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Among past interglacial periods, Marine Isotope Stage (MIS) 19 is particularly interesting because its orbital geometry is very similar to that of the present interglacial. Here we present a high-resolution (sub-centennial) multiproxy record covering the ca. 790-770 ka interval, i.e. the interglacial MIS 19c and the ensuing glacial inception of MIS 19b, from a lacustrine sediment sequence retrieved from the Sulmona Basin (central Italy). The record has an independent chronology based on radiometric dating of six volcanic ash layers, and the resulting age model has a mean associated uncertainty of ±2.6 kyr. Variations in sediment geochemistry and mineralogy are interpreted in terms of past hydrological and temperature changes. Several millennial and sub-millennial events of reduced precipitation are well expressed. Comparisons with continental and marine records from the mid-latitude and sub-polar North Atlantic suggest a broad spatial expression for the observed events. Events occurring within the interglacial are not clearly associated with changes in marine proxies in the Iberian Margin, although similarities with the record from the sub-polar North Atlantic can be recognized and tentatively linked to changes in local hydrography having a downstream effect amplified by changes in atmospheric circulation. During the glacial inception, changes in the Sulmona record are coherent with changes in North Atlantic records, with drier events likely associated with meltwater-induced intervals of AMOC weakening. An event at ca. 785.6 ka may also reflect oceanic changes caused by freshwater discharges from residual ice-sheets and an outburst flood, similar to the 8.2 ka event in the Holocene.

A specimen with joined valves of Pelecyora gigas, an extinct species, was collected in a sandy layer of Early Pliocene age in the northern part of the Siena Basin (Tuscany, Italy). XRD data demonstrated that the original mineralogical composition of the specimen was aragonitic and it maintained substantially the original structure and composition. Neglecting possible changes in sea salinity during different seasons, we can estimate, using oxygen isotope composition a maximum seasonal temperature differences of ca. 9 °C experienced during the life of the individual. An approximate estimation of past sea water composition allows to calculate an average temperature of 23.0±2.7 °C for the water where the shell lived, whereas calculated temperature extremes are 18.5 °C for the colder season and 27.6 °C for the warmer. These data are in a good agreement with those proposed on the basis of the Pliocene Mediterranean taxa nowadays living along the western African shores.

International audience; The period corresponding to Marine Isotope Stages 9 (MIS 9) offers the opportunity to study orbital and suborbital scale climate variability under boundary conditions different from those of better studied intervals such as the Holocene and the Last Interglacial. Yet, it is poorly represented in independently-dated continental archives around the Mediterranean Region. Here, we present a speleothem stable isotope record (delta O-18 and C-813) from the Former Yugoslavian Republic of Macedonia (F.Y.R.O.M., southern Balkans), which consists of two periods of growth broadly covering the ca. 332 to 292 ka and the ca. 264 to 248 ka intervals (MIS 9e-b and late MIS 8). We interpret the speleothem delta O-18 as mostly related to regional hydrology, with variations that can be interpreted as due to changes in rainfall amount, with higher/lower values associated to drier/wetter condition. This interpretation is corroborated by a change in mineralogical composition between aragonite and calcite at ca. 328 ka, which marks increasing precipitation at the onset of MIS 9 and occurs within a trend of decreasing delta O-18 values. Also the comparison with the multiproxy climate record available from the nearby Lake Ohrid seems to support the proposed interpretation. The MIS 9e interglacial appears to be characterized by wettest conditions between ca. 326 and 321 ka, i.e. lasting ca. 5 kyr. Decreasing precipitation and enhanced millennial scale variability matches the glacial inception (MIS9 d to b), with drier events at ca. 319 ka (ca. 2 kyr long) and 310 ka (ca. 1 kyr long), and a major rainfall reduction between 306 and 298 ka. The latter is followed by a prominent wetter period between 298 and 295 ka, for which carbon data values suggest high infiltration rate. Rainfall decreases again after 295 ka, and remain low until the growth interruption at ca. 292 ka. Resumption of the growth and progressive soil development, expressed by the carbon isotope record, occurred during the late part of MIS 8. Despite the rather high temporal uncertainty (average 6 ka), the speleothem hydrological record complements the environmental information provided by the Lake Ohrid record and also fits well to the framework of regional and extra-regional variability, showing similarities with pollen records from southern and western Europe, both at orbital and at sub-orbital time scale.

Understanding the mechanism of serpentinite weathering at low temperature – that involves carbonate formation – has become increasingly important because it represents an analog study for a cost-efficient carbon disposal strategy (i.e. carbon mineralization technology or mineral Carbon dioxide Capture and Storage, CCS). At Montecastelli (Tuscany, Italy), on-going spontaneous mineral CO 2 sequestration is enhanced by brucite-rich serpentinized dunites. The dunites are embedded in brucite-free serpentinized harzburgites that belong to the ophiolitic Ligurian Units (Northern Apennine thrust-fold belt). Two main serpentinization events produced two distinct mineral assemblages in the reactive dunite bodies. The first assemblage consists of low-T pseudomorphic, mesh-textured serpentine, Fe-rich brucite (up to 20 mol.% Fe(OH) 2 ) and minor magnetite. This was overprinted by a non-pseudomorphic, relatively high-T assemblage consisting of serpentine, Fe-poor brucite (ca. 4 mol% Fe(OH) 2 ) and abundant magnetite. The harzburgite host rock developed a brucite-free paragenesis made of serpentine and magnetite. Present-day interaction of serpentinized dunites with slightly acidic and oxidizing meteoric water, enhances brucite dissolution and leads to precipitation of both Mg-Fe layered double hydroxides (coalingite-pyroaurite, LDHs) and hydrous Mg carbonates (hydromagnesite and nesquehonite). In contrast, the brucite-free serpentinized harzburgites are not affected by the carbonation process. In the serpentinized dunites, different carbonate minerals form depending on brucite composition (Fe-rich vs Fe-poor). Reactions in serpentinized dunites containing Fe-rich brucite produce a carbonate assemblage dominated by LDHs and minor amount of hydromagnesite. Serpentinites with a Fe-poor brucite assemblage contain large amounts of hydromagnesite and minor LDHs. Efficiency of CO 2 mineral sequestration is different in the two cases owing to the distinct carbon content of LDHs (ca. 1.5 wt.%) and hydromagnesite (ca. 10 wt.%). Here, for the first time, we link the mineral composition of serpentinized ultramafic rocks to carbonate formation, concluding that Fe-poor brucite maximizes the mineral CCS efficiency.

Mineral fibres are ubiquitous on Earth. Because many of them possess outstanding technological properties, they have been used since ancient times for a huge number of applications. They are considered now one of the most interesting and complex examples of inorganic to organic sphere interaction with direct consequences for human health. The most important mineral fibres are serpentine asbestos (chrysotile), amphibole asbestos species and the zeolite erionite. If inhaled, because of their peculiar fibrous-asbestiform crystal habit and chemical-physical surface reactivity, these mineral fibres may induce, after a long latency period, fatal lung diseases. All amphibole asbestos minerals are banned worldwide whereas chrysotile is banned only in the countries strictly following the indication of the International Agency for Research on Cancer (IARC) which includes chrysotile in Group 1 "substance carcinogenic to humans". No ban has been proposed for the zeolite erionite so far. Explaining human toxicity of mineral fibres is not straightforward at all. The difficulties stem from the fact that mineral fibres possess a variety of chemical compositions, atomic structural arrangements, morphologies that affect biogeochemical reactions in the body. Due to the interplay of all these factors, the mechanisms by which mineral fibres induces cyto- and geno-toxic damage remain unclear. Our research group is actually involved in the study of the bio-interaction and toxicity of the mineral fibres from the well pondered assemblage of chemical-physical, mineralogical-structural, and biological information. In this work, we present the results of the mineralogical and chemical physical characterization of mineral fibres belonging to the major classes of mineral fibres of economic and social importance: three chrysotile species including the UICC standard, Balangero and Valmalenco (Italy), crocidolite UICC standard, amosite from Penge (South Africa), anthophyllite UICC standard, tremolite from Val d'Ala (Italy) and the zeolite erionite from Jersey valley (Nevada USA). Data are discussed in the frame of the existing contradictory literature data.

Atmospheric CO2 is spontaneously sequestered through the carbonation of serpentinites at Montecastelli (Tuscany, Italy). In the studied area, hydrated Mg-carbonates frequently form crusts, coating and spherules on exposed surfaces, in rock fractures, and on clast surfaces in mining dumps. XRD analyses indicated that precipitated minerals are hydromagnesite, nesquehonite, manasseite, pyroaurite, brugnatellite, often associated with aragonite. No silica has been detected. Brucite-rich serpentinites do not evidence any pervasive alteration, and water/rock interaction seems to be restricted to the fracture surfaces along which carbonation occurred. The sampled spring waters show high pH, relatively high TDS (Total Dissolved Solids) and high Mg/Ca molar ratio with respect to the local rainwater, indicating a chemical equilibration with serpentinites. Isotopic analyses (?18O, ?2H) of rainwaters, emerging waters and carbonates confirmed that the carbonates have been precipitated from superficial waters circulating into the serpentinite bodies. Overall, our data point to an on-going rapid uptake of atmospheric CO2, triggered by water flow in fractures and humid airflow on surfaces of the brucite-rich serpentinites. This natural process introduces new applications on the CO2 mineralogical sequestration and its study could open new solutions for the environmental sustainability and GHG reduction.

The Miller Butte (MIB) 03002 iron meteorite was found during the XIX (2003-2004) Antarctic campaign of the Italian Programma Nazionale delle Ricerche in Antartide (PNRA) in northern Victoria Land (Antarctica). MIB 03002 is classified as a medium octahedrite belonging to the rare IID chemical group, and it is the first IID iron among the 30,000 specimens so far returned from Antarctica. The bulk chemistry of this meteorite indicates that it represents an intermediate member of the differentiation series of IID irons. Polygonal kamacite, shear planes in the Widmanst5tten structure and relies of cross-hatched E-structure indicate that MIB 03002 experienced important shock metamorphism (T >= 700 degrees C and P >= 13 GPa) and post-shock annealing, after primary cooling. With a terrestrial age of similar to 610 ka, MIB 03002 is the oldest meteorite fall in northern Victoria Land so far, and the oldest Antarctic iron found on blue ice. Possible relationships between the old terrestrial age of MIB 03002 and the regional glacial dynamics of the East Antarctic Ice Sheet in northern Victoria Land are also discussed.

International audience; Tremolite is one of the most common amphibole species and, in the fibrous form (i.e., characterized by crystals/particles consisting of fibres with length > 5 µm, width 3), one of the six asbestos minerals. Until now the attention of crystallographers has focused only on samples from continental environment. Here we report the first chemical and structural data of a tremolite asbestos found along the Mid Atlantic Ridge (MAR) at the eastern intersection of the Romanche Transform Fault (Equatorial MAR). Tremolite is associated with chlorite and lizardite and was formed through the green shale facies lower than zeolite in a predominantly fluid system. MAR tremolite asbestos shows very slight deviations from the ideal crystal structure of tremolite. Differences in cation site partitioning were found with respect to tremolite asbestos from ophiolitic complexes, attributed to the different chemical–physical conditions during the mineral formation. In particular, oceanic tremolite asbestos is enriched in Al and Na, forming a trend clearly distinct from the continental tremolites.

We report the occurrence of microscopic inclusions of shocked quartz plus a Zr phase and trace of Fe oxide crystallites in Australasian microtektites recovered from deep-sea sediment cores within 2000 km of Indochina. The shocked quartz and the Zr phase are interpreted as relicts of the target rock. Furthermore, the internal homogeneity of Australasian microtektites in terms of abundance of relict mineral inclusions, vesicles, and schlieren increases with distance from Indochina. This finding strengthens the current hypothesis that the source crater of the largest and youngest tektite strewn field on Earth is located in the Indochina region, as internal heterogeneity characterizes normal impact glass found in or near the source crater. This finding also indicates that the Australasian microtektites with the longest trajectories underwent the highest temperatures or were heated longer. The definition of microtektites should include the possible occurrence of microscopic relict inclusions as an indication of proximity to the source crater.

This work reports the results of the structural study of three representative chrysotile samples of different provenance (Canadian UICC, and Italian Balangero and Valmalenco). Chemical composition was determined using EMPA and TG data. An innovative wet cryo-milling procedure was used to powder the flexible and durable chrysotile fibres. X-ray powder diffraction patterns were collected using both conventional and nonconventional sources. Collected data were used for Rietveld structural refinements and results were compared with available literature data. The three samples display similar structure models, although small differences were detected in the position of the oxygen atoms. Both the structural refinements and spectroscopic investigations confirms that Fe2+ and Fe3+ atoms in chrysotile are located in the octahedral cavities only, substituting for Mg2+. Regarding the atom coordinates, UICC chrysotile is the closest to the model reported by Falini et al. (2004). About the lattice parameters, the Valmalenco chrysotile is the closest, if compared with the Balangero and UICC, to both the model proposed by Whittaker (1956a,b) and Falini et al. (2004). This work is intended as a basis for subsequent studies aimed at understanding the toxicity of these mineral fibres.

The present research is focused on automation, miniaturization, and system interaction with high throughput for multiple and specific Direct Immersion-Solid Phase Microextraction/Fast Gas Chromatography analysis of the urinary ketones. The specific Mass Spectrometry instrumentation, capable of supporting such the automated changeover from Negative Chemical to Electron Ionization mode, as well as the automation of the preparation procedure by new device called MultiFiber Exchange, through change of the fibers, allowed a friendly use of mass spectrometry apparatus with a number of advantages including reduced analyst time and greater reproducibility (2.01–5.32%). The detection limits for the seven ketones were less than 0.004 mg/L. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative Mass Spectrometry fragmentation patterns together with the chromatographic separation and software automation are also investigated.