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International audience; Cultural heritage often brings to mind elements like sculptures, paintings, monuments, and buildings as well as archeological objects. Today, underwater heritage and its surrounding environment are also considered part of cultural heritage because communities identify themselves with the natural landscape. This study is focused on a shipwreck belonging to the second half of the 15th century that was discovered in 1998 by chance in the sediments of the Urdaibai estuary, in Urbieta (Gernika, Basque Country), at 4 m underground. A scientific study presented in this work was performed, as this archeological site was absolutely out of context and in need of a preservation and conservation procedure. Therefore, our aim was to shed light on the origin of the shipwreck and to assess the conservation state to develop a precise conservation plan. Pursuing this objective, a first analysis on three selected groups of iron nails was performed, looking at the raw materials and degradation patterns through the knowledge of the alteration compounds. By means of nondestructive analytical techniques such as Raman spectroscopy and X‐ray fluorescence, the presence of iron, zinc, and silicon was detected in the outer layer of the iron samples. The analysis of the nails and wood of the shipwreck confirmed that the presence of zinc in the pieces indicates an important impact of the contaminated sediments deposited in the last 80 years on the upper part of the burial in which the shipwreck was located.

International audience; Alcoholic beverages, especially great wines and spirits, are prime targets for counterfeiters. The simplest form of wine fraud involves fixing counterfeit labels of expensive wines to bottles of less expensive wine. However, time-consuming analytical techniques requiring liquid sampling are mainly used for authentication purposes, which irremediably degrade the value of the bottle. This work aims to develop a new diagnostic tool based on the direct analysis of label matrix and ink in order to obtain valuable information that would enable a preliminary non-destructive authentication. Raman and infrared spectroscopies have been applied for fast, reproducible and discernible molecular characterization since both analytical techniques are strictly non-invasive and do not require sample preparation. They were successfully applied to a selected number of genuine and counterfeited bottles (Pauillac, France) and a series of bottles which goes from 1969 to 2010 belonging to the same producer (Pomerol, France). Raman spectroscopy and infrared spectroscopy showed a great complementarity to clarify the molecular composition of label and inks. As a general overview, pigments are not useful for discrimination purpose in the pairs of original and counterfeited samples. However, several mismatch in label composition were identified, allowing the differentiation among samples. With respect to the second batch of bottles, Raman spectroscopy was able to trace the materials used in labels and inks, giving evidences about the chronologic order of manufacture. Despite the limited number of samples, mainly due to their uniqueness, the classification power of the proposed methodology has been clearly proven.

The development of non-invasive techniques for the characterization of pigments is crucial in order to preserve the integrity of the artwork. In this sense, the usefulness of hyperspectral imaging was demonstrated. It allows pigment characterization of the whole painting. However, it also sometimes requires the complementation of other point-by-point techniques. In the present article, the advantages of hyperspectral imaging over point-by-point spectroscopic analysis were evaluated. For that purpose, three paintings were analysed by hyperspectral imaging, handheld X-ray fluorescence and handheld Raman spectroscopy in order to determine the best non-invasive technique for pigment identifications. Thanks to this work, the main pigments used in Aragonese artworks, and especially in Goya's paintings, were identified and mapped by imaging reflection spectroscopy. All the analysed pigments corresponded to those used at the time of Goya. Regarding the techniques used, the information obtained by the hyperspectral imaging and point-by-point analysis has been, in general, different and complementary. Given this fact, selecting only one technique is not recommended, and the present work demonstrates the usefulness of the combination of all the techniques used as the best non-invasive methodology for the pigments' characterization. Moreover, the proposed methodology is a relatively quick procedure that allows a larger number of Goya's paintings in the museum to be surveyed, increasing the possibility of obtaining significant results and providing a chance for extensive comparisons, which are relevant from the point of view of art history issues.

International audience

The materials used for the building constructions can suffer during their life numerous deterioration processes induced by different anthropogenic and natural factors. For this reason, optimal restoration works are vitally necessary for a correct Built Heritage preservation process. One of the most critical environment is the marine atmosphere (marine aerosol impact following dry and wet depositions) where the climatic conditions are very aggressive. For this reason, the new building materials that will be used for a restoration must be selected taking into account the possible deterioration sources that are present in the vicinity of the building or construction. Among marine aerosol, other factors such as biodeterioration, water infiltrations, physical stress, even pollutants than can be deposited from the surrounding environment must be taken into account. This work is focused on the analytical and physical study of the different building materials used for the restoration works carried out in 2014 in the Tower of La Galea Fortress (Getxo, Basque Country, Spain), a historical construction placed in front of the sea. The analyzed materials were the weathered sandstone (original sandstone) and the one used to replace it (restoration sandstone), as well as restoration joint and rendering mortars. The results presented in this work offered a global idea of the correct material selection, taking into account the different factors that can affect the integrity of the whole building in the future. In order to test the durability of these materials against the surrounding environment, different analyses were carried out. On the one hand, X-ray Diffraction (XRD), Raman spectroscopy and Wavelength Dispersive X-ray fluorescence (WD-XRF) were used for chemical characterization of the materials. On the other hand, Mercury Intrusion Porosimetry (MIP) was used to understand the porous system and the thermal behavior was studied using Infrared Thermography (IRT). Finally, the thermal fatigue test was carried out to determine if temperature cycles could have impact in the structural integrity and aesthetic appearance (i.e. color changes) of these materials during time. Los materiales utilizados para las construcciones de edificios pueden sufrir durante su vida numerosos procesos de deterioro inducidos por diferentes factores antropogénicos y naturales. Por esta razón, los trabajos de restauración óptimos son vitalmente necesarios para un correcto proceso de preservación del Patrimonio Construido. Uno de los entornos más críticos es la atmósfera marina (impacto de aerosol marino después de depósitos secos y húmedos) donde las condiciones climáticas son muy agresivas. Por este motivo, los nuevos materiales de construcción que se utilizarán para una restauración deben seleccionarse teniendo en cuenta las posibles fuentes de deterioro que están presentes en las inmediaciones del edificio o la construcción. Entre los aerosoles marinos, deben tenerse en cuenta otros factores, como el biodeterioro, las infiltraciones de agua, el estrés físico e incluso los contaminantes que pueden depositarse en el medio ambiente circundante. Este trabajo se centra en el estudio analítico y físico de los diferentes materiales de construcción utilizados para los trabajos de restauración realizados en 2014 en la Torre de la Fortaleza de La Galea (Getxo, País Vasco, España), una construcción histórica situada frente al mar. Los materiales analizados fueron la arenisca erosionada (arenisca original) y la que se usó para reemplazarla (arenisca de restauración), así como la restauración de juntas y morteros. Los resultados presentados en este trabajo ofrecieron una idea global de la selección correcta del material, teniendo en cuenta los diferentes factores que pueden afectar la integridad de todo el edificio en el futuro. Con el fin de probar la durabilidad de estos materiales contra el ambiente circundante, se llevaron a cabo diferentes análisis. Por un lado, la difracción de rayos X (XRD), la espectroscopia Raman y la fluorescencia de rayos X dispersiva de longitud de onda (WD-XRF) se utilizaron para la caracterización química de los materiales. Por otro lado, se usó porosimetría de intrusión de mercurio (MIP) para comprender el sistema poroso y se estudió el comportamiento térmico mediante termografía infrarroja (IRT). Finalmente, se llevó a cabo la prueba de fatiga térmica para determinar si los ciclos de temperatura podrían tener un impacto en la integridad estructural y el aspecto estético (es decir, los cambios de color) de estos materiales durante el tiempo.

International audience

International audience

The cave known as La Pena de Candamo (Asturias, Northern Spain) was declared a World Heritage Site by UNESCO in 2008. That same year a comprehensive study of the cave was resumed, which had not been undertaken since its discovery in 1914. Current research being carried out has made it possible to locate a new area decorated with paintings and carvings, and in which evidence of human occupation has also been detected. This area is called the “ Gallery of Batiscias ”, located at the bottom of the cavity next to a small cone of clogged scree that seals off a now-blocked entry from the outside. Dating through Uranium series and 14 C, has enabled us to estimate the chronology of the archaeological evidence located in this area (lithic industry, ochres, bones and carbons), where the artistry was also carried out. Analyses have also allowed us to identify the Palaeolithic access points to this decorated gallery. In this regard, the U/Th Holocene age obtained for the speleothems that seal the corridor connecting the Great Hall to the Gallery of Batiscias indicates that circulation between the two areas was possible in the Palaeolithic age. In addition, the 28 ky dating obtained for the carbonate crust that seals the scree over the exit to the outside from the gallery shows that, as from that moment, access was only possible from the Great Hall .

International audience; During decades the use of gypsum in different buildings has been very common, especially in the Atlantic lands of Europe. Decay compounds like salt crystallizations are ones of the principal deterioration factors of such historical buildings. In this study, gypsum-based plasters from different inner rooms of the Igueldo Lighthouse (San Sebastian, Spain), a building dated back to 1860 that has been subjected to several repairs within these years, were investigated in order to ascertain the main mineral phases produced during the weathering process. A combination of Raman spectroscopy, X-ray diffraction, infrared spectroscopy in ATR mode, SEM-EDS imaging and Raman imaging was successfully applied to study the distribution of different decay compounds in the gypsum-based matrix and to establish the decay reaction pathway which leads to the formation of the identified decay compounds. Additionally thermodynamic chemical modeling was also performed to explain the formation of specific decaying compounds. According to the location of Igueldo Lighthouse (just above a cliff, close to the sea), this building experiments a wide influence of the marine aerosol (Na+, K+, Mg2 +, Cl− and NO3− input) and the influence of a high damp environment, giving rise to common efflorescence salts as well as to different mixed-calcium sulfates and mixed sulfate–nitrate salts, such as glauberite, syngenite, polyhalite and humberstonite. Dehydration process of gypsum from the plaster (leading to the presence of anhydrite and bassanite) was also identified.

International audience; This study was carried out to elucidate the causes of irregularities and discolorations on the surface of parts of a weathering steel sculpture which had been in contact with wood pallets. Non-destructive analysis of the samples by Raman spectroscopy revealed the presence of iron oxalates and calcium oxalates. Thermodynamic modeling suggested that the detected oxalates were produced by the reaction of oxalic acid, a potential metabolite excreted by microorganisms, and elements present in the steel surface such as iron. Carotenoids including β-carotene and astaxanthin, biomarkers for a large number of prokaryotic and eukaryotic microorganisms, were also detected in samples.

International audience; El proceso que va del descubrimiento de una pieza arqueológica a su musealización pasa necesariamente por una fase de restauración. En el caso de piezas de naturaleza metálica la restauración puede comportar la eliminación mecánica de las costras de degradación más externas. Los fragmentos eliminados contienen una gran cantidad de información que, si es extrapolada, puede ayudar a los restauradores a elegir los tratamientos más adecuados de conservación. Por esta razón, con el presente trabajo se pretende desarrollar un nuevo método que permita semicuantificar de manera rápida y fiable las fases de corrosión contenidas en los residuos de limpieza de hierros arqueológicos. Para realizar el trabajo ha sido utilizado el software PALME para el tratamiento de los resultados obtenidos mediante espectroscopia infrarroja (FTIR) sobre mezclas de corrosiones puras a concentración conocida. Gracias a los resultados obtenidos se puede afirmar que el método desarrollado, una vez optimizado, representará una herramienta útil para la rápida semicuantificación de las corrosiones que normalmente afectan los hierros arqueológicos.

International audience; Weathering steel was designed to resist against the atmospheric impact due to the development of a characteristic rust layer that protects the metal by reducing the corrosion rate. This rust layer is formed by different iron (oxy-hydr)oxides that acts as a barrier and provides the protective ability. In order to check the conservation state trough the protective capability, it is necessary to calculate the so-called protective ability index (PAI). It mainly takes into account the ratio (α/γ) between the mass of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH), present in the rust layer of weathering steel. Raman spectroscopy, apart from a qualitative technique, is recently becoming a semi quantitative approach. Therefore, it is a valuable tool for the calculation of the mentioned index. This paper is a widening of a previous work in which it was uncovered a problem in different weathering steel sculptures which are exposed to a Cl− and SO2-rich urban atmosphere because they present different esthetical problems on their surfaces, such as detachments of steel chips, discolorations and irregularities. In order to relate these problems on the surface and the rust layer composition, PAI calculations were performed from the phase identification obtained from Raman imaging and using spectra decomposition to quantify each compounds. Although goethite and lepidocrocite were the most commonly detected compounds, hematite, akaganeite and magnetite were also identified. Hematite is a sub product formed in rich SO2 atmospheres; therefore, a PAI with its content is proposed. Protective indexes obtained for the different artworks exposed in different places provide quantitative clues for the conservation diagnosis of weathering steel structures.

International audience