ALBERT

Beschreibung: The induced thermoluminescence properties of 24 samples of basalts from volcanoes in the eastern Snake River Plain, Idaho, were measured as part of an investigation into the possibility of using this technique for dating purposes. The volcanic flows sampled ranged in age from 2200 years to ~400,000 years. The TL sensitivity values obtained, i.e. maximum induced TL normalized to that of the Dhajala meteorite (where Dhajala = 1000), ranged from 1.6 ± 0.3 to 226 ± 15 and showed a correlation between log TL and age with an r 2 value of 0.47. Thus TL sensitivity values correlate with age in the manner expected, although there is a high level of scatter. We discuss various mechanisms for the correlation and scatter, particularly (1) the role of primary (igneous processes) and secondary (solid state processes), (2) composition of the plagioclase feldspar, (3) weathering. The induced TL signal from feldspars, the mineral responsible for the TL, is strongly dependent on their composition and correcting for this improved the correlation (r 2  = 0.7). Variations in primary feldspar are affecting the data but we find no evidence that weathering of the samples is important. Further work is required to explore the remaining causes for the scatter and the TL-age trend. However, it is clear from the present study that induced TL has the potential for dating volcanism on the 2200 to 400,000 year time frame. This dating method, if successful, would be well-suited to spacecraft use since it requires low mass and low power instruments with a low data demand.