na/Sr] might play an important role in Sr incorporation through the potential for Na to outcompete Sr for calcite non-lattice sites. D Ba in CD3 (0.086 ± 0.008) is similar to values derived by Day and Henderson (2013) under cave-analogue conditions, whilst D U (0.013 ± 0.002) is almost an order of magnitude lower, possibly due to the unusually slow speleothem growth rates (<1 μm a−1), which could expose the crystal surfaces to leaching of uranyl carbonate. Finally, laser-ablation ICP-MS analysis of the upper 7 μm of CD3, regarded as 'modern' for the purposes of this study, reveals considerable heterogeneity, particularly for Sr, Ba and U, which is potentially indicative of compositional zoning. This reinforces the need to conduct 2D mapping and/or multiple laser passes to capture the range of time-equivalent elemental variations prior to palaeoclimate interpretation. [ABSTRACT FROM AUTHOR]

The results of a petrographic and geochemical study carried out on archeological grindstones allow to provide new constraints on protohistoric commercial exchanges over the Mediterranean area. Eleven grindstones, discovered in an archeological site located in Milazzo (Messina, Sicily) and dated from the Early Bronze Age, have been investigated by geochemical and petrographic techniques. The raw materials are mainly volcanic rocks characterized by calc-alkaline and K-alkaline affinities with volcanic arc geochemical signature. Only one sample, made of basalt belonging to the Na-alkaline series, shows an intraplate signature. The comparison with the available literature data for similar rocks allowed constraining the volcanic origin of the exploited lavas. While the intraplate-type raw material came from Mt. Etna Volcano (Sicily), the arc-type volcanic rocks are mostly trachyandesites, basaltic andesites, and one rhyolite. Although most of them come from the Aeolian Arc, a provenance of some samples from the Aegean Arc cannot be excluded. This last region could represent the most probable provenance area for the rhyolite sample. [ABSTRACT FROM AUTHOR]

The annual production of driftwood in Italy has been estimated to be more than 60,000 tonnes. This wood can be used as an energy source. Particular attention should be paid to its content of alkali and alkaline earth metals, sulfur and chlorine. Few works are available in the literature on this topic. For this reason, the authors propose experimental tests of combustion, gasification and pyrolysis, to evaluate the fate of alkali and alkaline earth metals, sulfur and chlorine in the solid residues and compare the three thermal degradation technologies. The results show a release of alkaline earth metals of about 45% of the initial quantity for gasification and a release of 55% of the initial quantity for combustion (while pyrolysis at 600 °C has a very low release). The release of sodium is about 65% for gasification and 80% for combustion. It can be seen that the release of sodium is higher than that of alkaline earth metals; this is due to the divalency of the last ones. Dealing with the release of major elements (chlorine, sulfur and AAEMs) the tests have shown that pyrolysis process is a low emitting technology. [ABSTRACT FROM AUTHOR]

Abstract: Active serpentinization systems are abundant on present-day Earth and are of increasing interest because water–rock reactions lead to alkaline, Ca–OH fluids that have the potential to sequester CO2 and form reduced chemical species (e.g. CH4 and H2) that can support chemolithoautotrophy. We present a study of alkaline (pH 10–12) springs in the Voltri Massif (Italy) that focuses on the sources and cycling of inorganic carbon in the basement rocks, the interacting fluids, and the resulting surface carbonate deposits. Most springs are located in mantle rocks that underwent varying degrees of ocean-floor serpentinization and incorporation of carbon (as carbonate and organic carbon) in the Jurassic, which is preserved during subsequent subduction and uplift onto the continent. The springs are fed by meteoric water that evolves into alkaline, Ca-rich spring waters that have 2–3 times higher Ca concentrations than the adjacent rivers. Our study is consistent with previous reaction path modeling and identifies the formation of clay minerals in serpentinites that have been altered by alkaline fluids. These strongly altered basement rocks contain up to 2wt.% C in the shallow subsurface, also documented by the presence of late calcite veins. Concentrations of dissolved inorganic carbon (DIC) of the alkaline fluids are generally low (<16μmol/L) and δ13CDIC is between −24.2‰ and +1.3‰. We argue that the concentrations and isotopic composition of the DIC in the alkaline waters provide evidence for 1) the precipitation of calcium carbonate under closed-system conditions with respect to atmospheric CO2 and 2) removal of DIC by microbial activity in the subsurface. Late-stage uptake of atmospheric CO2 in the shallow subsurface or at the exit sites subsequent to water–rock–microbe interactions in the basement result in fluids with lower pH and Ca, and enrichment in DIC and 13C. At the surface, interaction of the high pH, Ca–OH fluids with atmospheric CO2 causes precipitation of carbonates as travertines or crusts on the basement rocks, storing CO2 as calcium carbonate. Carbonate precipitation at the exit sites is strongly dominated by kinetic processes leading to carbon and oxygen isotope compositions as low as −27.2‰ and −18.7‰, respectively. With increasing distance from the springs, the 13C and 18O content of the carbonate increases and the fluid pH changes towards neutral. Our study shows that surficial carbonate precipitation plays a subordinate role in carbon sequestration, but that the evolution from Mg–HCO3 spring waters to Ca–OH waters removes significant amounts of carbon, presumably in the subsurface. We calculate that the serpentinites have the capacity to sequester up to 0.50 to 2.05×109 mol carbon per year and conclude that they can take up significantly more CO2 than they currently contain. [Copyright &y& Elsevier]

Abstract: We address general features of carbonatite monogenetic volcanic fields located in continental settings which are peculiar being associated with kamafugites or melilite-bearing leucitites. Instructive examples are the Toro Ankole in Uganda, West Qinling in China, and Campo de Calatrava in Spain and the Intra-mountain Ultra-alkaline Province (IUP) of Italy. Maars are the typical volcanic forms, occurring in isolation or in clusters along fault systems. Concentric-shelled juvenile lapilli and bombs, having a upper-mantle peridotite kernel, are unique to this type of volcanism. These pyroclasts are interpreted as the result of deep-seated fragmentation of magma having a high carbon dioxide-water (CO2/H2O) ratio. The presence of discrete, large peridotitic nodules implies a high-velocity propagation of magma, while the associated large CO2 emission suggests a high proportion of juvenile CO2. Magma fragmentation is inferred to occur as a consequence of explosive CO2 exsolution at the upper mantle level (diatresis) followed by immiscibility. Based on field evidence, carbonatitic maar formation could be due to violent CO2 expansion and does not require phreatomagmatic phenomena. Extrusive carbonatites and associated rocks represent very primitive melts having a distinct High Field Strength Elements (HFSE) distribution, the source of which is related to enriched mantle. Carbonated peridotite is a stable paragenesis at depths of 400–600 km; thus, primary carbonatitic silicate magma can be produced at these depths as a consequence of rising deeper melt/fluids that are trapped at the transition zone. In our opinion, carbonatitic carbon is linked to the primary process of deep-mantle differentiation and Earth''s core degassing. [Copyright &y& Elsevier]

Abstract: In Roman and Byzantine times, natron glass was traded throughout the known world in the form of chunks. Production centers of such raw glass, active from the 4th to 8th century AD, were identified in Egypt and Syro-Palestine. However, early Roman primary glass units remain unknown from excavation or scientific analysis. The ancient author Pliny described in 70 AD that besides Egyptian and Levantine resources, also raw materials from Italy and the Gallic and Spanish provinces were used in glass making. In this study, the primary provenance of 1st–3rd century AD natron vessel glass is investigated. The use of combined Sr and Nd isotopic analysis allows the distinguishing and characterizing of different sand raw materials used for primary glass production. The isotope data obtained from the glass samples are compared to the signatures of primary glass from known production centers in the eastern Mediterranean and a number of sand samples from the regions described by Pliny the Elder as possible sources of primary glass. Eastern Mediterranean primary glass has a Nile dominated Mediterranean Nd signature (higher than −6.0 ɛ Nd), while glass with a primary production location in the western Mediterranean or north-western Europe should have a different Nd signature (lower than −7.0 ɛ Nd). Most Roman glass has a homogeneous 87Sr/86Sr signature close to the modern sea water composition, likely caused by the (intentional) use of shell as glass raw material. In this way, strontium and neodymium isotopes now prove that Pliny''s writings were correct: primary glass production was not exclusive to the Levant or Egypt in early Roman days, and factories of raw glass in the Western Roman Empire will have been at play. [Copyright &y& Elsevier]

Laser-induced breakdown spectroscopy (LIBS) is an important analytical technique in a variety of fields ranging from in-situ terrestrial geological field investigations to robotic exploration missions of extraterrestrial bodies such as Mars. In this study, the performance of a commercial handheld LIBS instrument was evaluated during an international summer school in 2019 that focused on the exploration of extreme environments on Earth and in space. Several sites on the Eolian island Vulcano (Italy) were investigated with different spectroscopic methods including LIBS. We focus here on the exploration of one particular outcrop with LIBS, where layered and colored ash deposits were observed. Furthermore, a laboratory study was performed to investigate and validate the effect of varying distance of the instrument to the sample. Unsupervised principal component analysis (PCA) for data exploration showed that elemental variations between the layers of the outcrop can be observed with the LIBS data from the handheld instrument. This was further confirmed by a layer-by-layer analysis of elemental correlations and depositional trends. Geologically relevant major elements such as Si, Al, Ca, Fe, K, Mg, and Na could be identified but also minor and trace elements such as F, Li, Mn, and Sr. Our results also show that the effects of varying distances of the instrument to the sample are critical for the quality of the data acquired and hence pose significant challenges to the analysis and interpretation. We propose a dedicated data pre-processing approach, which includes the masking of emission lines of Ar from the locally induced Ar atmosphere, as a possible solution to overcome this challenge. Overall, this study provides a better understanding of the performance and limitations of a handheld LIBS instrument, particularly in the context of future terrestrial and planetary field investigations. Unlabelled Image • Field investigation of volcanic ash layer deposits with handheld LIBS instrumentation • Analysis of samples in their original context • Demonstration of LIBS capability to reveal elemental variations among the layers • Evaluation and discussion of the performance of the handheld LIBS device for geological field investigations [ABSTRACT FROM AUTHOR]

A very-low volume sampler of particulate matter (PM) on membrane filters, recently developed with the purpose of allowing spatially-resolved determination of PM and of its chemical components, was employed from December 2016 to February 2018 in a wide and dense monitoring network across Terni, an urban and industrial hot-spot of Central Italy (23 sampling sites, about 1 km between each other). Terni basin can be considered as an open air laboratory for studying the spatial distribution of PM, as it includes several spatially disaggregated sources. PM 10 samples were chemically characterized for the water-soluble and insoluble fraction of 33 elements (Al, As, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, K, La, Li, Mg, Mn, Mo, Na, Nb, Ni, Pb, Rb, Sb, Sn, Sr, Ti, Tl, U, W, Zn, Zr). Spatial variability of the element concentrations across Terni was then mapped by using the ordinary kriging interpolation method. Spatial distribution of the analyzed elements successfully traced the various PM 10 sources. In particular, the spatial mapping of Ba (water-soluble fraction), Bi, Cu, Sb, Sn and Zr (insoluble fraction) traced PM 10 emission from the rail network and vehicular traffic, Ce, Cs, La, Li, Rb, Sr and U (insoluble fraction) traced soil resuspension, Cd, Cs, K, Rb and Tl (water-soluble fraction) biomass burning and Co, Cr, Mn, Nb, Ni, Pb (insoluble fraction), As, Cr, Ga, Li, Mo, Mn, W and Zn (water-soluble fraction) the steel industry pole. Principal component analysis was performed on the spatially-resolved chemical data to cluster the elements tracing the main PM 10 sources. The winter and summer size distribution of the water-soluble and insoluble elements was analyzed to verify their link with the emission sources. The proposed experimental approach promises to be very effective for the assessment of population exposure to different PM 10 sources. Unlabelled Image • Very-low volume PM 10 samplers worked in parallel for 15 months at 23 sampling sites in Terni; • PM 10 samples were analyzed for the water-soluble and insoluble fraction of 33 elements; • Spatial variability of the winter and summer element concentrations was mapped; • Spatial distribution of the analyzed elements successfully traced the main local PM 10 sources; • The proposed approach promises to be effective for the assessment of population exposure to PM 10 sources. [ABSTRACT FROM AUTHOR]