نتایج جستجو برای: pyroxene group
تعداد نتایج: 980267 فیلتر نتایج به سال:
[1] We investigated the continuous spectral features of fresh craters on the Moon accompanied by distinctive bright rays, with cavity diameters between 8 and 24 km.We used the data from the Spectral Profiler onboard SELENE (Kaguya) to gain a better understanding of the composition of the lunar highland crust. We found that the observed spectra exhibited strong symmetric absorption around 1 mm a...
[1] The Mössbauer (MB) spectrometer on Opportunity measured the Fe oxidation state, identified Fe-bearing phases, and measured relative abundances of Fe among those phases at Meridiani Planum, Mars. Eight Fe-bearing phases were identified: jarosite (K,Na,H3O)(Fe,Al)(OH)6(SO4)2, hematite, olivine, pyroxene, magnetite, nanophase ferric oxides (npOx), an unassigned ferric phase, and metallic Fe (k...
Reliable quantitative mapping of minerals exposed on Vesta’s surface is crucial for understanding the crustal composition, petrologic evolution, and surface modification of the howardite, eucrite, and diogenite (HED) parent body. However, mineral abundance estimates derived from visible–near infrared (VIS–NIR) reflectance spectra are complicated by multiple scattering, particle size, and nonlin...
Introduction: Numerous workers have recently focused attention on the issue of the oxygen fugacity (fO2) of martian samples [1,2,3,4,5]. Estimates of fO2 based on Fe-Ti oxides [6] and DEu/DGd and DEu/DSm ratios [3,4,7] suggest a range of fO2 values for SNC meteorites from IW+2.5 IW+3.5 for Shergotty to IW2.0 IW+0.2 for QUE94201 [3,4]. Fe/Fe is also a function of fO2, and synchrotron micro-XANES...
An undeformed metadolerite dyke cutting foliated pyroxene-granulite facies gneisses in the Jotunhelm, Norway, has almandine rods replacing the cores of plagioclase laths, although garnet is generally absent from the enclosing gneisses, and is not present in reaction zones between peridotites and gneisses. Chemical analyses of the dyke and its garnet, plagioclase, and clinopyroxene are given. Th...
Preliminary results of an investigation into the possible use of glass-ceramic frits from fly ash and glass cullet in terracotta (stoneware) tile manufacture are reported. Two new ceramics were studied and compared with a plant composition, containing 45 wt.% sodium feldspar. In the first ceramic batch 20% of the feldspar was substituted by frits and in the second the whole amount of feldspar w...
Raman microspectroscopy measurements were performed on Hayabusa sample RA-QD02-0197. The sample has been provided by JAXA to our consortium in the scope of the 1 International Announcement of Opportunity [1]. Raman microspectroscopy is an appropriate technique for a contactless mineralogical investigation and is applied to describe the mineralogical composition of the sample. For the noble gas ...
Lunar impact melt deposits have unusual surface properties, unlike any measured terrestrial lava flow. Radar observations suggest that they are incredibly rough at decimeter scales, but appear smooth in high-resolution, meter-scale optical images. The cause of their roughness is unknown. In this work, we investigate the properties from seven lunar craters, ranging size 7.5 to 96 km diameter, an...
Five Type A CAIs from three CV3 chondrites (Vigarano, Northwest Africa 3118, Allende), which differ in age by no more than ?105 years, show mineralogical and textural evidence of gradual transition into Bs, indicating that B inclusions formed evolution the solar nebula. This model differs conventional condensation aggregates condensate grains form different kinds depending on relative populatio...
Introduction: Komatiites provide several ways of assessing the chemical and thermal evolution of the mantle. Komatiitic liquids are produced from very high degrees of partial melting of the deep mantle, and erupted as extremely fluid lavas. Komatiites are important in the study of the early Earth because they are a significant constituent of the Archean crust. It has been proposed that komatiit...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید