The Cretaceous-to-Eocene Julian (JB) and Brkini (BK) flysch basins have recently been studied for their heavy mineral assemblages; however, the rutile component has so far been neglected. To fill this gap, this study explores their detrital rutile trace element contents and U-Pb ages to define their possible provenance(s). In JB, there are very few rutile grains, mainly related to amphibolite–eclogite facies metamorphic units, with about 80% metapelitic grains. Among the few rutile grains from JB, only eight gave robust U-Pb ages. These ages are all Palaeozoic, resembling those of the closure/opening of the Rheic Ocean and the Variscan orogeny. In BK, the number of rutile grains is much higher than in JB, testifying to differences in the supply areas. The rutile grains are mainly in the amphibolite–eclogite facies, but they decrease, moving upward, accompanied by an increase in UHT. The metapelitic rutile component is higher than 74%. When considering the BK rutile grains, there are no Palaeozoic ages at the bottom of the sequence, while they are newly visible upward. In BK, the most abundant rutile grains show Mesozoic ages that can be considered as representatives of the opening/closure of the Vardar Ocean and the ophiolite emplacement in the Dinarides area.

The Raibl mining district is one of more than 500 Pb-Zn deposits and occurrences hosted in the Triassic Platform carbonates of the Eastern and Southern Alps. Although mined since at least 1320 AD, with a total metal output of 18.2 million tonnes at 1.2% Pb and 6.0% Zn, outstanding questions remain on the timing of mineralization at Raibl, its relationship with other Alpine carbonate-hosted Pb-Zn deposits and the wider geodynamic context. In this contribution, we provide an updated petrography of the carbonate gangues associated with the Pb-Zn mineralization at Raibl and present new U-Pb crystallization ages for syn- to postmineralization carbonates. The results indicate protracted metal deposition spanning the Late Triassic to Early Jurassic (217.4 +/- 7.8 Ma to 192.4 +/- 21.1 Ma), in agreement with existing geochronological constraints on the neighbouring Bleiberg Zn-Pb deposit and suggesting metal deposition during a period of incipient regional extension and subsidence in a passive margin setting.

A commercial TiO2 sample functionalized with 3-aminopropyltrimethoxysilane (APTMS) and 4-carboxyphenylboronic acid (CPBA), has been previously proposed as a suitable photocatalyst to perform selective photocatalytic degradation of pollutants in aqueous streams, while avoiding the oxidation of valuable catechol simultaneously present in the reacting medium. In the present study, we highlight the adsorption mechanisms underlying the higher affinity of catechol, compared to phenol, with the surface of modified TiO2, quantitatively justifying the photocatalytic selective degradation results previously obtained. Moreover, a cooperative adsorption mechanism of phenol onto the TiO2 sample modified with APTMS has been for the first time observed. The resulting sigmoidal adsorption isotherms, satisfactorily fitted with the Hill model, could be attributed to the enhanced surface hydrophobicity and, more importantly, to alterations of the folding of APTMS molecules on the TiO2 surface occurring upon increasing the concentration of the phenolic compounds.Photocatalytic tests revealed that the existence of boronate groups on the surface of TiO2 hinders the photocatalytic degradation of catechol and facilitates a swifter oxidation of phenol. These findings confirm the potential for selective photocatalytic degradation, in line with modern conceptions of innovative and environmentally sustainable wastewater treatments.

The production of a significant thermal and fluid anomaly during the assembly of large magmatic bodies inevitably leads to a prolonged, post-magmatic evolution of the system. To shed light on the transition between magmatic and post-crystallization environment, we investigated the variation of OH-defects and trace elements content in quartz from intrusive and eruptive products of the Sesia Magmatic System (SW Alps, Italy). Specifically, quartz crystals were sampled from a floor-to-roof section of the Valle Mosso Pluton and two rhyolitic units of the Sesia Caldera, which represents the crystallized remnants of a magmatic plumbing system beneath a large Permian caldera. A total of 120 quartz crystals were analysed using Fourier Transform InfraRed (FTIR) spectroscopy to investigate OH-defects both quantitatively and qualitatively and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) to assess trace element abundances. Results indicate systematic variations: (1) intrusive quartz shows gradual decrease in Ti and increase in total defect water content (1-25 ppm), following the differentiation degree; (2) volcanic quartz displays variable Ti and water contents (2-14 ppm) comparable to those of the intrusive lithologies; (3) in both intrusive and eruptive units, lattice-bound Al-specific defects dominate over non-lattice bound Li-specific defects, except in a porphyritic dike showing evidence of fast cooling. Our findings suggest that, in absence of fast cooling, slow-diffusing elements and lattice-bound OH-defects (e.g. Al, Ti, AlOH) preserve primary magmatic signals, while fast-diffusing elements (e.g. Li) and interstitial defects (e.g. LiOH) provide insights into post-crystallization histories. The combined analysis of these features offers a powerful tool for reconstructing the thermal and chemical evolution of magmatic systems, from magma chamber processes to post-eruptive alteration. Moreover, it provides insights on the robustness of quartz OH-defects and trace element inventory as a tool for provenance indicator.

The potential impact of decommissioned mining areas on environmental quality is of major concern for local communities, posing a risk to water resources and human health. This study aims to investigate the impact of extraction activities on the surface environment by evaluating the occurrence of metal(oid)s, including potentially toxic elements (PTEs, i.e. As, Cd, Fe, Tl, Zn, Pb) and critical elements (As, Ge), at the Zn-Pb Raibl mining area (northeastern Italy). Elevated concentrations of metal(oid)s are found near mine waste heaps (< 100 mg/kg for Tl, Sb, Cd, Ge; > 1,000 mg/kg for As; > 1% for Pb and > 10% for Zn and Fe), which are made up of flotation tailings and waste rocks scattered around the mining village and stored in the tailings impoundments. Conversely, upstream from the mine, the environment is largely uncontaminated. According to the results, total and leachable metal(oid) concentrations are positively correlated. Tailings (65.1-754 mg/kg of Tl) are identified as the primary source of leachable Tl (11.4-255 mg/kg) and metal(oid)s are generally more mobile in organic-rich soils, suggesting increased metal(oid) mobility with soil ageing due to low soil pH and potential soluble organometallic complexes. Furthermore, the findings suggest that reprocessing of mine tailings could be a potential solution to recover valuable elements together with residue backfilling. Lastly, results from this study highlight how crucial mining site management is to limit PTE dispersion and reducing risks to the environment and public health.

The accurate textural characterization of mantle xenoliths is one of the fundamental steps to understanding the main processes occurring in the upper mantle, such as sub-solidus recrystallization, magmatic crystallization, and metasomatism. Texture, composition, and mineralogy reflect the temperature, pressure, stress conditions, melting, and/or contamination events undergone before and during the entrapment in the host magma. For these reasons, characterizing the three-dimensional (3D) texture of silicate, oxide, sulfide, and glass phases has great importance in the study of mantle xenoliths. We performed a multi-scale and multi-modal 3D textural analysis based on X-ray computed microtomography (mu-CT) data of three mantle xenoliths from different geodynamic settings (i.e., mobile belt zone, pericraton, oceanic hotspot). The samples were selected to represent different, variably complex internal structures composed of grains of different phases, fractures, voids, and fluid inclusions of different sizes. We used an approach structured in increasing steps of spatial and contrast resolution, starting with in-house X-ray mu-CT imaging (spatial resolution from 30 mu m down to 6.25 mu m) and moving to high-resolution synchrotron X-ray mu-CT at the micrometer scale. We performed a 3D characterization of mantle xenoliths, comparing the results with the analysis of conventional 2D images (thin sections) obtained by optical microscopy and simulating the random sectioning of several thin sections to estimate the probability of correct modal classification. The 3D models allow the extraction of textural information that cannot be quantified solely from thin sections: spinel layering, distribution of silicic glass, and related vesicles. Moreover, high-density volumes identified as sulfides were detected in two xenoliths, showing no relation with the spinel layering in one case and a preferential concentration along fractures in the other. Given the variety of textures and mineral assemblages of mantle xenoliths worldwide, the results are used to suggest experimental and analytical protocols for the characterization of these materials.

The integration of high-resolution seismic profiles, core data and radiocarbon plus U-Th datings, allows to document the late Quaternary succession of the Trieste Gulf, which represents the easternmost part of the northern Adriatic Sea. This succession consists of an alternation of shallow-marine and continental deposits organized to compose four transgressive-regressive sequences down to ca. 90 m below present sea level. The sequences terminate landwards against a stepped surface bounding the Eocene Trieste Flysch and produced by alternating episodes of wave erosion during transgressions and subaerial exposure during stages of relative sea-level fall and lowstand. Two shallow-marine wedges, in addition to the Holocene one, have been recognized; they are associated with the Marine Isotopic Stage (MIS) 5.5 (Tyrrhenian) and probably at least one of the peaks of MIS 7. The recognized shallow-marine wedges typically prograde just seaward of a buried wave-cut platform lying in front of a receding paleo-coastal cliff. A previously unrecognized stratigraphic hiatus of ca. 25 ka duration, containing the whole Last Glacial Maximum (LGM) phase, was found at the top of palustrine deposits that accumulated on the MIS 5.5 marine sediments until ca. 40 cal ka B.P. and a post-LGM peat bed accumulated during the Younger Dryas stadial. The beginning of the Holocene was characterized by marked fluvial aggradation preceding the marine transgression at ca. 11-10 cal ka B.P. This new evidence is invaluable for better understanding late Quaternary sedimentary and erosional episodes that characterized the easternmost part of the norther Adriatic Sea, in the frame of the well-known glacio-eustatic sea-level changes.

Nitrate radicals possess the unique capability to add to unsaturated bonds, leading to the formation of carbon-centred radicals evolving to organic compounds, which cannot be achieved through more common reactive oxygen centred species. Therefore, the possibility of generating nitrate radicals through heterogeneous photocatalysis endows this technology with unprecedented possibilities in the field of green organic synthesis. In particular, previous research showcased the promising potential of nitrate radicals in selectively conducting the photocatalytic oxidative cleavage of limonene to limononaldehyde. However, the role of silver ions, required for the reaction to occur, remained uncertain. This study aims at elucidating the role of silver in determining conversion of limonene and selectivity towards the corresponding oxidized compounds. In particular, it has been demonstrated that silver ions efficiently scavenge photogenerated electrons, thus making molecular oxygen available for the nitrate radical induced production of limononaldehyde, obtained with selectivity values up to 60%. In this study it is shown that, nitrate radical formation is as well boosted by silver nanoparticles, in the absence of silver ions. However, in this case, the consequent oxidation of limonene produced both 1,2-limonene epoxide and limononaldehyde. Notably, in the absence of silver ions, molecular oxygen is the main electron scavenger and its lower availability for the oxidative cleavage mechanism addresses the reaction towards the epoxide. Ab initio calculations, confirmed this hypothesis, showing that, while formation of limononaldehyde is thermodynamically and kinetically favoured, formation of the epoxide is kinetically limited. Therefore, its formation takes place when the formation of limononaldehyde is hindered by factors such as the reduced availability of molecular oxygen. The identification of key parameters governing the process offers possibilities to tune the selectivity of the reaction towards oxidative cleavage or epoxidation. Moreover, it allows to further optimize this reaction, which may become an appealing and versatile method of chemicals green synthesis.

This paper explores the development of pottery technology in the Trieste Karst region (North-East Italy) from the Neolithic to the Early Bronze Age (EBA). It also seeks to identify cultural links with other areas by examining potentially imported vessels. Archaeometric analyses (X-ray diffraction and optical microscopy) reveal significant differences between Neolithic ceramics (Danilo–Vlaška Group) and the majority of Late Copper Age (LCA)/Early Bronze Age (EBA) pottery (primarily associated with the Ljubljana Culture and a few with the Cetina Culture). Neolithic pottery displays consistent characteristics across all vessel types, including coarse grain, prevalent sparry calcite temper, and the absence of grog. In contrast, most LCA and EBA vessels exhibit distinct features such as very fine-grained paste, no sparry calcite, notable use of grog temper, higher quartz, muscovite, and flint content. Notably, from a technological perspective, the analyzed Cetina vessels bear a strong resemblance to the majority of LCA ceramics. The differences between Neolithic and LCA/EBA vessels clearly suggest the use of new raw materials, recipes, and techniques, likely reflecting changes in cultural and social contexts and potential connections with the core area of the Ljubljana Culture.

In the SE Alps, two Cretaceous–Eocene flysch basins, Julian and Brkini, filled with turbidite sediments, are present. This study novelly reports heavy mineral assemblage counts and detrital tourmaline characterization for 11 samples. It is possible to define three different groups, characterized by the presence of (1) a clinopyroxene–epidote–low-ZTR (zircon+tourmaline+rutile; 5%) sample association, (2) a high-ZTR (>48%)–garnet–apatite association and (3) a low-ZTR (<40%)–Cr-spinel–garnet association. Detrital tourmalines from both the Julian and Brkini flysch basins are rather similar in composition, associated with metapelites and metapsammites coexisting or not coexisting with an Al-saturating phase, ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks; however, their number is drastically different. In fact, even if the percentage of heavy minerals is very low and similar in both basins (0.17–1.34% in weight), in the Julian basin, the number of tourmaline crystals is much lower than that in Brkini (1–14 vs. 30–100), suggesting an important change in the provenance area. Interestingly, the presence of a high amount of tourmaline derived from ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks makes these two basins different from all the Cretaceous flysch basins of Bosnia and the Northern Dinaric zone, where these supplies are missing or very limited.

Decommissioned mines represent a worldwide concern due to the potential long-term effects related to the dispersion of potentially toxic elements (PTEs) in the environment. In this study, 176 water samples were collected in the period 2018-2021 at the carbonate-hosted Pb-Zn Raibl mine which is affected by neutral mine drainage (NMD). The post-flotation tailings are the main source of PTEs (Zn, Pb and especially Tl) in the river drainage system. Compared to other dissolved PTEs (Zn, Pb, Cd), Tl was found to be more mobile, reaching concentrations up to 120 mu g L-1 in waters flowing in the tailings impoundments. Modelling results suggest that Tl is mainly present in the Tl(I) ionic and mobile form thus suggesting that relevant natural attenuation processes for this element are not expected in the investigated area. In contrast, Zn and Pb attenuation pathways appeared to be governed by pH-dependent speciation and sorption processes, whereas elevated Zn concentrations were likely also limited by hydrozincite precipitation. Metalloids such as As and Sb were almost entirely released into the slightly alkaline waters of the mine drainage system, which are generally characterised by longer residence time or standing waters whereas As and Sb concentrations were negligible in the tailings-seepage waters. However, intense rainy events may increase PTE concentrations of one order of magnitude, especially in the tailings impoundment groundwater as a result of a rise in the water table, and PTE total dissolved loads of three orders of magnitude, in the main stream during high flow events, thus representing the most critical factor in regulating the remobilisation and downward dispersion of PTEs in the river drainage system.

The Sabzevar ophiolite belt consists of a series of thrust-bound massifs that widen in extent to similar to 150 km in NE Iran. The Kuh-Siah harzburgite-dunite massif in the central sector of this belt hosts abundant discontinuous pod-like chromitite deposits. These deposits are characterized by spinels with contrasting and variable compositions, but without any microtextural differences. The chromian spinel in these chromitite bodies displays a wide range of Cr-number (Cr/(Cr + Al)) atomic ratio from 0.50 to 0.77, and reveals a co-occurrence of Al-rich and Cr-rich chromitites within a single ophiolitic massif. Despite these chemical differences, primary spinels from both the high-Al and high-Cr chromitites have similar TiO2 contents, indicating that they formed in a single tectono-magmatic setting. Both high-Al and high-Cr chromitite samples display low to moderate total platinum group element (PGE) abundances (85-537 ppb). Solid phases hosted by Cr-spinel grains in chromitites and their host dunites can be divided into three categories: platinum group minerals (PGM), base-metal minerals (BMM), and silicates. Euhedral quadrangular and round-shaped silicate inclusions consisting of clinopyroxene, orthopyroxene, Na-bearing phlogopite, serpentine and chlorite, are sporadically scattered in the Cr-spinel grains. These inclusions are mainly single crystals and rarely occur as polyphase assemblages. The BMM are mainly euhedral Ni- and Cu-rich sulfides with rare occurrence of pentlandite. The most widespread PGM are crystals of the laurite-erlichmanite series with subordinate malanite, braggite and BM-PGE-rich sulfides. Textural relationships reflect that the PGM are of magmatic origin. The BMM, on the other hand, formed during both magmatic and post-magmatic processes. The occurrence of low-temperature inclusions within Cr-spinel and ferrian Cr-spinel, comprising tremolite, chlorite and serpentine, are interpreted as post-magmatic entrapments of already-formed silicate phases at the time of grain boundary migration. Our petrographic observations and geochemical interpretations reveal that chromitites in the Kuh-Siah peridotite massif formed during multistage melt/fluid-peridotite reaction processes in an extended intra-oceanic arc-forearc setting located between the Turan and Central Iran continental blocks in the Mid to Late Cretaceous. Mossbauer measurements of Fe3+/Sigma Fe ratios of Cr-spinels from the non-oxidized chromitite samples are relatively similar, more or less in the range 0.15-0.20, whereas those from the more oxidized chromitite samples have Fe3+/Sigma Fe ratios in the range 0.28-0.62. Field observations and textural studies suggest that the localized post-magmatic oxidation is linked to dominant hydrous fluids existing in the shear zone.

Glauconite mineral is one of the most sensitive indicators of low sedimentation rate in the marine environment. The time of residence of glauconites at the sea bottom before burial is reflected by their so-called maturity that is differentiated based on their K2O content. The present work aims to investigate the evolution of glauconites during the transition toward the highly evolved level. Complementary electron microprobe, Raman, and Thermogravimetric analysis were performed on glauconitic grains from the Belluno basin (N Italy) with different K2O content in order to verify whether the level of glauconites evolution affects the results of these surveys. The obtained results show that Raman spectra are sensitive to the grade of glauconite maturations. First, spectra of mature glauconites are more structured, due to the lower degree of Al substitution in the octahedral sites. Moreover, the position of the strongest Raman peak (Si-Ob-Si mode) at similar to 700 cm(-1) shows two contrasting behaviors in the early (K2O <8%) and late (K2O> 8%) stages of glauconites maturation, respectively. TGA measurements reveals that the presence of interlayer water is also related to the state of glauconites maturations. The obtained results were explained in the light of different isomorphic substitutions occurring at octahedral level in the mature and non-mature glauconites, thus allowing to obtain a deeper insight onto the mechanism of glauconites evolution.

A new synthetic protocol to produce the carbon fiber precursor polyacrylonitrile (PAN) and its block copolymers with polyethylene glycol (PEG) is proposed here. The constant flux of radical species produced at low concentrations during the oscillating Belousov-Zhabotinsky (BZ) reaction was properly exploited to initiate the radical polymerization reaction. Compared with conventional methods, this oscillating initiation decreases the probability of chain termination, thus favouring the production of high molecular weight polymers, and it does not require an inert atmosphere and elevated temperatures to be produced. The solubility of the polymeric chains during the polymerization reaction was improved by adding the anionic micelle-forming surfactant sodium dodecyl sulphate (SDS). Following the initiation step, short oligomer chains are able to overcome the micellar interface, thereby reaching a favourable environment for the increase of the polymeric chains, thus strongly contributing to the increase of the molecular weight of the fibers' precursors. The synthesis was conducted by adding the monomer acrylonitrile (AN) to the unperturbed and PEG-perturbed BZ system after the onset of the oscillations, in the absence and presence of increasing amounts of the SDS surfactant. The potentiometric technique was utilized to detect the dynamics of the oscillatory reaction. Preliminarily, the response of the BZ system to the monomer addition was investigated. Additional information was provided from the study of the effect of the SDS and PEG concentration on the dynamics of the BZ reaction during AN polymerization, thus obtaining a deepening in the understanding of the BZ mechanism. The characterization of the obtained polymers and copolymers, by melting point measurements, molecular weight determinations, Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) analyses, and thermal treatments, indicated that the proposed synthetic method produces carbon fiber precursors with high molecular weight and good thermal stability. The addition of the surfactant was revealed as a good method to improve and/or finely tune the precursor molecular weight. The proposed synthetic protocol represents a valuable alternative to conventional methods to produce high-performant precursors of carbon fibers.

The decommissioned fahlore Cu-Sb(-Ag) mine at Mt. Avanza (Carnic Alps, Italy) is a rare example of exploited ore deposits, as the tetrahedrite (Cu 6 [Cu 4 (Fe,Zn) 2 ]Sb 4 S 13 ) is the main ore mineral found. This multi-compartmental geochemical characterisation approach provides one of the first case studies regarding the geochemical behaviour and fate of Hg, Sb, As, Cu, and other elements in solid and water matrices and of Hg in the atmosphere in an environment affected by the mining activity of a fahlore ore deposit. Elevated concentrations of the elements (Cu, Sb, As, Pb, Zn, Hg) associated with both (Zn-Hg)-tetrahedrite and to other minor ore minerals in mine wastes, soils, and stream sediments were observed. Concentrations in waters and stream sediments greatly decreased with increasing distance from the mining area and the I geo index values testify the highest levels of sediment contamination inside the mine area. Thallium and Ge were associated with the “lithogenic component” and not to sulfosalt/sulphide minerals. Although mine drainage water often slightly exceeded the national regulatory limits for Sb and As, with Sb being more mobile than As, the relatively low dissolved concentrations indicate a moderate stability of the tetrahedrite. The fate of Hg at the investigated fahlore mining district appeared similar to cinnabar mining sites around the world. Weak solubility but the potential evasion of gaseous elemental mercury (GEM) into the atmosphere also appear to be characteristics of Hg in fahlore ores. Although GEM concentrations are such that they do not present a pressing concern, real-time field surveys allowed for the easy identification of Hg sources, proving to be an effective, suitable high-resolution indirect approach for optimising soil sampling surveys and detecting mine wastes and mine adits.

The authors would like to correct the published article [...]

Portable X-ray fluorescence (pXRF) is one of the main geochemical techniques employed in multi-elemental analysis screening for contaminated sites management. As the confidence of pXRF analyses are matrix-specific, efforts are made to provide studies of pXRF quality on different geochemical datasets, focusing on less investigated elements such as mercury (Hg) and antimony (Sb), to help both new and experienced users. The analysis of environmental solid samples from two decommissioned mining sites in NE Italy, characterised by Pb-Zn and (Hg-rich) Cu-Sb ore deposits, were prepared with two different protocols and compared with traditional destructive analyses. Sample composition was found strictly dependent to the occurrence of false positives and overestimation at low concentrations. In contrast, milling the sample did not produce major variations in the overall quality. Lead (Pb), Sb, and Zn reached the definitive data quality in at least one of the two datasets. Consequently, as far as a thorough QA/QC protocol is followed, pXRF can rapidly produce chemical data that is as accurate as that produced by destructive standard laboratory techniques, thus allowing to identify potential sources of contamination that could be reprocessed for the extraction of valuable elements and mitigating the dispersion of contaminants and ecological or health risks.

We analysed the major, minor and trace elements chemistry of forty-two Cr-spinels from four Siberian kimberlites. They showed a wide range in Mg# (Mg/(Mg + Fe2+); 0.42–0.78) and Cr# (Cr/(Cr + Al); 0.32–0.92) and a common trend of increasing Cr# with decreasing Mg#. The major element classification schemes suggested that there were spinels deriving from a peridotitic source (Xen) and spinels crystallised from kimberlitic melts (Chr). Laser-Ablation Inductively Coupled Plasma Mass Spectrometry on both groups showed that the trace elements with the highest abundance were Mn (985–3390 ppm), Ni (531–3162 ppm), V (694–2510 ppm) and Zn (475–2230 ppm). Testing the effectiveness of trace elements in determining the source for Cr-spinels, we found out that Cr-spinels crystallised directly from a kimberlitic melt usually showed higher Mn, Ni, Sc and V concentrations with respect to those of peridotitic origin. In addition, using the available partitioning models, we found that the correlations between major elements and Ni, Co, Sc and Ga in the Xen group could be explained by subsolidus equilibration between spinel, olivine and clinopyroxene at 800–1000 °C, thus supporting a peridotitic source for this group. Finally, we calculated the composition of the possible melts in equilibrium with the Cr-spinels of the Chr group, using a selected set of partition coefficients. Calculated abundances of Cu, Ga and Zr were comparable to those of the kimberlite, while V was never close to the kimberlite composition. This simulation highlighted the need for new data on the trace elements partition coefficients between kimberlitic melts and Cr-spinel.

Textural and compositional characteristics of mineral inclusions in podiform chromitites flourish thoughtful information about the genesis of the Ko center dot ycegiz ophiolite (SW Turkey). In the chromitite bodies, olivine, orthopyroxene, clinopyroxene, and sulfide inclusions are mostly sub-rounded or globular. Less abundant needleshaped silicate inclusions (10-50 mu m-long) are aligned along crystallographic orientations in the host magnesiochromite grains. Raman spectroscopy and micro analytical data indicate that these lamellar inclusions have consistently a diopside composition. Uncommon, discrete micro-diamonds and moissanite (SiC) particles, observed in some magnesiochromite grains, may suggest formation under ultra-high pressure (UHP) superreduced (SuR) conditions. The Ko center dot ycegiz chromitites are characterized by variable platinum-group element (PGE) abundances (80-441 ppb), with unfailing IPGE > PPGE contents. Fractionated chondrite-normalized PGE patterns of chromitites and associated peridotites and data scatter in the Pd/Ir versus Pt/Pt* space indicate chromitite formation by partial melting of the associated mantle rocks. The variable 187Os/188Os(i) (0.1278-0.1380) and gamma Os (-0.38 to +7.54) values demonstrate extensive contamination of crustal components, likely in a supra-subduction zone (SSZ) setting. Combined with the occurrence of unusual 'exotic' mineral inclusions, geochemical and isotopic characteristics of the Ko center dot ycegiz chromitites replicate superimposed deep mantle processes, recycling and subductionrelated phase transformations.

In the Ordovician limestone of the Thorsberg quarry (South Sweden), about 130 meteorites have been found. Among the extraterrestrial material, several terrestrial Cr-spinels and zircons have been found too. In particular, in the interval 416–447 cm above the Arkeologen bed, terrestrial Cr-spinels, compositionally different from previous studied Cr-spinels of the same sequence, are present. Previous studies on zircon provided depositional ages that range from 464.22 ± 0.37 Ma to 465.01 ± 0.26 Ma. The trace element content of zircons suggests different possible source rocks. In fact, zircons from the oldest ash layer resemble those from dolerite, while those in the youngest layers are similar to zircons commonly found in granitoids, with more than 65% wt. SiO2. The chemistry of Cr-spinels suggests a strong alteration, so that it is difficult to assign them to a specific area, however they recall the chemistry of altered spinels from ophiolitic occurrences (among other possibilities). The geological setting of the Laurentia and Baltica areas, including the description of basalts to rhyolite association and the presence of ophiolitic slices, makes us confident about the derivation of these zircons and Cr-spinels from those areas.