Osl dating sheffield
Measurements have been performed on different luminescence readers to study the possible contribution of instrument reproducibility.
These have shown that a great variability can be observed not only among the studied samples but also within a specific site and even a specific sample.
This means less sampling in the field, much less material to pack up and ship them home for full analsysis.
This is good because sediment samples are heavy and expensive to transport, and we would have also wasted a lots of laboratory time and chemicals preparing the samples and analytical time measuring those samples not relevant to the time frame we are interested in.
For example, if the question was ‘how dyanmic was dune accumulation and migration over the past 5,000 years’ we could rapidly make measurements on small amounts of material in the field to target those parts of the 34,000 km^2 of the Namib Sand Sea that were about 5,000 years old or less.
Then we would need only to sample those areas and depths into the sand dunes.
For this reason a number of researchers have been developing ways to assess the depositional age of materials more rapidly.
This rapid assessment of age might be particularly useful in the early stages of working out the approximate age of new sites, or if the research project is focussed on understanding landscape dynamics during a particular time period, such as the late Holocene or the Last Glacial Maximum.
Tight acceptance criteria to measured doses from natural, not exposed, aliquots have been applied.
It has an applicable age range from 10 to 500,000 years, depending on the type of sediment and the amount/rate of background radiation it has been exposed to.
However, as any luminescence dating practitioner is only too aware, the dating process is time consuming and complicated process, involving lots of time in a subdued-light laboratory, a reasonable volume of chemicals (to refine your sample down solely to quartz or to feldspar-dominated fractions) and some pretty expensive and weighty bits of analytical kit.
Therefore, we wanted to see how far we could get toward turning the intentisty of the light signal measured in the portable reader into a rough estimate of actual sample burial age… I chose samples which I had slavishly previously dated using both full sample preparation (to quartz in this case) and full established measurement protocols on which to also measure using the portable luminescence reader to make the comparison.
We chose to take a very simple approach to the comparison – that of making a linear regression of the portable reader signal intensity against established sample burial age (using full dating).