Isotopic composition of Xe in the most acid-resistant fractions of the Efremovka CV3 chondrite
Abstract
Isotopic compositions of three samples (E19, E20, and E22) of the Efremovka carbonaceous chondrite, obtained after 'hard' acid treatment of the original specimens were investigated. Results indicate that the fine-grained E19 contains Xe enriched by nucleogenic Xe-X. Samples E20 and E22 were found to be enriched by Xe-136, Xe-134, Xe-128, Xe-126, and Xe-124, in ratios that have no analogies among acid-resistant residues of other carbonaceous chondrites. It is suggested that the enrichment of Efremovka samples by heavy Xe isotopes was caused by the presence of Xe = H (CCF = Xe) or a mixture of extensively mass-fractionated solar Xe with Xe = X, whereas the enrichment by light Xe isotopes was caused by a intense neutron irradiation of some of the mineral phases of these samples previous to accretion.
- Publication:
-
Geokhimiia
- Pub Date:
- June 1991
- Bibcode:
- 1991Geokh......853F
- Keywords:
-
- Carbonaceous Chondrites;
- Isotopic Enrichment;
- Meteoritic Composition;
- Xenon Isotopes;
- Acids;
- Grain Size;
- Iodine Isotopes;
- Neutron Irradiation