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The geochemical characteristics of fluids that emerge at the Earth's surface are influenced by gas-rock-water interactions in the deep and shallow crustal layers, including mixing, outgassing of volatiles, and precipitation of minerals. The goal of the study was to understand the various interactions that influence the migration and behaviour of fluids within the Earth's crust and how they may change during the process of crustal fluid migration towards a hydrothermal system in the shallow crustal layers and within (Contursi basin, Italy). These processes can make it difficult to identify the source of deep gas by using the classical approach based on mixing processes of fluids and carbonate dissolution. Therefore, alternately the relationship between Total Dissolved Inorganic Carbon (TDIC) and the δ13CTDIC in groundwater from the Contursi hydrothermal system investigating the water-gas-rock interaction at the local scale through the detailed reconstructions of the geological framework at depth have been taken into consideration. We found that both the dissolved and free gas in the hydrothermal system probably originated from a deep CO2 endmember with a δ13CCO2 value ranging from +2.12‰ to +3.20‰ (PDB) depending on the presence of brine or freshwater in the local aquifers. However, we observed that this CO2 lost its pristine carbon isotopic signature during its storage in the deep dolomite-composed reservoirs (6-8 km), making it challenging to figure out its deep origin (decarbonation vs mantle/magmatic CO2). Our calculations also showed that the output of CO2, taking into account secondary processes (i.e. degassing CO2 and calcite precipitation) and interactions with water at different salt concentrations, could be at least 40% higher than estimates from the mixing-only approach, such that it is comparable with several active and quiescent worldwide volcanic systems. In order to interpret potential geochemical changes that may occur during future seismic events in sites like Contursi, which are earthquake-prone areas, it is necessary to implement models that can help us understand fluids origin and the processes that influence their chemical and isotopic signature.

The southern Apennines are affected by great crustal deformation and tectonic activity, where fluids from different reservoirs mix and rise to the surface through fault structures. Tramutola well (TRW) is an old borehole built by ENI, with the occurrence of bubbling gases located in the High Agri Valley (HAV), Southern Italy. The HAV is an inter-montane basin of the southern Apennine chain characterized by complex geological setting and high seismicity, this area hosts also the largest onshore Western European oil field. TRW is about 400 m deep it crosses clays, silicic clays and silicic limestone and is characterized by the continuous emission of thermal water (28°C) and bubbling gas. The water belong to Na-HCO3 hydrofacies. TRW gases are CH4-dominated (82,6 %), and low amounts of N2 (12,9%), CO2 (1,7%), C2H6 (0,3%). The noble gases are used to discriminate the fluids origin (atmospheric, crustal and mantle). The 4He/20Ne ratio values are in three orders of magnitude higher that air-one (0,318) and 40Ar/36Ar ratio it is about 320 (Air=295.5; Hilton and Porcelli, 2003), this confirm the atmospheric contribution is present. Value Helium isotope (3He/4He, expressed as R/Ra) is between 1,13 and 1,26 Ra, and indicate a radiogenic component with a contribution of a mantle-derived helium (~20%). Methane isotope composition indicates a likely microbial isotopic signature (δ13C-CH4 =-63‰, δD-CH4= −217‰), probably due to either (1) biodegradation processes of thermogenic hydrocarbons or (2) ongoing microbial methanogenesis in the shallow organic‐rich clays hosting the gas. The δ13C-CO2 value between of -3.5‰ and -6‰ VPDB, consistent with a mantle origin. The gases have low CO2/3He ratios compared to mantle carbon end-member, probably due to secondary processes such as calcite precipitation. In conclusion, at Tramutola well have three gas sources and their possible mixing processes: (1) Shallow source, highlighted by atmospheric gas and rainwater entering the system through water infliltration; (2) crustal sources, CH4-dominant gas sources in correspondence of the hydrocarbon reservoir; (3) SCLM mantle source, mantle-derived fluids uprising through lithospheric normal faults.

Mount Vulture is a stratovolcano (age 0.75-0.14 Myr) located in southern Italy, which despite being at the same latitude of Vesuvius and Phlegreian Fields, has several peculiarities about its setting and erupted magma composition. Indeed, if compared to other Italian Quaternary volcanoes, it is the only one located east of the Apennine Front, about 100 km off the axis of the Campanian Magmatic Province (Peccerillo et al., 2017). Furthermore, although being a quiescent volcano (last eruption dated 0.14 Myr), previous studies (e.g., Caracausi et al., 2015, Bragagni et al., 2022) have shown extremely high CO2 emissions (4.85 × 108 mol yr-1), which are likely related to the carbonatitic volcanism of its final phase of activity, as well as some petrological aspects in the erupted products pointing to a mantle source metasomatism.Recently, investigations on Vulture mantle xenoliths (Carnervale et al., 2022) revealed CO2-rich fluid inclusions (FIs) that indicate a primary depth of bubbles entrapment in olivine and pyroxene phenocrysts coinciding with the regional crust-mantle boundary (27-30km).This research focuses for the first-time noble gases isotopes (He, Ne, Ar) in FIs from lherzolite enclaves from Mt. Vulture tephra. The He isotopic ratios (as R/Ra; R is the 3He/4He ratio of the sample and Ra the same ratio in air), are between 6.2 and 5.4 ± 0.08. These values are lower than the signatures of the MORB upper mantle (8 ± 1Ra) and overlap the values of the Sub Continental Lithospheric Mantle (SCLM, 6.1 ± 0.9Ra). The Ne isotopic signatures (20Ne/22Ne and 21Ne/22Ne) are in the field of the MORB values.The He-Ne-Ar systematics is consistent with a SCLM source feeding the magmatism of the Vulture volcano. However, considering the noble gases He-Ne-Ar, in Vulture xenolites this mantle source has affinities with that feeding the volcanic activities of Mt. Etna (Nakai et al., 1997; Correale et al., 2014). This inference bears some evidence about the similitudes of the mantle below these two volcanic systems that is affected by mantle metasomatism, which is likely also responsible for the large CO2 fluxes and the carbonatitic magmatism (Bragagni et al., 2022). New measurements of the noble gases in free gases from the two volcanoes together with a detailed comparison between the geochemistry and petrography of the Vulture and Etna most primitive products will provide new constraints on the mantle typology below the two volcanoes and its relationship with the geodynamical evolution of the central Mediterranean.References Bragagni et al., 2021, GeologyCarnevale et al. (2022). Geophys. Res. Lett.Caracausi et al. (2015). Earth Planet. Sci Lett.Correale et al., 2014. LithosNakai et al., (1997). Earth Planet. Sci Lett.Peccerillo, A. (2017). Advances in Volcanology. Springer, Cham.

In this study total Cr, Cr(VI), Ni, major and some trace elements were determined in groundwater of northern sector of the Pollino Massif. The investigated area is characterized by ophiolitic rocks consisting of metabasites and cataclastic and highly fractured serpentinites. Two different hydro-facies were observed, reflecting low-temperature water-rock interactions. The Mg-HCO3 hydrofacies was determined through the weathering of serpentinites, the Ca-HCO3 groundwater are due to the interaction with calcschist and metabasites. High Cr(VI) concentrations were detected, exceeding the maximum admissible concentrations by Italian regulation, due to the release of Cr(III) from ophiolitic rocks into water and its oxidation to the hexavalent state. Remediation tests were performed at different liquid/solid concentration, and the kinetic data were interpreted with a suitable mathematical model.

This study provides the first micro-thermometric data of fluid inclusions (FIs) in mafic loose (disaggregated) xenocrysts and ultramafic xenoliths in explosive products of the melilitite-carbonatite Mt. Vulture volcano (southern Italy). Pure CO2 late stage FIs hosted in rock-forming minerals of wehrlite xenoliths and clinopyroxene xenocrysts were trapped at the local crust-mantle boundary (32 km). In contrast, trapping pressures within the loose olivine xenocrysts are from 3.2 to 4.5 kbar (8–13 km). Considering the ongoing degassing of mantle-derived CO2 rich gases, together with seismic evidences of the presence of low amount of melts at depth, and the tectonic control of the past volcanic activity, our study opens new perspective about the hazardous nature of the “quiescent” melilitite-carbonatite volcanoes.

In the Pollino Massif, in the southern Apennines, the asbestos minerals bearing serpentinites are widely exposed at several quarries (Pietrapica quarry, Timpa Castello quarry, Fagosa quarry and Ghiaia quarry), whose material was extracted and used as aggregates for construction, filling and embankments, and as ornamental stones. Airborne asbestos can be the result of extraction procedure as the stacking, storing and grinding of the serpentinites, so due to the environmental concerns the quarries have been abandoned. In the Pollino Massif serpentinites represent the lherzolitic to harzburgitic upper mantle basament of the Internal Liguride sequence of southern Apennines and can be classified as cataclastic and massive (Dichicco et al., 2015). Cataclastic serpentinites are fractured and deformed whereas those massive show a low fracturing and deformation. The serpentinites have homogeneous mineral compositions and are mainly composed by serpentine polimorphous, asbestiform tremolite, followed by actinolite, chlorite, magnetite and Cr-spinels, and subordinatly calcite, dolomite, and clay minerals. Further, edenite, currently not regulated by the Directive 2003/18/EC of the European Parliament and of the European Council of 27th March 2003, has been recently also detected for the first time (Dichicco et al., 2019). Serpentinite rocks can release significant amounts of fibers of hazardous minerals for the human health, into the air, water and soil, either through geogenic weathering processes or human activity. The observed fibers in the outcrops are of two types: 1) large and elongated fibers that occupy the entire surface of the rock; 2) tiny fibers forming a network throughout the rock.The aim of this work is to characterize in a detailed way the asbestos minerals of representative serpentinite samples taken from the four quarries using the combination of different analytical techniques: field surveys, X-Ray powder diffraction (XRPD), scanning electron microscopy combined with energy dispersive spectrometry (SEM/EDS), µ-Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) in order to assess the impact on the environment and public health.References:Dichicco, M.C.; Laurita, S.; Paternoster, M.; Rizzo, G.; Sinisi, R.; Mongelli, G. Serpentinite Carbonation for CO2. Sequestration in the Southern Apennines: Preliminary Study. Energy Procedia 2015, 76, 477-486.Dichicco, M.C.; Paternoster, M.; Rizzo, G.; Sinisi, R. Mineralogical Asbestos Assessment in the Southern Apennines (Italy): A Review. Fibers 2019, 7, 24.

Asbestiform minerals are potentially toxic and harmful to health and the environment and, in recent years, several studies have been made on the presence of asbestiform minerals in the Pollino Massif, on the border between Lucania and Calabria regions (southern Italy). Moreover, these small fibers can be easily inhaled by humans causing serious health problems especially to the respiratory tract. The formation of asbestiform minerals is related to metamorphism and/or metasomatic alteration of the metamorphic rocks. The main asbestiform mineral phases which have been found in the Pollino Massif are tremolite and, for the first time, edenite and Magnesium-riebeckite. The observed asbestiform minerals found in the metamorphic rocks of the Pollino Massif are thus: i) tremolite, which is characterized by acicular, friable, fibrous, and elongated habitus and was found as intergrowth with fibrous antigorite and chrysotile. In the analyzed rocks, tremolite was found in veins associated with clinopyroxene porphyroclasts; ii) edenite, which is often associated with serpentine, diopside and calcite or occurs as 30 to 80 µm-long single crystals with a fibrous habit. The presence of edenite in the ophiolitic sequences is quite rare and testifies a medium to high metamorphism; iii) magnesium-riebeckite, a record of metamorphic events in blueschist facies, composed of prismatic, acicular crystals with a fibrous habit having length ≥ 5 µm and width < 3 µm with aspect ratio > 3:1. These mineralogical phases were analyzed and characterized using different analytical techniques such as X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), electron probe micro analysis (EPMA) and X Ray Powder diffraction analysis (XRPD). The aim of this work is to create, for the first time, a geo-mineralogical map of the asbestiform minerals detected in these areas in order to evaluate their spatial distribution.References:Dichicco, M.C.; Laurita, S.; Sinisi, R.; Battiloro, R.; Rizzo, G. Environmental and Health: The Importance of Tremolite Occurence in the Pollino Geopark (Southern Italy). Geosciences 2018, 8, 98.Dichicco, M.C.; Paternoster, M.; Rizzo, G.; Sinisi, R. Mineralogical Asbestos Assessment in the Southern Apennines (Italy): A Review. Fibers 2019, 7, 24.Laurita, S.; Rizzo, G. The First Occurrence of Asbestiform Magnesio-Riebeckite in Schists in the Frido Unit (Pollino Unesco Global Geopark, Southern Italy). Fibers 2019, 7, 79.

In the Tethyan realm, leucocratic rocks were recognized as dikes and layers outcropping in the ophiolitic rocks of the Western Alps, in Corsica, and in the Northern Apennines. Several authors have suggested that the origin of leucocratic rocks is associated with partial melting of cumulate gabbro. Major and trace elements composition and paragenesis provided information about the leucocratic rocks genetic processes. This research aims at disclosing, for the first time, the petrographical and geochemical features of Timpa delle Murge leucocratic rocks, Pollino Massif (southern Italy), in order to discuss their origin and geodynamic significance through a comparison with other Tethyan leucocratic rocks. These rocks are characterized by high amounts of silica with moderate alumina and iron-magnesium contents showing higher potassium contents than plagiogranites, due to plagioclase alteration to sericite. Plagioclase fractionation reflects negative Eu anomalies indicating its derivation from gabbroic crystal mushes. The chondrite normalized REEs patterns suggest the participation of partial melts derived from a metasomatized mantle in a subduction environment. The results reveal some similarities in composition with other Tethyan leucocratic rocks, especially those concerning Corsica and the Northern Alps. These new data provide further clues on the origin of these leucocratic rocks and the Tethyan area geodynamic evolution.

In seismic active areas, the primary composition of natural gas emissions can be modified upon migration to the surface and storage in crustal reservoirs as the result of secondary chemical processes at shallow levels that can change the pristine composition of the fluids creating misunderstanding in the evaluation of the contributions due to different sources. Noble gases are among the most powerful indicators of such natural processes. In particular, Helium (hereafter He) is a reliable geochemical tracer for discriminating the crustal and mantle components in the outgassing gases due to the different origin of its two isotopes (3He has a primordial origin, whereas 4He is continuously produced by radioactive α-decay of 235,238U and 232Th). Therefore, the 3He/4He ratio is considered one of the most efficient geochemical tracers, whose variations can be directly ascribed to magmatic/crustal dynamics and therefore it is of primary importance in volcanic and seismic forecasting. In this study, we report chemical and isotopic (helium and carbon) data of gases and water emitted from three areas characterized by a high seismic hazard and located within the southern Apennines seismogenic belt. Through two fieldwork campaigns in 2019-2020, about 15 sites were inspected. Carbon dioxide is the main component in most of investigated sites (> 90 vol.%), except for Pozzo Tramutola, that is CH4-dominated. He and N2 concentrations are significantly variable (from 6 to 260 ppm and from 0.22 to 12.78 vol%, respectively). In agreement to previous investigations (Italiano et al., 2001; Caracausi and Paternoster, 2015), the sites in the Matese area are characterised by typical metamorphic [MOU1] N2 values and low content of He and Ar and seem to be the result of mixing processes between crustal and/or metamorphic and atmospheric or ASW end-member. The sampled fluids have 3He/4He ratios from 0.02 to 2.92 Ra with corresponding He/Ne ratios in the range of 0.353-508.10. These 4He/20Ne ratios are much higher than the same ratio in the atmosphere (He/Ne=0.318; Ozima-Podosek, 2002) supporting that atmospheric He component in the sampled fluids is negligible for most sites. In general, we recognized that 3He/4He ratios indicate mixing between radiogenic and mantle end-members and Mefite site has highest mantle values that are close to the ratio at Mt Vesuvio and Pleghreian volcanic systems (< 60 from the study area). The 40Ar/36Ar ratios show a small range from values close to atmosphere up to 40Ar/36Ar = 325. We also investigated the carbon species and their isotopes. To investigate the genetic origins of the methane we have used web-based machine learning tool that determines the origin of natural gases (Snodgrass-Milkov, 2020) and the results shown that methane is mainly thermogenic even if we also recognized an abiotic component in a few of sites. This study will provide data for the reconstruction of a basic model for interpreting the relationships between outgassing and tectonics, and further for interpreting possible seismic-induced variationOzima & Podosek. 2002. Noble Gas Geochemistry.Tsunogai & Wakita. 1995. ScienceSnodgrass and Milkov, 2020. Comput. Geosci

The Pietra del Pertusillo freshwater reservoir is a major artificial lake of environmental, biological, and ecological importance located in the Basilicata region, southern Italy. The reservoir arch-gravity dam was completed in 1963 for producing hydroelectric energy and providing water for human use, and nearby there are potential sources of anthropogenic pollution such as urban and industrial activities. For the first time, the minero-chemistry of the lake and fluvio-lacustrine sediments of the reservoir have been evaluated to assess the environmental quality. Moreover, the composition of fluvial sediments derived from the peri-lacual zone of the reservoir and of local outcropping bedrock were also studied to understand the factors affecting the behavior of elements in the freshwater reservoir, with particular attention paid to heavy metals. In Italy, specific regulatory values concerning the element threshold concentration for lake and river sediments do not exist, and for this reason, soil threshold values are considered the standard for sediments of internal waters. The evaluation of the environmental quality of reservoir sediments has been performed using enrichment factors obtained with respect to the average composition of a reconstructed local upper continental crust. We suggest this method as an innovative standard in similar conditions worldwide. In the studied reservoir sediments, the trace elements that may be of some environmental concern are Cr, Cu, Zn, As, and Pb although, at this stage, the distribution of these elements appears to be mostly driven by geogenic processes. However, within the frame of the assessment and the preservation of the quality of aquatic environments, particular attention has to be paid to As (which shows median value of 10 ppm, reaching a maximum value of 26 ppm in Quaternary sediments), constantly enriched in the lacustrine samples and especially in the fine-grained fraction (median = 8.5 ppm).

The High Agri Valley (southern Italy) is one of the largest intermontane basin of the southern Apennines affected by intensive agricultural and industrial activities. The study of groundwater chemical features provides much important information useful in water resource management. In this study, hydrogeochemical investigations coupled with multivariate statistics, saturation indices, and stable isotope composition (δD and δ18O) were conducted in the High Agri Valley to determine the chemical composition of groundwater and to define the geogenic and anthropogenic influences on groundwater quality. Twenty-four sampling point ( including well and spring waters) have been examined. The isotopic data revealed that groundwater has a meteoric origin. Well waters, located on recent alluvial-lacustrine deposits in shallow porous aquifers at the valley floor, are influenced by seasonal rainfall events and show shallow circuits; conversely, spring waters from fissured and/or karstified aquifers are probably associated to deeper and longer hydrogeological circuits. The R -mode factor analysis shows that three factors explain 94% of the total variance, and F1 represents the combined effect of dolomite and silicate dissolution to explain most water chemistry. In addition, very low contents of trace elements were detected, and their distribution was principally related to natural input. Only two well waters, used for irrigation use, show critical issue for NO3- concentrations, whose values are linked to agricultural activities. Groundwater quality strongly affects the management of water resources, as well as their suitability for domestic, agricultural, and industrial uses. Overall, our results were considered fulfilling the requirements for the inorganic component of the Water Framework Directive and Italian legislation for drinking purposes. The water quality for irrigation is from “good to permissible” to “excellent to good” although salinity and relatively high content of Mg2+ can occasionally be critical.

The Pietra del Pertusillo fresh-water reservoir is located in the High Agri Valley (Basilicata region, Southern Italy). The present work represents a first comprehensive study about the mineralogy and the geochemistry of fluvial-lacustrine sediments and bedrock lithologies of this fresh-water reservoir catchment area. Lacustrine (15 samples), fluvial-lacustrine (14 samples) and local bedrock sediments (27 samples) have been sampled and mineralogical and geochemical analyses have been performed on the sampled sediments. The mineralogical assemblage is mainly composed of quartz and calcite and minor feldspars, muscovite, illite, chlorite, and interstratified clay minerals. The geochemistry reveals that major oxides are SiO2, Fe2O3, Al2O3, and CaO. Attention has been paid to the presence of potentially toxic chemical elements (heavy metals) within the sampled sediments. The heavy metals are mainly enriched in the fine fraction of lacustrine sediments since they are mostly absorbed in the clay fraction (Geochemistry of fluvial-lacustrine and bedrock sediments revealed that, in some cases, several heavy metal elements like Cr, Co, Ni, Zn, As, Ni and Pb exceed some regulatory limits concerning their distribution in lake sediments. It should be noted that, in Italian legislation, there are no regulations concerning limit concentrations of heavy metals in fluvial and fluvio-lacustrine sediments and therefore, for lacustrine sediments, values related to aquatic environments are taken into account. The considered regulatory are the Canadian ISQG (Interim Freshwater Sediments Quality Guidelines) and the Italian D.M. 367/03 (Regulation on the setting of quality standards in the aquatic environment for dangerous substances).Furthermore, enrichment factors (EFs) for heavy metals were calculated, assuming Ti as an immobile element, both with respect to UCC (Upper Continental Crust) and local bedrock composition. Local bedrock composition was calculated based on the average composition and weighted on the areal extension of the outcropping bedrock lithologies. Enrichment factors showed that heavy metals like Pb, Zn, and Co, in relation both on UCC and local bedrock, showed values of EFs >2, which corresponds to a moderate enrichment. Other heavy metals, in particular Cu and As, showed EFs >5, which corresponds to a significant enrichment.This work aims to get a clear picture of the causes which control and influence heavy metals concentration as well as their distribution within sampled sediments. Finally, it would be appropriate to establish worldwide quality standards on all pollutants in different natural environments in order to obtain a homogeneous reference for all countries.References:Giocoli, A. , Stabile, T. A., Adurno, I., Perrone, A., Gallipoli, M. R., Gueguen, E., Norelli, E., Piscitelli, S., 2015. Geological and geophysical characterization of the southeastern side of the High Agri Valley (southern Apennines, Italy), Nat. Hazards Earth Syst. Sci. 15, 315-323.McLennan, S.M., Taylor, S.R., Hemming, S.R., 2006. Compostion differentiation and evolution of continental crust: constraints from sedimentary rocks and heat flow. In: Brown, M Rushmere T (eds) Evolution and differentiation of continental crust. Cambridge p 377.Reimann, C., De Caritat, P., 2005. Distinguishing between natural and anthropogenic sources for elements in the environment: regional geochemical surveys versus enrichment factors, Science of the Total Environment 337(1-3), 91-107.

The Latronico thermal area is located in the southern sector of the Apennines chains, in proximity to the south boundary of the Mt. Alpi. This area is a seismically active region and it is located between Val d’Agri basin and Pollino area, two of the highest seismic risk zones in Italy. It is well documented that tectonic discontinuities act as preferential channels for the uprise of deep fluids trough the continental crust towards the surface (e.g., Caracausi et al. 2013). Hence in seismically areas, these fluids can move across the volume of rocks characterized by an active field of stress and their fluids can take a memory of the occurring rock-water-gas interactions. Taking this into account, we sampled waters and dissolved gases released in the Latronico hydrothermal basin in order to define: i) water-rock interaction processes; ii) thermalism origin; iii) the geochemical model of fluid circulation in a seismic area. In details, we analysed the chemical and isotopic (C and noble gases) composition both groundwater and dissolved gases. The acquired knowledge will allow us to plan long-term geochemical monitoring useful for identification of the possible relationship between fluid circulation and regional-scale seismicity. We sampled 24 springs, of which 9 belonging to thermal set (Latronico Spa springs) and 15 to cold one. Thermal waters have an average temperature of 21°C, these are slightly alkaline (7.12 2 and He contents of 1 and 2 order of magnitude higher than cold water, respectively. The dissolved gases show an atmospheric component, being Air Saturated Water (ASW). 3He/4He ratios in the gases dissolved are 0.12 Ra ±0.2 (Ra is the He isotopic signature in the atmosphere, 1.39x10-6). Assuming that He isotopic signature in typical crustal fluids is < 0.05 Ra, the measured He data show traces of mantle-derived helium, to the mixing between atmospheric and radiogenic end-members (0.02 Ra). Coupling Total Dissolved Inorganic Carbon (TDIC) and δ13CTDIC data, 2 water sub-sets have been identified: (i) infiltrating waters, with low δ13CTDIC, and (ii) thermal waters with positive δ13CTDIC and high TDIC values, indicative of outgassing of deeply sourced CO2. This study for the first time proposes a model of fluids origin in the Latronico hydrothermal basin and the main processes that control their chemistry during their circulation through the crust. Hence, geochemical monitoring of the fluids in the region can provide if these fluids are sensitive to chemical variation due to a modification of the field of stress in the preparatory phases of an earthquake

In this study Cr(tot), Cr(VI), major and trace elements were determined in groundwater of northern sector of the Pollino Massif (southern Italy). The investigated area is characterized by ophiolitic rocks consisting of metabasites, shales and calcschists and fractured serpentinites. Two main hydro-facies were observed, reflecting low temperature water–rock interaction. The Mg-HCO3 hydrofacies is due to the weathering of serpentinites, Ca-HCO3 groundwaters are linked to the interaction with calcschist and metabasites. High Cr(VI) concentrations were detected, exceeding the maximum admissible concentrations by Italian regulation, due to the release of Cr(III) from ophiolitic rocks into water and its oxidation to the hexavalent state. Remediation tests were carried out using two synthetized nanomaterials, Fe(0) and magnetite, characterized by a mean size lower than 50 nm. The experiments were conducted at fixed nanoparticles/Cr(VI) molar ratio and according to previous studies. In addition, the kinetic data were interpreted with a suitable mathematical model.

In the Tethyan realm the carbonate-dominated Meso-Cenozoic South Tethyan Phosphogenic Province is of considerable economic importance since it represents the greatest accumulation of sedimentary phosphorites. In southern Italy, in the Salentine peninsula (the southern part of the Apulian Carbonate Platform, ACP), is well documented the occurrence of Cenozoic P-rich levels consisting of nodules and pebbles and showing a large P2O5 fluctuation (4.07–22.07 wt%), due to variable calcite abundance. The mainly observed P-bearing minerals are hydroxyapatite and carbonate fluorapatite and U, together with Sr and Pb, preferentially acts as Ca substitutes in both lattices. Minor authigenic monazite (LREE-bearing phosphate) and xenotime (HREE+Y-bearing phosphate), likely formed during sediment burial compaction and diagenesis. The total REEs' abundances and the shape of the shale-normalized REE-patterns in the P-rich nodules are in the range of those typically observed in Paleocene-Eocene through Pleistocene-Recent P-rich sediments, supporting the idea of a broadly consistent ocean chemistry in this span of geological time. The (La/Yb)N proxy is within the modern seawater range, signifying early diagenetic adsorption played only a minor role in affecting the REEs' distribution. The Ce and Pr anomalies suggest some P-rich nodules experienced very localized hypoxic to anoxic conditions promoting Ce/Ce* spurious results in a generally oxic to hypoxic environment causing real negative Ce anomaly. This scenario is reinforced by the lack of the coupled uranium-vanadium enrichment typically observed in an anoxic environment. Since the Pliocene the eastern Mediterranean was variously affected by oxygenation and productivity and it is likely the ACP phosphate-rich sediments formed under low sedimentation rates and authigenesis in a bottom current-dominated regime, as also indicated by the glauconite occurrence. Transgressions and sea levels rising following major glaciations may have favored the deposition of phosphate sediments by creating new restricted basin configurations and increased nutrient input promoted by upwelling processes.

In the northern sector of the Pollino massif (southern Apennines, Italy) well-exposed lens-shaped bodies of serpentinites and sediments of the Frido Unit belonging to the Liguride Complex crop-out. Most serpentinite rocks are cross-cut by carbonate and quartz-carbonate veins with different thickness. This study focuses on petrographic, mineralogical, geochemical, and isotopic analysis of the carbonate veins embedded in serpentinite rocks, collected at the Fosso Arcangelo site and at the Pietrapica quarry (Calabria-Lucanian boundary). The paragenesis of the carbonate veins from the Fosso Arcangelo site is dominantly made by calcite and aragonite with minor amount of rhodochrosite. In quartz-carbonate veins from Pietrapica quarry, dolomite, Mg-calcite, quartz, with minor ankerite were observed.The δ13CV-PDB isotope ratios of carbonates in the carbonate veins are in the range from +2.16‰ to -3.66‰ and corresponding δ18OV-SMOW values are between +15.02‰ and +21.53‰. The δ13CV-PDB values of carbonates in quartz-carbonate veins are in the range from -3.60‰ to -1.78‰ and the corresponding δ18OV-SMOW average value is around +21.3‰. The results suggest that the carbonate at both site occurredunder the same environmental conditions from crustal-derived andlow-moderate temperatures hydrothermal fluids having different chemical composition.

The Sardinia microplate in the western Mediterranean represents an ideal example for examining the relationship between fluid geochemistry, tectonic and heat sources in hydrothermal circuits. It consists of a portion of Variscan basement partly covered by sedimentary (mainly carbonate) and volcanic successions that record significant Permian to Pliocene geodynamic events within the southern European margin. The regional structure of the northern Sardinia is dominated by Tertiary ENE–WSW trending strike-slip and NNW–SSE trending normal faults, both capable of controlling deep and shallow fluid circulation. In this paper, results of a detailed geochemical investigation of waters and gases coming from a W-E trending section of central-north Sardinia are presented in order to explain the contrasting thermal and geochemical features of two - already known groups - of fluids. The Volcanic Logudoro Waters (VLW) is a group of cold to hypothermal Na–HCO3 waters characterised by high CO2 contents and mantle-derived He, that are localized in the volcanic-dominated Tertiary grabens. The He mantle signature within the VLW waters is associated with Plio-Pleistocene Quaternary volcanism where the outgassing of mantle-derived fluids is reasonably due recently active magma sources at depth. The currently active emission of mantle-derived gas linked to cold and hypothermal waters, provides evidence that the heat diffusion associated with the Plio-Pleistocene volcanism has already ended. In contrast, the Granite Variscan Basement Waters (GBW) group is characterised by hot-NaCl-rich waters, containing high concentrations of both dissolved N2 and radiogenic 4He. The high contribution of 4He produced by radiogenic decay of U and Th in the crust indicates a supply of radiogenic heat to the hydrothermal system localized within the granitic basement or in the tectonic contact between granite and Tertiary covers.

A comprehensive study of the serpentinite and associated veins belonging to the Frido Unit in the Pollino Massif (southern Italy) is presented here with the aim to provide new constraints about the hydrothermal system hosted by the accretionary wedge of the southern Apennines. The studied serpentinites are from two different sites: Fosso Arcangelo and Pietrapica. In both sites, the rocks show mylonitic-cataclastic structures and pseudomorphic and patch textures and are traversing by pervasive carbonate and quartz-carbonate veins. The mineralogical assemblage of serpentinites consists of serpentine group minerals (with a predominance of lizardite), amphiboles, pyroxene, chlorite, titanite, magnetite, and talc. In some samples, hydro-garnet was also detected and documented here for the first time. As for cutting veins, different mineralogical compositions were observed in the two sites: calcite characterizes the veins from Fosso Arcangelo, whereas quartz and dolomite are the principal minerals of the Pietrapica veins infill, suggesting a different composition of mineralizing fluids. Stable isotopes of C and O also indicate such a different chemistry. In detail, samples from the Pietrapica site are characterized by &delta, 13C fluctuations coupled with a &delta, 18O shift documenting calcite formation in an open-system where mixing between deep and shallow fluids occurred. Conversely, &delta, 13C and &delta, 18O of the Fosso Arcangelo veins show a decarbonation trend, suggesting their developing in a closed-system at deeper crustal conditions. Precipitation temperature calculated for both sites indicates a similar range (80 &deg, C to 120 &deg, C), thus suggesting carbonate precipitation within the same thermal system.

This work focuses on two fault-controlled deposits, the Atella and Rapolla travertines, which are associated with high-angle extensional faults of the Bradano Trough, southern Apennines (Italy). The Atella travertine is along a NW-SE striking, deep-seated extensional fault, already described in literature, which crosscuts both Apulian carbonates and the overlying foredeep basin infill. The Rapolla travertine is on top of a NE-SW striking, shallow-seated fault, here described for the first time, which is interpreted as a tear fault associated with a shallow thrust displacing only the foredeep basin infill. The results of structural, sedimentological, mineralogical, and C and O isotope analyses are here reported and discussed to assess the provenance of mineralizing fluids, and to evaluate the control exerted by the aforementioned extensional faults on deep, mantle-derived and shallow, meteoric fluids. Sedimentological analysis is consistent with five lithofacies in the studied travertines, which likely formed in a typical lacustrine depositional environment. Mineralogical analysis show that travertines mainly consist of calcite, and minor quartz, feldspar and clay minerals, indicative of a terrigenous supply during travertine precipitation. The isotope signature of the two studied travertines shows different provenance for the mineralizing fluids. At the Atella site, the δ13CPDB values range between + 5.2 and + 5.7‰ and the δ18OPDB values between − 9.0 and − 7.3‰, which are consistent with a mantle-derived CO2 component in the fluid. In contrast, at the Rapolla site the δ13CPDB values vary from − 2.7 to + 1.5‰ and the δ18OPDB values from − 6.8 to − 5.4‰, suggesting a mixed CO2 source with both biogenic-derived and mantle-derived fluids. The results of structural analyses conducted along the footwall damage zone of the fault exposed at the Rapolla site, show that the whole damage zone, in which fractures and joints likely channeled the mixed fluids, acted as a distributed conduit for both fault-parallel and cross-fault fluid migration.

In this paper we provide a systematic geochemical study of the Monticchio maar lakes, on the Mt. Vulture volcano, southern Italy, to understand the processes affecting the distribution of chemical elements. A high-resolution conductivity–temperature–depth profile was obtained, and water samples were collected at various depths for analyses of major and trace elements. Although the two lakes are separated by less than 200 m, they exhibit different behaviour. The Ca–Na–HCO 3 composition of “Lago Grande” water suggests that low-temperature fluids are leached from the host volcanic rocks. Na–Ca–HCO 3 in near-surface “Lago Piccolo” water is derived from the dissolution of local volcanic rocks, while the deepest water samples are bicarbonate alkaline-earth in composition and generally show an enrichment in solutes with respect to the epilimnion layer (except for SO 4 2 − content). The hypolimnion water is principally governed by both the input of saline groundwater from the lake bottom and authigenic processes within bottom sediments. In addition, the occurrence of anoxic conditions and microbial activity is responsible for the transformation of sulphates to hydrogen sulphide, and for the precipitation of Fe sulphide phases. Both processes cause a change in the chemical composition of saline groundwater as it moves upwards. Overall, the water chemistry of the Monticchio lakes is principally affected by: i) the input of CO 2 -rich volcanic gas; ii) evaporative processes that deplete near-surface water in some elements; and iii) the occurrence of chemical, physical and biological conditions causing the transformation of molecular complexes and consequently promoting mineral precipitation.

The Mount Vulture basin, which mainly consists of pyroclastic and subordinate lava flow layers, is one of the most important aquifers for drinking water and irrigation supply in southern Italy. In this study, we investigated the geochemical behaviour of the rare earth elements (REEs) in the groundwater of this aquatic system, assessing fractionation patterns and performing speciation calculations to elucidate the geochemical processes affecting the REEs' distribution. The groundwater collected was separated into two subsets corresponding to recharge and discharge water. Overall, the groundwater exhibited REE concentrations well below 1000 ng/l, and the average content measured in the discharge water is approximately three times higher than that of the recharge water. In the recharge water, the shale normalised patterns are characterised by a more negative average Ce anomaly, a more positive average Eu anomaly, and a larger average (La/Yb)PAAS. The observed relationship between Ce anomalies and dissolved oxygen (DO) supports the idea that Ce oxidative scavenging has a role in determining the size and shape of the Ce anomaly. Further, the less negative average size of the Ce anomaly in the discharge zone also suggests Ce desorption due to changes in redox conditions. As for the Eu anomalies, the largest Eu* are associated with the recharge zone, characterised by higher average Eh and DO values. The volcanics in the Mt. Vulture lithologies have post-Archean average shale (PAAS) normalised patterns showing positive Eu anomalies due to feldspars occurrence. This indicates that the Eu* of groundwater in the recharge zone is mostly produced by the dissolution of feldspars. In the discharge zone, most samples are in equilibrium with smectite and Eu2+ adsorption onto the clay phase surface or its inclusion in the mineral structure as exchangeable cations likely lead to the smaller average size of Eu*. The possible occurrence of secondary minerals preferentially scavenging light REEs may also explain the difference in the (La/Yb)PAAS index observed between the recharge and discharge zones. Speciation calculations indicate that dissolved REEs consist mainly of carbonato complexes (LnCO3+) whereas the percentage of dicarbonato complexes (Ln(CO3)2−) increases in samples with circa-neutral pH. At acidic pH, the Ln3+ species are numerous and, in samples with large amounts of dissolved sulphate, derived by feldspathoids dissolution, from the discharge zone, the percentage of LnSO4+ species is not negligible.

Mantle volatiles are mainly lost from the Earth to the atmosphere through subaerial and submarine volcanism. Recent studies have shown that degassing of mantle volatiles also occurs from inactive volcanic areas and in tectonically active areas. A new challenge in Earth science is to quantify the mantle-derived flux of volatiles (e.g., CO2) which is important for understanding such diverse issues as the evolution of the atmosphere, the relationships between magma degassing and volcanic activity, gas pressure and seismogenic processes, and the hazards posed by volcanic lakes. Here we present a detailed study of mantle-derived CO2 budget from Mt. Vulture volcano in the Apennines, Italy, whose latest eruption occurred 141 ± 11 kyr ago. The relationship between δ13CCO2 and total dissolved carbon at Mt. Vulture volcano indicates that the emitted CO2 is a mixture of a biogenic end-member with an average δ13CCO2 of about − 17 ‰ and a mantle-derived CO2 end-member with δ13CCO2 values from − 3 ‰ to + 2 ‰ . These values of mantle-derived δ13CCO2 are in the range of those for gas emitted from active volcanoes in the Mediterranean. We calculated the contribution of individual components (CO2 in groundwater, in lakes and from main pools) to the total CO2 budget in the area. We used new measurements of water flow, combined with literature data, to calculate the CO2 flux associated with groundwater, and measured the gas flux from the main pools on the volcanic edifice. Finally, we calculated the CO2 flow in the lakes based on the gradient concentration and eddy diffusivity. The total mantle-derived CO2 budget in the area is 4.85 × 10 8 mol yr − 1 , which is more than double previous estimates. This is higher than those observed in younger volcanic systems elsewhere, thereby supporting the existence of actively degassing mantle melts below Mt. Vulture volcano. A structural map highlights the tectonic control on CO2 flow across the Mt. Vulture volcanic edifice. Indeed, the tectonic discontinuities that controlled the magma upwelling during the most recent volcanic activity are still the main active degassing structures. The new estimate of CO2 budget in the Mt. Vulture area, together with literature data on CO2 budget from historically active and inactive Italian volcanoes, suggests a power-law functional relationship between the age of the most recent volcanic eruption and both total discharged CO2 ( R 2 = 0.73 ) and volcano size-normalized CO2 flux ( R 2 = 0.66 ). This relation is also valid by using data from worldwide volcanoes highlighting that deep degassing can occur over very long time too. In turn, the highlighted relation provides also an important tool to better evaluate the state of activity of a volcano, whose last activity occurred far in time. Finally, our study highlights that in the southern Apennines, an active degassing of mantle-derived volatiles (i.e., He, CO2) occurs indiscriminately from west to east. This is in contrast to the central–northern Apennine, which is characterized by a crustal radiogenic volatile contribution, which increases eastward, coupled to a decrease in deep CO2 flux. This difference between the two regions is probably due to lithospheric tears which control the upwelling of mantle melts, their degassing and the transport of volatiles through the crust.

This paper presents new data on the chemical composition of precipitation in a selected area of the southern Apennines of Italy; these data are used to assess natural and anthropogenic contributions to the precipitation. The town of Potenza was used as a representative urban site, and the major and minor element (Na + , K + , Ca 2 + , Mg 2 + , NH 4 + , Cl − , NO 3 − , SO 4 2 − , and Li + , NO 2 − , F − , Br − , PO 4 3 − ) and trace element (Zn, Fe, Al, Sr, Mn, Ba, Cu, Cr, V, As, Pb, Ni, and Cd) concentrations of bulk precipitation from three different sampling sites within the study area were determined between June 2011 and May 2012. The majority of the collected rainwater has pH values higher than 5.6. The composition of this rainwater was dominated by Ca 2 + the element with the highest total volume-weighted mean concentration (TVWA), followed by Cl − , SO 4 2 − , Na + , NO 3 − , K + , Mg 2 + , and NH 4 + . The TVWA of the trace metals decreased in the order Zn > Fe > Al > Ba > Sr > Mn > Pb > Cu > As. Neutralising factor (NF Xi ) values indicate that Ca 2 + is the dominant neutralising cation within this rainwater, with lower contribution from NH 4 + and Mg 2 + . The precipitation analysed during this study has a negligible marine influence as determined using Cl − concentrations as a proxy for the abundance of sea salts. Precipitation F i values (marine fraction of element i) indicate that Na + is the element with the highest seawater component, and we found partial marine contributions for the SO 4 2 − and Mg 2 + concentrations within this rainwater. Enrichment factors (EF) of selected elements were calculated to identify the sources of non-crustal elements: K + , Mg 2 + , Fe, and Ca 2 + are the only elements dominantly sourced from the crust, whereas Mn and Ba have highly variable EF values (10–100) suggesting that a small proportion of these elements was derived from anthropogenic sources in addition to a more significant crustal contribution. Sr, Cu, Pb, Zn, and As are highly enriched with respect to average crustal compositions, confirming that the concentrations of these elements within precipitation are significantly controlled by human activities.

Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, δ34S and δ18O levels in dissolved SO4 suggest that water–rock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future.

[1] We report on the first geochemical investigation of the Monticchio maar lakes (Mt. Vulture volcano, southern Italy) covering an annual cycle that aimed at understanding the characteristic features of the physical structures and dynamics of the two lakes. We provide the first detailed description of the lakes based on high-resolution conductivity-temperature-depth (CTD) profiles, chemical and isotopic (H and O) compositions of the water, and the amounts of dissolved gases (e.g., He, Ar, CH4, and CO2). The combined data set reveals that the two lakes, which are separated by less than 200 m, exhibit different dynamics: one is a meromictic lake, where the waters are rich in biogenic and mantle-derived gases, while the other is a monomictic lake, which exhibits complete turnover of the water in winter and the release of dissolved gases. Our data strongly suggest that the differences in the dynamics of the two lakes are due to different density profiles affected by dissolved solutes, mainly Fe, which is strongly enriched in the deep water of the meromictic lake. A conceptual model of water balance was constructed based on the correlation between the chemical composition of the water and the hydrogen isotopic signature. Gas-rich groundwaters that feed both of the lakes and evaporation processes subsequently modify the water chemistry of the lakes. Our data highlight that no further potential hazardous accumulation of lethal gases is expected at the Monticchio lakes. Nevertheless, geochemical monitoring is needed to prevent the possibility of vigorous gas releases that have previously occurred in historical time.

The Mt Vulture carbonatites are the only carbonatite occurrence in the southern Apennines. We present new trace element data for these rocks in order to evaluate the factors influencing rare earth element (REE) and other trace element fractionations and their REE grade. This study focuses on massive hyalo-alvikites from two lava flows and one dike, which have different relative abundances of silicate and carbonate (i.e. Si/Ca). These differences are also evident from CaO/(CaO + MgO + FeO(T) + MnO) and Sr/Ba ratios. The REE grade of the Mt Vulture carbonatites is very similar to that of the global average for calcio-carbonatites. R-mode factor analysis shows that most of the trace element variance reflects the relative roles of carbonate and silicate minerals in influencing trace element distributions. Silicates largely control heavy rare earth element (HREE), transition metal, Zr, and Th abundances, whereas carbonate minerals control light rare earth element (LREE), Ba, and Pb abundances. In addition, apa...

We report the results of a geochemical study of gas emissions along a NE–SW transect in southern Italy in order to test the hypothesis that the region around Monte Vulture is affected by degassing of mantle-derived fluids through a lithospheric discontinuity. We also investigated lavas from the Monte Vulture volcano displaying 3 He/ 4 He (up to ~ 6.0 Ra) and Sr isotopes that are consistent with an origin in mantle that has had minimal pollution from subducted Adriatic slab. Similar 3 He/ 4 He in fluids from around Mt. Vulture indicate that the deep volcanic system is still degassing. Mantle-derived He occurs in fluids along the length of the Vulture line, reinforcing the hypothesis that it is a deep tectonic discontinuity along which mantle fluids and/or melts advect to the surface. The CO 2 / 3 He ratios are highly variable (2.7 × 10 8 –2.15 × 10 11 ) in response to processes such as gas dissolution into aquifers, addition of crustal gases and degassing fractionation.

Identifying the origin of nitrate is important for the control and management of groundwater quality in aquifer systems. In the southern Apennines (Italy), the Mount Vulture volcanic aquifer is a large and valuable resource of potable and mineral water supply. Unfortunately, signs of anthropogenic impact, especially nitrogen contamination, have recently become evident. In this study, and for the first time, stable isotope ratios (δ15N and δ18O) of NO3− were determined in groundwater to identify their origins and evaluate the presence of transformation processes. The Mount Vulture groundwaters are meteoric in origin, as demonstrated by measurements of δD and δ18O, and can be divided into two distinct areas based on their NO3− content. In the southeastern area, characterized by active agricultural land use, the high NO3− content and the δ15N–NO3 isotopic values are due to anthropogenic contamination (inorganic fertilizer). In groundwaters from the western area, the NO3− contents below 4 mg/L and the δ15N–NO3 values can be associated at organic soil N. Evidence for local denitrification may be assumed in a few groundwater samples of the western area showing relatively heavy δ15N values and low concentrations of nitrate. Finally, the low measured δ18O values indicate that nitrification occurred in both investigated areas.

In this paper we provide a geochemical investigation on 34 groundwater samples in the Mt. Vulture volcanic aquifer representing one of the most important groundwater resources of the southern Italy pumped for drinking and irrigation supply. The present study includes the first data on the abundance and mobility of minor and trace elements and the thermodynamic considerations on water–rock interaction processes in order to evaluate the conditions of alkali basalt weathering by waters enriched in magma-derived CO 2 . The results highlight the occurrence of two hydrofacies: bicarbonate alkaline-earth and alkaline waters deriving from low-temperature leaching of volcanic rocks of Mt. Vulture, and bicarbonate-sulfate-alkaline waters (high-salinity waters) related to prolonged water circulation in alkali and feldspathoids-rich pyroclastic layers interbedded with clay deposits. The Al-normalized relative mobility (RM) of metals in Vulture's aquifer varies over a wide range (10 − 1 4 ), confirming that the basalt weathering is not a congruent and isochemical process. Chemical equilibrium studies show that the bicarbonate alkaline-earth and alkaline waters, having a short interaction with silicate minerals, plot very close to the kaolinite–smectite stability boundary, whereas the high-salinity waters fall in the stability field of smectite and muscovite because of prolonged interaction with alkali and feldspathoids-rich pyroclastic layers. Overall, for the bicarbonate alkaline-earth and alkaline waters, the release of toxic metals in solutions is related to the spatial variation of host-rock geochemistry, the high-salinity waters, collected near urban areas, show values higher than legal limits for Ni and As, likely as a consequence of anthropogenic contribution.

Environmental isotope techniques, hydrogeochemical analysis and hydraulic data are employed to identify the main recharge areas of the Mt. Vulture hydrogeological basin, one of the most important aquifers of southern Italy. The groundwaters are derived from seepage of rainwater, flowing from the highest to the lowest elevations through the shallow volcanic weathered host-rock fracture zones. Samples of shallow and deep groundwater were collected at 48 locations with elevations ranging from 352 to 1,100m above sea level (a.s.l.), for stable isotope (δ18O, δD) and major ion analyses. A complete dataset of available hydraulic information has been integrated with measurements carried out in the present study. Inferred recharge elevations, estimated on the basis of the local vertical isotopic gradient of δ18O, range between 550 and 1,200m a.s.l. The isotope pattern of the Quaternary aquifer reflects the spatial separation of different recharge sources. Knowledge of the local hydrogeological setting was the starting point for a detailed hydrogeochemical and isotopic study to define the recharge and discharge patterns identifying the groundwater flow pathways of the Mt. Vulture basin. The integration of all the data allowed for the tracing of the groundwater flows of the Mt. Vulture basin. Se emplearon técnicas isotópicas ambientales, análisis hidrogeoquímicos y datos hidráulicos para identificar las principales áreas de recarga de la cuenca hidrogeológica del Mt. Vulture, uno de los más importantes acuíferos del sur de Italia. Las aguas subterráneas provienen de la infiltración del agua de lluvia, flujo desde las elevaciones más altas a las más bajas a través de zonas de fracturas someras de rocas reservorio volcánicas meteorizadas. Se recolectaron muestras de aguas subterráneas someras y profundas en 48 sitios con alturas en el intervalo que va de 352 a 1,100 m por sobre el nivel del mar (m s.n.m), para análisis de isótopos estables (δ18O, δD) e iones mayoritarios. Se integró una completa base de datos de la información hidráulica disponible con las mediciones llevadas a cabo en el estudio presente. Las alturas de recarga deducidas, estimadas sobre la base de gradiente isotópico vertical local de δ18O, oscilaron entre 550 y 1,200 m s.NM El patrón isotópico del acuífero Cuaternario refleja la separación espacial de diferentes fuentes de recarga. El conocimiento de la configuración hidrogeológica local fue el punto de partida para un estudio isotópico e hidrogeoquímico detallada para definir el esquema de la recarga y descarga identificando las trayectorias de flujo subterráneo de la cuenca del Mt. Vulture. La integración de todos los datos permitió el seguimiento de los flujos de las aguas subterráneas de la cuenca del Mt. Vulture., Department of Geological Sciences, University of Basilicata, Italia, Department of Chemistry, University of Basilicata, Italia, Unidad de Sevilla, Instituto Geológico y Minero de España, España, Institute of Geological Sciences, Freie Universität Berlin, Alemania, Unit Potsdam, Isotope Laboratory, Alfred Wegener Institute for Polar and Marine Research, Alemania, Department of Structural Engineering, Geotechnical Engineering, Engineering Geology, University of Basilicata, Italia

Mn-rich layers and interbedded shales from a well exposed natural section of the Northern-Calabrian Unit (Late Jurassic‐ Early Oligocene) in the surroundings of the Terranova del Pollino village, southern Italy, have been mineralogically and chemically analyzed, in order to reveal the factors controlling their formation. Mn-rich layers are composed of micas/clay minerals, rhodochrosite, siderite, chlorite and quartz whereas shales are formed by micas, clay minerals, chlorite, quartz, and feldspars. The MnO abundances in the Mn-rich layers, which are depleted relatively to the UCC in SiO2, TiO2, Al2O3, Na2O, K2O, and P2O5, are in the range of 11.01 18.41 (wt. %). R-mode Factor analysis indicate that SiO2, Al2O3, TiO2, Na 2 O and K 2 O have high positive weights in the first factor (59.8% of the total variance) whereas high negative weights are observed for Fe2O3, MnO, and CaO. This factor accounts for the competition between the terrigeneous component, the authigenic carbonate phases accumulating Mn and Fe which likely formed during paucity of detrital supply. The negative weight of CaO and MnO in this factor, the higher Ca contents in the Mn-rich layers compared to shales, and the lack of calcite, suggest the presence of a mixed Mn‐Ca carbonate rather than pure rhodochrosite. It is generally retained that Ca‐ rhodochrosite precipitates within the pore waters of reducing sediments since neither rhodochrosite nor siderite can form in equilibrium with bottom seawater. Thus the resulting sediment should be a mixing between the detrital component and the authigenic one. Assuming Al2O3 as an index of the detrital component, it is clearly envisaged that in the Al2O3/MnO vs. Al2O3 diagram the carbonate-rich samples fall on the mixing curve having as end members the average shale and the richest MnO sediment. This supports the idea that carbonate-rich samples formed through precipitation of carbonate minerals in the pore waters of the terrigenous detritus accumulating at the sea bottom. Further the REE distribution of unaltered marine carbonates is expected to be representative of ambient seawater where carbonates precipitated. Carbonates normalized to fine-grained siliciclastic sediments, have typical HREE enrichment, negative Ce-anomaly, and lower total REE. In our case, the carbonate-rich samples normalized to the average composition of the interbedded freecarbonate shale, show HREE enrichment, lower total REE contents, and the lack of negative Ce-anomaly, due to the anoxic environment of formation for Mn‐ and Fe‐carbonate. Finally was observed that the mineralization is enhanced if the site of accumulation is protected from dilution by clastic sediment input. The alternation between Mn‐ and Fe‐carbonate silts and carbonate-free shales along the studied sedimentary succession, were likely controlled by eustatic sea-level oscillations which are well documented in the western Tethys during Middle and Late Triassic.

We report the chemical composition of groundwaters—including the first data on the sulfur isotopic composition of dissolved sulfate—from the volcanic aquifers of Mt. Vulture, one of the most important hydrological basins of southern Italy. A total of 27 water samples taken at different altitudes among drilled wells and springs were collected. The majority of groundwaters have a bicarbonate alkaline and bicarbonate alkaline-earth composition. High-salinity waters are sulfatebicarbonate alkaline in composition. The water-rock interaction process is mainly affected from uprising of CO2-rich gases which cause an increase of the water acidity promoting basalt weathering with an enrichment in certain chemical species (i.e., Na+, Ca2+, SO4 2–) and a high total carbon content. The δ34S values of dissolved sulfate ranging from +4‰ to +8.6‰ can be explained by leaching of volcanites. Higher δ34S values (from 9.6‰ to 10.4‰) detected in a few water springs can be ascribed either to the interaction with the pyroclastic layer rich in feldspathoids, such as hauyna, that have sulfur isotopic compositions up to +10.6‰ or animal manure contamination inducing localized bacterial sulfate reduction with an increase in the δ34S of sulfate. Taking into account that Upper Triassic evaporite deposits have higher δ34S values (from +13.5‰ to +17.4‰,) than those measured in all water samples the dissolution of these deposits could be excluded.

Geochemical investigations have shown that there is a considerable inflow of gas into both crater lakes of Monticchio, Southern Italy. These lakes are located in two maars that formed 140 000 years ago during Mt. Vulture volcanos last eruptive activity. Isotopic analyses suggest that CO2 and helium are of magmatic origin; the latter displays 3 He ⁄ 4 He isotope ratios similar to those measured in olivines of the maar ejecta. In spite of the fact that the amount of dissolved gases in the water is less than that found in Lake Nyos (Cameroon), both the results obtained and the historical reports studied indicate that these crater lakes could be highly hazardous sites, even though they are located in a region currently considered inactive. This could be of special significance in very popular tourist areas such as the Monticchio lakes, which are visited by about 30 000 people throughout the summer, for the most part on Sundays.

Geochemical investigations carried out at the Campano–Lucano Apennine (Southern Italy) revealed the presence of fluids composed of a mixing between components of shallow and deep origin, where mantle-derived helium is also detectable. For the gas phase, the deep component is represented by both CH4 and CO2-rich gases, while the shallow one is N2-dominated. Coinciding with the 3 April 1996 ML=4.9 earthquake, the CH4-rich component mixed with the shallow, N2-dominated one at the Tramutola well (Val d’Agri), displaying wide variations in mixing proportions. In contrast, no significant modifications occurred in relation to the 1998 ML=5.5 event. According to the collected data, an earthquake-related transient modification of local crustal permeability is suggested for the 1996 event. The different crustal response to the two events may be related to different stress distributions around the epicentres or may suggest a different tectonic connection between the Val d’Agri and the two earthquake locations.

Two distinct eruptive events characterize the volcanic activity at Mount Etna during the 2002 to 2005 period. We identified signals of magma ascent preceding these eruptions by geochemical monitoring of both chemical composition and He-isotope ratio of gas emissions from five locations in the peripheral area of the volcano. The geochemical signals are interpreted using the models proposed by Caracausi et al. (2003a, 2003b) and allow identification of episodes of magma ascent and estimation of the pressures of degassing magma. As observed for the 2001 eruption (Caracausi et al., 2003b), magma ascent probably triggered the onset of the 2002–2003 eruption, and minor events of magma ascent were observed between May and December 2003. In contrast to the previous two eruptions, the 2004–2005 eruption was not preceded by significant geochemical signals of volcanic unrest, suggesting that this eruption was mainly triggered by the failure of the upper portion of the volcanic edifice under the magmatic hydrostatic pressure in the conduits. High 3He/4He ratio revealed new volatile-rich magma accumulation. The 2002–2003 eruption was preceded by a much shorter period of new magma accumulation from deep levels of the feeding system. Few minor signals of magma migration were detected at some of the sites during the months preceding the 2004–2005 eruption, suggesting that the degassed 3He-depleted magma resident in the volcanic conduits was not replaced by new volatile-rich magma. This is in agreement with the lack of explosive activity during the 2004–2005 eruption and with petrologic observations that the parent magma probably erupted in 2000 and 2001. New geochemical signals of magma ascent from the deep reservoir have been identified since June 2005, indicating that the volcanic activity of Mount Etna is evolving toward new pre-eruptive conditions.

During “Mineral CO2 sequestration” the CO2 is chemically stored in solid carbonates by the carbonations of minerals. The sequestration of CO2 is permanent and safe. Mineral carbonation is an exothermic reaction and occurs naturally in the subsurface as a result of fluid–rock interactions within serpentinite. In situ carbonation aims to promote these reactions by injecting CO2 into porous, subsurface geological formations. In the northern sector of the Pollino Massif (southern Italy) extensively occur serpentinites; they are the subject of a project devoted to their possible use for in situ geological sequestration of CO2.

This study deals with a chemical survey (major ions and Li+, F–, Br–, and ) on water samples collected from April 1998 to April 1999, from the Telese thermal spring, southern Italy, in order to investigate possible variations in the chemical composition of the spring. Water samples are of the calcium bicarbonate type, with small fluctuations in outlet temperature (20.05 ± 0.23°C), pH (6.23 ± 0.16), and TDS (2415 ± 35 mg/l). The concentrations of major ions stayed nearly constant, except for . All analyzed waters are saturated or oversaturated relative to calcite and dolomite. The higher saturation indices of the water samples relative to calcite and dolomite observed during the summer of 1998 is interpreted in terms of the lower rainfall during the dry season, inducing a lower supply of CO2 to the feeding aquifer at depth. The sharp decrease of in the December 1998 to January 1999 water samples during the wet season may be ascribed to a drop in the supply of H2S from a deepseated source due to a temporary change of stress regime. We suggest that the crustal permeability has diminished in coincidence with the end of a seismic swarm, inducing a change in the sulfate content.