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The Ychsma society was one of the most important civilizations developed between 900 and 1532 CE in Lima, the present Peruvian capital, situated on the central coast of Peru. The Ychsma territory included the lower basin of the Rímac and Lurín valleys in the current city of Lima (Peru). Around 1470 CE, the Ychsma region was conquered and placed under the control of the Inca Empire, which ruled the region until the Spanish conquest in 1532 CE. Despite this, the Inca rule allowed local elites to maintain their position and control of the population. The archaeological site of Armatambo was an important administrative center of the Ychsma society. This site was actively occupied during the Middle Ychsma (1250–1350 CE) and Late Ychsma (1350–1532 CE) phases, and as the capital of the Sullco Curacazgo controlled a large part of the lower Rímac valley. During excavations at this site, many materials associated with ceramic production were found. One aspect crucial to the study of ceramic materials is the reconstruction of ceramic production and distribution networks, which allows us to obtain information linked to the social and economic interaction between communities. To determine the local or non-local origin of the materials found at Armatambo, 61 samples were analyzed using ICP-MS, Petrography, and SEM. The results were compared with archaeological and geological data from the Rímac valley to determine whether or not production there was local or non-local and to identify possible sources of raw materials. The authors would like to acknowledge the funding granted by IDEX-Bordeaux which allowed the realization of the doctoral project. The funding of the Euroregion Nouvelle-Aquitaine/Euskadi-Navarra for the mobility funding (Dossier n°60161). Javier G. Iñañez thanks the Spanish Ministry of Economy and Competitiveness for a Ramon y Cajal contract (RYC-2014-16835).

The Mars Sample Return (MSR) is a near future mission to return samples from the surface of Mars to the Earth. The field operations to carry out data collection, selection of the samples, and sampling procedure, mainly related to the CanMars MSR analog mission, are well-studied and published. In contrast, studies related to the methodology implemented to characterize the mineralogy of the returned samples are scarcer and focused on biosignature detection. This work presents a non-destructive analytical methodology based on Raman microscopy (single point and imaging), micro-energy dispersive X-ray fluorescence imaging analysis, and scanning electron microscopy coupled to energy dispersive spectroscopy that could be used as a first analytical characterization for the Martian samples that will be returned to the Earth in the upcoming MSR mission, before any destructive analysis. The analytical methodology has been tested on a fragment of the Northwest Africa 1950 Martian meteorite, which gives us a mineralogical characterization of the meteorite. This methodology also allowed to define several chemical reactions taking place in some of the mineral phases (olivines and ilmenite) of the meteorite. In addition to the geochemical characterization of the samples, the fact that this methodology allows to assess the chemical transformations in several minerals gives important clues for describing mineral processes and geological evolution that took place on Mars. This work also shows the advantages and disadvantages that each of the techniques employed has when performing a mineralogical characterization, the information that each one can provide and the importance of combining them. This work has been financially supported through the RamOnMars project: “Contribution of the Raman spectroscopy to the exploration of Mars and Martian Moons: ExoMars, Mars 2020, and MMX missions” (Grant ESP2017-87690-C3-1-R), funded by the Spanish Ministry of Science and Innovation (MICINN) and the European Regional Development Fund (FEDER) and by the Spanish Agency for Research (AEI-MINECO/FEDER) through the Project Science and Instrumentation for the Study of (bio)geochemical processes in Mars (Sigue-Mars), Grant no. RED2018-102600-T. C. García-Florentino is grateful to the Basque Government for her Postdoctoral Grant. J. Huidobro is grateful to the Basque Government for her Predoctoral contract. I. Torre-Fdez acknowledges his predoctoral contract from the University of the Basque Country (UPV/EHU). J. Aramendia is grateful to the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 754513 and The Aarhus University Research Foundation for her fellowship. The authors thank the General Service of Electron Microscopy and Materials Microanalysis Laboratory from the SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) of the University of the Basque Country for their collaboration in the analyses.

Introduction Jarosite (KFe3(SO4)2(OH)6) was found by rover Opportunity in Martian surface at Meridiani Planum as well as by Spirit at Gusev crater. This mineral needs specific conditions to be formed, such as acid pH and oxidant environment1. In addition, this mineral has been found in meteorites, related to other compounds like olivine, goethite or gypsum. There are different hypothesis for the formation of jarosite from olivine. Hereunder, two of them are exposed. The first one described the jarosite formation in nakhlite meteorites, when the olivine transform to iddingsite. Iddingsite is a mixture formed by smectite clays, iron oxides and ferrihydrite2. Besides, some studies propose that jarosite forms part of iddingsite3. The formation of jarosite from olivine in iddingsite phase can be explained by the dissolution of the latter. The minerals formed depend on pH and the ions present in the solution. The formation of jarosite can be explained by these reactions, considering an olivine with 1.8 proportion of Mg and 0.2 of Fe4 which is dissolved in acid conditions (reaction 1). To form jarosite, the cation Fe2+ must be oxidized to Fe3+ (reaction 2). Finally, this Fe3+ can react with dissolved sulphate to form jarosite. Depending on the presence of other cations in the solution, different types of jarosite can be formed. Other hypothesis5 proposed for the formation of jarosite can be made considering that in the history of Mars there were cold and dry climate periods. Moreover, in Mars there was also a high volcanic activity that formed sulphate-rich deposits. Considering this, Niles et al.5 suggested that olivine grains in Martian surface could form Fe-rich sulphates, as jarosite, if they were exposed to H2SO4 rich aerosols at temperatures around -40 °C (cryogenic conditions). The cations needed to form jarosite could be incorporated from different minerals, being olivine the most important source5. In Martian nakhlite Miller Range 090030 (MIL 090030), jarosite has been found next to olivine and rasvumite (KFe2S3) recurrently. This fact, lead to the assumption that they were related. However, to this day, no explanation for the presence of jarosite together with rasvumite and olivine has been proposed. In this study, a hypothesis for an alternative formation of jarosite is made based on Raman image analyses carried out on the MIL 090030 Martian meteorite. Materials and method A thick slide of the MIL 090030 meteorite was analyzed by means of Raman spectroscopy image. For this aim, an inVia confocal micro-Raman spectrometer, provided with 785 nm and 532 nm excitation lasers and CCD detector, was used coupled to HR StreamLine Imager. Results and discussion After detecting all minerals around olivine grains in the bulk of the meteorite, the distribution of the different mineral phases can be obtained using Raman image. In this way, Figure 1 shows the mineral distribution of a rasvumite/jarosite rich region in MIL 090030. Moreover, it can be appreciated how jarosite and rasvumite are surrounded by magnetite and cristobalite. Figure 1. Raman image performed on the MIL090030 meteorite in a rasvumite/jarosite rich region. Based on the findings detected in the analysed MIL 090030 fragment, the formation of jarosite from olivine and rasvumite is proposed following these four reactions: On the one hand, rasvumite could react with H2O and O2 from Martian atmosphere to form magnetite (Fe3O4) (reaction 4). The soluble ions formed can arrive to other zones of the Martian surface travelling through cracks and pores. The protons formed in reaction 4 can dissolve partially the olivine giving rise to an olivine richer in forsterite (reaction 5). The SiO2 formed can be dissolved in water to form H2SiO3 or H4SiO4. This solution can then precipitate as quartz when water evaporates. On the other hand, rasvumite can react also directly with H2O and O2 to form jarosite and free sulphate anion (reaction 6). Sulphate anions formed in reactions 4 and 6, can interact with iron cations from reaction 5 and potassium cations from reaction 4 to form jarosite (reaction 7). The high pressures and temperatures reached during the impacts suffered by the meteorite can alter some minerals present in the meteorite. In the MIL 090030 meteorite, quartz was not detected. Instead of this mineral phase, its high temperature and pressure polymorphs (cristobalite, coesite and stishovite) were detected in the rasvumite/jarosite rich region. The presence of these polymorphs indicates that the reactions 1-4 occurred in Mars. Conclusions According to the mineral distribution in MIL 090030, based on Raman image results, an explanation for the formation of jarosite from olivine and rasvumite is proposed. This formation is related to reactions of rasvumite with Martian atmosphere compounds and dissolution of olivine from the Martian surface. Acknowledgments: Authors are grateful to NASA for accessing to the MIL 090030 Martian meteorite sample through the loan agreement between NASA's JSC and the UPV/EHU. This work has been funded by the “Raman On Mars” project (Grant No. PID2019-107442RB-C31), funded by the Spanish Agency for Research (MICINN and the European Regional Development Fund), and the “Study of Alteration Processes in Terrestrial and Planetary materials” strategic project (ref. PES 21/88), funded by the University of the Basque Country (UPV/EHU. Bibliography: 1) Papike, J.J., Karner, J.M., Shearer, C.K.: Comparative planetary mineralogy: implications of martian and terrestrial jarosite. A crystal chemical perspective, Geochim. Cosmochim. Acta., Vol. 70, pp. 1309-1321, 2006. 2) Swindle, T.D., Treiman, A.H., Lindstrom, D.J., Burkland, M.K., Cohen, B.A., Grier, J.A., Li, A., Olson, E.K.: Noble gases in iddingsite from the Lafayette meteorite: evidence for liquid water on Mars in the last few hundred million years. Meteorit. Planet. Sci., Vol. 35, pp. 107-115, 2000. 3) Noguchi, T., Nakamura, T., Mizawa, K., Imae, N., Aoki, T.,Toh, S.: Laihunite and jarosite in the Yamato 00 nakhlites: Alteration products on Mars? J. Geophys. Res., Vol. 114, 2009. 4) King, H.E., Plümper, O.,Geisler, T.,Putnis, A.: Experimental investigations into the silicification of olivine: Implications for the reaction mechanism and acid neutralization. Am. Min., Vol. 96, pp. 1503-1511, 2011. 5) Niles, P.B., Michalski, J., Ming, D.W., and Golden, D.C. Elevated olivine weathering rates and sulphate formation at cryogenic temperatures on Mars. Nat. Commun., Vol. 8, 2017.

Introduction It is widely known that ionic compounds are hardly detected by Raman spectroscopy. Ionic bonds provide weak or no Raman signal under normal conditions but recent studies [1] have demonstrated that at high pressures and high temperatures quality Raman spectra can be obtained. Unfortunately, high pressures and temperatures change the structural composition of the sample to analyze. This is not the best option when the aim of the analysis is to characterize an unknown sample. The characterization of ionic compounds such as chlorides is gaining strength in the space exploration field. For instance, in Mars surface phenomena linked to the past presence of water the characterization of chloride bearing deposits is crucial. The molecular characterization of these deposits could provide information about climate, water history and deposition dynamics [2, 3]. Moreover, in the study of terrestrial analogues it is also important in order to ascertain the capability of different compounds to preserve microorganisms, as a background science for Mars exploration. Considering that Raman spectrometers were sent for the first time to the Mars surface onboard Perseverance Rover (MARS2020 mission), an effort to counter the weaknesses of this technique results worthy, even more, if it is focused on the resolution of key issues for Mars exploration. In this way, in this work an indirect way to detect the presence of chlorides using the water molecules as a traceable Raman fingerprint is provided. Materials and methods For the mentioned aim, a terrestrial brine sample was used as an analogue of a Mars chloride-bearing deposit. In addition, some hydrated chlorides standards such as MagCl2∙6H2O, CaCl2∙2H2O, FeCl3∙6H20 were also analyzed. In order to understand the contribution in the Raman signal of the major chloride in the sample, a standard of NaCl was also measured by Raman spectroscopy. Finally, a gypsum standard was considered for the work as it was the main Raman signal obtained in the analysis of the sample. For the analysis, a Renishaw InVia Raman confocal microscope was employed provided with several excitation lasers (532, 633 and 785 nm lasers) and a CCD detector. Its high spectral resolution (up to 1 cm-1) allowed obtaining high quality results. The measuring conditions were optimized at 20 seconds and 2 accumulations to obtain a good signal to noise ratio for the sample as well as for the analyzed standards in order to carry out fair comparisons. Results As expected, Raman spectroscopic analyses performed on the brine samples did not provide any signal of the major compounds present in the sample which were mainly chlorides. Instead of that, the only detectable Raman signals were the bands for gypsum. The transparency of the major compounds allows the detection of a minor compound as it is the gypsum. However, it does not provide a complete characterization of the sample. Considering this, an indirect identification through the presence of water molecules detected by the mentioned technique was tested. First of all, the band area for the –OH region was measured for the sample Raman spectra. Then, as the gypsum was the only detected signal, a gypsum standard was measured in order to compare the –OH region area with the sample one. In this way, it was observed that the gypsum water molecules did not contribute enough to explain the area present in the sample spectrum. Therefore, by the comparison of the –OH region, a clear input of other hydrated phases to the –OH signals was observed in the sample. Taking into account that NaCl was expected to be the main compound in the analyzed sample, analysis of a NaCl standard was also performed. In this way, it was confirmed the lack of Raman signal even on the –OH region as it was not hydrated. Thus, the lack of signals in the Raman region of the spectrum (different to that of gypsum), indicated that this extra –OH input belonged to other ionic hydrated species. Several hydrated chloride standards were analyzed in order to evaluate their contribution in the –OH region. The contribution of the –OH band area of the analyzed compounds fit perfectly the –OH band area obtained for the sample. In this way, it was confirmed by Raman spectroscopy that other hydrated chlorides were present in the sample (Figure 1). Figure 1. Raman spectra of a brine sample (3_bs) in green, NaCl in red, CaCl2 2H2O in purple and MgCl2 6H2O in cyan. Conclusions Raman spectroscopy has been found as a successful technique to detect hydrated chlorides in brine samples. An accurate identification of the compounds was not possible yet but an indirect unambiguous methodology to detect their presence in a complicated sample is presented in this work. Raman spectroscopic analyses performed on hydrated chloride standards provide some broad and overlapping Raman bands. Nevertheless, the spectra obtained for the real sample did not present those bands. Therefore, the methodology presented on this work can be very useful. References [1] Tian Y., Xiao W., He Y., Zhao H., Jiang F., Tan D., Chen M., Raman spectroscopy of sodium chloride under high-pressure and high-temperature. 2019, https://doi.org/10.48550/arXiv.1903.11824 [2] Leask E. K., Ehlmann B. L., Evidence for Deposition of Chloride on Mars From Small-Volume Surface Water Events Into the Late Hesperian-Early Amazonian. AGU Advances 3, e2021AV000534, 2022. [3] Uriarte L. M., Dubessy J., Boulet P., Baonza V. G., Bihannic I., Robert P. Reference Raman spectra of synthesized CaCl2 ·nH2O solids (n=0, 2, 4, 6). Journal of Raman Spectroscopy 46, 822–828, 2015. Acknowledgements This work has been funded by the “Raman On Mars” project (Grant No. PID2019-107442RB-C31), funded by the Spanish Agency for Research (MICINN and the European Regional Development Fund), and the “Study of Alteration Processes in Terrestrial and Planetary materials” strategic project (ref. PES 21/88), funded by the University of the Basque Country (UPV/EHU.

A lunar feldspathic breccia meteorite, the Northwest Africa (NWA) 11273, was analyzed to compensate the lack of scientific data available about its mineralogy and geochemistry. In order to obtain a deeper characterization of the sample, a strategy based on the combination of nondestructive spectroscopic techniques such as X-ray fluorescence and Raman spectroscopy is used. Both techniques are being used in spatial missions by the Perseverance Rover, so their combination in the laboratory is here proposed as an optimal strategy to study the complete mineralogy of the sample. In addition to finding the minerals indicated by the Meteoritical Society (anorthite, olivine, pyroxene, kamacite, and troilite), other minor minerals were identified, such as zircon and ilmenite, which are minerals related to the Moon geology, as well as calcite and sulfate which can be considered products of terrestrial weathering. Finally, secondary minerals related to alteration processes were also found, such as hematite, quartz, and anatase. In this work, the alteration processes that gave rise to the detected secondary minerals have been proposed.

Calcium sulfates are known to be potential reservoirs of organic compounds and have been detected on Mars. However, not all data that indicate the presence of sulfates collected by the Mars Exploration Rovers (Spirit and Opportunity) and Curiosity rover can be explained by the different calcium sulfate polymorphs, and therefore, mixtures of calcium sulfates with other single sulfates must be considered. In addition, the presence of mixed calcium sulfates supports the data and indicates that the molar ratio of sulfate/calcium is1. To obtain adequate spectroscopic information of mixed-cation sulfates to be used in the interpretation of data from Mars in the next few years, the thermodynamically stable syngenite (K

The toxicity and the health risk assessment associated to the presence of some hazardous elements (HEs) in dried (infant formula and powdered) milks due to manufacturing and packaging process, raw materials used, environmental conditions, etc. need to be determined. With this aim, a new methodology based on the combination of health risk quotients and non-supervised (as cluster analysis (CA) and principal component analysis (PCA)) chemometric techniques is proposed in this study. The methodology was exemplified using the concentration of 27 elements, some of them HEs, measured in 12 powdered milk samples produced for children and adults in Brazil and Colombia. The concentration values were obtained by inductively coupled plasma-mass spectrometry (ICP-MS) after acid microwave digestion. Elemental concentrations vary depending upon the type of milk (initiation, growing-up, follow-on milks and adult milks). However, hazard quotients (HQ) and carcinogenic risk (CR) values showed no risk associated to the presence of HEs on milks. The methodology designed made possible to conclude that adults' milks are more characteristic of elements naturally present in milk. Children milks present major presence of trace and minor elements. Between infant milks, sample H, designed for babies between 12 and 36 months, was identified as of poor quality. Moreover, it was possible to deduce that while the fortification process applied to children powdered milks is a probable metal and metalloid source, together with the manufacturing, the skimming process is not a contamination source for milks. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has been financially supported by the Basque Country government through the Consolidated Research Group Project ref. IT-1213-19.

[EN] The study of space has always been a field of great interest and thus space missions are becoming more and more ambitious with time. Therefore, with the 50th anniversary of the first spacecraft to land on Mars, a review about how traditional analytical techniques have been adapted to the era of in situ space exploration is presented. From the Viking Project to the future MMX mission, the techniques used for the in situ study of the geochemistry of the Martian surface is described. These techniques have been differentiated according to the type of analysis: elemental and molecular. On the one hand, among the elemental analytical techniques the XRF, APXS, ISE and LIBS stand out. On the other hand, GCMS, TEGA, MBS, XRD, Raman and IR spectroscopy have been the molecular techniques used in the missions to Mars. Miniaturization, real-time measurements, automation, low power consumption and reliability of operation under extreme conditions are some of the major challenges that analytical chemistry has faced as a result of the technological and scientific requirements of space missions. In this way, this review gathers all the in situ analytical techniques that have reached the surface of Mars onboard landers or rovers with the aim of studying its geochemistry. J. Huidobro is grateful to the Basque Government for her pre-doctoral contract. J. Aramendia is grateful to the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 754513 and the Aarhus University Research Foundation for her fellowship.

[EN] Nowadays, miniaturization and portability are crucial characteristics that need to be considered for the development of water monitoring systems. In particular, the use of handheld technology, including microfluidics, is exponentially expanding due to its versatility, reduction of reagents and minimization of waste, fast analysis times and portability. Here, a hybrid handheld miniaturized polymer platform with a paper-based microfluidic device was developed for the simultaneous detection of nitrite and nitrate in real samples from both, fresh and seawaters. The platform contains an ionogel-based colorimetric sensor for nitrite detection and a paper-based microfluidic device for the in situ conversion of nitrate to nitrite. The platform was fully characterized in terms of its viability as a portable, cheap and quick pollutant detector at the point of need. The calibration was carried out by multivariate analysis of the color of the sensing areas obtained from a taken picture of the device. The limits of detection and quantification, for nitrite were 0.47 and 0.68mgL-1, while for nitrate were 2.3 and 3.4mgL-1, found to be within the limits allowed by the environmental authorities, for these two pollutants. Finally, the platform was validated with real water samples, demonstrating its potential to monitor nitrite and nitrate concentrations on-site as a first surveillance step before performing extensive analysis. This project has received funding from the European Union Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241. The funding support from Gobierno de España, Ministerio de Ciencia y Educación de España” under grant PID2020-120313 GB-I00/AIE/10.13039/501100011033, and Gobierno Vasco Dpto. Educación for the consolidation of the research groups (IT1271-19) are also acknowledged. RC-C acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 778001. Special thanks to (SGIker) of the University of the Basque Country (UPV/EHU). FB-L and LB-D acknowledge the “Red de Microfluídica Española” RED2018-102829-T.

1. Introduction Olivine, (Mg, Fe)2SiO4, is a mineral composed of the two endmembers of its solid solution series: forsterite (Fo, Mg2SiO4) and fayalite (Fa, Fe2SiO4). It is a silicate mineral present in Mars usually alongside with plagioclase and pyroxene, as they are all present in basalts and igneous rocks. The forsterite and fayalite proportions in the olivine is a key factor in order to study this type of rocks. Active and upcoming Mars missions will study areas of ancient Mars using, among others, Raman spectroscopy in the instrumental payload, being a relevant technique for space exploration. There are several papers proposing Raman spectroscopy to quantify the ratio Fo/Fa based on the wavenumbers of the two most intense bands. However, the proposed calibration models have an uncertainty of around 10 %, too high to obtain reliable conclusions form the studied samples. In this work a new model that greatly improves the accuracy and uncertainty is presented. 2. Data set A collection of Raman spectra from olivines with a known composition was collected to develop a calibration model for the determination of the metallic content (Mg, Fe) of the mineral. The collection included 64 data points from 14 different research papers where different Raman instruments and acquisition parameters were used, which eliminates any possible bias that the instrumentation could introduce in the model. In addition to the set of olivines used for the calibration, a commercial pure olivine of known metallic concentration, Fo89.5±1.8Fa10.5±0.5, was used as the standard to validate the proposed models. This olivine was analyzed by WD-XRF and its mineral purity was checked by XRD. The Raman measurements were carried out with an Invia High Resolution micro-Raman spectrometer (Renishaw, UK) instrument, using a 532 nm excitation laser with a spectral resolution of 1 cm-1. 3. Results and Discussion Two different regression curves were developed to characterize the olivine concentration ratio by Raman spectroscopy using their two main Raman features (OB1, 812-825 cm-1, and OB2, 837-857 cm-1). These regression curves with their residuals can be observed in Figure 1 and Figure 2 and their equations are shown in Equation 1 and 2, respectively. The two red lines depicted in the calibration curve plots represent the calculated confidence interval for all the data at a 95 % confidence level. OB1 (cm-1) = 3.63·10-4·Fox2 + 0.0667·Fox + 814.2 (Equation 1) OB2 (cm-1) = 3.00·10-4·Fox2 + 0.142·Fox + 839.6 (Equation 2) As can be observed, all the data used to develop both models fit inside the confidence interval, which implies that there are not outliers among the set of data used. Regarding its quality parameters, the determination coefficient (r2) obtained for the quadratic regression models expressed in Equation 1 and 2 are 0.970 and 0.984, with a typical error of ±0.61 and ±0.73, respectively. The uncertainties in both residual plots scattered randomly, without showing any trend. In addition, all the points are equally distributed around the zero horizontal line and all of them are at the same range of distance from it. All of these facts implies that the proposed models for the data set used are the correct ones and that the model’s predictions should be correct on average, rather than systematically too high or too low. In order to check the accuracy of the two models, the standard commercial olivine described above was used (Fo89.5±1.8Fa10.5±0.5). The concentrations obtained using the OB1 and OB2 models can be observed in Table 1. As observed, the OB1 and OB2 forsterite confidence interval results overlap perfectly with the real concentration confidence interval, which means that the predicted concentrations with these two models were correct. In addition to the standard olivine, the calibration models were tested using the 64 data values that were used for their development. The wavenumber position of OB1 and OB2 were introduced in the respective regression curves and the forsterite value corresponding to each value was calculated. On average, it was observed that the OB1 model had better accuracy for the forsterite rich olivines, while the OB2 model was better for the fayalite rich olivines. Thus, as a good compromise solution, the best alternative would be to always use both models and to average their result, independently on the forsterite and fayalite concentrations of the mineral. This method was tested with the standard olivine, obtaining an uncertainty of ±2.1 % for the forsterite content and of ±2.0 % for the fayalite one. Uncertainties given with the 95 % level of confidence using expanded uncertainty (k=2). The proposed equations have been applied in the study of several Lunar and Martian meteorites where olivine is present. In the NWA 11273 Lunar meteorite olivine ranged from Fo56Fa44 to Fo83Fa17, a little bit broader than the values summarized in the Meteoritical Bulletin. In the NWA 10628 Martin shergottite, the Raman bands only showed the presence of fayalite, in agreement with the data from the Meteoritical Bulletin, while the Martian shergottites RBT 0462 gave a short range (Fo9.1±0.1Fa90.9±0.1), NWA 1950 a broader range (Fo60Fa40 to Fo80Fa20) and the DaG 735 the most extended range (Fo53Fa47 to Fo80Fa20). 4. Conclusions The study of olivines by the active and upcoming Mars missions could provide very relevant information about the evolution of the geology of Mars. One of the key parameters of this mineral is its metallic content, in other words, the ratio of forsterite and fayalite that compose them. In this work, a method to calculate that ratio by averaging the results of two calibration models that use the two main Raman bands of the mineral is proposed. With this method, an uncertainty of only 2 % is achieved, which is a significant improvement over the models already developed in literature, which have an uncertainty of around 10 %. With this model, it should be possible to provide an accurate olivine metallic characterization for the olivine Raman spectra that are found on Mars.

Introduction The recently landed Perseverance rover from the Mars2020 mission is the first rover to select samples with the future objective of taking them back to the Earth in the Mars Sample Return future mission. Until then, Martian meteorites are still the only samples that we have on Earth to study the composition and formation of Mars. Due to the scarce abundance and the importance of these samples, the development of non-destructive characterization methodologies is of great importance. In this case, the Martian Shergottite NWA1950, considered one of the less studied Martian meteorites, has been selected with the double objective of performing the characterization of its original and altered minerals and of contributing to ascertain the degradation reactions. Experimental Instead of using the classical methods of analysis, a non-destructive analytical methodology that make use of spectroscopic techniques has been used. This approach could also be employed to study other meteorites or even in the future returned samples from Mars. The analytical methodology proposed is mainly based on the effectiveness of Raman microscopy for the molecular characterization, assisted by Energy Dispersive X-Ray Fluorescence (ED-XRF) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) to clarify the distribution of elements in the sample. In addition, Raman microscopy and µ-ED-XRF imaging analyses also allows performing the characterization of the whole surface of the meteorite obtaining the molecular and elemental distributions maps respectively. Results and Discussion The applied methodology on the NWA1950 sample showed a main matrix composed of pyroxenes and olivines. The identification of pyroxenes showed the presence of both, ortopyroxenes (low in Ca) and clinopyroxenes (high in Ca). Different olivines with different proportions of fayalite (Fe2SiO4):forsterite (Mg2SiO4) were detected by Raman, specifically olivines varying from 63 to 77% of Mg content. The study of the olivines also showed different degradations on them. The most common degradation suffered by the olivines was the oxidation of part of the iron(II) resulting in the identification of hematite (Fe2O3) grains over olivines enriched in Mg content due to the partial Fe loss after its oxidation. In other cases, the oxidation of the iron present in the olivine lead to the formation of magnetite (Fe3O4). Both reactions should lead also to the formation of silica (SiO2) and this study has identified vitreous silica by Raman spectroscopy in the olivines with less than 69% Forsterire. This observation may indicate the initial oxidation of the olivine occurred on Mars and therefore the quartz was transformed into vitreous silica due to the high temperatures and pressures suffered by the meteorite after the shock. Among the minor compounds, it is important to highlight the presence of ilmenite (FeTiO3). In this case, the Raman bands obtained for ilmenite are shifted to higher wavenumbers than the theoretical ones. This may be indicative of a shocked Ilmenite, subjected to the high pressures of the ejection, and therefore indicating its possible Martian origin. In addition, Ilmenite can be oxidized into TiO2 that can appear as different polymorphs, rutile and anatase mainly. In this case, the identified polymorph was anatase that is formed at low temperatures, indicating that anatase is not an alteration compound from Mars but rather a terrestrial alteration mineral formed after the oxidation of ilmenite once the meteorite was on Earth. Merrillite (Ca9NaMg(PO4)7) was also detected as an important mineral phase in this meteorite. The elemental calcium and phosphorous ED-XRF distributions can be appreciated in Figure 1, showing the overlap between these two elements, matching perfectly with the molecular Raman distribution of merrillite in one of the faces of the meteorite. Figure 1. ED-XRF elemental distribution maps of Ca and P, showing in orange the overlaping of both elements (top) and the Raman image showing the molecular distribution of merrillite (down). Iron chromites (FeCr2O4) were also detected, by means of Raman and SEM-EDS microscopic techniques, as abundant particles distributed all along the surface of the meteorite by means of Raman and SEM-EDS. Two different calcites were identified by Raman microscopy. One of them is due to the presence of terrestrial calcite with its main characteristic band at 1086 cm-1. However, most were shocked calcites due to the shift of the main Raman band to higher wavenumbers (to 1088 and even to 1089 cm-1), suggesting again the effect of the pressure that suffered the meteorite and thus showing the Martian origin of these shocked calcites. The non-shocked calcites should be considered as terrestrial weathering compounds. Finally, some sulfides were identified as chalcocite (Cu2S) and acanthite (β-Ag2S) by means of Raman and SEM-EDS microscopy. The origin of acanthite cannot be confirmed as Martian because if argentite (α-Ag2S), the high temperature stable phase of silver sulfide, was formed during the harsh conditions that suffered the meteorite during its ejection from Mars, the formation of argentite is reversible when the pressure ceases, and after the entrance in Earth atmosphere, the acanthite will be formed again. Conclusions As can be seen, the employed analytical methodology allowed us to characterize the original Martian mineral composition of the meteorite as well as the presence of alterations minerals originated in Mars but also after terrestrial weathering processes. In none of the analyses the sample was manipulated or treated chemically nor physically, all the measurements were performed over the surface of a thin section of the meteorite. Therefore, the same non-destructive analytical methodology could be followed for the characterization of other meteorites from other origins and also for the Mars samples when they are back on the Earth as first non-destructive characterization step that can lead to much information.

The Nerbioi-Ibaizabal estuary (Bilbao, Basque Country) suffered an important input of contaminants, including metals and metalloids, between 1875 and 1975. We collected sediments in the tidal part of the river in January 2018 and measured the concentrations of 27 elements in them. At that time, two important construction works were taking place in the area: the extension of the commercial port and the opening of long semi-closed channel. Comparing the current metallic hotspots with the geographical distribution of elements in previous years (2009, 2010 and 2014) showed us that these works seem to have significantly influenced the distribution of toxic elements in the estuary, even if the critical point of the second one is still to arrive with the inundation of the connection to the mainland. Long term pollution monitoring reveals as a powerful tool to check the effects of ongoing engineering works in estuarine environments.

Punta Begoña Galleries, built in 1918 and located in the municipality of Getxo (Bizkaia, Spain) have a remarkable glazed ceramic decoration, whose current state of conservation presents an advanced level of deterioration. The study of the historical cultural property is framed within a multidisciplinary project, which aims to restore, recover and improve its historical and artistic value. In this sense, the recovery of the ceramic tiles is one of the crucial points, since it involves one of the visually most notorious elements. On the surface of the tiles, different degradations were observed, being the yellowish patina, one of the most significant.In order to carry out a cleaning treatment, the nature of the patina was evaluated, whose coating is a consequence of atmospheric contamination, as the chemical analyzes showed. Furthermore, a comparison was performed among four reactants both applied in reproduced pieces and in situ. To evaluate the effectiveness of the products, a quantitative evaluation was applied by colorimetry.In addition, this work shows an interdisciplinary methodology based on the scientific method as the best guide to achieve durable, safe and effective restoration methods. Resumen: Las Galerías Punta Begoña, construidas en 1918 y ubicadas en el municipio de Getxo (Bizkaia, España) poseen una destacable decoración de cerámica vidriada, cuyo actual estado de conservación presenta un avanzado nivel de deterioro. El estudio del inmueble histórico cultural está enmarcado dentro de un proyecto multidisciplinario, que tiene como fin restaurar, recuperar y mejorar su valor histórico y artístico. En este sentido, la recuperación de la cerámica es uno de los puntos más cruciales, ya que supone uno de los elementos visualmente más notorios. En la superficie de los azulejos, se observaron diferentes degradaciones, siendo la pátina amarillenta, una de las más significativas.Con el fin de llevar a cabo una limpieza de la misma, se evaluó la naturaleza de la pátina, cuya veladura es consecuencia de la contaminación atmosférica, como mostraron los análisis químicos. A continuación se llevo a cabo una comparación entre cuatro disolventes orgánicos, aplicados tanto en probeta como in situ. Para evaluar la efectividad de los reactivos, se realizó una valoración cuantitativa mediante colorimetría.Además, el presente trabajo muestra una metodología interdisciplinaria basada en el método científico como la mejor guía a seguir para lograr métodos de restauración duraderos, seguros y efectivos. Keywords: Cultural heritage, Coatings, Non-destructive testing, Restoration, Palabras clave: Patrimonio cultural, Revestimientos, Ensayos no destructivos, Restauración

Compositional analysis of ceramics plays a crucial role in Archaeology because following the proper methodology, it enables to obtain knowledge about past human behavior. In this regard, X-Ray Fluorescence Spectrometry (XRF) involves promising possibilities on the non-destructive analysis of pottery. Nonetheless, in comparison to traditionally employed techniques such as ICP-MS or NAA, there are several limitations to overcome (e.g. limits of detection, precision, accuracy, etc.). The goal of this work was to develop a non-destructive multi-point strategy based on ED-XRF and, subsequently, assess to what extent a destructively obtained classification by ICP-MS can be reproduced by the one obtained non-destructively. The experiment was applied to a set of 47 representative Medieval and post-Medieval ceramics from the Iberian Peninsula corresponding to 4 archaeological sites. The results from both methods were explored statistically (HCA and PCA) and showed that the classification obtained non-destructively achieved a high-level of correspondence with the one obtained by ICP-MS. Thus, the screening potential of the methodology was demonstrated. Likewise, factors involved in the geochemical characterization such as instrumental parameters, concentration ranges of these ceramics typologies, their heterogeneity and the role of the ubiquitous lead glazes were addressed.

The village of Orduna is located in the north of the Iberian Peninsula and has played throughout centuries as an important exchange point, connecting the Spanish plateau with the Basque coastline villages. Furthermore, several trade agreements converted the village into an important trade-center for goods from the 13th century CE onwards. Despite the historical importance of this village, little is known about the pottery activity and its diachronic evolution, which would have experimented a drastic change during the 18th century. Recently, first material relicts evidencing pottery production were found in archaeological excavations, where numerous ceramic sherds along with at least one ceramic kiln dated back to the 17th–19th century were unearthed. These findings constituted an unprecedented framework of reference and paradigm for the study of the ceramic materials from other plots of the villa as well as other Basque villages. In the present work, a selection of 100 sherds, which were representative of the different typologies found, have been subjected to a multi-analytical approach by ICP-MS, XRD and SEM-EDS in order to shed light on these ceramic materials and to obtain a better understanding on their historical implications in relation to regional and extra-regional trading activity. The results allowed establishing seven compositional groups that not only respond to the different technotypes, but they also depict the diachronic evolution of the ceramic production, showing compositional differences throughout time. In addition, characterization of the glazes was performed. Thus, the main technological features used by the potters of Orduna were identified.

The conservation of iron objects exposed to marine aerosol is threatened by the formation of akaganeite, a highly unstable Cl-bearing corrosion phase. As akaganeite formation is responsible of the exfoliation of the rust layer, chlorides trigger a cyclic alteration phenomenon that often ends with the total consumption of the iron core. To prevent this degradation process, movable iron elements (e.g. archaeometallurgical artefacts) are generally immersed in alkaline dechlorination baths. Aiming to transfer this successful method to the treatment of immovable iron objects, we propose the in-situ application of alkaline solutions through the use of highly absorbent wraps. As first step of this novel research line, the present work defines the best desalination solution to be used and optimizes its extraction yield. After literature review, a screening experimental design was performed to understand the single and synergic effects of common additives used for NaOH baths. Once the most effective variables were selected, an optimization design was carried out to determine the optimal conditions to be set during treatment. According to the experimental work here presented, the use of 0.7 M NaOH solutions applied at high temperatures (above 50 °C) is recommended. Indeed, these conditions enhance chloride extraction and iron leaching inhibition, while promoting corrosion stabilization. This work has been funded by the DEMORA project (Grant No. PID2020-113391GB-I00), funded by the Spanish Agency for Research (through the Spanish Ministry of Science and Innovation, MICINN, and the European Regional Development Fund, FEDER).