نتایج جستجو برای: ordinary chondrite
تعداد نتایج: 50446 فیلتر نتایج به سال:
A new type of carbonaceous chondrite, the Tagish Lake meteorite, exhibits a reflectance spectrum similar to spectra observed from the D-type asteroids, which are relatively abundant in the outer solar system beyond the main asteroid belt and have been inferred to be more primitive than any known meteorite. Until the Tagish Lake fall, these asteroids had no analog in the meteorite collections. T...
Chromium (Cr) isotopes play an important role in cosmochemistry and planetary science because they are powerful tools for dating (53Mn–53Cr short-lived chronometry), tracing (54Cr nucleosynthetic anomalies) the origins of materials, studying processes involved volatile element fractionation differentiation (Cr stable isotopic fractionation). To use Cr these purposes, it is essential to precisel...
Introduction: Early differentiation in evolving planetesimals likely involved a variety of different physical mechanisms. Fe-rich metallic liquid segregation can occur in a solid, partially molten, or purely molten silicate body, with or without the presence of deformation. Deformation may assist the segregation of low degree metallic melts. Segregation of Fe-S-Ni liquids formed by variable deg...
One primary characteristic of chondrite groups is their distinctive size-frequency chondrule distributions [1,2, 3]. The restricted ranges of chondrule size has been interpreted as indicative of a sorting mechanism, such as some form of aerodynamic drag [3, 4]. We re-examine this concept in light of the current database. The database and its limitations. Chondrule sizes are typically determined...
Murrili, the third meteorite recovered by Desert Fireball Network, is analyzed using mineralogy, oxygen isotopes, bulk chemistry, physical properties, noble gases, and cosmogenic radionuclides. The modal magnetic susceptibility, isotopes of Murrili point to it being an H5 ordinary chondrite. It heterogeneously shocked (S2–S5), depending on method used determine it, although not obviously brecci...
Kashmar granitoids of Taknar zone, in north part of Lut block, intruded into volcanic rocks and consist of granites, granodiorites, monzodiorite and gabbrodiorites. They are composed of mainly plagioclase, alkali-feldspar, quartz, amphibole, biotite and pyroxene minerals. Harker diagram variation, including negative correlations CaO, MgO, FeO, TiO2 and V and positive correlations K2O, Rb, Ba, a...
Here, we report the mineralogy, petrography, C-N-O-stable isotope compositions, degree of disorder of organic matter, and abundances of presolar components of the chondrite Roberts Massif (RBT) 04133 using a coordinated, multitechnique approach. The results of this study are inconsistent with its initial classification as a Renazzo-like carbonaceous chondrite, and strongly support RBT 04133 bei...
NASA’s Dawn spacecraft observations of Asteroid (4) Vesta reveal a surface with the highest albedo and color variation of any asteroid we have observed so far. Terrains rich in low albedo dark material (DM) have been identified using Dawn Framing Camera (FC) 0.75 lm filter images in several geologic settings: associated with impact craters (in the ejecta blanket material and/or on the crater wa...
We identify spectral similarities between asteroids and meteorites. matches 500 asteroid spectra over 1,000 samples of RELAB meteorite 0.45-2.5 microns. reproduce many major previously known meteorite-asteroid connections find possible new, more rare or less-established connections. Well-established include: ordinary chondrites (OC) with S-complex asteroids; pristine CM carbonaceous Ch-type hea...
Abstract Samples from asteroid 25143 Itokawa returned by the Hayabusa mission have been identified as LL4-6 ordinary chondrite materials and shown it to be a rubble pile that aggregated after break-up of parent body. Here we investigate particle RB-CV-0038 regolith using scanning transmission electron microscopy energy dispersive spectroscopy. We identify cubanite-chalcopyrite-troilite-pyrrhoti...
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