Challenges of dating quartz OSL samples with saturated grains: Lessons from single-grain analyses of low dose-rate samples from Victoria Falls, Zambia

A suite of samples from an extensive aeolian sandscarp near Victoria Falls, Zambia was used to explore several different methods of calculating optically stimulated luminescence (OSL) ages that account for the effects of saturated quartz grains. Beta dose rate heterogeneity and early OSL signal saturation of the samples exacerbate the impact that saturated grains have on the equivalent dose (De) values calculated. Saturated grains that cannot calculate De values are often rejected but the minimum burial dose information they contain can have a significant impact on a sample's average De value. This study compares multiple techniques for combining luminescence measurements that enables inclusion of this data and their sensitivity to a criterion that rejects grains with early OSL signal saturation. The methods tested are found to have different advantages and disadvantages, but reasonable agreement between the De values they calculate suggests that including data from saturated grains makes a more significant difference to De values calculated than the specific method used to combine the data.