Grass 'skeletons' hint at 25,000-year-old Indigenous fire ritual in cave

Traces of grass used in Indigenous rituals 25,000 years ago unearthed in Victorian cave Wed 22 Jul 2026 at 2:09pm In short: Evidence of ancient grasses being used by the GunaiKurnai people for fire rituals has been unearthed in Cloggs Cave in Victoria. Dating of plant "skeletons" indicates grasses in the cave were burnt at least 25,000 years ago during the last Ice Age. GunaiKurnai cultural history indicates the cave was used by mulla-mullung, learned men and women, for magic, healing, cursing and spiritual practices For thousands of years, GunaiKurnai ancestors burnt grasses inside a cave in Eastern Victoria, potentially to undertake magic, healing and other ritual practices. That's according to evidence, published in a new study in Frontiers in Environmental Archaeology of burnt plant remains dated up to 25,000 years combined with cultural knowledge held by elders and recorded in western journals in the 19th century. "We show the old ancestors selected whole grasses from the wider landscape and carried them into Cloggs Cave to spread out in thin layers and burn," said the study's lead author Elle Grono, an archaeologist at Australian National University, in a statement. "Sediments covered these burnt layers, preserving each layer on top of another over thousands of years," Dr Grono said. The finding pushes back evidence of ritual fire use by GunaiKurnai in the cave to at least the peak of the Ice Age. Ritual burning for magic and healing is different from traditional land management practices such as cultural burning. Carolyn Spry, an archaeologist at La Trobe University who was not involved in the research, said the study provided "exciting" evidence of grass use from the region. "It brings to life an evocative image of GunaiKurnai ancestors bringing bundles of whole grasses into Cloggs Cave for burning practices," Dr Spry said. Unearthing cultural history Cloggs Cave is located on GunaiKurnai country near the Snowy River about 300 kilometres east of Melbourne. The site and rock shelter has significant evidence of use by past generations of GunaiKurnai people — culturally known as old ancestors — including evidence of campfires, food preparation and stone tools. Archaeological excavations began at Cloggs Cave in the 1970s without the permission of the traditional owners. But a collaboration between the GunaiKurnai Land and Waters Aboriginal Corporation and researchers has produced a number of published discoveries, including the oldest-known wooden artefacts in Australia in 2024. Such insights were part of "a broader story about our people, our belief systems, our traditions, and it's important to share that", GunaiKurnai elder Russell Mullet said at the time. The previous discoveries alongside cultural knowledge, pointed to the cave being used by mulla-mullung, learned men and women, for magic, healing, cursing and spiritual practices. Mr Mullett, who is also a co-author on the new study, said these people could be both accepted and feared. "These were doctors, and they were sought after by families to provide cures," he said. "But they had these other powers, too, that could harm people." While the firestick discovered in 2024 was about 12,000 years old, the new study pushes back evidence of ritual fire use much further. What grass 'skeletons' can tell us about the past The researchers focused on phytoliths in the cave, which are hard structures that remain long after the rest of a plant has decayed. "It's helpful to think of them like skeletons in a way," Dr Spry said. "They're really helpful for trying to investigate plant sources that were preserved at that location." The researchers found that almost all of the phytoliths were from grasses, with only small number from woody plants and herbs. Dr Grono noted that not only the edible parts of grasses were brought into the cave. "[They] were from different parts of grass plants such as stems, leaves, flowers and roots, indicating that whole grasses were brought in," she said. The phytoliths also preserved evidence of being burnt, which added to the evidence that it was handled by humans. "At Cloggs Cave, we studied phytoliths from throughout the excavation layers and found that whole grass plants had been brought into the cave by people and burned to create layers of ash," Dr Grono said. The team looked at dozens of layers of these burnt phytoliths, finding the oldest samples they could securely date were between 25,800 and 24,000 years old. At that time Australia was cooler and much drier then it is today and shifting sand dunes would have covered half of the country. The youngest samples were around 3,400 and 1,500 years old. Bruno David, study co-author and Monash University archaeologist, said there were older samples, but these couldn't be accurately dated. "The precise age of those deeper levels is less secure because prior to 25,000 years ago rock fell from the cave's walls and ceiling, mixing the earlier deposits together," Professor David said. Use of ash in rituals Dr Spry said the paper looked at ancient human use of plants in a way "not usually seen in archaeology." "Traditionally in Australian archaeology, we often see a focus on activity traces that you can see without a microscope, like stone tools," she said. "So it's always exciting when we dig a little deeper into the hidden clues that buried sediments can hold." Professor David said analysis of the evidence in the cave suggested the GunaiKurnai ancestors used ash to perform magic and rituals as well as track the footsteps of anyone coming in, including spirit beings. "Other macro-botanical evidence such as fat-smeared trimmed wooden sticks from Casuarina trees were also found in deeper and older deposits, indicating that other kinds of rituals using woody plants were also performed," he said. Dr Spry said the study's authors explanation that fire at the site was used for ritual purposes as opposed to other reasons like for cooking or staying warm was a thorough and "careful interpretation" of the findings. "They found a lot of fine ashy deposits that are consistent with grass. And they've also considered literature that shows that people in ritual performances often used ash and smeared it."