Access

Letters to Nature

Nature 305, 611-612 (13 October 1983) | doi:10.1038/305611a0; Accepted 22 August 1983

Measurements of 129I in meteorites and lunar rock by tandem accelerator mass spectrometry

K. Nishiizumi*, D. Elmore†, M. Honda‡, J. R. Arnold* & H. E. Gove†

  1. *Department of Chemistry, B-017, University of California, San Diego, La Jolla, California 92093, USA
  2. †Nuclear Structure Research Laboratory, University of Rochester, Rochester, New York 14627, USA
  3. ‡Permanent address: Department of Chemistry, College of Humanities and Sciences, Nihon University, Setagaya, Tokyo, Japan.
Top

The radioisotope 129I (half life, t½=1.57times107 yr) offers the possibility of extending the time span over which cosmogenic radioisotopes can be used to study extraterrestrial and terrestrial phenomena. Its half life falls between that of 53Mn (3.7times106 yr) and 40K (1.28times109 yr) in a region where interesting effects can be expected. The target elements for z>28 are normally present in low concentration in natural materials, making detection difficult. We report here the first precise measurements of 129I in extraterrestrial materials: three meteorites of different classes and one lunar surface rock.