Dating intramontane alluvial deposits from NW Argentina using luminescence techniques: Problems and potential

Through careful analysis of the alluvial sedimentology and choice of sampling environments we have been able to locate suitable samples in most vertical sequences studied. A post-infrared-OSL approach demonstrated that contaminant signals were resulting in protocol test failure and, conversely, circumvention of this problem has increased confidence and reliability in the dating results. Assessment of dose-response characteristics suggests that the luminescence for the oldest samples is not likely to be saturated and in turn ages are not considered to be underestimated. Finally, different statistical tests have enabled objective identification of single low-dose populations in complex distributions and confirmed that broad distributions in some samples may be treated as single populations. These statistical approaches have considerably lowered uncertainty on OSL ages and confirmed concordance with other dating evidence.