When electron spin resonance (ESR) is applied to sedimentary quartz, dealing with the poor bleachability of the signals is particularly challenging. In this study, we used both the single-grain optically stimulated luminescence (OSL) and the single aliquot ESR dating of quartz from deep sand deposits preserving a Stone Age archaeological sequence to combine the advantages of the two methods: good bleaching behaviour and extended age range. Using the youngest samples at each sampling site we were able to calculate the mean ESR residual age from the difference between the OSL ages and the apparent ESR ages. Focusing mainly on the single aliquot regenerative dose (SAR) protocol here, we were able to calculate the mean ESR residual age for the Ti and Al centres, including the non-bleachable signal component for the latter. For the NP site, residual ages of 209 ± 13 ka and 695 ± 23 ka were calculated for the two centres, whereas for the ZS site 268 ± 39 ka and 742 ± 118 ka were determined. These residual ages are significant and cannot be neglected. Thus, the residual age was subtracted from the apparent ESR ages. The validity of the residual subtraction method was tested through a comparison of the oldest OSL age from each site with the residual subtracted ESR age. For both NP and ZS sites, the residual subtracted Ti and Al ages were consistent with the OSL age within 2-σ uncertainty, and therefore confirm the robustness of the subtraction method. Within the NP sequence, we were able to locate the end of the Early Stone Age at 590 ± 86 ka, and this provides a maximum age for the transition to the Middle Stone Age in this part of south-central Africa.

当电子自旋共振 (ESR) 应用于沉积石英时，处理信号的较差可漂白性尤其具有挑战性。在这项研究中，我们同时使用了来自保存石器时代考古序列的深层砂沉积物中石英的单粒光致发光 (OSL) 和单等分 ESR 测年，以结合两种方法的优点：良好的漂白行为和延长年龄范围。使用每个采样点的最年轻样本，我们能够根据 OSL 年龄和表观 ESR 年龄之间的差异计算平均 ESR 剩余年龄。这里主要关注单等分再生剂量 (SAR) 协议，我们能够计算 Ti 和 Al 中心的平均 ESR 剩余年龄，包括后者的不可漂白信号分量。对于 NP 站点，两个中心的剩余年龄分别为 209 ± 13 ka 和 695 ± 23 ka，而 ZS 站点的剩余年龄分别为 268 ± 39 ka 和 742 ± 118 ka。这些剩余年龄很重要，不容忽视。因此，从表观 ESR 年龄中减去剩余年龄。通过将每个站点的最老 OSL 年龄与剩余减去的 ESR 年龄进行比较来测试剩余减法方法的有效性。对于 NP 和 ZS 位点，剩余减去的 Ti 和 Al 年龄在 2-σ 不确定性内与 OSL 年龄一致，因此证实了减法方法的稳健性。在 NP 序列中，我们能够将早期石器时代的结束定位在 590 ± 86 ka，这为非洲中南部这一地区过渡到中石器时代提供了最大年龄。