Variation in beta dose rate within rocks may impact the results of rock surface luminescence dating, for both the burial age of cobbles and exposure age of rock surfaces. Current methods of rock surface luminescence dating assume that radionuclides are homogeneously distributed inside rocks. In this study, two rapid methods based on beta counting and on a portable XRF instrument were developed to measure the radioactivity of rock slices. These methods were applied to rock slices from four glaciofluvial granite cobbles that had previously been used for equivalent dose determination to test whether beta dose variation could be observed. Results from beta counting and K content from XRF show similar patterns and both vary along the depth profiles, but the magnitude of this variability is very different amongst the four cobbles. In rocks where the dose rate is highly variable, bleaching may not be the only source of variation of L_n/T_n or equivalent dose (D_e) along the luminescence-depth profile of cobbles, and it may be necessary to measure the beta dose rate for every single slice to determine whether multiple bleaching events are recorded or variations in D_e are due to dose rate heterogeneity.

岩石内β剂量率的变化可能会影响岩石表面发光测年的结果，包括鹅卵石的埋藏年龄和岩石表面的暴露年龄。目前的岩石表面发光测年方法假设放射性核素均匀分布在岩石内部。在这项研究中，开发了两种基于 β 计数和便携式 XRF 仪器的快速方法来测量岩石切片的放射性。这些方法应用于四个冰川花岗岩鹅卵石的岩石切片，这些鹅卵石以前曾用于确定等效剂量，以测试是否可以观察到 β 剂量变化。来自 XRF 的 beta 计数和 K 含量的结果显示出相似的模式，并且两者都随着深度剖面而变化，但这种变化的幅度在四个鹅卵石中非常不同。_n /T _n或沿鹅卵石发光深度剖面的等效剂量 (D _e )，可能有必要测量每个切片的 β 剂量率，以确定是否记录了多个漂白事件或 D _e的变化是由于剂量率异质性。