Thermoluminescence dating of sand dunes in rajasthan
We report here a new application of thermoluminescence (TL) for dating sand dunes.
This application assumes that exposure to sunlight causes bleaching of the geological TL of a sediment to a residual value and that TL accumulation starts again when the sediment is buried under fresh deposit and is thus shielded from the Sun.
The nemesis that overtook northwestern Indias plenty and prosperity along with the disappearance of the river Saraswati, has been a subject engaging several minds over the last hundred and fifty years.
However, convincing explanations about what caused all the changes were available only in the later half of the current century through data gathered by archaeologists, geologists, geophysicists, and climatologists using a variety of techniques.
The TL dates at Amarpura suggest that the dune building activity at Amarpura in the Rajasthan desert terminated at around 13,000 years B.
Mejdahl, Risoe National Laboratory, DK-4000 Roskilde, Denmark.
It uses various methods to stimulate and measure luminescence.
Subsequent irradiation, for example if an x-ray is taken, can affect accuracy, as will the "annual dose" of radiation a buried object has received from the surrounding soil.The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried.Stimulating these mineral grains using either light (blue or green for OSL; infrared for IRSL) or heat (for TL) causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral.This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it.If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file.