Deep inside Cloggs Cave in southeastern Australia, researchers have found something that plant remains almost never leave behind: a direct, physical trail of ceremonial life stretching back thousands of years.
A newly published study examined microscopic plant fossils called phytoliths pulled from ash layers inside the cave, home to the GunaiKurnai Aboriginal nation for an estimated 25,000 years. The team, led by archaeologist Elle Grono of Australian National University, analyzed 29 distinct plant types across pits containing 73 ashy layers dated to between 1,600 and 4,000 years ago. Roughly 18 percent of the samples showed signs of burning or melting.
What makes the find significant is how the plants got there in the first place. No vegetation grows inside the cave itself because there is no light, meaning every phytolith had to be carried in, either by people or by animals passing through. Grono noted that phytoliths, unlike wind-dispersed pollen, tend to stay put once a plant decays, which lets researchers pin the material to a specific spot rather than a general area.
The distribution of burnt remains lines up with documented GunaiKurnai traditions of using fire and ash in healing, cursing and protective rituals, according to co-author Bruno David of Monash University. Excavators also uncovered a standing stone roughly 11 inches tall, likely used ceremonially around 2,000 years ago, along with fat-smeared wooden sticks that may have played a role in the same practices.
The GunaiKurnai Land and Waters Aboriginal Corporation only began formally partnering with archaeologists at the site in 2019, decades after the cave was first excavated in the 1970s. That collaboration is part of what makes this study unusual for Australian archaeology, a field where plant-based evidence has historically been underrepresented compared to stone tools and bones.
The researchers are careful to note their interpretation is one plausible reading of the evidence rather than a settled conclusion, but the case for intentional, repeated ritual use of the cave is, in their words, compelling.