A practical correction for sensitivity change in thermoluminescence multi-aliquot-regeneration dating of feldspar dominated fine grain loess

Multi-aliquot (MA) thermoluminescence (TL) has been used little since the advent of modern single-aliquot-regenerative-dose (SAR) sediment dating methods for both quartz and feldspar. However, for dating unheated feldspar-bearing sediments older than 100–200 ka, MA TL can still be useful. To improve precision in burial-dose estimation from TL, a post-bleaching regenerative-dose procedure is beneficial. However, the long-known regenerative-dose TL sensitivity changes cause significant age under-estimation in such MA TL. Here a practical procedure is demonstrated to correct for this post-bleaching sensitivity change. Two samples of fine grain, polymineral loess having independent ages of ∼130 ka and ∼350 ka are employed with the use of the SLIDE (combined additive-dose and regenerative-dose responses) procedure to show that not only accuracy but improved precision can be attained with use of this practical procedure. The procedure employs an operational definition of laboratory-dose sensitivity change with respect to a second-glow TL signal, and corrects for the sensitivity change as a function of laboratory dose and of glowcurve temperature.

► A practical method for correcting regeneration TL sensitivity changes in old loess. ► Overcomes age-underestimation problem associated with use of TL regeneration method. ► Demonstrates accurate and precise regeneration TL dating up to ca. 350 ka.