^(39)Ar recoil losses and presolar ages in Allende inclusions
- Creators
- Villa, I. M.
- Huneke, J. C.
-
Wasserburg, G. J.
Abstract
Ar analyses are reported for five coarse-grained, Ca-Al-rich inclusions from the Allende meteorite. The samples were neutron-irradiated in individual evacuated ampoules, and the Ar gas in the ampoules as well as the samples was analyzed. A large fraction (up to 60%) of the ^(39)Ar from ^(39)K (n, p) reactions was lost out of the inclusions into the ampoules. The ^(39)Ar losses resulted in substantial increases in the apparent ^(40)Ar-^(39)Ar ages of the samples. ^(39)Ar recoil loss during neutron-irradiation is a major effect and must be accounted for in ^(40)Ar-^(39)Ar dating. All of the Allende inclusions studied contained substantial trapped ^(36)Ar. The origin of the trapped ^(36)Ar is unknown, and the possible presence of trapped ^(40)Ar cannot be excluded. Ar measurements on Allende inclusions which have yielded anomalously old ages must be re-examined in the context of ^(39)Ar recoil loss and possible contributions of trapped ^(40)Ar. Allende inclusions appear on both accounts to be poor candidates to search for relicts of presolar materials with well-defined K/Ar ages.
Additional Information
© 1983 Elsevier Science Publishers B.V. Received July 19, 1982; Revised version accepted January 11, 1983. D. and T. Papanastassiou provided lodging for one of us. Evelyn Brown provided stability to the Lunatic Asylum inmates. Comments from the reviewers and the editorial review by F. Begemann aided us in clarifying several issues. This work was supported by NASA grant NGL 05-002-188 and NSF grant PHY 81-19964.Additional details
- Eprint ID
- 41213
- Resolver ID
- CaltechAUTHORS:20130910-134304904
- NASA
- 05-002-188
- NSF
- PHY 81-19964
- Created
-
2013-09-17Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Lunatic Asylum Lab
- Other Numbering System Identifier
- 422