Terrestrial laser scanning in the Namibian desert. Credit: University of Southampton
A 13,000-Year-Old Puzzle Finally Solved
For centuries, Earth’s geological records have been conspicuously devoid of star-shaped sand dunes—majestic formations with arms radiating from a central peak. Despite their prevalence in modern deserts and even on other planets, these structures seemed absent from ancient Earth history. Now, a groundbreaking study has unraveled this mystery.
The Enigma of the Missing Star Dunes
Star dunes, known for their towering heights and complex shapes, are among the largest sand formations on Earth. One such dune, Lala Lallia in Morocco’s Erg Chebbi desert, stands as a testament to nature’s architectural prowess. Despite their prominence today, geologists have struggled to find evidence of these dunes in the geological record. Their absence posed questions about Earth’s climatic and environmental past.
Illuminating the Past with Modern Techniques
Researchers from Aberystwyth University, Birkbeck, and University College London employed advanced ground-penetrating radar (GPR) and luminescence dating to delve into Lala Lallia’s secrets. Their findings revealed that while the base of the dune dates back approximately 13,000 years, the majority of its structure formed rapidly within the last millennium. This rapid formation challenges previous assumptions about the timescales required for such massive dunes to develop.
Terrestrial laser scanning equipment in Namibian desert. Credit: University of Southampton
Implications for Earth’s Geological Record
The study suggests that the unique formation processes of star dunes, combined with their rapid development, might explain their scarcity in ancient records. Their complex internal structures could have been misinterpreted or overlooked in past geological analyses. Understanding these processes not only fills a gap in Earth’s geological history but also aids in identifying similar formations on other planets, offering insights into extraterrestrial landscapes.
A Glimpse into Earth’s Dynamic Past
The formation of Lala Lallia coincides with the Younger Dryas period, a time of abrupt climatic cooling. This correlation hints at the influence of climatic shifts on dune formation and desert landscapes. Such insights are crucial for reconstructing past environments and understanding how Earth’s surface responds to climatic changes.
