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Scientists have determined the time that has passed since the creation of one of Earth’s most ancient dunes, marking a significant development that may provide further insights into the environmental and wind patterns of the past.
Star dunes are the tallest and most complex type of desert sand formations, reaching hundreds of meters in height.
These structures are known as pyramidal formations with arms that radiate outwards. They are commonly found in desert areas such as the sand seas of Africa, Arabia, China, and North America. They can also be found on other planets such as Mars and Saturn’s moon Titan.
These unique formations, known as star dunes, are a result of wind patterns switching direction, but their age has not been determined in the past.
Researchers have determined the age of a star dune known as Lala Lallia in Morocco for the first time.
The researchers discovered that the star-shaped dune in the Erg Chebbi sand sea in southeast Morocco was created 13,000 years ago. It currently stands at a height of approximately 100 m and is 700 m wide.
Researchers discovered that there has been a significant increase in the amount of sand over the last millennium, and it is moving in a westward direction.
The shoreline of Florida’s beaches is facing erosion as a result of strong storms.
Researchers have discovered that the most recent research suggests that the development of the star-shaped dune was linked to shifts in wind patterns over time.
In the future, this research may help identify “star dunes” when examining the rock record.
Scientists approximated that the dune, standing at a height of 100 m, potentially ceased its growth for a period of 8,000 years before experiencing rapid expansion over the next few thousand years.
During the time when the dune ceased its growth, there are pieces of broken pottery scattered on the eastern side of the sandy structure.
This indicates that there may have been moisture present during the time when the dune was expected to have been stabilized by plants.
These discoveries also prompt inquiry into the process by which this enormous sand dune evolved and sustained its average yearly movement of 50cm.
Researchers utilized a novel approach to determine the age of a geological feature known as dines, estimating the moment at which sand grains were last exposed to sunlight.
The sand grains tend to absorb radiation from their surroundings which they release in the lab under specific conditions.
When left undisturbed for extended periods, they assimilate increased amounts of radiation, assisting in the development of a chronological sequence of sand layers.
The intensity of the glow from certain grains indicates their age.
With this method, scientists could evaluate the amount of energy released by various layers in order to determine their age.
According to the research, there is a break in the record dating back around 8000 years at the foot of the dune. However, the dune has been expanding quickly over the past 1000 years, reaching a height of 100 meters, and is currently moving towards the west.
Source: independent.co.uk
