Isotopically anomalous silver in the Santa Clara and Piñon iron meteorites
- Creators
- Kaiser, T.
- Kelly, W. R.
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Wasserburg, G. J.
Abstract
The isotopic composition and concentration of Ag and the concentration of Pd have been determined in the Santa Clara and Piñon iron meteorites. It is shown that these meteorites contain isotopically anomalous Ag with an excess of ^(107)Ag relative to normal Ag, confirming earlier findings. Using an improved procedure for cleaning the sample surface from terrestrial Ag, a new concentration of 1-4×10^(11) atoms of ^(109)Ag/g meteorite is established which is an order of magnitude below the levels found earlier. As a result ratios of ^(107)Ag/^(109)Ag were found which are enriched in ^(107)Ag by 60% to 160%. The existence of an excess ^(107)Ag in these two meteorites, which have high ^(108)Pd/^(109)Ag ratios of ∼ 7×10^4, is established. These findings are consistent with the in situ decay of extinct ^(107)Pd (τ_½ = 6.5×10^6y) produced by a late nucleosynthetic event shortly before solar system formation; however, production of Ag isotopes by reaction of cosmic ray secondaries with the Pd isotopes in the meteorites cannot be excluded.
Additional Information
© 1980 American Geophysical Union. Received January 17, 1980; accepted February 5, 1980. We wish to dedicate this paper to the discoverer of Pluto, Prof. Clyde W. Tombaugh, the New Mexico State University, who generously made available the main mass of Piñon for study. We are indebted to Dr. Moore, the Arizona State University, for kindly and efficiently providing us with meteorite samples. One of us (TK) thanks Dr. Papanastassiou for valuable advice in many different fields. Another (WRK) thanks the Center for Analytical Chemistry, National Bureau of Standards, for permitting him to return to the Lunatic Asylum for three weeks. He also acknowledges and thanks S.B. Jacobsen for numerous stimulating lunchtime discussions on solar system chronology. This work was supported by NASA grant NGL-05-002-188 and NSF grant PHY 76-83685. Contribution 3352(333), Division of Geol. and Planet. Sciences.Attached Files
Published - grl1257.pdf
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Additional details
- Eprint ID
- 43038
- Resolver ID
- CaltechAUTHORS:20131217-085152103
- NGL-05-002-188
- NASA
- PHY 76-83685
- NSF
- Created
-
2013-12-17Created 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
- 333