Stable Isotopes: Elements Other than Rare Gases

Abstract

Probably the single most important conclusion resulting from the study of the isotopic composition of relatively nonvolatile meteorite elements is that the meteorites are samples of normal solar system material. This conclusion is based on the fact that, as of now, all nonvolatile elements have the same isotopic compositions in meteorites as in terrestrial and lunar samples. In fact, the recent history of isotopic investigations of meteorites is a story of anomalies discovered and anomalies lost. For a period of about five years starting in 1962 various elements in certain meteorites were reported to have isotopic compositions which differed from those found in terrestrial samples. Later, more painstaking research has invariably shown the reverse. Detailed reviews are given by Reynolds (1967) and Voshage (1968a, b). Since the publication of these papers, previously reported anomalies have been disproved for the elements Li (Gradsztajn and Guez, 1970), Mg (Schramm et al., 1970), and Ba (Eugster et al., 1969). Elements having identical isotopic compositions in meteoritic and terrestrial samples include Cr (Murthy and Sandoval, 1965), Ga (de Laeter, 1972), Mo (Wetherill, 1964) and Sn (de Laeter and Jeffery, 1967).