Researchers have revealed new details about the ancient environment of South Australia in the region of the Rawnsley Quartzite. This feature contains an important collection of Ediacara Biota fossils, which provide insight into the evolution of complex life on Earth. The conditions in which the Rawnsley Quartzite communities lived, died, and were preserved has been a topic of debate among scientists. It is not known if this region was a deep marine, shallow marine, or terrestrial environment during the Ediacaran Period.

A key feature of the Rawnsley Quartzite Ediacara Biota is the presence of iron oxide coatings. Some theories argue that these coatings are evidence that the area was a terrestrial environment. However, the new paper outlines sedimentological and geochemical studies that show that the iron oxides underwent extensive fluid‐rich alteration. The results indicate that iron oxide features in this area cannot be used as evidence of a terrestrial paleoenvironment.

The paper, “The late‐stage “ferruginization” of the Ediacara Member (Rawnsley Quartzite, South Australia): Insights from uranium isotopes,” was published in the journal Geobiology. The work was supported by NASA Astrobiology through the Exobiology & Evolutionary Biology Program.

Related Links:
Cementing a Theory About the Sea Creatures of the Ediacara Biota
A Puzzle of Ediacara Biota
Newly Discovered Fossils Strengthen Proposition that World’s First Mass Extinction Engineered by Early Animals