ABUNDANCES OF RUTHENIUM, OSMIUM AND URANIUM IN SOME COSMIC AND TERRESTRIAL SOURCES
Determinations of ruthenium and osmium in ten chondrites by neutron activation analysis give average concentrations of 0.89 x 10/sup -6/ g Ru/g meteorite and 0.91 x 10/sup -6/ g Os/g meteorite. With proper assumptions these values lead in turn to cosmic abundances (per 10/sup 6/ Si atoms) of 1.3 for Ru and 0.73 for Os. The averages cited include Ru and Os concentrations for a carbonaceous chondrite, which, though below average, fall within the range of concentrations found for the non-carbonaceous chondrites. The range in both the Ru and Os concentrations from about 0.6 x 10/sup -6 to 1.4 x 10/sup -6/g/g reflects not only the variable amount of metal content in the chondrites. but also the variation in Ru and Os concentrations in the metal phase. Analyses of the separated metal and siliceous phases of two chondrites show a marked enrichment of Ru and Os in the metal phase, and they further show that significant amounts of these elements are present in the siliceous phase. Ruthenium and osmium concentrations in Canyon Diablo troilite are found to be suppressed y from 92% to 6 two orders of magnitude to attribute the presence of Ru and Os in the siliceous phase of chondrites to sulfide inclusion. The isotopic ratio Os-814/Os-190 for osmium in meteorites agrees with that in terrestrial material to y from 92% to 6 1%, within the limits of experimental error. The agreement of Ru-96/ Ru-102 for ruthenium in meteoritic and terrestrial sources is y from 92% to 6 2--3%. Uranium concentrations are reported for a few samples including the standard rocks G-1 and W-1. Two achondrites, a tektite, and several terrestrial samples contained ruthenium and osmium concentrations 2--3 orders of magnitude below those in chondrites, giving evidence of the marked depletion of these elements in differentiated silicate matter. (auth)
- Research Organization:
- Argonne National Lab., Ill.
- DOE Contract Number:
- W-31109-ENG-38
- NSA Number:
- NSA-17-019001
- OSTI ID:
- 4708608
- Report Number(s):
- TID-16599; UAC-6583
- Country of Publication:
- United States
- Language:
- English
Similar Records
DETERMINATION OF ZIRCONIUM AND HAFNIUM IN METEORITES, SEDIMENTS, AND TERRESTRIAL MATERIALS BY NEUTRON ACTIVATION ANALYSIS (thesis)
ABUNDANCES OF THE FOURTEEN RARE-EARTH ELEMENTS, SCANDIUM, AND YTTRIUM IN METEORITIC AND TERRESTRIAL MATTER