Reaching depths of up to 280 meters and widths of more than six kilometers, giant underwater canyons in South Australia’s Flinders Ranges were carved by dramatic sea level changes hundreds of millions of years ago.
The geological features created conditions that preserved some of Earth’s earliest complex life, according to a university statement released Monday.
Led by Australia’s Adelaide University, the research examined rock formations known for late Ediacaran fossil deposits. These fossils preserve evidence of soft-bodied organisms—known as the Ediacaran biota—that lived more than 538 million years ago before the explosion of animal diversity seen later in Earth’s history, as detailed in findings published in Earth and Planetary Science Letters.
Researchers found evidence that these vast, southeast-oriented canyons were largely formed by underwater erosion triggered when sea levels fell significantly. Some of the features may have also developed through erosion above sea level before they eventually became submerged.
As sea levels subsequently rose, seawater flooded the area and sediments gradually filled the canyons. This process helped create the specific geological conditions required for the preservation of the region’s rich fossil deposits.
According to the study, the shape of the canyons and the types of sediment filling them point to powerful underwater flows. These currents were capable of transporting large amounts of material across the terrain, showing how environmental changes accompanied the rise of early animal life.
The research was announced in Canberra on Nov. 9, following the release of the university statement detailing the discoveries made by the Adelaide University-led team examining the rock formations.
