Alkali feldspars are routinely used in retrospective dosimetry using luminescence methods. However there is a signal loss over time, termed ‘anomalous fading’, which results in age underestimation if uncorrected. Although significant improvements have been made in recent years, luminescence dating of feldspars remains challenging. This paper investigates the relationships between chemistry, structural state and the scale of exsolution with thermoluminescence (TL) emission spectra and infrared stimulated luminescence (IRSL) fading rates.

We measure TL emission spectra, where possible linking the recombination site to physical features of the feldspar crystals. We show that fading rates are lowest in ordered end-member Na- and K-feldspars but significantly greater in disordered end-members, showing that Al–Si order influences fading. As well as having very low fading rates, ordered end-member samples have distinctive TL emission spectra, with the yellow-green emission dominant, while all other samples have a dominant blue emission. Perthites, i.e. exsolved members of the (Na,K)-feldspar solid solution, show greater fading than disordered end-members and fading is greatest in semi-coherent macroperthite. We propose that the state of Al–Si-order, and the occurrence of defects and dislocations at the perthite lamellar interfaces influence anomalous fading rates in feldspars.

碱长石通常用于采用发光法的回顾剂量法中。但是，随着时间的流逝会有信号丢失，称为“异常衰落”，如果不进行校正，则会导致年龄被低估。尽管近年来已经取得了显着的进步，但长石的发光定年仍然具有挑战性。本文研究了化学性质，结构状态和具有热发光（TL）发射光谱和红外激发发光（IRSL）衰落速率的解离尺度之间的关系。

我们测量TL发射光谱，在可能的情况下将重组位点与长石晶体的物理特征联系起来。我们表明，有序端成员Na和K长石中的衰落率最低，而无序端成员中的衰落率则明显更高，这表明Al-Si顺序会影响衰落。除具有非常低的衰落率外，有序的末端成员样品还具有独特的TL发射光谱，其中黄绿色发射占主导，而所有其他样品则具有占主导的蓝色发射。蠕虫，即（Na，K）-长石固溶体的溶解成员，比无序末端成员显示出更大的褪色，并且在半相干大蠕虫中褪色最大。我们提出，Al-Si有序状态以及在珍珠岩层状界面处缺陷和位错的发生会影响长石的异常衰落率。