Young and Majestic

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Star dunes are one of nature’s architectural marvels.

These massive, pyramid-shaped dunes can reach hundreds of feet high and have multiple arms radiating out like the points of a star.

Created by opposing winds that change direction throughout the year, they are mainly found in remote locations across Africa, Asia, North America, and even Mars.

But apart from their beauty, these colossal formations are also scientific gold mines.

Scientists have just revealed that one of Earth’s largest and most complex star dunes, Lala Lallia, formed a mere 13,000 years ago.

Located in southeast Morocco’s Erg Chebbi sand sea, these wonders of nature are up to 330 feet tall and 2,300 feet wide.

For their paper, study authors Geoff Duller and Charles Bristow used a technique called luminescence dating to establish the dune’s age by analyzing when the sand grains were last exposed to sunlight.

The findings showed that Lala Lallia’s formation follows a fascinating timeline: The sands near the base were buried around 13,000 years ago, marking the initial creation of the dune.

But for the next 8,000 years, the region experienced a significant hiatus in sand accumulation, which coincided with the Sahara’s shift to a warm, wet climate around 11,700 years ago – a period that marked the end of the last ice age and the start of the Holocene epoch.

During this time, the Sahara transformed into a green, marshy landscape with vegetation stabilizing the sand, evidenced by pottery fragments and stone tools found around the dune.

Then, some 4,000 years ago, the Sahara began to dry out again. Even so, Lala Lallia did not start building up immediately, but instead took several millennia before the dune began its rapid growth, a process that only started within the past 900 years.

“The thing that stood out most was how young it is,” Bristow told Live Science. “We expected that a sand dune that is (330 feet) high was going to be … thousands of years (old), maybe tens of thousands of years.”

Star dunes have often eluded detailed study because of their remote and challenging locations. Even so, the authors noted that studying them can offer a window into prehistoric climates and wind patterns.

“This research is really the case of the missing sand dune – it had been a mystery why we could not see them in the geological record,” Duller said in a statement.

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