title: Thermoluminescence signal in K-feldspar grains: Revisited.
abstract: Recent work has shown that infrared stimulated luminescence (IRSL) signals in sedimentary coarse-grain K-feldspars are derived mainly from high temperature thermoluminescence (TL) peaks around 400°C, and the fading components of the IRSL signal can be preferentially removed by prior IR stimulation at relatively low temperature. Considering the complexity of TL signal for very old samples, we may choose non-fading components from K-feldspar TL signals using the combination of optical and thermal activation methods. This paper examines a protocol of post-IR isothermal TL (i.e. pIRITL) signal for sedimentary coarse-grain K-feldspars, which results from isothermal TL measurements following elevated temperature IR bleaching. We show that a sum of two exponential decay functions can fit well to the pIRITL decay curves, and both the holding temperature for isothermal TL measurements and the prior elevated temperature IR bleaching can affect greatly the fast components of pIRITL signal. The dose response ranges of pIRITL signal are wider than those of post-IR IRSL signals, but the relative high residual pIRITL signal means that it is not appropriate for dating young samples. It is expected that one isothermal TL signal for K-feldspar measured at ~400°C following IR bleaching at 290°C (i.e. pIRITL400) is useful for dating very old samples.
authors.affiliation: State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou, China; Nordic Laboratory for Luminescence Dating, Department of Earth Sciences, Aarhus University, Risø-DTU, DK-4000 Roskilde, Denmark.
authors.forename: Gelian
authors.initials: G
authors.lastname: Gong
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Sun
authors.affiliation: School of Computer Science and Engnieering, South China University of Technology, 510006 Guangzhou, China.
authors.forename: Hongyun
authors.initials: H
authors.lastname: Xu
keywords: IRSL; Isothermal TL; K-feldspar; Non-fading