|may be used for dating these environmental archives in the time range 0-1000 years. It has the potential to fill the gap between the shorter-lived and bomb-produced isotopes and cosmogenic 14C.|
Cosmogenic 32Si, with a half-life of ca. 140 years, is ideally suited to provide time information in the range 50-1000 years. Detection of 32Si is, however, very difficult due to extremely low natural concentrations and isotopic ratios. The difficulties of setting up extremely low background systems, and the need for large samples have previously deterred wider use of 32Si. At GNS we have developed improved methods for radiometric detection of natural 32Si [Morgenstern et al., 2001] and, in collaboration with Australian National University, have succeeded in measuring natural 32Si by accelerator mass spectrometry (AMS) [Morgenstern et al., 2000, Fifield and Morgenstern 2008].