Scientists Discover Age of Moroccan Desert's Giant Sand Dune

Scientists have calculated the age of a massive “star dune” in the Moroccan desert to be 13,000 years old. It's a discovery that could help them learn about the climate of the era when it first formed.

The giant sand dune is named Lala Lallia. That means “highest sacred point” in the Berber language. It stands 100 meters tall (328 feet) and 700 meters wide (2,300 feet) in the Erg Chebbi sand sea. That's near Morocco.   

Scientists used a technique called luminescence dating to figure out the dune’s age. Experts used tubing to dig deep into the lower sections of the dune and gathered samples. The sand grains were viewed in a lab under dim red light.    

This analysis determines the sand’s level of radioactivity. That comes from energy stored inside the sand crystals. The longer the sand is buried, the more radioactivity that is stored. In the lab, light is released. That allows scientists to measure the brightness of the light and calculate the grain’s age.  

“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,” Geoff Duller explained to the BBC. He's a professor at the Aberystwyth University in the UK.

The lower section of the dune is 13,000 years old. But the upper levels were formed just 1,000 years ago. “It turned out to be surprisingly young,” Duller told The Guardian. Duller said the desert’s climate must’ve been wetter than today. That's because they found traces of plant roots.     

Reflect: How can learning about the past help solve the problems of today?

Photo of Erg Chebbi dunes in Morocco courtesy Rosino on Wikimedia Commons.