IntroductionFuture Mars astrobiology missions require landing sites that balance scientific potential for biosignature detection with engineering safety. This study addresses the need for systematic identification of optimal sites targeting ancient aqueous environments distinct from previously explored terrains.MethodsA multi-criteria GIS-based analysis was conducted to evaluate five candidate landing sites (Aram Chaos, East Meridiani Planum, Ottumwa Crater, East Margaritifer Terra, and Nili Fossae) using global and regional datasets including MOLA topography, MOCAAS mineralogy, HiRISE imagery, and thermal inertia measurements. Sites were assessed against engineering constraints (latitude ±30°, elevation <−0.5 km, slopes <15°, thermal inertia >100 J m−2 K−1 s0.5) and scientific criteria (diversity, context, habitability, and biosignature preservation potential).ResultsEast Meridiani Planum emerged as the top-ranked candidate. The site features unique evaporite karst geomorphology (ridges, dolines, salt pans), extensive hydrous sulfate and Fe/Mg phyllosilicate deposits, and favorable engineering parameters (elevation: −1.1 km; thermal inertia: 200–450 J m−2 K−1 s0.5; slopes <5°). The proposed 25 km × 20 km landing ellipse at 0.74°N, 4.44°E provides access to the Noachian-age (∼3.7 Ga) Upper Etched Unit, offering a distinct paleoenvironment from the Hesperian hematite plains explored by the Opportunity rover.DiscussionThis site offers exceptional potential for investigating Mars' hydrological evolution and detecting preserved organic molecules. The dual mineralogy—neutral-pH smectite clays favorable for molecular preservation and acidic sulfate evaporites conducive to morphological biosignature preservation—enables testing of multiple biosignature hypotheses. The combination of high scientific value, minimal aeolian cover, and flat topography makes East Meridiani Planum an optimal target for future astrobiology missions seeking evidence of ancient Martian habitability.
Fundamental science can sometimes take a long time until it is useful for practical applications, as was the case for Raman spectroscopy. For a long time, it lacked powerful excitation sources and sensitive detectors. However as technology evolved, the number of exciting applications has boomed. Modern Raman spectroscopy has significant advantages, especially in sample preparation. Handheld Raman devices can be very compact and therefore be easily taken to the sample instead of bringing the sample to the lab. Non-destructive measurements obviously are important in gemmology and mineralogy, even in space. In the field of archaeology, pigments in precious ancient paintings, scrolls or books can be identified. This application is also used to identify fraud and falsification and in studies from a medical school they have reported that Raman spectroscopy can be applied to distinguish cancerous tissue from healthy tissue. Due to the mobility and ruggedness of the handheld hardware, Raman spectroscopy can be used for police, firefighters, and military applications for identification of explosives and illicit drugs or warfare substances. With SERS (Surface Enhanced Raman Spectroscopy), Raman spectroscopy can even be used for trace analysis. The SERS effect enhances the sensitivity of the Raman signal by a factor of up to 107. This enables, for example, measuring pesticide residuals on fruit or vegetable surfaces for food safety. It can also be used to identify traces of drugs, e.g. in urine. However, one of the most common Raman-applications is the identity check or verification of incoming goods (RMID) in the pharma industries, directly in the warehouse. Users appreciate the ease of use and the ruggedness of the Raman hardware.
Walczak Katarzyna A., Włodek Adam, Cuthbert Simon
et al.
This short report presents the investigation results on the zircon from meta-andesitic rock from the Ankarede Volcanite Formation of the Lower Köli Nappe Complex in Scandinavian Caledonides. Previous U-Pb dating revealed a wide span of dates ranging from ca. 520 to ca. 480 Ma, with a mean age of 491 ± 3 Ma for the zircon cores. Using cathodoluminescence and back-scattered electron imaging, along with chemical mapping, we identified distinct zones within the zircon grains; 1) cores of clear magmatic provenance, 2) mantles also of magmatic origin but with a slightly different chemical composition and 3) zircon rims that suffered metamictisation and fluid-induced alterations. These findings highlight a complex growth history and alteration of studied zircon that affect the interpretation of zircon dating results. This research underscores the importance of detailed zircon studies for understanding the intricate processes involved in the magmatic and metamorphic evolution of Virisen terrain in Scandinavian Caledonides.
Wuyang He, Fudong Wang, Carlos Pérez-Mejías
et al.
Calcium carbonate particles are common in many sedimentary environments, with the formational processes unresolved. Due to the variety of sedimentary environments, these particles exhibit significant variations in their petrographic, mineralogical, and geochemical features, as well as their genetic mechanisms. In the Huanglong travertine system, Sichuan, China, unique calcium carbonate particles, resembling sand grains, have been identified and are referred to as sand-like particles (0.5–3.0 mm). This study systematically investigates the mineralogical, petrographic, and geochemical characteristics of these particles. The particles form in a high-Ca2+ cold spring environment (Ca2+ >3.00 mM, T < 13 °C) through an exceptional aggregation-cementation-accretion-compaction process involving both detrital fragments and newformed calcite crystals. The particle growth is primarily controlled by hydrodynamic fluctuations and microbial mediation, with extracellular polymeric substances (EPS) templating calcite nucleation while kinetic disequilibrium drives rapid crystallization. These composite particles preserve distinct microtextural signatures of multiple diagenetic phases, offering new insights into non-classical carbonate formation. This study highlights the complexity and diversity of localized travertine deposition, bridging the gap between macroscopic sedimentary frameworks and localized depositional processes. The Huanglong system represents a unique natural laboratory for studying carbonate sedimentation under hydrochemical gradients. This research provides fundamental insights into the complex interplay between inorganic processes (hydrochemical precipitation driven by high Ca2+ and CO2 degassing) and organic mediation (microbial activity and extracellular polymeric substances) in these unique high-calcium aquatic systems. This not only elucidates the diversity of carbonate deposition mechanisms in Huanglong’s environment, but also holds significant implications for understanding the establishment of similar coupled physicochemical-biological systems in other high-altitude, calcium-rich spring environments worldwide.
A.M. Yuminov, Sh.Kh. Kuldashev, I.A. Blinov
et al.
The article considers the geological setting and mineralogy of oxidation zone of the Vorovskaya Yama copper occurrence (South Transurals), which was exploited in 17th–16th centuries BC by miners of the Alakul culture. The ore occurrence is confned to the contact of serpentinites and Devonian basalts; mineralization is associated with small intrusive bodies of syenites and belongs to skarn type. Andradite and clinopyroxene are major minerals of skarns. The oxidation zone contains subordinate (plagioclase, amphibole, epidote, chlorite, quartz, zoisite, muscovite, and malachite), accessory (Cr-rich spinel, magnetite, barite, chalcopyrite, covellite, pyrrhotite, cubanite, and native gold) and supergene (smectites, Fe oxyhydroxides, opal, native copper, and iodargyrite) minerals. The upper horizons of the oxidation zone with weathered skarns and malachite were exploited in the Bronze Age. Copper ore of the Vorovskaya Yama type in the South Urals Bronze Age settlements can be identifed by the presence of garnet, as well as the presence of Zn, Ag and Se in oxidized ore.
The study of minerals with modern electron microscopes requires the solution of anatomical problems of the crystals. To obtain consistent spectroscopic data from different instruments, it is necessary to point the microprobe directly to the same element of the crystal anatomy. This is diffcult to do unknown details of an anatomical pattern. The article provides the examples of complex arrangement of elements of crystal anatomy of different minerals to accumulate ontogenetic information for the formulation of the postulates.
Ilya N. Bindeman, Dmitri A. Ionov, Peter M. E. Tollan
et al.
The 18 O/16 O ratio of the subcontinental mantle has decreased by 0.2‰, while crustal values increased by 4‰ via fluid transfer since the Archean due to the initiation of plate tectonics and subduction, in line with the crust-upper mantle mass balance
Pabllo Henrique Costa dos Santos, Marcondes Lima da Costa
Abstract Cenozoic world-class bauxite deposits developed on sedimentary sequences of the Parnaíba and Amazon Basins. The Décio pilot mine, excavated in the Rondon do Pará bauxite deposit, exposes a 3 m thick bauxite-bearing lateritic profile on the top of a 350 m high plateau. From the base to the top, this profile is composed of clayey bauxite; porous microcrystalline bauxite; spherulitic ferro-aluminous duricrust, fragmentary on the top; as well as loose ferro-aluminous spherulites and nodules, embedded in clay. The lower horizons represent a classic lateritic succession, while the top of the profile was produced through post-lateritic reworking. During this process, Ga, Cr, Mo, As, Pb, Hg, Sb, Zn, V and Sc were captured by the iron oxi-hydroxides; and REE, Hf, Nb, Ta, Y remained carried by relict zircon. Isocon diagram and mass balance demonstrate the affinity of the bauxite with claystone from Itapecuru Formation.
The article is devoted to tomamaeite Cu3 Pt from inclusions in a native osmium grain from alluvial river sediments in the Nizhnie Sergi region, Sverdlovsk oblast. It is the fourth finding of this mineral in the Urals. In addition to tomamaeite, native osmium Os0.36Ir0.33Ru0.31 contains the inclusions of digenite (or, possibly, roxbyite), millerite, Fe-Ni-Pt alloy, an unidentified Pd mineral, magnesiohornblendite, and lowCa pyroxene. In composition, tomamaeite is close to the ideal formula Cu3 Pt and contains minor amounts of (wt. %) Pd (up to 2.0), Ir (up to 1.7), Ru and Ni (up to 0.6), and Fe (up to 0.2). In addition to native osmium, two grains of native ruthenium Ru0.54Os0.23Ir0.23 and Ru0.40Os0.31Ir0.29 are found in sediments. Our data suggest that the PGE minerals in river sediments could be sourced from mafic-ultramafic massifs located in the Nizhnie Sergi area. The formation of tomamaeite and coexisted minerals is related to the process of postmagmatic transformation of the primary PGE mineral assemblage, probably, during serpentinization of ultramafic rocks.
Microbial-mediated iron (Fe) oxidation and reduction greatly contribute to the biogeochemistry and mineralogy of ecosystems. However, knowledge regarding the composition and distribution patterns of iron redox cycling bacteria in peatlands remains limited. Here, using high-throughput sequencing, we compared biogeographic patterns and assemblies of the iron redox cycling bacterial community between soil and water samples obtained from different types of peatland across four regions in Northeast China. A total of 48 phylotypes were identified as potential iron redox bacteria, which had greater than 97% similarity with Fe(II)-oxidizing bacteria (FeOB) and Fe(III)-reducing bacteria (FeRB). Among them, Rhodoferax, Clostridium, Geothrix, Sideroxydans, Geobacter, Desulfovibrio, and Leptothrix could be used as bioindicators in peatlands for characterizing different hydrological conditions and nutrient demands. Across all samples, bacterial communities associated with iron redox cycling were mainly affected by pH, dissolved organic carbon (DOC), and Fe2+. Distance–decay relationship (DDR) analysis indicated that iron redox cycling bacterial communities in soil, but not in water, were highly correlated with geographic distance. Additionally, null model analysis revealed that stochastic processes substituted deterministic processes from minerotrophic fens to ombrotrophic bogs in soils, whereas deterministic processes were dominant in water. Overall, these observations suggest that bacteria involved in iron redox cycling are widespread in diverse habitats and exhibit distinct patterns of distribution and community assembly mechanisms between soil and water in peatlands.
Viktor I. Malkovsky, Sergey V. Yudintsev, Michael I. Ojovan
et al.
Self-irradiation can affect durability of glasses used to immobilize high-level nuclear waste (HLW). The stability of glasses can also be indirectly affected by the radiolytic changes in contact water leading to decrease in its pH although this is unlikely to occur for disposal systems where the interaction of groundwater with glass is delayed to times when radiation dose rates are decreased to levels insignificant to cause such effects. Besides, interaction of the water influenced by radiation with other repository protective elements (container and bentonite) will suppress the radiolytic changes. Literature analysis shows practical absence or very weak effect of self-irradiation on structure and characteristics of borosilicate glasses with typical content of nuclear waste. Data for aluminophosphate glass used in Russia have showed that, after γ-irradiation with a dose of 6.2·107 Gy, the leaching rates of elements were decreased approximately twice relatively to pristine samples.
The aim of this work is to understand aerosol transfers to the snowpack in the Spanish Pyrenees (Southern Europe) by determining their episodic mass-loading and composition, and to retrieve their regional impacts regarding optical properties and modification of snow melting. Regular aerosol monitoring has been performed during three consecutive years. Complementarily, short campaigns have been carried out to collect dust-rich snow samples. Atmospheric samples have been chemically characterized in terms of elemental composition and, in some cases, regarding their mineralogy. Snow albedo has been determined in different seasons along the campaign, and temporal variations of snow-depth from different observatories have been related to concentration of impurities in the snow surface. Our results noticed that aerosol flux in the Central Pyrenees during cold seasons (from November to May, up to 12–13 g m<sup>−2</sup> of insoluble particles overall accumulated) is much higher than the observed during the warm period (from June to October, typically around 2.1–3.3 g m<sup>−2</sup>). Such high values observed during cold seasons were driven by the impact of severe African dust episodes. In absence of such extreme episodes, aerosol loadings in cold and warm season appeared comparable. Our study reveals that mineral dust particles from North Africa are a major driver of the aerosol loading in the snowpack in the southern side of the Central Pyrenees. Field data revealed that the heterogeneous spatial distribution of impurities on the snow surface led to differences close to 0.2 on the measured snow albedo within very short distances. Such impacts have clear implications for modelling distributed energy balance of snow and predicting snow melting from mountain headwaters.
Yoel Aguirre-Breffe, Tomás Fernández-Columbié, Isnel Rodríguez-González
et al.
Se realizó la caracterización microestructural de las transformaciones que ocurren en el hierro gris FG 24 sometido a tratamiento térmico. Seis muestras de la aleación fueron recocidas durante tiempos distintos (2 h y 3 h), a una misma temperatura (740 oC), con enfriamiento en el horno. En ambos tratamientos se obtuvieron microestructuras de hojuelas de grafito laminar en una matriz de ferrita, con tamaño número 4 del grafito para el tratamiento a dos horas y tamaño número 3 para el de tres horas. Se evidenció que se mantiene la distribución tipo A del grafito para ambos tratamientos. En los perfiles de dureza, esta propiedad varía desde 230 HB para la muestra patrón, hasta 160 HB para el mayor tiempo de permanencia en el horno.
Elissavet Dotsika, Dafni Kyropoulou, Vassilios Christaras
et al.
Samples of mortars were collected from lime and hydraulic mortars affected by environmental degradation. A total of 63 samples were obtained from Hellenistic, Late Roman and Byzantine historic constructions located at Kavala, Drama and Makrygialos in North Greece. Samples were collected in sections from the surface up to 6 cm deep using a drill-core material. The first sample was collected from the external layer, while the internal samples were collected each 1cm beeper from the previous, in order to monitor the moisture ingress. Isotopic data will make it possible to create an ideal Hellenistic and Byzantine mortar layer and to provide weathering gradients. The isotopic values comprise a range of δ13C and δ18O values from −17.1‰ to 1.2‰ and −25.9‰ to −2‰, respectively. The weathering process of Hellenistic and Byzantine are expressed, by the regression lines δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 1.9 and δ18Ocalcite matrix = 0.6 × δ13Ccalcite matrix − 2.0 for hydraulic and Lime mortars respectively. Pronounced isotopic shift to heavy or light δ13C and δ18O in the carbonate matrix was attributed to the primary source of CO2 (atmospheric versus biogenic) and H2O (evaporation of local primary water), in residual limestone and in secondary processes such as recrystallization of calcite with pore water and salts attack. Exogenic processes related to biological growth are responsible for further alterations of δ18O and δ13C in lime mortars. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of carbonate, the environmental setting conditions of mortar, origin of CO2 and water during calcite formation and to determine the weathering depth and the potential secondary degradation mechanisms.
A.M. Kosarev, S.A. Svetov, S.Yu. Chazhengina
et al.
The Baymak ore district hosts numerous small Au-rich massive sulfide polymetallic deposits, which is a distinctive feature in comparison with other regions of the West-Magnitogorsk zone (Seravkin, 1986). According to geophysical data, the Baymak block is characterized by low level of gravity field intensity because of significant volume of felsic rocks and reduced thickness of the granulite-basite layer (Seravkin, Tsvetkova, 1982). The volcanic and volcanosedimentary rocks, which host massive sulfide deposits of the district, belong to the upper subformation of the Baymak-Buribay Formation (D1ems22) in the upper part of the frontal island arc (Kosarev et al., 2005). The objects of study are felsic rocks of extrusive and subvolcanic facies of the East Baymak district with phenocrysts of quartz, hornblende, pyroxene, and plagioclase. These rocks are characterized by unusual presence of relic unaltered clinopyroxene. The study of chemical composition of minerals allowed us to show that the formation of extrusive and subvolcanic felsic rocks was affected by hybridism processes responsible for the high Mg contents. These rocks belong to Mg calc-alkaline petrochemical series.
Stephanie Turner, Robert Mikutta, Sandra Meyer-Stüve
et al.
Along a long-term ecosystem development gradient, soil nutrient contents and mineralogical properties change, therefore probably altering soil microbial communities. However, knowledge about the dynamics of soil microbial communities during long-term ecosystem development including progressive and retrogressive stages is limited, especially in mineral soils. Therefore, microbial abundances (quantitative PCR) and community composition (pyrosequencing) as well as their controlling soil properties were investigated in soil depth profiles along the 120,000 years old Franz Josef chronosequence (New Zealand). Additionally, in a microcosm incubation experiment the effects of particular soil properties, i.e., soil age, soil organic matter fraction (mineral-associated vs. particulate), O2 status, and carbon and phosphorus additions, on microbial abundances (quantitative PCR) and community patterns (T-RFLP) were analyzed. The archaeal to bacterial abundance ratio not only increased with soil depth but also with soil age along the chronosequence, coinciding with mineralogical changes and increasing phosphorus limitation. Results of the incubation experiment indicated that archaeal abundances were less impacted by the tested soil parameters compared to Bacteria suggesting that Archaea may better cope with mineral-induced substrate restrictions in subsoils and older soils. Instead, archaeal communities showed a soil age-related compositional shift with the Bathyarchaeota, that were frequently detected in nutrient-poor, low-energy environments, being dominant at the oldest site. However, bacterial communities remained stable with ongoing soil development. In contrast to the abundances, the archaeal compositional shift was associated with the mineralogical gradient. Our study revealed, that archaeal and bacterial communities in whole soil profiles are differently affected by long-term soil development with archaeal communities probably being better adapted to subsoil conditions, especially in nutrient-depleted old soils.
Todor Serafimovski, Goran Tasev, Sabina Strmić Palinkaš
et al.
<p class="CM3">The paper presents data about geology, geochemistry, structure, genesis and specific features of the Bučim, porphyry Cu deposit with active mining in Macedonia. The porphyry mineralization (0.3 % Cu, 0.3-0.5 ppm Au) is spatially and temporarily associated with Tertiary subvolcanic intrusions of latitic and latitic-andesitic composition. The intrusions took place<em> </em>during Oligo-Miocene time (24 to 27 Ma), a period of intensive tectono-magmatic and ore-forming processes..</p> The latest results of this study to an array of major ore (hypogen) minerals such chalcopyrite, pyrite, magnetite, hematite, cubanite, valleriite, native Au and bornite and secondary enrichment zone minerals (within Čukar ore body) chalcocite, covellite, tenorite, native Cu, malachite, azurite etc added minerals such calaverite, krennerite, electrum, petzite and bismuth±selenium minerals (bismuthinite, galenobismutite, krupkaite, friedrichite, emplectite, cosalite, laitakarite and native bismuth). Variations of the δ<sup>34</sup>S values for the whole Bučim ore deposit ranged from +0.2 ‰ to +2.5 ‰ while δ<sup>13</sup>C‰ and δ<sup>1</sup><sup>8</sup>O‰ isotope values ranged from -10.8 to -3.8‰ and from +14.0 to +22.7 ‰, respectively. In regards to fluid inclusions it was confirmed that beside dominated gas-liquid, two-phase inclusions, there are also three-phase fluid inclusions (gas + liquid + solid phase). Also, recent Sr and Nd isotope ratios (<sup>87</sup>Sr/<sup>86</sup>Sr 0.70666-0.70741 and <sup>143</sup>Nd/<sup>144</sup>Nd 0.512487–0.512489) indicated slight contamination of the magmatic products by continental crust material, due to a partial melting of the deep parts of continental crust underthrusted by collision of continental blocks. In direction were results from the REE data, manifested through high contents of large ion lithophile elements (LILE), high Ba/Nb ratio (116.72-190.72) and depletion in high field strength elements (HFSE) and Europium negative anomaly (0.68893-0.91251).
Dingdaohengite-(Ce), an extremely rare mineral species of the chevkinite group, was found as black grains to 2 mm in syenitic pegmatites of Obukhovskiy Uval, South Urals (first find in Russia). Its empirical formula with suggested distribution of cations at octahedral sites: (Ce1.91La1.10Pr0.14Nd0.13Ca0.61Th0.10) Σ3.99Fe2+1.00(Ti1.07Mg0.53Fe2+ 0.22Al0.18)Σ2.00(Ti1.75Nb0.25)Σ2.00Si4O22. Due to the metamict state of the mineral, its X-ray diffraction data were obtained on annealed material. The mineral is monoclinic: a = 13.522(1) Å, b = 5.705(6) Å, c = 11.019(1) Å, β = 100.72(1)°, V = 835.3(1) ų.