In brief
Research led by Adelaide University found that dramatic sea‑level changes carved massive southeast‑oriented canyons in the Flinders Ranges, which later filled with sediment as waters returned, preserving rich Ediacaran fossil deposits. The study, published in "Earth and Planetary Science Letters," offers new insights into the environmental changes that accompanied the rise of early animal life.
Geologists from Adelaide University announced on Monday that dramatic sea‑level changes carved giant underwater canyons in South Australia’s Flinders Ranges, creating conditions that preserved some of Earth’s earliest complex life, according to a Xinhua report.
The canyons, southeast‑oriented, reach depths of up to 280 metres and widths exceeding six kilometres. Study authors argue they were largely formed by underwater erosion when sea levels fell, and that some may have eroded above sea level before submerging.
As sea levels rose, seawater flooded the landscape and sediment gradually filled the canyons, creating geological conditions favourable for the preservation of the region’s rich late‑Ediacaran fossil deposits, the researchers said. The sediment types and canyon shapes point to powerful underwater flows that transported large amounts of material.
The findings shed light on environmental changes accompanying the rise of the Ediacaran biota, a group of soft‑bodied organisms that lived more than 538 million years ago, the study notes. These fossils preserve evidence of early complex life before the later explosion of animal diversity.
The research was published in the journal "Earth and Planetary Science Letters" and confirms that ancient geological processes helped create a fossil record of early animal evolution.
Some aspects, such as whether all canyons formed completely underwater or whether some originated as above‑sea‑level erosion before becoming submerged, remain unconfirmed and are discussed as possibilities in the study.
