Minerals olivine

Figure 4 Spectrum of diffusion in the mineral olivine ((Mg, Fe)2 SiO ) taken using nonresonant profiling technique with the reaction (p, a) Both the a particles resulting from the nuclear reaction and backscattered protons are collected. Inset shows expanded region of the spectrum, where a yield indicates diffusion of into the material.

Fig. 8.33 Left, robotic arm with MIMOS II positioned on the rock Adirondack, as seen by the navigation camera of the rover Right. Mossbauer Spectrum (14.4 keV temperature range 220-280 K) of the rock Adirondack at Spirit landing side Gusev Crater, plains. The data were taken at the as-is dusty surface (not yet brushed). The spectrum shows an olivine-basalt composition, typical for soil and rocks in Gusev plains, consisting of the minerals olivine, pyroxene, an Fe doublet, and nonstoichiometric magnetite...

Mixtures of iron and stone principally as the silicate mineral olivine, (Mg,Fe)2Si04, with additional Fe and Ni... 

Figure 3-5 MnO partition between and diffusion in two minerals, olivine and garnet. Diffusional anisotropy of olivine is ignored. Initially, MnO in both phases were 0.2 wt%. As the two minerals come into contact, there will be diffusion to try to reach the equilibrium state. The partition coefficient (Mn)oiiv/(Mn)gt is assumed to be 0.59. The diffusivity in olivine is assumed to be 10 times that in garnet, resulting in a wider diffusion profile with a smaller slope in olivine.

Consider Ca in a basaltic melt inclusion concentric with the host mineral olivine. The radius of the inclusion is SOfim. The olivine radius is 1 mm. The Ca partition... 

The acapulcoites (Fig. 6.7a) have recrystallized textures, but a few relict chondrules have been reported (McCoy et al., 1997a). The relative proportions of the minerals (olivine, orthopyroxene, diopside, plagioclase, metal) in acapulcoites are similar to those in ordinary chondrites, and the abundances of the major elements are nearly chondritic. However,... 

Figure 7.13 Noble gas amounts (labeled as Released Amount in the ordinate), which were implanted on target minerals (olivine and ihnenite), are plotted against irradiation dose. Acceleration energies of the implanted noble gases range from 20 to 200 KeV (total energy). After Futagami et al. (1993).

The Earth s early atmosphere provides the carbon dioxide. Several reactions could be the source of the hydrogen. Hydration of the mineral olivine to serpentine releases hydrogen as a by-product, as does the oxidation of methane and gasification of carbon. 

Once we have established the fields shown in Fig. 7.4, we can use the map as follows If we discover a new mineral with = 90 pm and /-q = 30 pro, we should expect it to have the same structure as the mineral olivine. (Mg.Fte)2SiOa. but we should not be too surprised if ii turned out to be isomoq>hous with Ihcnardite. Na2S04-... 

During metamorphism and recrystallization, oxygen isotopes are redistributed among mineral phases, according to the mass-dependent equilibrium fractionations corresponding to the peak metamorphic temperature. The measured mineral-pair fractionations (usually for major minerals olivine, pyroxene, and feldspar) can then be used for metamorphic thermometry, yielding temperatures of 600 °C for an L4 chondrite, and 850 50 °C for several type-5 and type-6 chondrites (Clayton et al., 1991). Isotopic equilibration, even in type-6 chondrites, involves oxygen atom transport only over distances of a few millimeters (Olsen et al., 1981). 

Figure 11 Wetting behavior of iron-Ught-element alloys, (a) Effect of bght element on surface tension at 1 bar (lida and Guthrie, 1988). (b) Effect of light elements on dihedral angle at 3-4 GPa (Minarik et at., 1996). (c) Effect of pressure on dihedral angle of Fe-Ni-S melt in equilibrium with mantle minerals (olivine, )8-phase, and y-phase below 25 GPa, magne-siowustite, perovskite, and y-spinel at 25 GPa, Shannon and Agee (1998)).

Chondrites are ultramafic in composition and contain the minerals olivine, pyroxene, and metallic iron. They are composed of three main components (see Fig. 2.9), each of which represents a different component of primitive solar nebula material ... 

The principal rock-type of the upper mantle comprising the minerals olivine and pyroxene. There are a number of different types of peridotite - see dunite,... 

Primary MORE magmas are generated by partial melting of the upper mantle believed to be composed of a rock type termed peridotite which is primarily composed of the minerals olivine, pyroxenes (enstatite and diopside), and minor spinel or garnet. 

The centred log-rado covariance matrix shows negadve covariances between Mg-K, Mg Ti, Mg-P, Mg-Na and Mg-Q., emphasizing the strong antipathy between Mg (in olivine) and the elements K, Ti, P, Na and Ca which are concentrated in the melt. The positive covariance between Fe and Mg is reflected in the strong association between Mg and Fe in the mineral olivine. In contrast the elements with very small covariances Si, Al, Fe, Mn and Ca show no strong association with most other elements. 

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