Optically Stimulated Luminescence Dating of Sediments over the Past 200,000 Years

Abstract

Optical dating of sediment using optically stimulated luminescence has become important for studying Earth surface processes, and this technique continues to develop rapidly. A group of closely linked luminescence methods can be used to estimate the time since grains of quartz and feldspar were last exposed to daylight by detecting their subsequent response to environmental ionizing radiation exposure. The technique is well suited to the dating of deposits as young as one year to several hundred thousand years. Recent technical developments have established a dating protocol with improved precision, a high degree of reliability, and an in-built means to detect incomplete signal removal during deposition. This approach has been extended to age estimation for single grains, opening up a wider range of potential environments and new possibilities for understanding postdepositional grain movement. Ongoing research offers the possibility of significant age range extension and novel applications including low-temperature thermochronology.