Scientists calculate age of largest desert sands on earth: summary

What we know:

• Scientists have calculated the age of the Star Dune, one of the largest types of sand dunes situated in the Sahara Desert for the first time. Star Dunes get their name from their distinctive shapes and reach hundreds of metres in height.
• The dune in southeast Morocco called Lala Lallia which means “highest sacred point’’ in the local Berber language was discovered with sand at the base which traces back to 13,000 years.
• Researchers used dating techniques called luminescence to measure when the sand was last exposed to sunlight to understand the age of the dune. Samples of sand were taken in the dark from Morocco and analysed in a lab in dim red light conditions.
• The sand beneath the dune is exposed to more radioactivity over the years as it is buried, building more energy which it releases in light form, leading to the calculations.
• The dunes were said to have stopped growing for about 8,000 years after its initial formation and quickly expanded in the past several thousand years.

What they said:

According to Prof Geoff Duller at the University of Aberystwyth who published the research with Prof Charles Bristow at the Birkbeck Univerisity, understanding the age of the dunes formed by opposing winds that change direction helps scientists understand the winds that form them and unpick the climate of the particular era. "These findings will probably surprise a lot of people as we can see how quickly this enormous dune formed, and that it is moving across the desert at about 50cm a year," Prof Duller was quoted by the BBC, adding, “In our dark laboratory, we see light from these sand grains. The brighter the light, then the older the sediment grains and the longer it is since they've been buried”.