The GunaiKurnai, an Australian Aboriginal nation, are recognized as the traditional custodians of Gippsland and the southern Victorian Alps. Caves within their lands have long been linked to spiritual practices. Accounts recorded in the 19th century, together with oral traditions, describe them as places where powerful learned women and men known as ‘mulla-mullung’, along with other spiritual practitioners, carried out rituals involving magic, healing, and cursing.
Archaeological evidence now shows that one of these sites, Cloggs Cave, was used for such activities over an extraordinary span of roughly 25,000 years.
“Here we show that the Old Ancestors selected whole grasses from the wider landscape and carried them into Cloggs Cave to spread out in thin layers and burn. Over time, sediments covered these burnt layers, preserving each layer on top of another over thousands of years,” said Dr Elle Grono, a postdoctoral researcher at the Australian National University and the corresponding author of a new study published in Frontiers in Environmental Archaeology.
Microscopic Clues From Ancient Plants
Grono and researchers from Australia, France, and New Zealand examined phytoliths recovered from buried sediments inside Cloggs Cave. Phytoliths are microscopic silica structures that form within plant tissues and can survive long after the plants themselves have disappeared.
The research grew out of archaeological excavations carried out in 2019 and 2020. Those excavations were designed to determine how people collected and used plants inside the cave in the distant past. The work was requested by the GunaiKurnai Land and Waters Corporation, and GunaiKurnai representatives were involved in the research design, fieldwork, interpretation, and communication of the findings.
“Unlike pollen, which is dispersed by wind or insects, phytoliths mostly accumulate at the spot where a plant decays. No plants grow inside the cave due to a lack of light, so the phytoliths must have been carried in by people or by animals such as possums on their fur or through their scats,” explained Grono. “We focused on half-burnt phytoliths from ashy layers, which can only have been brought in by people, as unburnt ones might have arrived through either means.”
Because vegetation cannot grow naturally inside the dark cave, the burned plant remains offered especially strong evidence that people had intentionally carried grasses into the site.
Layers of Ash and a Standing Stone
Using microscopy, the researchers classified thousands of phytoliths collected from two excavation pits measuring 1.5 m and 2.3 m deep.
The upper sections of those pits contained 73 thin layers of ash deposited by people between approximately 4,400 and 1,600 years ago. Researchers established those ages using optically stimulated luminescence and carbon dating via accelerator mass spectrometry.
Hidden among the layers was another striking discovery: a standing stone measuring 28 cm high. Later analysis showed that Old Ancestors had intentionally placed the stone inside the cave for ritual purposes around 2,000 years ago.
Grasses Were Carefully Chosen
The team identified 29 different kinds of phytoliths representing grasses, herbs, and woody plants. Many were exceptionally well preserved, including delicate silica structures such as hair cells.
Grass phytoliths dominated the samples, accounting for as much as 97% of the total. They included members of the Pooideae subfamily, which favor temperate or cool conditions, as well as Panicoideae grasses, which generally thrive in warmer and more humid environments.
Phytoliths from Chloridoideae grasses, which tolerate drought and are adapted to warm, dry arid conditions, appeared less frequently. Remains from herbs and woody plants were also uncommon.
The pattern suggests that Old Ancestors did not simply gather whatever vegetation was nearby. Instead, they deliberately selected particular grasses.
Before European settlement, the landscape around Cloggs Cave included riparian forest and open woodland containing many different plant species. Yet those plants were largely absent from the archaeological deposits. The people using the cave instead chose grasses growing relatively close to its entrance.
“The phytoliths found at Cloggs Cave were from different parts of grass plants such as stems, leaves, flowers and roots, indicating that whole grasses were brought in, including the inedible parts,” said Grono.
Evidence of Ritual Burning Across Millennia
As much as 18% of the phytoliths showed signs of burning or melting. Those altered plant remains occurred throughout the dated deposits, suggesting that people repeatedly carried vegetation into the cave and burned it there across the span of the past 25,000 years.
The finding fits with other archaeological evidence indicating that Cloggs Cave was a place of long-lasting ritual activity rather than an ordinary living site.
Professor Bruno David from Monash University, who co-led the excavations with GunaiKurnai Land and Waters Corporation, concludes that “their burning is consistent with GunaiKurnai traditional practices of using ash to perform magic and rituals, and also to track the footsteps of anyone coming in, including spirit-Beings. Other macro-botanical evidence, such as fat-smeared, trimmed wooden sticks from Casuarina trees, was also found in deeper and older deposits, indicating that other kinds of rituals using woody plants were also performed.”
