Optically stimulated luminescence dating of fluvial deposits a review
Quartz OSL ages can be determined typically from 100 to 350,000 years BP, and can be reliable when suitable methods are used and proper checks are done.
Feldspar IRSL techniques have the potential to extend the datable range out to a million years as feldspars typically have significantly higher dose saturation levels than quartz, though issues regarding anomalous fading will need to be dealt with first.
This study shows the importance of using an adequate statistical approach to calculate reliable OSL ages from fluvial sediments.
Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating.
For the investigated coarse grain quartz samples all ages calculated from the MAM-3, including their uncertainties, are within the historical documented age.
Results of the polymineral fine grain samples are overestimating the historically documented depositional age, indicating undetectable incomplete bleaching.
This can result in a scattered distribution of equivalent doses (D), leading to incorrect estimation of the depositional age.The minerals that are measured are usually either quartz or potassium feldspar sand-sized grains, or unseparated silt-sized grains.There are advantages and disadvantages to using each.For quartz, blue or green excitation frequencies are normally used and the near ultra-violet emission is measured.For potassium feldspar or silt-sized grains, near infrared excitation (IRSL) is normally used and violet emissions are measured.