The legacy of former uranium (U) mining activities led to the dispersion of inherited materials enriched with U-series nuclides and metal-rich minerals. In this study, the fate of U and associated metals i.e., copper (Cu) and lead (Pb) in a wetland located downstream of a former U mining site was evaluated. This assessment was conducted through the identification of U sources in wetland soils, the solid speciation of U and co-occurring metals, and their reactivity under oxidizing conditions.Our results confirmed that the mining materials in the wetland originated from the physical and chemical treatments of two U ores (Bois-Noirs-Limouzat (BNL) and Rophin). The investigation of solid metal-bearing species revealed that, in the pure BNL-inherited layer, U, Cu, and Pb species were associated to amorphous and crystalline Fe oxyhydroxides and clay minerals and to a lesser extent, in the form of U oxides and chalcopyrite. For the Rophin-originated deposits, the absence of crystalline U-inherited minerals was highlighted, with a significant association of U and Pb with organic matter, Fe-bearing species, and/or the clay mineral fraction. These results suggested redistribution from primary to secondary phases during alteration and pedogenesis processes. Deionized water-normalized leaching tests indicated different mass amounts mobilized from the two types of U-mining materials identified. These differences could be attributed to i) the occurrence of redox-sensitive minerals and ii) the presence of organic matter, which led to the formation of secondary higher stable metal species. This study provided new insights into the post-depositional transformation of mining-derived materials and the need to consider the mineralogy of parent materials.

Tourmalines, a complex borosilicate mineral supergroup, are significant in geological studies due to their chemical and mechanical stability across various temperature and pressure conditions, making them useful as source rock indicators. A major issue in the characterization of tourmaline composition is the consideration of the iron oxidation state, which can significantly influence the distribution of elements at each site. This study reports the enhancement of a previous model that correlates Raman spectral parameters of dravite-schorl tourmalines with their composition, taking into account the Fe valence state in Y and Z sites measured through micro-x-ray absorption near edge structure (mu XANES) spectroscopy. Raman spectroscopy was employed in a prior study on these two tourmaline species by correlating peak positions and intensities with differences in the magnesium-iron ratio. However, it was assumed that all iron was in the ferrous oxidation state (Fe2+), which led to a misrepresentation of the Fe3+ content in certain samples. The model has been thus implemented in this work by using mu XANES, enabling the accurate quantification of Fe2+ and Fe3+ in dravite-schorl minerals, hence refining Mg/(Mg + Fe2+) ratios for Raman spectral analysis. Results demonstrate the validity of the correlation between Raman peaks in both the fingerprint and OH stretching regions and the magnesium-ferrous iron ratio. Our research confirms that Raman spectrum analysis is an effective method for recognizing tourmalines from the dravite-schorl series and evaluating their composition, including now the evaluation of the Fe2+ and Fe3+ occupancy. By integrating mu Raman and mu XANES techniques, one can acquire insights into the oxidation state of iron in tourmalines from the dravite-schorl series, thereby enhancing the accuracy of the Mg/(Mg + Fe2+) ratio. The observed linear correlations for P2 peak position, P1/P2 relative intensities, and WOH(3) peak position in the Raman spectrum enable the rapid identification of dravite and schorl tourmalines, as well as the retrieval of relative Mg and Fe2+ contents.

The standard scenario for the origin of jawed vertebrates depicts a transition from benthic grazers to nektonic predators1-3, facilitated by a suite of anatomical innovations, including elaborate sensory systems, a high-flow heart and the integration of jaw-opening muscles with the craniothoracic hinge4-7. However, the lamprey-like internal anatomy8-13 reconstructed for osteostracans, the sister group of jawed vertebrates, seem to lack these gnathostome traits, implying a morphological gap despite phylogenetic proximity. Here, using synchrotron-based X-ray microtomography on the model osteostracan Norselaspis glacialis, we reveal derived gnathostome traits straddling a uniquely ossified head-trunk interface in this jawless fish. The inner ear of Norselaspis shows sensory elaborations (enlarged pars inferior and sinus superior) acquired well before the origin of jaws. As in crown gnathostomes, paired venous drainage channels blood into a high-volume cardiac tract. We also confirm a feature not yet demonstrated in any other vertebrate, to our knowledge: the most anterior trunk nerve extends its single trunk to the pectoral fin. In this respect, our reconstruction challenges the hypotheses14-16 that the gnathostome shoulder evolved from the gill apparatus. Our observations highlight Norselaspis as a prelude to the intercalation of the muscular neck and throat that would power the early jaw apparatus. Therefore, the vertebrate jaw-often considered the functional driver for 'gnathostome' innovations1-3-evolved instead as a follower to the sensory enhancement, increased cardiac output and greater locomotory control now inferred in the jawless sister group.

Bromine (Br) is found in nature primarily as part of inorganic salts, with a significant presence in seawater, and is also found in soil, contributing to its natural occurrence in human and animal diets. As an element in the human body, bromine is essential for health, particularly as a cofactor for the enzyme peroxidase (PXDN). This role is critical for the formation of sulfilimine bonds within collagen IV, which are necessary for basement membrane assembly and proper tissue development. During collagen cross-linking, bromine is released into the extracellular matrix, underscoring its important role in maintaining tissue structure. In our exploratory study, micro- and nano-X-ray fluorescence (XRF) imaging at two different synchrotron beamlines was used to analyse Br distribution in bovine ovarian sections, as well as in human healthy endometrium and ovarian endometriotic lesions. Bromine was found to be widely distributed in both normal ovarian and endometriotic tissues, with maximal concentrations in specific areas corresponding to follicles and vessel walls.

Cuneiform tablets were a primary writing medium in the ancient Near East from the late fourth millennium BCE to the first century CE. Although these clay tablets were durable for daily use, prolonged burial over millennia has made them vulnerable to salt damage. Fluctuations in temperature and humidity cause the migration of salts to the surface of the tablets, damaging them and covering the inscriptions, making the text unreadable. Traditional preservation and restoration techniques, such as firing and tetraethyl orthosilicate (TEOS) treatments, although effective in making the text legible again, cause irreversible physicochemical alterations, compromising the historical integrity of the tablets. To address this issue, we used synchrotron radiation X-ray fluorescence (SR-XRF) spectroscopy to analyze cuneiform tablets covered by salts. This method enabled the recovery of previously unreadable texts without altering the nature of the tablets. Our findings highlight the importance of non-invasive methods for preserving and studying cuneiform tablets, maintaining their physicochemical integrity, and allowing for future analyses.

This work shows that the plastic debris accumulated along with stranded Sargassum biomass in Guadeloupe’s beaches contains different forms of arsenic. Results from synchrotron nano X-ray Fluorescence (nanoXRF) and nano X-ray Absorption Near Edge Structure (nanoXANES) show that arsenate (As(V) in a tetrahedral coordination) present in seawater is complexed in the algae cell walls in an octahedral As(V) form, which is subsequently reduced to As(III) within the algae. Inorganic As(III) is either excreted or may undergo methylation and/or binding to glutathione, which is then stored in the algal cells or excreted. The areas where As is colocalized with a variety of metals (Si, K, Ca, Fe, Ni Cu and Zn) may correspond with areas in which algae tissues remain adhered to the surface of the plastics. On the opposite, the areas in which As is found together with Ti or Cl may correspond with areas in which the algae has been decomposed or in which As has been adsorbed after being secreted by the algae. Results from this study should be taken into account to assess the ecotoxicological impacts of Sargassum biomass accumulated on beaches, as well as for the planning of its valorization. Plastics within the Sargassum biomass can act as vectors for arsenic, facilitating its transfer to other environmental compartments where the biomass is used or when it is ingested by various organisms. In a context of a growing problem of plastic pollution and a more and more frequent algae blooms, these results are particularly relevant.

In palaeontology, the observation of morphological characters is at the heart of species determination. Nonetheless, since most fossils have undergone considerable morphological loss, distortion, and/or flattening throughout their taphonomic history, the use of visual techniques often remains limited. Complementary approaches such as geochemical analyses or molecular palaeontology are increasingly developed. However, them as well remain limited by the preservation state and diagenetic overprinting of the vast majority of fossils. Based on data obtained by state-of-the-art non-destructive synchrotron micro-X-ray fluorescence (µXRF) major-to-trace elemental mapping of Early Triassic Paris Biota fossils, we show here, at least within a single fossil fauna, the existence of a clade-specific elemental signature. Using complete multi-elemental µXRF spectra instead of elemental quantifications/concentrations, we set a data-formatting protocol that allows us to compare the morphology of the spectra. We then statistically demonstrate the existence of a geochemical discrimination between specimens of different clade despite intra-clade mineralogical variability, and build a "elemental-comparative taxonomic identification" model accordingly. The latter, that goes beyond the simple distinction of tissue nature or type of preservation, is all the more important as it appears to hold the potential to identify some hitherto unrecognizable specimens of the fossil record.

Identifying evidence of human modification of extinct animal remains, such as Pleistocene megafauna, is challenging due to the similarity of anthropogenic and non-anthropogenic taphonomic features observed under optical microscopy. Here, we re-investigate a Late Pleistocene ground sloth tooth from northeast Brazil, previously suggested as human-modified based only on optical observation. To characterize the macro- and micro-morphological characteristics of the marks preserved in this tooth and evaluate potential human modification, we used stereomicroscope and scanning electron microscopy (SEM) supplemented by energy dispersive spectroscopy (EDS), UV photoluminescence (UV/PL), synchrotron-based X-ray fluorescence (SR-XRF), and synchrotron micro-computed tomography (SR-µCT). These methods allowed us to discriminate non-anthropogenic taphonomic features (root and sedimentary damage), anthropogenic marks, and histological features. The latter shows the infiltration of exogenous elements into the dentine from the sediments. Our evidence demonstrates the sequence of anthropogenic and non-anthropogenic taphonomic modification of this tooth and supports its initial intentional modification by humans. We highlight the benefits of emerging imaging and spectral imaging techniques to investigate and diagnose human modification in fossil and archaeological records and propose that human modification of tooth tissues should be further considered when studying possibly anthropogenically altered fossil remains.

The chemical in situ study of red coloring matter from Paleolithic cave art is challenging because the same trace elements can be present both in the matter and in the calcitic support, and the two present a heterogeneous composition. In this study, thirteen red iron oxide-based coloring matter samples obtained at drip points coming from eight locations within the Techo de los Polícromos, Altamira cave (Spain), have been analyzed by highly sensitive synchrotron-induced micro-X-ray fluorescence (SR-µXRF). Our analyses improved the characterization of red Paleolithic pigments by establishing characteristic trace element patterns, additionally facilitating a comparison of the distinct representations within the cave. Furthermore, new differentiation criteria between the composition of the calcitic walls and that of the red coloring matter could be established, helping to improve future non-invasive analyses.

Early Palaeozoic sites with soft-tissue preservation are predominantly found in Cambrian rocks and tend to capture past tropical and temperate ecosystems. In this study, we describe the diversity and preservation of the Cabrières Biota, a newly discovered Early Ordovician Lagerstätte from Montagne Noire, southern France. The Cabrières Biota showcases a diverse polar assemblage of both biomineralized and soft-bodied organisms predominantly preserved in iron oxides. Echinoderms are extremely scarce, while sponges and algae are abundantly represented. Non-biomineralized arthropod fragments are also preserved, along with faunal elements reminiscent of Cambrian Burgess Shale-type ecosystems, such as armoured lobopodians. The taxonomic diversity observed in the Cabrières Biota mixes Early Ordovician Lagerstätten taxa with Cambrian forms. By potentially being the closest Lagerstätte to the South Pole, the Cabrières Biota probably served as a biotic refuge amid the high-water temperatures of the Early Ordovician, and shows comparable ecological structuring to modern polar communities.

The recent upgrading of synchrotron radiation (SR) sources has favored, in the last few years, the construction and design of beamlines optimized for the study of cultural heritage materials, which may require ad hoc setups, specific spatial resolutions, and detection limits. In the field of cultural heritage, integrated approaches combining different techniques are often required, even at large facilities, where some beamlines offer the possibility of performing different types of measurements at the same point of analysis, complementing preliminary information usually obtained by conventional laboratory and/or portable in situ methods. An overview of the last ten years of synchrotron applications for the study of pigments is given, with discussion of upstream and downstream challenges to methods and techniques. The possibilities offered by the synchrotron techniques are illustrated by a case study of a particular class of painted ceramics, as an example of different research questions that are solved by a combination of SR-based methods.

Chemical in situ study of red coloring matter in cave art is challenging because characteristic trace elements can be present both in the matter and in the wall support, and the latter has a quite heterogeneous composition.In this study, a stalactite presenting red iron oxide coloring matter from La Garma cave, Northern Spain, has been analyzed with complementary techniques. The aims are, on the one hand, confirming for the first time the feasibility of confocal XRF (CXRF) depth-resolved scans to successfully separate the complex stratigraphy of red prehistoric coloring matter on a calcitic support. On the other hand, finding differentiation criteria and improving the characterization of this red iron-based coloring matter would help understand and virtually separate it from its support, as well as improve future in situ analyses in cave sites.CXRF depth-resolved scans were performed using the LouX3D device available in our laboratory. With this technique, we can precisely determine the chemical depth composition of an object, layer by layer, with a spatial resolution in the micrometer scale. These measurements were combined with a synchrotron induced micro-X-ray fluorescence (SR-µXRF) chemical mapping performed at the PUMA beamline, SOLEIL synchrotron. These highly sensitive measurements not available with any other non-destructive lab-based technique allow seeing a greater number of trace and minor elements associated with Fe. Complementing them with the direct depth-resolved information given by CXRF, it was possible to find differentiation criteria distinguishing the wall support and the coloring matter, finely characterize this red iron-based matter, and confirm the feasibility as well as the advantages of applying CXRF for the non-invasive technical study of prehistoric cave figures.

The PUMA beamline, created for the heritage community and accessible by all fields of science, welcomed its first users in 2019. Its optical layout uses a horizontal focusing mirror to prefocus the light emitted from the wiggler source for the experimental endstation. It provides a 5 µm × 7 µm microbeam for XRF, XAS, XRD and XEOL analysis or a wide 20 × 5 mm full field when the beam is defocused, and the KB mirrors are retracted. An extremely stable fixed-exit Si(111) monochromator is used to select the wavelength. Many experiments have been performed at PUMA, particularly in archaeology, paleontology, conservation, art history and in identifying safer conditions of irradiation for precious heritage samples. XRF analysis has been used, for example, to show the effects of the interaction of Palaeolithic ivory with soil; to identify the elemental composition of mineralized textiles and to reveal hidden morphologies of fossils.

Looting and plough damage to the eighth–fifth centuries BC tumulus of Creney-le-Paradis, France, hinders interpretation of this potentially significant site. Nevertheless, application of novel microtomographic techniques in combination with optical and scanning electron microscopy allows the first detailed examination of 99 textile fragments recovered from the central pit. The authors argue that the diversity of textiles revealed—at least 16 different items—and the quality of weaving involved confirm earlier interpretations of the high status of this burial, which is comparable, at least in terms of textiles and metal urns, with other ‘aristocratic’ tombs of the European Iron Age.

Managing reservoir sediments remains challenging due to their propensity to significantly sequestrate trace elements. Moreover, many artificial reservoirs were located downstream of former mining sites. However, the knowledge of the exact trace element speciation and its fate in sediments submitted to reoxidation and drying events, such as dredging operations, is still limited.In this study, we examined the degree of contamination and solid speciation of trace elements and radionuclides in case of lake sediments dredging influenced by former mining activities. Finally, to assess the consequences such management i.e., dredging, by mimicking drying and oxidizing conditions, Toxicity Characterizing Leaching Procedure (TCLP) tests combined with parallel chemical extractions and mineralogical analyses were performed.Our results showed enrichments for Cu, Sn and Bi related to the former extractions activities of Charrier Cu–Sn mining site, as well as an enrichment for U partially due to the Bois-Noirs-Limouzat U mining site, in lake sediments. Moreover, the reoxidation and drying of initially anoxic sediments led to metal solid speciation dominated by: (i) Cu and Bi inherited sulfide minerals such as chalcopyrite, (ii) Cu, Bi and U associated with natural organic matter, and (iii) large grain-size refractory cassiterite SnO2 crystals. Additionally, results from the TCLP indicated a limited leachability of the studied elements, confirming the significant stability of U, Cu and Bi associated with natural organic matter. Finally, Cu and U concentrations extracted by TCLP are lower than threshold values indicating that these sediments are not considered as hazardous regarding these elements.