OPTICALLY STIMULATED LUMINESCENCE DATING OF YOUNG SEDIMENTS AND DUSTS

In many geological and archaeological studies investigated within a Late Quaternary timeframe, one or more of a suite of different optically stimulated luminescence (OSL) approaches may now be applied to provide critical chronological constraint. Such luminescence applications might be in instances where age exceeds radiocarbon limits or there is a paucity of organic material.

Accurate luminescence geochronology of very young (10s to 100s yr timeframe) deposits is also achievable, provided that certain luminescence characteristics and depositional environment factors hold true. Important considerations are: sufficiently high specific luminescence sensitivity to enable measurement of very small doses; whether thermal transfer signals lead to dose overestimation; a more familiar problem of extent of optical resetting; and, whether the dose-rate is accurately reconstructed for shallow-depth surficial deposits with changing depositional environment.

Data from studies over the last few years will be used to illustrate the challenges of OSL dating of very young sediments, including recent work on attic dust deposits and the specific problems of dose-rate reconstruction for very thin (~5 mm) layers.