Despite the prevalence of giant star-shaped sand dunes in modern deserts across the globe, it is surprising that they have not been found in geological records, with only one dating back over 250 million years in north-east Scotland. This discrepancy has puzzled scientists for decades, especially considering the presence of these unique dunes on Earth and even on extraterrestrial deserts like Mars and Titan.
A New Study Sheds Light on the Mystery
A recent study conducted by researchers from University College London and Aberystwyth University in the UK provides a possible explanation for the absence of star dunes in geological records. The study focused on the Lala Lallia dune in southeast Morocco, offering the first detailed analysis of a star dune to aid in their identification in sedimentary rock.
Geoff Duller, a professor in Geography and Earth Sciences at Aberystwyth University, describes the research as uncovering the mystery of the missing sand dunes in geological records. The Lala Lallia dune, standing at 100 meters high with radiating limbs extending 700 meters, was found to be approximately 13,000 years old at its base. Surprisingly, much of the dune’s formation occurred in the last thousand years, with the structure gradually moving westward across the desert.
Star dunes, characterized by shifting wind patterns, are among the tallest dunes on Earth, with some reaching up to 300 meters in height. Despite their majestic presence, there has been a limited number of studies conducted on these unique geological features. The challenge now lies in revisiting the geological record with the insights from this new study to identify star dunes that might have been overlooked due to a lack of understanding of their size and patterns.
Uncovering the Secrets of Star Dunes
Sedimentologist Charlie Bristow, from University College London, emphasizes the importance of using ground-penetrating radar to study the internal structure of star dunes. By gaining a better understanding of how these immense dunes form, geologists can develop a new model to aid in the identification of star dunes in the rock record. The advancement of technology plays a crucial role in unraveling the secrets of these enigmatic desert features.
The study of star-shaped sand dunes offers new insights into the geological record and highlights the importance of utilizing modern technology to uncover hidden natural phenomena. By bridging the gap between modern observations and ancient records, scientists can continue to unravel the mysteries of our planet’s dynamic landscape.