Isotopes in Meteorites

Oxygen Isotopes in Meteorites

Oxygen isotope abundance variations in meteorites are very useful in elucidating chemical and physical processes that occurred during the formation of the solar system (Clayton, 1993). On Earth, the mean abundances of the three stable isotopes are O: 99.76%, O: 0.039%, and O: 0.202%. It is conventional to express variations in abundances of the isotopes in terms of isotopic ratios, relative to ...

OXYGEN ISOTOPES IN CIRCUMSTELLAR Al20 3 GRAINS FROM METEORITES AND STELLAR NUCLEOSYNTHESIS

We have found a ~311m Al20 3 grain (B39) in the Bishunpur LL3.1 chondrite that is enriched in 170 by a factor of ~6.8 e60/170 = 385 ± 9) and depleted in 180 by almost 60% e60/180 = 853 ± 30) relative to solar system oxygen and has an initial 26Al/27Al = 1.7 ± 0.2 x 103, ~34 times greater than the initial solar system value. The isotopic compositions of B39 and two other Al20 3 grains previously...

Fe Isotopes in Martian Meteorites: Role of Water and Possibility of Life on Mars

Analytical developments for high-precision measurements of W isotopes in iron meteorites.

A procedure was developed to accurately measure the W isotopic compositions of iron meteorites with a precision of better than +/-0.1 epsilon on epsilon182W and epsilon184W (normalized to 186W/183W). Purification of W was achieved through a two-step, ion-exchange procedure. In most cases, the yield is better than 80%, and purified W solutions are clear of matrix elements and direct isobars of W...

The Effect of Cosmic Ray Irradiation on Platinum and Palladium Isotopes in Iron Meteorites

Introduction: Dating of early solar system processes such as differentiation and core formation of planetesimals and planets frequently relies on shortlived decay systems such as Hf-W [e.g. 1] or Pd-Ag [e.g. 2,3]. However, these systems are susceptible to the effects of galactic cosmic rays (GCR) and hence, acquiring correct ages requires knowledge of the exposure history of the meteorite. Expo...