Archaeologists have uncovered evidence that elaborate rituals involving burning grass took place in Cloggs Cave in south-eastern Australia for at least 25,000 years.
Researchers led by Bruno David of Monash University and GunaiKurnai elder Russell Mullett found thousands of preserved phytoliths from burnt grasses in the cave. These microscopic plant cells formed repeated thin layers of ash, indicating that whole grasses including roots were brought inside and burned repeatedly.
The practice dates back 25,000 years, with more frequent burning occurring between 4,400 and 1,600 years ago. Around 2,000 years ago a standing stone was placed in the cave, and grass burning continued around it for the next 400 years.
The findings link to 19th-century accounts by anthropologist Alfred Howitt, who described similar ash rituals performed by GunaiKurnai medicine men and women. The cave lies in GunaiKurnai homeland in Victoria.
Anna Florin of the Australian National University called the study a strong example of combining scientific analysis with Indigenous cultural knowledge.