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The outcrop of “Los Azulejos” is visible at the interior of the Cañadas Caldera in Tenerife Island (Spain). It exhibits a great variety of alteration processes that could be considered as terrestrial analogue for several geological processes on Mars. This outcrop is particularly interesting due to the content of clays, zeolite, iron oxides, and sulfates corresponding to a hydrothermal alteration catalogued as “Azulejos” type alteration. A detailed analysis by portable and laboratory Raman systems as well as other different techniques such as X ray diffraction (XRD) and Mössbauer spectroscopy has been carried out (using twin-instruments from Martian lander missions: Mössbauer spectrometer MIMOS-II from the NASA-MER mission of 2001 and the XRD diffractometer from the NASA-MSL Curiosity mission of 2012). The mineral identification presents the following mineral species: magnetite, goethite, hematite, anatase, rutile, quartz, gregoryite, sulphate (thenardite and hexahydrite), diopside, feldspar, analcime, kaolinite and muscovite. Moreover, the in-situ Raman and Micro-Raman measurements have been performed in order to compare the capabilities of the portable system specially focused for the next ESA Exo-Mars mission. The mineral detection confirms the sub-aerial alteration on the surface and the hydrothermal processes by the volcanic fluid circulations in the fresh part. Therefore, the secondary more abundant mineralization acts as the color agent of the rocks. Thus, the zeolite-illite group is the responsible for the bluish coloration, as well as the feldspars and carbonates for the whitish and the iron oxide for the redish parts. The XRD system was capable to detect a minor proportion of pyroxene, which is not visible by Raman and Mössbauer spectroscopy due to the “Azulejos” alteration of the parent material on the outcrop. On the other hand, Mössbauer spectroscopy was capable of detecting different types of iron-oxides (Fe3+/2+-oxide phases). These analyses emphasize

[ES] Se ha llevado a cabo una selección de varios afloramientos volcánicos en la Isla de Tenerife (La Caldera de las Cañadas, vulcanismo histórico y la zona del Malpaís de Güimar) como posibles análogos terrestres de Marte, considerando los procesos volcánicos ocurridos durante algunas de las etapas geológicas del planeta rojo. En la selección de las áreas de estudio se han tenido en cuenta la diversidad de procesos de alteración, que incluyen fenómenos como meteorización y alteración hidrotermal. Estos procesos terrestres podrían servir como modelo de la actividad volcánica primitiva en Marte. Los materiales seleccionados se han analizado mediante espectroscopia micro-Raman, difracción de rayos X (DRX) y espectroscopia Mössbauer. Los resultados revelan que la mineralogía de los afloramientos está constituida por una matriz de olivinos, piroxenos y feldespatos. Además, se ha detectado una gran variedad de especies minerales correspondientes a procesos de alteración como óxidos, arcillas y carbonatos. Los resultados obtenidos han demostrado ser un punto de partida para desarrollar investigaciones en estos entornos volcánicos especialmente enfocados al desarrollo de la ciencia de instrumentación para exploración planetaria. La instrumentación utilizada en la investigación ha sido a través de prototipos gemelos empleados en la exploración espacial, como DRX (actualmente en la misión NASA-MSL-Curiosity), espectroscopia Mössbauer (a bordo de la misión NASA-MER) y el futuro instrumento Raman de la misión ESA-ExoMars. Además, la mineralogía detectada coincide con los resultados reportados en Marte. Los métodos de análisis Raman, tanto de caracterización e identificación, mediante el estudio de patrones espectrales se han aplicado exitosamente, donde el análisis de los perfiles Raman son de extrema utilidad para aclarar el origen de las especies minerales. La espectroscopia Mössbauer y la difracción de rayos X han confirmado los resultados Raman., [EN] Several volcanic outcrops from Tenerife Island (Las Cañadas Caldera, historical volcanism and Güimar-Malpaís outcrop) has been selected as a potential terrestrial analog for Mars, regarding the Martian mineralogy and its volcanic characteristic. Diverse alteration processes, including weathering and hydrothermal alteration have been detected in these volcanics environments, which could be considered as part of a model for the primitive volcanic activity of Mars. The selected materials have been measured by micro-Raman spectroscopy, XRD and Mössbauer spectroscopy. The results show the primary mineralogy comprises on olivine, pyroxene and feldspar. Also, a wide variety of alterational materials, including oxides, clay minerals and carbonates have been detected. The results have proven to be a starting point to develop research focused to the development of science instrumentation for planetary exploration in volcanic environments. The instrumentation used was primarily through twin prototypes applied in space exploration such as XRD (on board at the NASA-MSL-Curiosity mission), Mössbauer spectroscopy (on board at the NASA-MER mission) and the future Raman instrument on ESA mission -ExoMars. In addition, the detected mineralogy is consistent with results reported on Mars. The Raman spectral analisys methods, characterization and identification, have been applied, where the analysis of the Raman profiles are extremely useful to clarify the geochemical origin of the mineral species. On the other hand, the results obtained by Raman have been confirmed by Mössbauer spectroscopy and X-ray diffraction.

A detailed vibrational Raman-IR spectroscopic and diffractional analyses have been performed on basalts from two locations from Tenerife Island: (1) the Arenas Negras volcano which belongs to the historical eruption not showing visible alteration and (2) Pillow Lavas zone from Anaga Massif which shows a clearly fluid-rock interaction caused by submarine alteration. These places have been extensively studied due to its similarity with the surface of Mars. The analysis is based on the mineral detection of selected samples by a Micro-Raman study of the materials. The complementary techniques have confirmed the mineralogy detected by the Raman measurement. The results show a volcanic environment behavior with primary phases like olivine, pyroxene, and feldspar/plagioclase. Moreover, the presence of accessory minerals or secondary mineralization like phosphate, iron oxides, zeolite or carbonates shows the alteration processes on each outcrop. Moreover, the variation in the crystallinity and amorphous phases is related to fluid-rock interaction caused by hydrothermal episodes and external weathering processes, which shows several analogies with the ancient volcanic activity from Mars.

[ES]El reciente descubrimiento de minerales hidratados sobre la superficie de Marte sugiere la presencia de importantes cantidades de agua líquida durante algunas etapas de su historia geológica. A raíz de este hallazgo, los estudios sobre minerales hidratados en ambientes terrestres como potenciales análogos marcianos han adquirido gran relevancia. En el presente trabajo se han estudiado las características mineralógicas y geoquímicas de minerales hidratados procedentes de varias cuevas y minas españolas y de la región minera de Iglesias-Carbonia (Cerdeña, Italia) mediante técnicas espectroscópicas implicadas en misiones de exploración marciana presentes y futuras, con el fin de evaluar su potencial para la detección de este tipo de minerales. Por un lado, se ha utilizado la espectroscopia Raman, que formará parte de la carga científica de la misión ExoMars de la Agencia Espacial Europea. Por otro lado, la espectroscopia de IR, otra de las técnicas involucradas en esta misión de la ESA, así como la espectroscopia LIBS y la combinación de difracción-fluorescencia de rayos X (DRX-FRX), ambas a bordo de la misión MSL de la NASA. Estas técnicas han permitido identificar sulfatos (yeso, epsomita, jarosita y glaucocerinita), silicatos (hemimorfita) y carbonatos (hidrocincita e hidromagnesita), todos ellos minerales hidratados y algunos de los cuales también han sido descritos en Marte. Por otro lado, se han abordado los procesos de formación de estos minerales y las potenciales analogías con la mineralogénesis en Marte. Del conjunto de técnicas empleadas, la combinación Raman-LIBS se perfila como la opción más eficiente para la detección de minerales hidratados en condiciones marcianas., [EN] The recent discovery of hydrated sulfates on the Martian surface suggests that widespread wet conditions were present during its early geological history. Upon this discovery, a growing interest has emerged in the study of this group of minerals from terrestrial environments as potential Martian analogs. Here, we evaluate the potential of various analytical techniques involved in current and future mission to Mars for detecting hydrated minerals from caves and mines of Spain and the mining district of Iglesias-Carbonia (Sardinia, Italy). Minerals were analyzed by Raman spectroscopy, which will be included in the payload of the ESA’s 2018 ExoMars mission. On the other hand, IR spectroscopy, also included in the ExoMars mission, as well as LIBS spectroscopy and a combined XRD-XRF analyzer, both onboard the Curiosity rover of NASA’s MSL mission, were utilized. Hydrated sulfates (gypsum, epsomite, jarosite and glaucocerinite), silicates (hemimorphite) and carbonates (hydrozincite and hydromagnesite) were characterized. Most of these minerals have also been detected on the Martian surface. The mechanisms involved in the genesis of these minerals and the potential analogies with the minerogenesis on Mars are discussed. The Raman-LIBS combination appears to be the most powerful tool for detecting hydrated minerals in Martian conditions. This technology will probably be considered to be onboard of further planetary missions

A comprehensive micro-Raman spectroscopic analysis of the Nakhla and Vaca Muerta meteorites is reported. The major and minor mineral components were identified from comparison with mineralogical standards and literature databases. The compositions of pyroxenes and olivines were obtained using only this technique and correlation data between band parameters and the chemical composition of reference materials existing in the literature. The presence of calcite in both meteorite specimens was noted; its identification inside eucrite grains in the Vaca Muerta meteorite is particularly noteworthy. Their spectral parameters show strong similarities. Aragonite associated with calcite is reported for the first time in Vaca Muerta meteorite. Spectra of siderite, which appears associated with clinopyroxenes, are also reported in Nakhla meteorite. Iron oxides were analysed in detail in both meteorites. Magnetite is the main oxide phase observed in Nakhla and goethite, lepidocrocite and magnetite in Vaca Muerta. In both cases haematite was not observed. A comparison of the spectral parameters of these mineral phases observed in both meteorites was made and their possible origin as secondary minerals is discussed. This study stresses the potential of Raman spectroscopy in the mineralogical characterization of meteorites on a very small scale and also the potential applications of Raman spectroscopy for use on landers or rovers on the surface of Mars or other planetary bodies.