Define luminescence dating
The quartz from the specimen under investigation is divided into two parts one of which is heavily bleached under a UV sunlamp.This exposure effectively removes almost all of the previously acquired TL leaving only what is termed as the unbleachable TL.The technique is best suited to the age determination of sediments which have undergone long transport distances and, in the case of water borne sediments, as suspended load under shallow water, low energy conditions.Aeolian sediments are more likely to have undergone considerable solar exposure prior to deposition and therefore are more likely to have been effectively zeroed.A sample of recently deposited similar material should also be submitted in order that the TL starting point at the time of deposition can be measured and a suitable correction applied.In the case of an aeolian deposit this may be collected as a surface peel on adhesive tape or from the subsurface of the deposit.
This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process.
The exposed material at either end of the tube is used in the determination of the annual radiation dose and the internal unexposed portion for the palaeodose determination.
The sample collected should be taken from the centre of a homogenous sphere of 30cm radius.
TL Age = Palaeodose (P) _____________ (ARD) TL samples may be collected in open ended or opaque PVC tubes approximately 12cm in length and 6cm in diameter.
Whilst it advisable to protect the sample from direct sunlight there is no need to sample at night and the orientation of the specimen is not important.