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Difficulties in dating Mississippi Valley–type (MVT) mineral deposits and the often closely associated dolomitization have led to controversy regarding their origin. We report the first radiometric ages for the Gorno mining district in northern Italy, an example of the Alpine subclass of MVT deposits. U-Pb ages of hydrothermal carbonates pre- and postdating the ore-forming event show that base-metal mineralization occurred shortly after the deposition of the Carnian host rocks. This implies that the Gorno ore deposits formed at shallow burial depth prior to the Early Jurassic western Tethys rifting phase. Contemporaneous Triassic magmatism and extensional tectonics likely contributed to the high geothermal heat fluxes required to drive the mineralizing system. Our study reinforces the need for reliable geochronological data for metallogenic models and warns against a general application of classic North American MVT models to similar deposits worldwide.

In the SW Alps, at the NE margin of the Argentera Massif, the occurrence of isolated bodies of silicate-bearing marbles (Valdieri Marble), laterally passing to non-metamorphic Mesozoic limestones of the Dauphinois succession, appears enigmatic, since their origin cannot be related to the regional metamorphism. The stratigraphic, geometric, petrographic, and geochemical features of the Valdieri Marble indicate that it originated from the upflow of hydrothermal fluids which deeply recrystallised the limestone and provoked the abundant neoblastesis of silicate minerals, at an estimated crystallisation temperature of ca. 350 °C. This paper provides for the first time an absolute U/Pb age, comprised between 30 and 31.6 Ma (early Oligocene), for the Valdieri Marble, which is affected by a syn-genetic shear foliation in turn crosscut by the main Alpine tectonic foliations. The hydrothermal fluids that formed the Valdieri Marble migrated along low-angle shear zones, mostly parallel to the sedimentary primary bedding, which were downward connected with high-angle master faults of the “Alpine SW transfer”, a main Oligocene–early Miocene transcurrent shear zone at the southern termination of the Western Alps. The localized heat flow sustaining the hydrothermal system could be related to the early Oligocene thermal event, well documented by magmatic activity in the Western and Central Alps.

The Provençal and Dauphinois Mesozoic successions cropping out at the southeastern margin of the Argentera Massif (Maritime Alps, NW Italy) were deposited at the transition between the Provençal platform and the Dauphinois basin, marked in the study area by a partly preserved Mesozoic palaeoescarpment. These successions show important lateral variations occurring over relatively short distances, probably related to syndepositional tectonics. Different stratigraphic intervals of the pelagic-hemipelagic Dauphinois succession contain resedimented deposits, made up of both intra- and extrabasinal material, which provide a twofold evidence of syndepositional tectonics indicating both tectonically-triggered gravitational processes and a tectonically-driven evolution of the source areas. Two stages of syndepositional tectonics have been recognized: the first in the earliest Cretaceous, which is related to the deposition of carbonate breccias in the Dauphinois succession and to hydrothermal dolomitization of the Middle Triassic-Jurassic Provençal carbonates, and the second in the Late Cretaceous, which triggered the deposition of different detrital lithozones in the Upper Cretaceous Puriac Limestone. The cited evidence indicates that syndepositional tectonics continued to influence the evolution of the Alpine Tethys European passive margin long after the Late Triassic-Early Jurassic syn-rift stage, which caused the differentiation between the Dauphinois basin and the Provençal platform., Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), V. 123, N. 3 (2017)

Seep carbonate deposits of Messinian age have been recently found in the Tertiary Piedmont Basin (NW Italy). These carbonates are preserved as blocks within a chaotic unit emplaced during the Messinian salinity crisis (MSC). They show negative δ 13 C values (from − 27 to − 15‰ VPDB) that indicate the involvement of hydrocarbon-rich fluids in their genesis. Three types of carbonates are recognised: (i) vuggy carbonates; (ii) Lucina carbonates; and (iii) tubeworm carbonates. Vuggy carbonates are characterised by carbonate pseudomorphs after gypsum and probably formed during the first stage of the MSC. They are the product of a complex diagenesis, influenced by both hypersalinity and seepage of hydrocarbon rich fluids. These rocks lack chemosymbiotic assemblages, reflecting their formation under extreme environmental conditions, inhospitable for most metazoans. In contrast, Lucina and tubeworm carbonates are characterised by chemosymbiotic macrofauna, represented respectively by Lucina bivalves and putative vestimentiferan tubeworms. The latter have not commonly been documented in ancient seep carbonates and have never been reported from the Messinian sediments of the Piedmont Basin. Both Lucina and tubeworm carbonates are interpreted as the product of hydrocarbon seepage during the second MSC stage. These two types of carbonates formed under less severe conditions than the vuggy carbonates, allowing the survival of seep-dwelling metazoans. During the second MSC stage, the seafloor was probably characterised by an irregular topography and a thin bottom layer of dense anoxic brines, produced by the dissolution of gypsum. It is suggested that vestimentiferan worms were able to thrive on morphologic highs with the posterior part of tubes just below the oxic–anoxic interface, but the anterior part projecting into oxic water. The infaunal Lucina bivalves were only able to live at seeps with an overlying oxic water column. The studied carbonate deposits show features reflecting the uncommon interaction of hydrocarbon-rich seep fluids and sulphate-enriched waters – the latter resulting from both evaporation and dissolution of gypsum – and allow to reconstruct the evolution of a seepage system during the MSC.

This paper deals with a definition of the lower boundary stratotype of the Tithonian Stage in the Upper Jurassic succession of Monte Inici, Western Sicily. The upper member of the Rosso Ammonitico Fm. is 27 m thick and shows a typical nodular-calcareous lithofacies; its lower beds have been sampled for biostratigraphic and paleomagnetic purposes. Though the succession is affected by high stratigraphic condensation, the resulting hiatuses have been shown to be below biochronological resolution and thus do not hinder any biostratigraphic definition. The biostratigraphic analysis has been based on the rich ammonite assemblages in which the common genus Hybonoticeras is the index-key for characterizing the Kimmeridgian-Tithonian boundary. Four ammonite biozones have been identified; the basal Tithonian one is defined by the assemblage of Hybonoticeras gr. hybonotum and Haploceras staszycii. The recorded calcareous nannofossil bioevents allow recognition of the V. stradneri and C. mexicana Zones, whose boundary is located a little below the identified Tithonian lower boundary. The paleomagnetic record shows normal polarity in the S. darwini/V. albertinum Zone and mainly reverse polarity in the H. beckeri and H. hybonotum Zones, with three minor normal polarity intervals; the lower boundary of the Tithonian falls in the oldest of these intervals. The integrated multidisciplinary stratigraphic information gathered from the Contrada Fornazzo section defines the lower boundary of the H. hybonotum Zone at the base of Bed 110, and supplies elements of chrono-correlation sufficient to regard this section as a possible G.S.S.P. of the Tithonian Stage., Rivista italiana di Paleontologia e Stratigrafia, Vol 110, No 1

The growing masses of digital traces generated by the datafication process make the algorithms that manage them increasingly central to contemporary society.There is widespread agreement in considering traces and algorithms as complex objects that intertwine social and material practices with their own cultural, historical, and institutional nature (Halford et al., 2010).Accordingly, given this strong intertwining between the social world and the digital world that is formed by material and technological objects, it becomes possible to consider the algorithms and traces as socio-digital objects. For this reason, this article aims to identify the features that allow us to frame them as socio-digital objects starting from concepts borrowed from the actor-network theory (Latour and Woolgar 1879). In particular, we will first discuss opacity, authority and autonomy concepts and then see how those features emerge in digital geographical traces.

Banfield, D. et al., The atmosphere of Mars is thin, although rich in dust aerosols, and covers a dry surface. As such, Mars provides an opportunity to expand our knowledge of atmospheres beyond that attainable from the atmosphere of the Earth. The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander is measuring Mars’s atmosphere with unprecedented continuity, accuracy and sampling frequency. Here we show that InSight unveils new atmospheric phenomena at Mars, especially in the higher-frequency range, and extends our understanding of Mars’s meteorology at all scales. InSight is uniquely sensitive to large-scale and regional weather and obtained detailed in situ coverage of a regional dust storm on Mars. Images have enabled high-altitude wind speeds to be measured and revealed airglow—faint emissions produced by photochemical reactions—in the middle atmosphere. InSight observations show a paradox of aeolian science on Mars: despite having the largest recorded Martian vortex activity and dust-devil tracks close to the lander, no visible dust devils have been seen. Meteorological measurements have produced a catalogue of atmospheric gravity waves, which included bores (soliton-like waves). From these measurements, we have discovered Martian infrasound and unexpected similarities between atmospheric turbulence on Earth and Mars. We suggest that the observations of Mars’s atmosphere by InSight will be key for prediction capabilities and future exploration., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737); Centro de Desarrollo Tecnológico e Industrial (CDTI), Ministerio de Economía y Competitividad and the Instituto Nacional de Técnica Aeroespacial (INTA).

This work analyzed the influence of different application protocols on the efficacy of two biocides against the foliose lichen Xanthoparmelia tinctina on the sandstones of the Roman Archaeological site of Luni (Italy). The hypotheses that (a) biocide application tools (brush vs. poultice), (b) pre-treatment hydration, and (c) post-treatment washing may affect devitalization success were verified by monitoring chlorophyll a fluorescence of thalli, both in situ and in laboratory conditions. The hypothesis that (d) stone substrate may act as reservoir for later biocide release under repeated cycles of wetting and drying was also assayed. Analyses confirmed the importance of the application tool, with cellulose poultice being more effective than brush. Hydration influenced the biocide absorption by thalli. Moreover it modulated the metabolic activity and susceptibility to the available toxic compound, hindering lichens from entering a dormant state to tolerate stress. Depending on the preparation solvent (water vs. white spirit), the biocide application benefited from pre-treatment hydration and/or a post-treatment washing. Lastly, we showed that different sandstones variously adsorb the biocides and potentially contribute as a reservoir for their long-term release at low concentrations during successive hydration events.

The post-Miocene marine succession of the «Apricena horst» is described with the purpose to verify the chronostratigraphic constraints for the type-locality of the Pirro Nord Faunal Unit. The stratigraphic succession has been subdivided in four units bounded by ubiquitous unconformities with evidence of subaerial exposure. The two basal units (dated late Zanclean to at most early Piacenzian) are formally grouped in the Lago di Varano Fm. that on the whole consists of sediments ranging from lagoonal to circalittoral environments. Within the lowermost unit, a megabreccia is interpreted as the product of a tsunami event. The third unit, Gelasian in age, is informally cited as Calcari a Briozoi Fm. The last unit, the Lower Pleistocene Serracapriola Fm., consists of siliciclastic deltaic sediments and represents the closure of the marine cycle. Conspicuous lateral facies and thickness changes, and the frequency of unconformities are the consequence of an intense synsedimentary tectonic activity developed in the frame of the southern Apulia foredeep closure. In the study area, such activity is documented by two E-W trending normal faults which, during Zanclean and at least the earliest Gelasian, controlled the Pliocene horst-graben system of the Apricena-Poggio Imperiale area.