Abundances Of Te Research Articles

The Holbrook, Arizona, chondrite

The Holbrook chondrite has been reanalysed, with the following results: Fe 7·18, Ni 1·09, Co 0·054, Cu 0·0096, FeS 7·94, SiO 2 40·11, TiO 2 0·14, Al 2O 3 1·90, Cr 2O 3 0·51, FeO 12·01, MnO 0·37, MgO 25·18, CaO 1·74, Na 2O 0·93, K 2O 0·10, P 2O 5 0·40, H 2O 0·27, C 0·06 total 99·99. The mineralogical composition is olivine (Fo 74), hypersthene (En 76), plagioclase (An 15), nickel-iron, troilite, chromite, and possibly apatite. The density of the meteorite is 3·56. A summary of the data on the abundances of Ba, Bi, Cs, Cu, In, Pb, Li, Hg, Rb, Se, Se, Sr, Te, Tl, Th, U, V, Y and Zr in this meteorite is included.

10. General Discussion

1. p. SELINOV: Anomalous abundances of Te and Xe isotopes in meteorites and in the Earth permit us to draw some conclusions concerning the age of uranium and the processes of nucleogenesis. According to the estimate by Hoyle the amount of 254Cf disintegrated during a super-nova outburst is of the order of io29 g or io~4 of the stellar mass. According to the fission-yield curve the isotopes of Te comprise about 1 % of the mass of fission products. The abundances of Te 128-131 are anomalously high, due to the fission of heavy nuclei. The element abundances do not permit us to draw any conclusions about the r-process. The isotopes of Te and Xe with even mass numbers give evidence in favour of the r-process (anomalously high abundances). But the amount of Te in meteorites and in Earth is about 1000 times less than it should be if formed during the outburst. The Sikhote- Alin meteorite shows the same anomaly. We may conclude that the heavy elements of the solar system have been formed not in a single super-nova outburst, but as a result of mixing from the totality of outbursts. According to Hoyle, this gives a definite estimate for the age of uranium.