Search results for "MINERALOGY"
showing 10 items of 1516 documents
Soils of Eagle crater and Meridiani Planum at the Opportunity Rover landing site.
2004
The soils at the Opportunity site are fine-grained basaltic sands mixed with dust and sulfate-rich outcrop debris. Hematite is concentrated in spherules eroded from the strata. Ongoing saltation exhumes the spherules and their fragments, concentrating them at the surface. Spherules emerge from soils coated, perhaps from subsurface cementation, by salts. Two types of vesicular clasts may represent basaltic sand sources. Eolian ripples, armored by well-sorted hematite-rich grains, pervade Meridiani Planum. The thickness of the soil on the plain is estimated to be about a meter. The flatness and thin cover suggest that the plain may represent the original sedimentary surface.
Iron mineralogy and aqueous alteration on Mars from the MER Mössbauer spectrometers
2008
The twin Mars Exploration Rovers Spirit (Gusev crater) and Opportunity (Meridiani Planum) used MIMOS II Moessbauer spectrometers to analyze martian surface materials in the first application of extraterrestrial Moessbauer spectroscopy. The instruments acquired spectra that identified the speciation of Fe according to oxidation state, coordination state, and mineralogical composition and provided quantitative information about the distribution of Fe among oxidation states, coordination states, and Fe-bearing phases. A total of 12 unique Fe-bearing phases were identified: Fe(2+) in olivine, pyroxene, and ilmenite; Fe(2+) and Fe(3+) in magnetite and chromite; Fe(3+) in nanophase ferric oxide (…
A mesoscopic approach to radiation-induced defect aggregation in alkali halides stimulated by the elastic interaction of mobile Frenkel defects
1994
The radiation-induced aggregation of Frenkel defects in alkali halides is studied in terms of a mesoscopic approach. The asymmetry in elastic interactions between mobile interstitials (I–I) and bet...
High Temperature Study of Metamict Rinkite
2013
Metamict minerals contain radioactive elements that degrade their crystal structure. During the annealing process under ambient pressure in argon atmosphere the sample of metamict rinkite recrystallizes to the primary crystalline form at 700°C. Further heating leads to the formation of a new crystalline phase.
Major and trace element compositions (including REE) of mineral, thermal, mine and surface waters in SW Germany and implications for water–rock inter…
2013
Abstract The near-surface water cycle in a geologically complex area comprises very different sources including meteoric, metamorphic and magmatic ones. Fluids from these sources can react with sedimentary, magmatic and/or metamorphic rocks at various depths. The current study reports a large number of major, minor and trace element analyses of meteoric, mineral, thermal and mine waters from a geologically well-known and variable area of about 200 × 150 km in SW Germany. The geology of this area comprises a Variscan granitic and gneissic basement overlain in parts by Triassic and Jurassic shales, sandstones and limestones. In both the basement and the sedimentary rocks, hydrothermal mineral…
Metamorphic reaction rates at ∼650–800°C from diffusion of niobium in rutile
2014
Abstract The ability to quantify the rates at which metamorphic reactions occur is critical to assessing the extent to which equilibrium is achieved and maintained in a variety of dynamic settings. Here we investigate the kinetics of rutile replacement by titanite during amphibolite-facies overprinting of eclogite, garnet amphibolite and anorthosite from Catalina Island, CA, the Tromso Nappe, Norway, the North Qaidam terrane, China, and the Guichicovi Complex, Mexico. Trace element concentration profiles across rutile rimmed by titanite, as determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), reveal Nb zoning in rutile that we interpret as the result of Nb …
Radiation in the Atmosphere - A Course in Theoretical Meteorology
2007
This book presents the theory and applications of radiative transfer in the atmosphere. It is written for graduate students and researchers in the fields of meteorology and related sciences. The book begins with important basic definitions of the radiative transfer theory. It presents the hydrodynamic derivation of the radiative transfer equation and the principles of variance. The authors examine in detail various quasi-exact solutions of the radiative transfer equation and give a thorough treatment of the radiative perturbation theory. A rigorous treatment of Mie scattering is given, including Rayleigh scattering as a special case, and the important efficiency factors for extinction, scat…
Geochemistry and mineralogy of sediments and authigenic carbonates from the Malta Plateau, Strait of Sicily (Central Mediterranean): Relationships wi…
2010
Abstract A mud volcano field was recently discovered within the Malta Plateau in the Strait of Sicily (Central Mediterranean Sea). Box-core sediments and associated authigenic carbonates have been collected in water depths of 140–170 m from two distinctive sectors of the area, and analyzed for major, trace and rare earth elements, stable isotopes, and mineralogy. Relative homogeneity in the mineralogy and geochemistry of bulk sediments, and 210Pb activity distributions, argue against an active mud ejection activity. In the Malta Plateau western sector, the sediments show high concentrations of Fe, As, Sb, and Mo, exceeding the background values estimated for the Strait of Sicily. Active flu…
Morphometry of micrite particles in cretaceous microporous limestones of the Middle East: influence on reservoir properties.
2011
24 pages; International audience; Microporosity may account for a significant part of the total porosity of Cretaceous limestone reservoirs of the Middle East. In these microporous facies porosity is moderate to excellent (up to 35%) while permeability is poor to moderate (up to 190 mD). Micritic limestones also may form dense layers with very low porosity and permeability values. Micritic samples were collected from three fields of the Habshan and Mishrif Formations, to examine the spatial relationship with their porosity, permeability and pore throat radius distributions. Two key parameters of the micritic particles are studied using scanning electron microscopy: their morphology (shape a…
Investigation of a tunnel pasteurizer for “Nocellara del Belice” table olives processed according to the “Castelvetrano method”
2014
The influence of pasteurization temperature and time of treatment on the flesh firmness and the evolution of microbial communities was studied for table olives Cv. Nocellara del Belice, packed in glass jars and processed with a tunnel pasteurizer. The experiment was first carried out on the laboratory level in order to select the optimal combination of pasteurization time/temperature so as to obtain the proper balance between the consistency of the pulp and the microbiological quality of the final product. Pasteurization at industrial scale was then carried out in a tunnel pasteurizer applying the treatment at 75 °C for 8 min in the thermal center of the jars. Besides flesh firmness and mic…