Application of different protocols and age-models in OSL dating of earthen mortars

In this study, OSL dating was applied to earthen mortars, consisting in a quartz-rich aggregate dispersed in silty-clayey matrix. The samples were taken from two independently dated structures in Cremona, Northern Italy (Palazzo Raimondi, 1495–1499 AD and Palazzo Soldi, 1770–1790 AD). The evaluation of the equivalent dose (D_e) was attempted with both the multigrain and the single grain protocols using the 150–250 μm quartz fraction.

The reliability and effectiveness of the various statistical methods in identifying the well-bleached samples were tested. The use of the multi-grain technique gave unreliable results, due to the high amount of poorly bleached grains. With the single-grain technique, more promising results were obtained: in particular, the un-log MAM3 and IEU models allowed an accurate evaluation of the mortar expected age in most cases, even if the precision is still relatively low.