Electron spin resonance spectroscopy

The ESR spectrometer at ANU is one of the most versatile spectrometers. It has X-band and Q-band microwavebridges and measurements can be carried out between 3 and 700K.

At present, there are two research foci:

Dating of human fossils

It has been shown repeatedly that it is difficult to date human fossils via associated material because in many instances, the human bodies were buried or have been excavated a long time ago and therefore their association with other material is uncertain. The only way to address these problems is by analysing human remains directly. Apart from gamma spectrometry, we have developed ESR dating of tooth fragments which, after ESR analysis, are re-inserted into the original teeth. In this way we have established the ages of human fossils from Florisbad, Skhul, Atapuerca and Tabun.

Establishment of the dose response characteristics of paramagnetic centres in quartz

We have developed a new technique for the assessment of denudation rates by using Ti and Al centres in quartz. Their effective closure-temperatures are lower than those of established methods (e.g. K/Ar, fission track or (U,Th)/He) and allow the calculation of differential erosion rates in the Quaternary.