⁴⁰Ar-⁴⁰K ages of silicate inclusions in iron meteorites
Abstract
Analyses of the argon and potassium in silicate inclusions were made on Weekerro Station, Toluca, Four Corners and Kodaikanal. The ⁴⁰Ar-⁴⁰K ratios of all samples except Kodaikanal are compatible with an age of 4.5 ± 0.15 × 10⁹ yr. These results are in agreement with the Sr-Rb results obtained previously but not with the so-called ⁴⁰Ar-⁴⁰K ages determined on iron meteorites by other workers. The ⁴⁰Ar-⁴⁰K age of 3.5 ± 0.1 × 10⁹ yr on Kodaikanal is consistent with the ⁸⁷Sr-⁸⁷Rb age of 3.8 ± 0.1 × 10⁹ yr. Estimates of the U + Th content of the silicate inclusions were made based on the ⁴He contents. Kodaikanal was found to have a very young exposure age for an iron meteorite (⪅40 m.y) based on upper limits to the cosmogenic He, Ne and Ar in the metal phase.
Additional Information
The meteorite samples were obtained through the cooperation of C. Frondel (Harvard University), V. Manson (American Museum of Natural History), C. Moore (Nininger Meteorite Collection) and E. Olsen (Chicago Museum of Natural History). We thank Pai Young and Theodore Wen for assisting in the measurements. This research was supported by grants from the National Science Foundation (NSF GA-464 and NSF GP-7976 (formerly GP-5391)), the office of Naval Research (Nonr 220-47) and the National Aeronautics and Space Administration NGR 05-002-044Additional details
- Alternative title
- 40Ar-40K ages of silicate inclusions in iron meteorites
- Eprint ID
- 117919
- Resolver ID
- CaltechAUTHORS:20221121-280779900.4
- GA-464
- NSF
- GP-7976
- NSF
- GP-5391
- NSF
- Nonr 220-47
- Office of Naval Research (ONR)
- NGR 05-002-044
- NASA
- Created
-
2022-11-29Created from EPrint's datestamp field
- Updated
-
2022-11-29Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Division of Geological Sciences
- Other Numbering System Identifier
- 1504