A team of experts has determined the age of a star dune called Lala Lallia (can be translated as the “highest sacred point” from the Berber language) in a remote part of Morocco and unearthed information regarding its development and movement across the desert, according to the new study published in the journal Scientific Reports.
The scientists were shocked to learn that the top of the dune had only formed in the previous 1,000 years or so, even though they found that the dune's base was 13,000 years old.
“It turned out to be surprisingly young,” Prof Geoff Duller, the co-author of the research paper, told the Western media.
The base kept building up until roughly 9,000 years ago.
“Then the surface stabilized. We think it was a bit wetter than today. We can see traces of old plant roots, suggesting the dune was stabilized by vegetation. It seems to have stayed like that for about 8,000 years. Then the climate started to change again, and this star dune started to form,” Duller was quoted as saying.
The expert explained that the dune was created by the convergence of winds blowing from the southwest and northeast, causing sand to accumulate. The dune is slowly moving westward at a pace of roughly 50 centimeters per year due to a third wind that blows steadily from the east.
The age of the star dune was determined by the scientists using a method known as luminescence dating, which allows them to calculate the last time the sand grains were exposed to light.
“We’re not looking at when the sand was formed – that’s millions of years ago – but when it was deposited. The grains of quartz have a property like a mini rechargeable battery,” the scientist said, as cited by the media.
Sand samples from Morocco were collected in the dark and then examined in a lab under dim red light, similar to that of an old-fashioned photography workshop.
The thing is, the longer the sand is buried underground, the more radioactive energy it builds up. So, when grains are exposed in the lab, they release that energy in the form of light, allowing scientists to determine their age.
At the end of last year, scientists managed to solve another mystery of the distant past, namely, what Gorgosaurus dinosaurs ate. Experts believed that the young lizards hunted relatively small and agile prey, including bird-like dinosaurs.
Interestingly, Gorgosaurus was a selective predator, as it limited itself to biting off and swallowing only the shins of its victims, without consuming the entire prey.