Volcanic sediments are generally difficult to date using luminescence dating methods, but many important archaeological and palaeoanthropological sites are located in volcanic regions. Here we present an improved dating procedure for grains with composite mineralogies deposited at Liang Bua, the type locality of Homo floresiensis in Indonesia, using the post-infrared infrared stimulated luminescence (pIRIR) signal. Individual mineral grains that emit detectable pIRIR signals are composed of a range of feldspar varieties, quartz, clay minerals, heavy minerals and volcanic glass, rendering the isolation of individual potassium-rich feldspar grains infeasible. We investigate the luminescence behaviour of these composite mineral grains in detail, including their thermal stability, anomalous fading and dose-response characteristics. A standardised growth curve is developed to enable more time-efficient measurements, together with a ‘micro-aliquot’ approach in which each hole on a disc contains approximately 8–10 grains. Less than 1% of grains yield detectable pIRIR signals when measured individually, so the use of micro-aliquots provides, in effect, a means of estimating the equivalent dose (D_e) at single-grain resolution. Our results show that the pIRIR signal measured at 275 °C is suitable for estimating D_e values of these composite grains, without the need for residual dose or fading corrections.

通常使用发光测年法很难确定火山沉积物的年代，但是许多重要的考古和古人类学遗址都位于火山地区。这里，我们提出对谷物的改进的约会过程沉积在梁不啊的类型，局部性复合矿物学弗洛里斯人在印度尼西亚，使用后红外红外激发发光（pIRIR）信号。发出可检测到的pIRIR信号的单个矿物颗粒由多种长石变种，石英，粘土矿物，重矿物和火山玻璃组成，这使得单个富含钾的长石颗粒的分离变得不可行。我们详细研究了这些复合矿物晶粒的发光行为，包括其热稳定性，异常褪色和剂量响应特性。制定了标准的生长曲线，以实现更省时的测量，以及“微量等分试样”方法，其中光盘上的每个孔都包含大约8-10个晶粒。单独测量时，不到1％的谷物会产生可检测的pIRIR信号，因此使用微量等分试样实际上可以提供_e）以单颗粒分辨率。我们的结果表明，在275°C下测得的pIRIR信号适合估算这些复合颗粒的D _e值，而无需残留剂量或褪色校正。