Meteorites krypton

There are traces of krypton in some minerals and meteorites. Krypton is found beyond Earth in space. 

Krummenacher D., Merrihue C. M., Pepin R. O., and Reynolds J. H. (1962) Meteoritic krypton and barium versus the general isotopic anomalies in meteoritic xenon. Geochim. Cosmochim. Acta 26, 231 —249. 

Marti K, Eberhardt P, Geiss J (1966) Spallation, fission, and neutron capture anomahes in meteoritic krypton and xenon. Z Naturforschung 21a 398-413... 

The anomalous micro-composition of the Martian atmosphere with regard to nitrogen, argon, neon, krypton and xenon has also been compared with trapped gases for the Martian meteorite collection (12 in total). The isotope ratios for... 

Bogard D. D. and Garrison D. H. (1998). Relative abundances of argon, krypton, and xenon in the Martian atmosphere as measured in Martian meteorites. Geochimica et Cosmochimica Acta, 62(10) 1829-1835. 

Ott U (1993) Physical and isotopic properties of surviving interstellar carbon phases. In Protostars Planets III. Levy Hand Lunine JI (eds) University of Arizona Press, Tucson, p 883-902 Ott U (1996) Interstellar diamond xenon and timescales of supernova ejecta. Astrophys J 463 344-348 Ott U, Begemann F, Yang J, Epstein S (1988) S-process krypton of variable isotopic composition in the Murchison meteorite. Nature 332 700-702... 

Wieler, R., Baur, H. (1994) Krypton and xenon from the solar wind and solar energetic particles in two lunar ilmenites of different antiquity. Meteoritics, 29, 570-80. 

For krypton and xenon abundances were derived from computer hts of aN (neutron capture cross-section times abundance) versus mass number. Nuclei that are shielded from the r-process, so-called s-only nuclei, were used for the ht and the abundances of Kr and Xe were calculated. From these data, and the isotopic composition of the solar wind, the krypton and xenon elemental abundances were calculated (Palme and Beer, 1993) and are listed in Table 1. The meteorite data given in Table 1 will be discussed in a later section. 

For most of the chemical elements, the relative abundances of their stable isotopes in the Sun and solar nebula are well known, so that any departures from those values that may be found in meteorites and planetary materials can then be interpreted in terms of planet-forming processes. This is best illustrated for the noble gases neon, argon, krypton, and xenon. The solar isotopic abundances are known through laboratory mass-spectrometric analysis of solar wind extracted from lunar soils (Eberhardt et al., 1970) and gas-rich meteorites. Noble gases in other meteorites and in the atmospheres of Earth and Mars show many substantial differences from the solar composition, due to a variety of nonsolar processes, e.g., excesses of " Ar and... 

Limitations, (i) As with other radionuclide-based ages, the terrestrial age of the sample must be known, (ii) Concentrations of Kr are quite low in most meteorites, typically just 5 X 10 atomg in chondrites. For this reason, Kr measurements are still scarce and their uncertainties can be relatively large, often —20%. (iii) Production rates for krypton isotopes may vary with the abundances of rubidium, yttrium, and zirconium relative to strontium. It should be understood that the original basis for the calculation of Pgi/Fgs was a set of relative cross-section measurements for the production of krypton from silver (Marti, 1967). 

As all known lunar meteorites are finds (and therefore have nonzero terrestrial ages), we need at least four measured quantities to determine the four parameters of a simple one-stage history. Similarly, for a simple two-stage history, we need at least six measured quantities. Typically the data set available comprises He, Ne, Ne, Ar, C1, A1, and e. Occasionally we may have other information— the concentrations of spallo-genic krypton isotopes, spallogenic xenon isotopes, " Ca, and Mn, the densities of nuclear tracks (tracks/unit area), and the concentrations of certain isotopes produced by thermal neutrons, e.g., Ar (from C1) and Gd. 

Gilabert E., Lavielle B., Michel R., Leya L, Neumann S., and Herpers U. (2002) Production of krypton and xenon isotopes in thick stony and iron targets isotropically irradiated with 1600 MeV protons. Meteorit. Planet. Sci. 37, 951—976. 

The prior presence of " Pu, the only transura-nic nuclide known to have been present in the early solar system, can be inferred from its spontaneous-fission decay branch, through production of fission tracks and, more diagnostically, by production of fission xenon and krypton. The identification of " Pu as the fissioning nuclide present in meteorites is unambiguous, since the meteoritic fission spectrum is distinct from that of but consistent with that of artificial " Pu (Alexander et al, 1971). The demonstration of the existence of " Pu in the solar system reinforced the requirement (from the presence of I) of a relatively short time between stellar nucleosynthesis and solar-system formation and made it incontrovertible, since while it might be possible to make in some models of early solar system development, the rapid capture of multiple neutrons (the r-process) needed to synthesize Pu could not plausibly be supposed to have happened in the solar system. 

Wacker J. F. (1989) Laboratory simulation of meteoritic noble gases III. Sorption of neon, argon, krypton, and xenon on carbon elemental fractionation. Geochim. Cosmochim. Acta 53, 1421-1433. 

Noble gases and nitrogen in martian meteorites reveal several interior components having isotopic compositions different from those of the atmosphere. Xenon, krypton, and probably argon in the mantle components have solar isotopic compositions, rather than those measured in chondrites. However, ratios of these noble gas abundances are strongly fractionated relative to solar abundances. This decoupling of elemental and isotopic fractionation is not understood. The interior ratio in martian meteorites is similar to chondrites. 

Xenon and krypton in silicate-graphite inclusions of the El Taco iron meteorite. In... 

Kuroda PK (1960) Nnclear fission in the early history of the earth. Nature 187 36-40 Lewis RS (1975) Rare gases in separated whitlockite from the St. Severin chondrite Xenon and krypton from fission of extinct " " Pu. Geochim Cosmochim Acta 39 417-432 Lewis RS, Ming T, Wacker JF, Steele IM (1987) Interstellar diamonds in meteorites. Nature 326 160-162 Lipschutz ME, Gaffey ME, Pellas P (1989) Meteorite parent bodies nature, number, size and relation to present-day asteroids. In Asteroids 11. Binzel RP, Gehrels T, Matthews MS (eds) University of Arizona, Tucson, p 740-788... 

Krypton. The average isotopic composition of cosmogenic Kr in lunar soils and in chondrites is given in Table 4. These data are from compilations by Pepin et al. (1995) and Lavielle and Marti (1988). When correcting a measured Kr composition for a trapped component, the assumption is commonly made that the cosmic-ray-produced contribution on Kr can be neglected, so that the measured Kr can be assumed to be entirely trapped. Note that in different meteorites may contain variable contributions from... 

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