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L’articolo presenta alcuni elementi dello studio di uno dei più interessanti siti costieri dell’intera regione ligure: la Grotta Marina di Bergeggi (SV). L’ipogeo è costituito da una parte emersa, scoperta nel XIX secolo, e una parte oggi sommersa, indagata per la prima volta negli anni ’70 del secolo scorso. Sebbene sia stato esplorato a più riprese in diversi interventi, il sito non è mai stato tuttavia oggetto di studi e scavi sistematici. Tra gennaio e dicembre 2014, è stato possibile sottoporre a nuove indagini sia la parte emersa sia i cunicoli sommersi, ottenendo importanti informazioni utili alla conoscenza dell’evoluzione geomorfologica della grotta e all’interpretazione delle sue destinazioni d’uso nelle varie fasi di occupazione antropica, che datano dal Paleolitico medio all’età del Ferro. Contemporaneamente, è stato possibile esaminare alcune collezioni ceramiche provenienti dall’ipogeo, conservate presso il Museo “Paolo Graziosi” di Firenze. Tra i materiali, frutto di raccolte di superficie e di diversi interventi effettuati nel sito tra l’ultimo quarto del XIX secolo e il 1950, si contano anche diversi frammenti riferibili all’età del Bronzo. Anche se il numero dei frammenti riferibili alle ultime fasi dell’età del Bronzo e all’inizio dell’età del Ferro non sembra essere sufficiente a garantire una corretta ed esaustiva analisi del fenomeno, il riconoscimento di alcuni evidenti parallelismi tra il sito ligure e alcuni siti italiani e francesi consente di evidenziare l’esistenza di alcuni parallelismi tra la Liguria occidentale e la Provenza orientale che non possono considerarsi delle semplici casualità. In particolare, alcuni motivi decorativi, tra cui la croce incisa su un fondo ad anello, e alcune forme rinvenute all’interno della grotta nella “Galleria Modigliani” sembrano tracciare un parallelo diretto con forme e decorazioni attestate in alcuni siti provenzali, come ad esempio nella Grotte du Chateau a Nizza. Questa corrispondenza, insieme ad altri elementi, sembra conferma l’ipotesi di una relazione tra queste due aree tra la tarda età del Bronzo e la prima età del Ferro, probabilmente legata d una rotta marittima. Sfortunatamente, la limitatezza dei dati provenienti da siti contemporanei, soprattutto per l’area ligure, rappresenta un grande ostacolo per la corretta comprensione di questa relazione e delle dinamiche demografiche della parte costiera di questa regione durante l’età del Bronzo. La Grotta Marina di Bergeggi, tuttavia, grazie alla sua particolare struttura geomorfologica, al suo record archeologico e alla sua posizione di collegamento tra il mare e la via di risalita verso l’entroterra padano lungo la Val Bormida, potrebbe essere un buon punto di partenza per un'indagine più approfondita., IpoTESI di Preistoria, Vol 13 (2020)

In the past 15 years several expeditions by French, American and especially Italian cavers have surveyed over 15 km of salt cave passages in the Cordillera de la Sal, close to San Pedro de Atacama village (Atacama Desert, Northern Chile). Over 50 caves have been explored up to now at an elevation around 2,500 m asl. These karst systems are characterized by in-cave temperature of around 17 °C and a relative humidity always very low, with a maximum of 15%. This extreme aridity is due to the severe conditions of the area with only a couple millimeters annual rainfall and several years without rain. Currently the rare precipitation events are enough to allow the dissolution of the salt rock and crusts, and the deepening of underground meandering river passages. Moreover, after the sporadic rain events, the water penetrating the cave’s host rock along fractures and bedding plains leads to the dissolution of primary minerals and allows the formation of seeping brines with dissolved salts. Both these processes selectively add solutes to the incoming undersaturated rainwater. The evaporation of these resulting salt-rich fluids at the cave atmosphere interface causes secondary minerals to precipitate. Mineral samples have been collected in eight caves, and include stalactites, flowstones, precipitates that form crusts in the streambeds and at the groundwater seeps, parietal coatings, earthy masses from the cave floors and efflorescence salts on ceiling rock outcrops. Most secondary deposits are composed of halite, but also other halides, carbonates, sulphates, nitrates, phosphates, and silicates have been discovered. Among the sixteen observed minerals, antarcticite, leonite, darapskite, blödite, atacamite and anhydrite are worth mentioning. The peculiar climate (extremely arid) and the very special environment dominated by NaCl and CaSO4, allow the crystallization primarily of halite. Atacamite was found where local enrichment in Cu (of hydrothermal origin) occurs, and antarcticite precipitates by the final evaporation of SO4-depleted brine (after early precipitation of anhydrite). Among sulphates, the metals necessary for the formation of these mineral species (magnesium, potassium, sulphate) derive from the cave sediments while nitrates are supplied by bird guano. Salt mineral precipitation is controlled by the temperature dependence solubility of the species in saline water, so that different secondary minerals were observed.

Karst aquifer, artificial tracer test, Supramonte aquifer, Sardinia., Flowpath 2017, National meeting on hydrogeology 2017

Drought climate change hot spots, Su Gologone, Sardinia, water pumping management., Flowpath 2017, National meeting on hydrogeology 2017

Although occupying a critical position at the center of the Mediterranean Sea, the Island of Sardinia (Italy) has never been the focus of multi proxy data-based palaeoclimate studies. An excellent way to obtain information about late Quaternary terrestrial climate oscillations in the region is the study of carbonate speleothems, because they allow the reconstruction of palaeohydrology through the geochemical properties of the their growth layers (Fairchild and Treble, 2009; McDermott, 2004) and are highly suited to accurate independent chronologies (Richards and Dorale, 2003; Scholz et al., 2012). To this end, U-Th series dating, δ18O and δ13C isotope analysis and petrographic observations have been applied to a ~30 cm long stalagmite (BMS1) sampled in the Bue Marino coastal cave (western Sardinia) providing the first palaeoclimate record for this area. Seventeen U-Th ages attest to the formation of BMS1 during MIS5d, between ~110 and ~115 thousand years BP, a period of intense climate perturbations that followed the last interglacial peak (Dansgaard et al., 1993). A positive correlation between δ18O and δ13C, and its correspondence with carbonate fabric variations, reflects variations in drip rate, in turn related to secular variation in the rainfall quantity reaching the cave site during its formation. Furthermore, a hiatus at around 111ky BP marks the interruption of a general isotopic enrichment trend, and probably corresponds to the arrival of a short-lived arid-cold period in the region comparable to a sub-D-O cycles (Capron et al., 2010). The presence of intra millennial climate events has already been reported in Alpine speleothems (Boch et al., 2011) but never in the Mediterranean sea region. For this reason further analyses are planned in order to better understand this variability in Sardinia, that represents an exceptional opportunity to correlate existing and future palaeoclimate records from the peri-Mediterranean European and African mainland. Boch, R., Cheng, H., Spötl, C., Edwards, R. L., Wang, X., and Häuselmann, P., 2011, NALPS: a precisely dated European climate record 120–60 ka: Climate of the Past, v. 7, no. 4, p. 1247-1259. Capron, E., Landais, A., Chappellaz, J., Schilt, A., Buiron, D., Dahl-Jensen, D., Johnsen, S. J., Jouzel, J., Lemieux-Dudon, B., Loulergue, L., Leuenberger, M., Masson-Delmotte, V., Meyer, H., Oerter, H., and Stenni, B., 2010, Millennial and sub-millennial scale climatic variations recorded in polar ice cores over the last glacial period: Climate of the Past, v. 6, no. 3, p. 345-365. Dansgaard, W., Johnsen, S. J., Clausen, H. B., Dahl-Jensen, D., Gundestrup, N. S., Hammer, C. U., Hvldberg, C. S., Steffensen, J. P., Sveinbjornsdottir, A. E., Jouzel, J., and Bond, G., 1993, Evidence for general instability of past climate from a 250-kyr ice-core record: Nature, v. 364, p. 218-220. Fairchild, I. J., and Treble, P. C., 2009, Trace elements in speleothems as recorders of environmental change: Quaternary Science Reviews, v. 28, no. 5-6, p. 449-468. McDermott, F., 2004, Palaeo-climate reconstruction from stable isotope variations in speleothems: a review: Quaternary Science Reviews, v. 23, no. 7-8, p. 901-918. Richards, D. A., and Dorale, J. A., 2003, Uranium-series chronology and environmental applications of speleothems, Volume 52. Scholz, D., Hoffmann, D. L., Hellstrom, J., and Bronk Ramsey, C., 2012, A comparison of different methods for speleothem age modelling: Quaternary Geochronology, v. 14, p. 94-104.

Il margine interno del Supramonte costiero (Sardegna centro-orientale) è orlato dall’affioramento di graniti e/o filladi appartenenti al basamento paleozoico, messi a nudo dalle dislocazioni terziarie e dall’erosione delle coperture giurassiche. Questa successione sedimentaria è costituita alla base da livelli di argille, marne, conglomerati e sabbie di spessore variabile (generalmente qualche metro), seguita da dolomie sabbiose che diventano progressivamente più carbonatiche (Formazione di Dorgali). Nel settore centro-occidentale dell’altopiano (zona di Marghine – Su Canale) si sviluppano alcuni sistemi carsici allineati lungo il contatto tra i litotipi cristallini e quelli carbonatici. Con i loro piccoli corsi d’acqua, questi reticoli sotterranei drenano gli apporti allogenici di modeste depressioni, impostate sul basamento impermeabile. La tipica morfologia delle grotte è caratterizzata dall’assenza di superfici di dissoluzione e dalla presenza di ampi vuoti che aumentano le loro dimensioni in profondità, con volumi che la ricarica disponibile non sembrerebbe giustificare. Il soffitto è generalmente piatto e relativamente basso, mentre il pavimento è mascherato dall’accumulo di depositi graviclastici. Parte di questi ambienti vadosi sono a volte sviluppati per diversi metri dentro le rocce insolubili del basamento e in alcuni casi i passaggi sono completamente scavati nei graniti o nelle rocce metamorfiche. L’analisi mineralogica dei prodotti di alterazione al contatto tra le rocce paleozoiche e i sedimenti mesozoici ha rivelato la presenza di tipici minerali secondari prodotti dall’idrolisi dei silicati quali montmorillonite, caolinite e clorite. La speleogenesi di questi sistemi carsici può quindi essere spiegata con una prima fase dissolutiva del cemento carbonatico degli strati basali di dolomia sabbiosa. Questo stadio origina un materiale sciolto che può essere facilmente asportato dall’erosione esercitata dalle acque correnti e, una volta raggiunte le dimensioni critiche del vuoto, la successiva formazione della grotta avviene molto rapidamente portando ad ambienti ampi in poche migliaia di anni.

The atmosphere is a fluid shell whose dynamic reflects the biogeochemical processes of the biosphere and especially perturbations induced by human activities. Its mixing is so efficient to connect ecosystems at global scale, leading an important role in global change. In fact, local emissions may be carried in the distant regions of the planet, transmitting the impacts of activities and actions at the global or regional scale and vice versa. Hence the interest to know the potential negative impact on climate of some pollutants in natural ecosystems and the transport of the same, especially in areas of significant natural value at the edge of highly industrialized zones such as Asinara, a small island of approximately 50 km2 in the northwestern coast of Sardinia (Italy). This island is located a few kilometers from a factory which manufactures organic chemical products with direct discharge of emissions to air. Asinara has a multitude of biotic and abiotic environments in a small area and it has been recognized at Community level as a special protection zone for the conservation of biodiversity that makes the impacts of human activity more visible and more easily observable. By its nature, an Environmental Observatory has been settled on the island and equipped with a continuous monitoring system of air quality that measures the concentration of the main recognized atmospheric contaminants, such as particulate matter (PM10), sulfur dioxide (SO2), ozone (O3) and nitrogen oxides (NOx). At the same time meteorological and carbon flux data are also recorded. In this work the results of the study carried out for the period 2006-2015 are presented with the ambitious project that aims to differentiate between natural factors and other situations due to the action of global change that induce changes in atmospheric chemistry and pollutants deposition.

The quest of exploring and looking for life in new places is a human desire since centuries. Nowa- days, we are not only looking on planet Earth any more, but our endeavours focus on nearby planets in our solar system. It is therefore of great importance to preserve the extra-terrestrial environment and not to contaminate it with terrestrial / human associated bacteria. At this point in time we are not able to send crewed missions to other planets; however, analysing the impact of human exploration on environments is of great planetary protection concern. This can be achieved by obtaining samples from a subterranean environment, where only ex- pert speleologists have access and the human impact is considered very low. For this study, astronauts participating in the 2014 ESA CAVES (Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills) training course, obtained samples from deep within a subterranean environment and returned them to the laboratory for molecular microbial analysis. The diversity of the returned soil samples was analysed by molecular means such as clone library and next-generation sequencing (NGS). It was found that humans have an immense impact on the microbial diversity in the environment. Although the cave system is sparsely entered by humans, a high relative abundance of Staphylococcus spp. and Propionibac- teria spp., organisms that are characteristic for human skin, have been recovered. Some samples even showed the presence of human gut associated methanogenic archaea, Methanomassiliicoc- cus spp. The obtained data from this investigation indicate that human exploration is strongly polluting an environment and may lead to false-positive sign of life on other planets. It is therefore imperative to increase our awareness to this problem as well as work towards new protocols to protect a pristine extraterrestrial environment during exploration.

A series of mineral crusts and speleothems currently forming in the abandoned tunnels and shafts of the Pb- Zn-As-Sb Argentiera mine (Sassari) have been sampled and analysed. Over 20 crystalline phases have been determined, among which many sulphates (barite, copiapite, epsomite, gypsum, jarosite, melanterite, metavoltine, and sideronatrite) and carbonates (aragonite, calcite, dypingite, giorgiosite, hydromagnesite, and hydrozincite). Also several oxides (hematite, akaganeite, and pseudoboleite), hydroxides (goethite, lepidocrocite, and todorokite) and silicates (quartz, illite, and feldspar) have been found. The most interesting mineral paragenesis (akaganeite, dypingite, giorgiosite, and hydromagnesite) has been discovered on a nail that has given both iron and magnesium necessary to their formation.

Coastal karst areas often host many indices of past sea level changes, such as marine terraces, fossiliferous sediments, tidal notches and coastal caves. Tectonic movements can then displace these ancient coastlines vertically. The interplay between rising or falling sea level and uplifting or subsidence can be very complex and difficult to unravel. The combination of a detailed knowledge of marine terraces and the study of some flank margin caves located at various altitudes have allowed to reconstruct the speleogenetic history of the coastal plain of Cornino-Custonaci (NW Sicily). Along the centraleastern coast of Sardinia, instead, the detailed study of the Fico Cave has allowed to recognise it as a flank margin cave developed on five levels, related to Pleistocene sea level highstands. These studies show that this type of mixing corrosion caves is much more widespread than previously thought also in telogenetic limestones. These caves, being excellent sea level markers, might help coastal geomorphologists to understand more on both sea level rise and fall and tectonic movements in coastal areas.

Sa Corona ‘e sa Craba (Barbusi, Carbonia, Southwest Sardinia) is a natural cave almost entirely developed within a quartzite vein. Its natural entrance, enlarged during mining operations, opens at 260 m asl. The cave is composed of an over 200 m long and 20 m wide gallery developed in a NW-SE direction. During our surveys we collected over 50 small samples of crusts, coatings and spars from all over the cave, on which we performed X-ray diffraction analysis in order to understand the speleogenetic pathways. These samples ranged in color from yellow to red, purple, brownish, grey, white, pinkish, bluish and black. Beside the already known minerals, the following have been discovered for the first time within this cavity: sulfide: cinnabar; sulfates: alunite, natroalunite, basaluminite, walthierite and gypsum; phosphates: taranakite, spheniscidite, robertsite, Al-rich strengite, hydroxylapatite, vashegyite and an unnamed Pb-Mo oxide phosphate; silicates: halloysite, lizardite and clay minerals of the illite and smectite group; oxyhydroxides: hematite, goethite, pyrolusite and todorokite.

Anthropic areas, such as cities, are recognized to constitute the major source of the CO2 emitted into the atmosphere, and Greenhouse Gases Emissions (GHG) in urban environment derive from different sources (human respiration, domestic heating/cooling, transportation, etc.). Cities, therefore, can affect the global carbon cycle, the atmosphere, and the climate. The link between urbanization and global climate change is complex, and since the urbanization process is increasing worldwide, it becomes crucial to better understand the role of cities in the global warming phenomenon, the interaction between natural and anthropogenic processes, and quantify the urban carbon exchanges. As part of a Regional Project, in the city of Sassari (Sardinia, Italy) a research activity has been carried out with the general aim to quantify urban fluxes and identify the main GHG emissions sources. A combined methodology is used for this purpose: (1) direct measurements and (2) an inventory approach. An Eddy Covariance tower is to be set up in the Sassari city center to constantly monitor energy, water, and carbon fluxes at about 24 m above the ground. In addition, a meteorological station and radiometers are to be installed to analyze the environmental characteristics affecting urban fluxes. A local simplified GHG emissions inventory, developed through standardized procedure guidelines, is also compiled and city emissions were quantified and classified by type of greenhouse gas, manufacturing activity, and source emissive. The inventory tool also allowed a spatio-temporal analysis of the emissions and the temporal disaggregation of the collected annually emissions to produce data on a monthly, and/or daily, and/or hourly time scale. The combined methodology is able to provide information on the current status of emissions and removals of CO2, through direct measurements and the local inventory, which will help local stakeholders to identify low carbon emissions options for the future planning strategy. The projects activities, methodologies applied, as well as the preliminary results will be reported here.

All’interno della Miniera di Naica (Chihuahua, Messico), la parte più interna e profonda della Cueva de las Espadas ospita una sequenza verticale di oltre 5 metri di cristalli di gesso, precipitati sulle pareti della galleria ad opera di fluidi ipogenici risalenti dalla profondità, le cui dimensioni risultano essere perfettamente gradate in modo diretto. Le analisi morfologiche, tessiturali e mineralogiche di questi cristalli, assieme ai dati relativi agli studi geochimici sulle inclusioni fluide in essi presenti, hanno permesso di dimostrare che il processo di gradazione dimensionale è stato controllato dall’oscillazione della falda freatica proprio in corrispondenza del livello di sviluppo della grotta e in un periodo di tempo compreso nell’arco degli ultimi 15.000 anni. Tale oscillazione, oltre ad aver permesso a parte della cavità di emergere a più riprese dalle acque termali, favorì l’instaurarsi di un’alternanza di fenomeni di evaporazione, che coinvolsero relativamente piccoli volumi di acqua a livello del “lago terminale”. A essi fecero seguito brevi periodi in cui le acque profonde risalenti riallagarono quasi totalmente quest’area. In questo contesto la sovrasaturazione risultò essere massima a livello dell’interfaccia acqua-aria e progressivamente registrò un calo verso le parti inferiori dove invece fu minima, limitando così la probabilità di nuova nucleazione e creando il gradiente osservato con una distribuzione continua di grossi individui nelle parti basse della parete che sfumano gradualmente verso l’alto in una densa concentrazione di cristalli più piccoli. In the Naica Mine (Chihuahua, Mexico), the deepest area of the Cueva de las Espadas hosts a 5 m high sequence of gypsum crystals. These crystals were deposited by hypogene uplifting fluids and their dimensions progressively decrease from the floor to the ceiling of the cave. The morphological, textural and mineralogical analyses of these crystals, together with the geochemical data on the fluid inclusions made possible to demonstrate that the dimensional gradation of these crystals was controlled by the swinging of the groundwater just at the level of the cavity and the development of these crystals occurred in the last 15,000 years. The swinging of the groundwater dried up the upper part of the Cueva de las Espadas several times thus inducing the evaporation of relatively small volumes of water confined in “terminal lake” just the deepest part of the cave. These periods were followed by short floods which brought the water practically to refill the whole cavity. The processes induced the supersaturation to be the highest at the air-water boundary and to lower progressively toward the bottom of the lake where it resulted the lowest thus hindering the probability of new nucleation. The result was that the biggest crystals developed on the lake’s bottom while the size of the crystals progressively lowered toward the ceiling.

On the basis of the previous studies, the aim of this research is to extend and detail the geological mapping of zeolitized volcanoclastic units, essentially pyroclastic and epiclastic rocks, of Mores, Bonnanaro and Torralba areas in the Eastern Logudoro. The stratigraphic succession comprise two different ignimbritic units separated by an epiclastic layer, overlain by trasgressive conglomerate which mark the base of Miocene limestones. In the most valuable sectors of this area, we produce 1:10,000 geological and zeolite grade maps (evaluated by means of XRPD analysis - Rietveld/RIR methods). The most autigenic phase is clinoptilolite, always associated with opal-CT and sometime with smectite. These minerals constitute the cement in epiclastite and unwelded pyroclastic flows and they derive from the transformation of precursor rhyolitic glass with a zeolitizzation process after deposition. The secondary mineralization was favored by hydrothermal fluids preferentially circulating through fault system. Finally, a semi-quantitative evaluation of mineral resources in these deposits is performed.