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In the Northern Apennines, the Internal Ligurian Units are considered deformed and metamorphosed fragments of the Ligure-Piemontese oceanic basin. In this paper, we report on the temperature and pressure conditions of the metamorphic peak for four Internal Ligurian Units, estimated using different geothermometers and geobarometers based on the white mica and chlorite compositions. These minerals were formed during the D1 deformation phase in the pre-Oligocene. The results indicate that the Portello and Gottero units are both characterized by metamorphic conditions pertaining to low blueschists facies, while the Colli-Tavarone and Bracco-Val Graveglia Units show a lower metamorphic imprint that produces assemblages of prehnite-pumpellyite facies. The estimated geothermal gradient for the metamorphic peak achieved by the analyzed Internal Ligurian Units during the D1 phase is 7–15 °C/Km, which is indicative of deformation in a subduction setting. Under these conditions, the D1 phase developed in these units as a result of underplating at the base of the accretionary wedge during the closure of the Ligure-Piemontese basin. These data indicate a close geodynamic correlation among the Internal Ligurian Units and the ophiolite-bearing units of the Alps. [ABSTRACT FROM AUTHOR]

In the hinterland of Soverato (in the Catanzaro province CZ) in Calabria, Italy, in the territory of Gagliato, on a series of terraced plains, the remains of an extensive settlement have been identified with archaeological evidence that includes the various phases of the protohistoric period and the Greek age. In the settlement, numerous protohistoric ceramic finds consisting in fragments of vascular shapes of various sizes and large dolia were recovered. This paper presents the preliminary results of the mineralogical, petrographic and paleontological analyses performed on dolia samples selected on the basis of the typology and the characteristics of the ceramic impasto. The dolia analyses were obtained through various analytical techniques. Petrographic and micropaleontological studies were performed using polarized optical microscopy (POM). The mineralogical analyses were carried out using X-ray diffractometry (XRD), both on selected ceramics and on the clayey and sandy sediments sampled for comparison around the settlement area. Furthermore, micromorphological observations have been performed, using scanning electron microscopy (SEM), on selected foraminiferal tests picked up from the clay sediments collected in the study area. Data highlight the remarkable compatibility between the mineralogical composition of the dolia and the sampled sediments, and they confirm that the raw materials for ceramic production may have occurred in an area not far from the settlement, as assumed by archaeologists. [ABSTRACT FROM AUTHOR]

The recent (<190 ka) volcanic history of Pantelleria is characterized by the eruption of nine peralkaline ignimbrites, ranging in composition from comenditic trachyte to comendite to pantellerite. The ~46 ka Green Tuff (GT) was the last of these ignimbrites, which was followed by many effusive and explosive low-volume eruptions of pantellerite from vents within the caldera moat and along the caldera rim. Although recent studies have shed additional light on the age, petrochemistry, and volcanology of the older ignimbrites, there is very little knowledge of magmatism that occurred between these older ignimbrites, primarily due to the very scarce exposures. In this paper, we present new field descriptions and geochemical data for three local peralkaline centers never studied before, two pre-GT and one post-GT, which share a similar setting with respect to the caldera scarps but differ in terms of their age, composition, and eruptive style. These centers include: (i) the older (~125 ka) Giache center (comenditic trachyte), (ii) the ~67 ka Attalora center (comendite, pantellerite), and (iii) the younger (~14 ka) Patite center (pantellerite). [ABSTRACT FROM AUTHOR]

Pyrite decay is arguably the major problem in geological and palaeontological conservation, as it can cause total destruction in valuable specimens. Various methods have been devised since the 19th century to treat and prevent it with different degrees of success. Nevertheless, the conservation of large fossils at risk of pyrite decay remains an unsolved issue, because a feasible method for maintaining them in a controlled microclimate that is suitable for specimens on public display has remained elusive. This paper describes the study carried out to investigate the alterations that developed in a large fossil palm of the collection of the Museum of Geology and Palaeontology in Padova (Italy), already treated for pyrite decay several years before. Results of X-ray powder diffraction and Raman spectroscopy performed on samples collected from that fossil palm confirmed that the alterations were due to pyrite decay. The microclimate indoors (inside showcases and in the Hall itself) and outdoors was monitored for one year to investigate its possible relation with the damage observed. The measured thermo-hygrometric conditions exceeded the recommended thresholds for the prevention of pyrite oxidation and indicated the fossils were at high risk of damage from that process. This study demonstrates that treatment alone is not sufficient for the conservation of fossils at risk of pyrite decay and that it can be ineffective without a proper management of the microclimatic conditions under which the fossils are preserved. [ABSTRACT FROM AUTHOR]

The eruptive products of the last 1000 years at La Fossa volcano on the island of Vulcano (Italy) are characterized by abrupt changes of chemical composition that span from latite to rhyolite. The wide variety of textural features of these products has given rise to several petrological models dealing with the mingling/mixing processes involving mafic-intermediate and rhyolitic magmas. In this paper, we use published whole-rock data for the erupted products of La Fossa and combine them in geochemical and thermodynamic modelling in order to provide new constrains for the interpretations of the dynamics of the active magmatic system. The obtained results allow us to picture a polybaric plumbing system characterized by multiple magma reservoirs and related crystal mushes, formed from time to time during the differentiation of shoshonitic magmas, to produce latites, trachytes and rhyolites. The residing crystal mushes are periodically perturbated by new, fresh magma injections that, on one hand, induce the partial melting of the mush and, on the other hand, favor the extraction of highly differentiated interstitial melts. The subsequent mixing and mingling of mush-derived melts ultimately determine the formation of magmas erupted at La Fossa, whose textural and chemical features are otherwise not explained by simple assimilation and fractional crystallization models. In such a system, the compositional variability of the erupted products reflects the complexity of the physical and chemical interactions among recharging magmas and the crystal mushes. [ABSTRACT FROM AUTHOR]

Discrete zircons, up to 9 mm in length, occur in alluvial deposits from the Veneto area. They are likely derived from the disaggregation of lamprophyric rocks belonging to a regional, pervasive dyke-swarm. Zircon and REE phases occur in both alkaline lamprophyres and connate calcite-bearing felsic lithics and their debris in lamprophyre breccia. We present 36 new complete U–Pb and trace element analyses of zircons and associated inclusions. We used a statistical approach on a larger dataset using new and literature data to evaluate the confidence figure to give an estimation of age of zircons. Inclusions suggest a genetic link with an S–CO2–ZrO–BaO–SrO–CaO-rich fluid/melt possibly associated with carbonate-rich alkaline parental magma and a metasomatised mantle source. This paper confirms the importance of calcite–syenite and lamprophyre genetic link and zircon magmatic origin, in contrast with hydrothermal and metamorphic zircons. U–Pb dating by LA-ICP-MS provides time constrains (40.5–48.4 Ma, Lutetian), consistent with the age of the alkaline magmatic event. Trace element data indicate a link to anorogenic magmatism associated with mantle upwelling. Complex zoning is highlighted by cathodoluminescence images. The Veneto zircons are helpful for regional geological information and may have commercial potential as a critical resource for green technologies. [ABSTRACT FROM AUTHOR]

The Campi Flegrei geothermal system sets in one of the most famous and hazardous volcanic caldera in the world. The geothermal dynamics is suspected to have a crucial role in the monitored unrest phases and in the eruption triggering as well. Numerical models in the literature do not properly consider the geochemical effects of fluid-rock interaction into the hydrothermal circulation and this gap limits the wholly understanding of the dynamics. This paper focuses on fluid-rock interaction effects at the Campi Flegrei and presents relevant information requested for reactive transport simulations. In particular, we provide: (1) an extensive review of available data and new petrographic analyses of the San Vito cores rearranged in a conceptual model useful to define representative geochemical and petrophysical parameters of rock formations suitable for numerical simulations and (2) the implemented thermodynamic and kinetic data set calibrated for the San Vito 1 well area, central in the geothermal reservoir. A preliminary 0D-geochemical model, performed with a different contribution of CO2 at high (165 °C) and low (85 °C) temperatures, firstly allows reproducing the hydrothermal reactions over time of the Campanian Ignimbrite formation, the most important deposits in the case study area. [ABSTRACT FROM AUTHOR]

Seismic hazard reduction policies usually utilize earthquake catalogues and probability evaluations of occurrence. Further geophysical and geochemical parameters could contribute to hazard reduction policies as is currently the case in some countries, such as Iceland, Taiwan, China and Russian Federation. In the past four decades, intense research activity carried out by many different institutions in Italy has allowed us to recognize the most relevant sensitive sites for detecting acceleration in crustal deformation processes by means of geofluids monitoring. All scientific papers published in the period 1976–2020 concerning tectonic-related signals in geofluids have been considered. An in-depth review of previous and present-day research activities, as well as an update of two unpublished time series recorded in Central and Southern Italy, has contributed to identifying areas where an instrumental array is still lacking and the most relevant priority areas for monitoring activities in geofluids. An atlas of all experimental sites utilized in recent decades has been obtained with the purpose of contributing to identifying the most suitable monitoring areas. [ABSTRACT FROM AUTHOR]