In a remarkable feat, scientists from the UK have unraveled the mystery surrounding Earth's oldest sand dunes. Their jaw-dropping revelations promise to reshape our understanding of geological wonders, especially of the sand seas.
Scientists from the UK have successfully unravelled secrets behind the earth's oldest sand dunes which are also known as ‘star dunes' or 'pyramid dunes’. The star dunes phenomenon is seen in various deserts ranging from North America, China, Africa, and Arabia. Such natural phenomena also occur on Mars and Saturn's moon Titan.
A team of scientists reached Morocco to investigate one of the earth's most prominent star dunes. They used a scientific method called luminescence dating to know the age of the star dunes called Lala Lallia. The technique identifies the age by calculating when the grains of sand were last exposed to daylight.
Lala Lallia which is in the Southern Eastern part of Morocco is 100-metre-high and 700-metre-wide making it one of the most unique star dunes. The scientists made the mysterious discovery about the age wherein they found that the dune was 13,000 years old, but the upper part of the dune was only formed in the last 1,000 years.
Lala Lallia formed over 900 years ago, adding 6,400 metric tonnes each year. After its initial growth, it paused for about 8,000 years before experiencing rapid expansion in the past few thousand years. The major factor in the formation of the sand dune is due to a change in the wind direction over the years.
Birkbeck University and fellow study co-author Charlie Bristow said, ''Star dunes are formed in areas with complex wind regimes, which means winds blowing from different directions, and net sand accumulation, points within the desert where big piles of sand can be blown around to form giant dunes. They form extraordinary and awe-inspiring landscapes. From the ground, they can be intimidating, mobile mountains of sand.'’