Re-Os Ages of Group IIA, IIIA, IVA, and IVB Iron Meteorites

  title={Re-Os Ages of Group IIA, IIIA, IVA, and IVB Iron Meteorites},
  author={Michael I. Smoliar and Richard J. Walker and John W. Morgan},
  pages={1099 - 1102}
Rhenium and osmium concentrations and osmium isotopic ratios of group IIA, IIIA, IVA, and IVB iron meteorites were determined by negative thermal ionization mass spectrometry with modified digestion and equilibration techniques. Precise isochrons are defined for all four groups. An absolute age of 4558 million years is assumed for group IIIA irons, leading to closure ages of 4537 ± 8, 4456 ± 25, and 4527 ± 29 million years for the group IIA, IVA, and IVB irons, respectively. The initial osmium… 
Mn‐Cr chronology of five IIIAB iron meteorites
Abstract— Mn‐Cr systematics in phosphates (sarcopside, graftonite, beusite, galileiite, and johnsomervilleite) in IIIAB iron meteorites were investigated by secondary ion mass spectrometry (SIMS). In
Rhenium‐187—osmium‐187 in iron meteorites and the strange origin of the Kodaïkanal meteorite
Abstract— A set of iron meteorites was investigated for Re‐Os isotopes and provides a well‐defined isochron age of 4.624 ± 0.017 Ba and an initial 187Os/188Os ratio of 0.095636 ± 0.00009. Actual ages
Compositions of group IVB iron meteorites and their parent melt
Osmium isotopic compositions of Os‐rich platinum group element alloys from the Klamath and Siskiyou Mountains
[1] We present new measurements of Os-186/Os-188 and Os-187/Os-188 in 10 Os-rich platinum group element (PGE) alloys from placer deposits formed by the mechanical erosion of peridotite-bearing
Re-Os isotope geochemistry of three Chinese chondrites
Three Chinese ordinary chondrites, including Jilin (H5), Boxian (LL3.8) and Lujiang (LL6), have been studied for their Re and Os abundances and Os isotopic composition in whole-chondrite samples,


Rhenium-Osmium Isotope Constraints on the Age of Iron Meteorites
Age constraints imply that the parent body of the IIAB magmatic irons melted and subsequently cooled within 100 million years after the formation of the oldest portions of chondrites.
Neodymium, strontium and chromium isotopic studies of the LEW86010 and Angra dos Reis meteorites and the chronology of the angrite parent body
Neodymium, stontium, and chromium isotopic studies of the LEW86010 angrite established its absolute age and the formation interval between its crystallization and condensation of Allende CAIs from
Wasserburg, Geochim. Cosmochim
  • ibid. 54,1729
  • 1990