Recuperated OSL dating of fine-grained quartz in Chinese loess

The thermally transferred optically stimulated luminescence (OSL) signal from fine-grained quartz extracted from Chinese loess can be separated into two components, the recuperated and the basic transferred OSL signal. The recuperated OSL signal continues to grow with dose, beyond the dose region where the conventionally measured fast component of the OSL signal is close to saturation. A multiple-aliquot, two-part, regenerative-dose protocol, has been developed as a recuperated OSL dating method to extend the application of luminescence dating further back in time. Using the protocol the recuperated OSL signal is separated and used to estimate the equivalent dose for fine-grained quartz in Chinese loess. Ages obtained using equivalent doses determined by the recuperated OSL dating method for 12 samples from the last interglacial–glacial loess–palaeosol sequence are in agreement with multiple aliquot OSL ages and previous stratigraphic information. Ages obtained for four Chinese loess samples from close to the Brunhes/Matuyama (B/M) boundary were also consistent with the expected age of 776 ka. The recuperated OSL dating method, therefore, can go beyond the last interglacial and cover the total Brunhes epoch in Chinese loess.