Comparative post-IR IRSL (pIRIR290) K-feldspar age estimates for Qinghai Lake highstands: A comment

Using a post-IR IRSL (pIRIR290) K-feldspar luminescence dating method, Long et al. (2018) suggest the highest exposed shoreline features of Qinghai Lake date to early MIS 3. This age estimate is in conflict with a host of quartz and post-IR IRSL (pIRIR290) K-feldspar luminescence age estimates suggesting lake highstands in other basins, which, like Qinghai Lake, are also fed by Qilian Mountains precipitation, date to MIS 5. We think the apparent conflict may be due to the use of different average water content estimates. Depending on whether estimates of 10-20% are used, many samples can date to anywhere from late MIS 5 to early MIS 3. It thus becomes critical that better ways to estimate water content must be developed before OSL chronologies can be used for understanding lake histories, and by extension, climatic change.