All six minerals defined as “asbestos” by the existing regulation on asbestos hazard, i.e., actinolite, tremolite, anthophyllite, crocidolite and amosite amphiboles, and the serpentine-group mineral chrysotile are typical constituents of mafic and ultramafic magmatic rocks of ophiolitic sequences. However, little is known about the presence and distribution of naturally occurring asbestos (NOA) in plutonic felsic rocks. The Isadalu magmatic complex outcropping in central Sardinia and belonging to the post-variscan Permian volcanic cycle, is described here as an interesting occurrence of fibrous amphiboles in granitoid rocks. Field work and collected mineralogical/petrological data show that NOA fibers from the Isadalu complex belong compositionally to the actinolite-tremolite series. They were generated by metasomatic growth on pristine magmatic hornblende, at ca. 470 °C at 1 kbar, during sodic-calcic hydrothermal alteration. In terms of environmental hazard, the Isadalu complex represents a high-value case study, since the actinolite-bearing felsic rocks outcrop in a strongly anthropized area. Here, towns with local and regional strategic infrastructures (dams, pipes, hydroelectric power plants, water supply, roads) have been developed since the last century, also using the granitoid asbestos-rich stones. The aim of this study is to demonstrate that NOA and relative hazard are not univocally connected to a restricted typology of rocks. This result should be taken into account in any future work, procedure or regulation defining asbestos occurrences in natural environments.
In this work, we studied the hydrothermal agates from the Neogene–Quaternary volcanic district of Allumiere-Tolfa, north-west of Rome (Latium, Italy) using a combination of micro-textural, spectroscopic, and geochemical data. The examined sample consists of (1) an outer cristobalite layer deposited during the early stages of growth, (2) a sequence of chalcedonic bands (including i.e., length-fast, zebraic, and minor length-slow chalcedony) with variable moganite content (up to ca. 48 wt%), (3) an inner layer of terminated hyaline quartz crystals. The textures of the various SiO2 phases and their trace element content (Al, Li, B, Ti, Ga, Ge, As), as well as the presence of mineral inclusions (i.e., Fe-oxides and sulfates), is the result of physicochemical fluctuations of SiO2-bearing fluids. Positive correlation between Al and Li, low Al/Li ratio, and low Ti in hyaline quartz points to low-temperature hydrothermal environment. Local enrichment of B and As in chalcedony-rich layers are attributed to pH fluctuations. Analysis of the FT-IR spectra in the principal OH-stretching region (2750–3750 cm−1) shows that the silanol and molecular water signals are directly proportional. Strikingly, combined Raman and FT-IR spectroscopy on the chalcedonic bands reveals an anticorrelation between the moganite content and total water (SiOH + molH2O) signal. The moganite content is compatible with magmatic-hydrothermal sulfate/alkaline fluids at a temperature of 100–200 °C, whereas the boron-rich chalcedony can be favored by neutral/acidic conditions. The final Bambauer quartz growth lamellae testifies diluted SiO2-bearing solutions at lower temperature. These findings suggest a genetic scenario dominated by pH fluctuations in the circulating hydrothermal fluid.
<p><span>The increase in urbanization requires intense energy consumption and causes an increase in emissions from transportation and industrial sources. As a result, a variety of pollutants are released into the atmosphere with negative effects on the health of organisms and ecosystems as well as on human health. In this perspective, coastal areas are considered "hot</span><span>spot</span><span>s" of environmental contamination since they often host multiple human activities. This issue is particularly dramatic close to important maritime hubs, as a matter of fact overall 25% of the world energy consumption (a major source of pollution) is employed for transport, and over 80% of world trade is carried by sea (Gobbi et al. 2020). </span><span>During 2019-2020 we carried out a continuous monitoring of particulate matter in a fixed station to understand the sources of air pollution in the northern Latium coastal area. This area has been selected for the presence of industrial activities located in a few kilometers of coast (Piazzolla et al. 2020). </span><span>The amount and typology of solid particles present in the environment have been assessed by implementing a reliable cost-effective device (Gozzi et al. 2015, 2017) which integrates an optical particle counter and a filtering set-up able to collect particulate matter with dimension > 400 nm (Della Ventura et al. 2017). Filters were periodically removed from the device and recovered microparticles were subjected to microscopic (optical and electron), spectroscopic (IR, Raman), and microchemical (SEM-EDS) characterization. Results were related to the wind speed and direction measured by</span><span>&#160;the </span>Civitavecchia Coastal Environment Monitoring System<span> (</span><span>Bonamano et al. 2015), allowing an evaluation of the contribution of anthropic (industrial and maritime) activities to the pollution in this area.</span></p><p>Bonamano S., Piermattei V., Madonia A., Mendoza F., Pierattini A., Martellucci R., ... <span>& Marcelli M. (2016). The Civitavecchia Coastal Environment Monitoring System (C-CEMS): a new tool to analyze the conflicts between coastal pressures and sensitivity areas. Ocean Science, 12(1).</span><span> DOI 10.5194/os-12-87-2016</span></p><p><span>Della Ventura G., Gozzi F., Marcelli A. (2017) The MIAMI project: design and testing of an IoT lowcost device for mobile monitoring of PM and gaseous pollutants. Superstripe Press, Science Series, 12, 41-44, ISBN 9788866830764</span></p><p>Gobbi G.P., Di Liberto L., Barnaba F. (2020). <span>Impact of port emissions on Eu-regulated and non-regulated air quality indicators: the case of Civitavecchia (Italy). Science of the Total environment, 719. DOI 10.1016/j.scitotenv.2019.134984 </span></p><p><span>Gozzi, F., Della Ventura, G., Marcelli, A. (2015) Mobile monitoring of particulate matter: State of art and perspectives. Atmospheric Pollution Research, 7, 228-234. DOI 10.1016/j.apr.2015.09.007.</span></p><p><span>Gozzi F., Della Ventura G., Marcelli A., Lucci F. (2017) Current status of particulate matter pollution in Europe and future perspectives: a review. Journal of Materials and Environmental Science, 8, 1901-1909. ISSN 2028-2508</span></p><p><span>Piazzolla D., Cafaro V., de Lucia G. A., Mancini E., Scanu S., Bonamano S., ... & Marcelli M. (2020). Microlitter pollution in coastal sediments of the northern Tyrrhenian Sea, Italy: microplastics and fly-ash occurrence and distribution. </span>Estuarine, Coastal and Shelf Science, 106819. DOI 10.1016/j.ecss.2020.106819</p>
<p>Coasts are extremely sensitive areas and are internationally considered &#8220;hotspot&#8221; of environmental contamination. The presence of multiple human activities in these areas frequently lead to the potential increase in organic and inorganic pollutants. In particular, industrial and maritime activities, tourism, recreational activities, aquaculture and fishing contribute to the pollutants release in the coastal environments. In this context, northern Latium coastal area (northern Thyrrenian Sea, Italy) hosts several industrial activities of national and international relevance, located in a very restricted seaside area: the Port of Civitavecchia, one of the most important hub for cruise and commercial traffic in the Mediterranean Sea, the Torrevaldaliga Nord coal-fired power plant of the national energy company (ENEL), and the Tirreno Power combined cycle (gas-fueled) power plant. All these activities strongly contribute to the increase of pollutant load to the land as well as marine coastal environment.&#160;For this reason, a research project aimed at understanding the main source for the pollution has been undertaken in the last years. The project is particularly aimed at designing and testing of reliable low-cost devices (Gozzi et al., 2015, 2017) able to provide both the amount and typology of solid particles spread in the environment.</p><p>As a first step, the air quality inside the Civitavecchia harbor has been monitored for six months by measuring the content of PM1, PM2.5, and PM10 simultaneously to environmental parameters such as air temperature and humidity. The sensing station (Della Ventura et al., 2017) was equipped with a filtering set-up able to collect the solid load in the atmosphere with dimension > 400 nm. The filters were periodically removed from the station and studied by combining microscopic (optical and electron), spectroscopic (IR, Raman) and microchemical (SEM-EDS) techniques for a full characterization of microparticles typologies. Collected information, augmented by environmental (wind, rain) data from local broadcasting stations provides a valuable tool for assessing the contribution of anthropic (industrial and maritime) activities to the pollution in this coastal area.</p><p>&#160;</p><p>References</p><p>Gozzi, F., Della Ventura, G., Marcelli, A. (2015) Mobile monitoring of particulate matter: State of art and perspectives. Atmospheric Pollution Research, 7, 228-234. DOI:10.1016/j.apr.2015.09.007.</p><p>Gozzi, F., Della Ventura, G., Marcelli, A., Lucci, F. (2017) Current status of particulate matter pollution in Europe and future perspectives: a review. Journal of Materials and Environmental Science, 8, 1901-1909. ISSN: 2028-2508</p><p>Della Ventura, G., Gozzi, F., Marcelli, A. (2017) The MIAMI project: design and testing of an IoT low-cost device for mobile monitoring of PM and gaseous pollutants. Superstripe Press, Science Series, 12, 41-44, ISBN 9788866830764.</p>
<p>Opals and cryptocrystalline silica may be found in a very broad range of geological environments (Chauvir&#233; et al., 2017), systematically related to the availability of an aqueous fluid. Due to its conditions of formations, opal may contain abundant H<sub>2</sub>O, CO<sub>2</sub> or both (Sodo et al., 2017), and the presence of these molecules may provide information of their genetic context. In this work we studied a series of samples from the volcanic region of Allumiere-Tolfa, north of Rome (Latium, Italy). This district has a Pliocene-Pleistocene age and is related to the Tuscan acid volcanism. It shows a very intense late-stage hydrothermal alteration that gave rise to two distinct ore basins: one to the south of the Allumiere town, consisting of sulfide (Pb, Fe, Zn, Hg) and Fe-oxide mineralizations, and a second, to the north, mainly consisting of alunite and kaolin. Both ore deposits were intensely exploited during the medieval to recent period. The hydrothermal alteration giving rise to the sulfate and clay deposits is also associated with a pervasive deposition, within the early volcanics, of opaline or microcrystalline silica, consisting of mineral replacements, veins and formation of agate druses. Although the sulphide-sulfate and clay products have been studied, due to their interest as georesources, and relevant petrological, geochemical and isotopic data can be found in the oldest literature (Lombardi and Sheppard, 1977), the silica mineralizations have never been addressed. We studied here a series of samples occurring as vein depositions or as banded crystallizations from different areas in the volcanic district. The samples were examined by using a combination of XRD, SEM-EDS and FTIR + Raman imaging. Opaline silica with different degree of order, from opal AN (hyalite) to opal A to opal CT, was identified. Some samples contain CO<sub>2</sub> besides H<sub>2</sub>O/OH. The banded agates were found to consist of a layering of micro-crystalline and fibrous quartz (chalcedony) with different water contents, interbedded with moganite-rich layers; moganite, in particular was found to be associated to lower H<sub>2</sub>O contents. The <sup>18</sup>O and D/H isotopic data of Lombardi and Sheppard (1977) indicate temperatures around 120-100&#176;C for the hydrothermal process responsible for the hydrothermal deposits, in close agreement with the typical range of T for the formation of opaline silica (Heaney, 1993). The ore forming process can be thus interpreted following the classical model of hydrothermal/metasomatic phenomena at low-depth, accompanied by extensive alteration of the pre-existing rocks, due to mixed magmatic/meteoric fluids, with the formation of kaolinite + alunite + sulfates + silica (Hedenquist et al., 2000).</p><p>&#160;</p><p>References</p><p>Chauvir&#233;, B., Rondeau, B., Mangold, N. (2017) Eur. J. Miner. 29, 409-421</p><p>Heaney, P.J. (1993) Contrib. Mineral. Petrol., 115, 66-74.</p><p>Hedenquist, J.W., Arribas, A.R., Gonzalez-Urien, E. (2000) SEG Reviews, 13, 245-277.</p><p>Lombardi, G. and Sheppard, S.M.F., (1977) Clay Miner., 12, 147-161.</p><p>Sodo, A., Casanova Municchia, A., Barucca, S., Bellatreccia, F., Della Ventura, G., Butini, F., Ricci M.A. (2016) J. Raman Spec. 47, 1444-1451.</p>
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