Lunar origin, meteorites

Norman M., Borg L., Nyquist L., and Bogard D. (2003) Chronology, geochemistry, and petrology of a ferroan noritic anorthosite clast from Descartes breccia 67215 clues to the age, origin, structure, and impact history of the lunar crust. Meteorit. Planet. Sci. 38, 645-661. 

Miscellaneous other uses of emission spectroscopy should be mentioned. The cement and glass industries use spectroscopic methods for quality control. The food and beverage industries monitor trace element concentrations during processing. Spectroscopy is used for forensic purposes, usually to help identify samples as to source or origin. Meteorite composition also has been studied by spectroscopic methods, as have lunar samples returned to earth by astronauts. Emission spectroscopy also has served as a research tool in chemistry and physics by providing composition information on research samples. 

Origin. Typical meteorites have formation ages of 4.55 Gyr and exposure ages of only 10 years, duting which time they existed as meter-sized bodies unshielded to the effects of cosmic rays. With the exception of the SNC (Martian) and lunar meteorites it is widely befleved that most conventional... 

Stable isotope analysis of Earth, Moon, and meteorite samples provides important information concerning the origin of the solar system. 8lsO values of terrestrial and lunar materials support the old idea that earth and moon are closely related. On the other hand three isotope plots for oxygen fractionation in certain meteoric inclusions are anomalous. They show unexpected isotope fractionations which are approximately mass independent. This observation, difficult to understand and initially thought to have important cosmological implications, has been resolved in a series of careful experimental and theoretical studies of isotope fractionation in unimolecular kinetic processes. This important geochemical problem is treated in some detail in Chapter 14. 

Stable isotope analysis of earth, moon and meteorite samples has provided important information concerning the origin of the solar system. Lunar samples returned to earth during the Apollo missions show 8170 and 8lsO enrichment patterns which are virtually identical to those of earth-bound rocks and minerals. On 3-isotope plots like those in Figs. 9.5 and 14.3, a uniform isotope reservoir is represented by a single... 

Lunar surface materials (Apollo and Luna returned samples and lunar meteorites) are classified into three geochemical end members - anorthosite, mare basalt, and KREEP. These components are clearly associated with the various geochemically mapped terrains of different age on the lunar surface. The composition of the lunar interior is inferred from the geochemical characteristics of basalts that formed by mantle melting, and geochemistry provides constraints on the Moon s impact origin and differentiation via a magma ocean. 

Ganapathy, R., Keays, R. R., Laul, J. C. Anders, E. 1970 Trace elements in Apollo 11 lunar rocks Implications for meteorite influx and origin of Moon. Proc. Apollo Lunar Sci. 2, 1117-1442. 

Black, D. C. (1972) On the origin of trapped helium, neon, and argon siotopic variations in meteorites - I. Gas-rich meteorites, lunar soil and breccia. Geochim. Cosmochim. Acta, 36, 347-75. 

Because most work has been done on lunar samples and because some meteorites originate from the Moon and some processes affecting both types of sample are similar, a brief description is given of these observations. The CL spectra are dominated by two bands centered near 450 (deviation of +16 to -20nm) and 559nm (deviation of +16 to -6.5nm), while a peak near 730nm (deviation of +20 to... 

Definition of the ultimate origin of the carbon in the samples will certainly be difficult, if not impossible, because the processes occurring at the lunar surface must inevitably lead to some loss of identity. This is particularly applicable to any mechanism involving meteorite impact. 

Individual metal particles magnetically separated from lunar samples were studied intensively by Goldstein et al. 75-77 Wanke et al.6 78 and Wlotzka et al.19 80 From their trace element composition as well as from their content of Ni and Co, it was clear that the majority of the particles are of meteoritic origin. 

Ashwal L. D., Warner J. L., and Wood C. A. (1982) SNC meteorites evidence against an asteroidal origin. Proc. Lunar Planet. Sci. Conf. 13(suppl.) J. Geophys. Rev. 87, A393-A400. 

Keil K. (1982) Composition and origin of chondritic breccias. In Workshop on Lunar Breccias and Soils and their Meteoritic Analogs, LPI Technical Report 82-02 (eds. G. J. Taylor and L. L. Wilkening). The Lunar and Planetary Institute, Houston, pp. 65-83. 

MaePherson G. J., Grossman L., Allen J. M., and Beckett J. R. (1981) Origin of rims on coarse-grained inclusions in the Allende meteorite. Proc. 12th Lunar Planet. Sci. Conf., 1079-1091. 

Marti K. and Matthew K. J. (2002) Near-Earth asteroid origin for the Farmington meteorite. Lunar Planet. Sci. XXXIII, 1132. Lunar and Planetary Institute, Houston (CD-ROM). 

Huss G. R. and Alexander E. C., Jr. (1987) On the pre-solar origin of the normal planetary noble gas component in meteorites. Proc. 17th Lunar Planet. Sci. Conf J. Geophys. Res. 92, E710-E716. 

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