Australian cave discovery shows grass was burned for magic, cures and curses for 25,000 years

Australian cave discovery shows grass was burned for magic, cures and curses for 25,000 years Sadie Harley Scientific Editor Robert Egan Senior Editor The GunaiKurnai, an Australian Aboriginal nation, are the acknowledged traditional custodians of Gippsland and the southern Victorian Alps. Within their territory are caves known from 19th-century ethnographic reports and oral traditions to have been settings for magic, healing and cursing rituals by powerful learned women and men called "mulla-mullung," as well as by other spiritual practitioners. Archaeologists have shown that people have been visiting one of these caves, Cloggs Cave, for such activities over the past 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 burned 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.

Phytoliths and a standing stone Grono and colleagues from Australia, France and New Zealand studied the phytoliths—microscopic silica bodies from plant tissues—recovered from buried deposits in Cloggs Cave. The study was part of archaeological excavations undertaken in 2019 and 2020 that aimed to understand how people gathered plants for use inside the cave in the past. These excavations had been requested by the GunaiKurnai Land and Waters Corporation, with representatives of the GunaiKurnai community taking part in the study design, fieldwork, interpretations and dissemination of the results.

"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-burned phytoliths from ashy layers, which can only have been brought in by people, as unburned ones might have arrived through either means." The scientists used microscopy to assign taxonomic groups to thousands of phytoliths from two pits, respectively 1.5 m (4.9 feet) and 2.3 m (7.5 feet) deep.

The top strata of these pits consisted of 73 thin ashy layers laid down by people between approximately 4,400 and 1,600 years ago, as calculated by optically stimulated luminescence and carbon dating via accelerator mass spectrometry. Within those ashy layers, they unexpectedly uncovered a 28-cm-high (11-inch-high) standing stone, subsequently shown to have been erected in the cave by Old Ancestors for ritual purposes around 2,000 years ago. Grasses preferred In total, the authors found 29 different types of phytoliths from a range of plant groups including grasses, herbs and woody plants.

They were mostly well-preserved, with even the most delicate silica structures, such as hair cells, surviving intact. The most abundant, up to 97%, were from grasses, both from the subfamily Pooideae, which prefers temperate or cool climates, and from Panicoideae, which mostly grows under warm and humid conditions.