Thermal metamorphism of primitive meteorites—II. Ten trace elements in Abee enstatite chondrite heated at 400–1000°C

Trace Element Contents of Selected Antarctic Meteorites.I. Weathering Effects and ALH A77005, A77257, A77278 and A77299

“…While the neutron flux Avas less thermalized than that in the Argonne CP-5 reactor we used previously, results from Allende standard reference meteorite powder irradiated in both reactors by Ngo and Lipschutz [9] were quite comparable and indicated no self-shielding effects for the elements considered here. Chemical and counting procedures, summarized in part by Ngo and Lipschutz [9], for most elements were generally modifications of those described by Binz et al [5], Ikramuddin et al [8] and Bart et al [10]. Additional elements -As, Cu, Rb, Sb -were interposed in the analytical scheme with As and Sb being precipitated as sulfides in acid medium from the supernate after precipitation of basic sulfides from the dissolved Na202-Na0H fusion cake.…”

“…Samples were prepared for irradiation as in Ikramuddin et al [8]. All irradiations were 4-days' long and were performed at the University of Missouri research reactor; fluxes were ~ 1.2 x 10 14 neutrons cm 2 /sec.…”

Production rates and proton‐induced production cross sections of 129I from Te and Ba: An attempt to model the 129I production in stony meteoroids and 129I in a Knyahinya sample

“…Using the Te concentration of 2.5 mg/kg used by Nishiizumi et al (1983) for Abee from Ikramuddin et al (1976) and 2.8 mg/ kg Ba compiled for EH chondrites (Wasson and Kallemeyn 1988), we can calculate a 129 I production rate of 1.39 × 10 −3 atom 129 I min −1 (kg m) −1 for 13 cm shielding depth (Nishiizumi et al 1983) in a body of 32 cm radius. This rate is in excellent agreement with the experimental production rate of 1.40 × 10 −3 atom 129 I min −1 (kg m) −1 (Nishizumi et al 1983).…”

On volatile element trends in gas-rich meteorites

“…We note however that Rieder and Wanke's datum for Leighton light falls outside the range reported for In in H5-6 chondrites while our result is within the range in H3-4 chondrites (cf. Binz et al, 1976). Fortunately, our conclusions are unaffected by these discrepancies.…”