Disappearing ancient Indonesian rock art
Cave weathering is accelerating in pace with climate change, study finds.
Some of the world’s earliest known cave art in Indonesia is “weathering at an alarming rate”, according to a study in Scientific Reports.
Local archaeologists and site keepers for the ancient artworks of Maros-pangkep in Sulawesi, including intergenerational custodians, told the scientists that the rock art “is disappearing now faster than any other time in living memory”, says lead author Jillian Huntley from Griffith University, Queensland.
The paintings are dated to the Pleistocene era, at least 44,000 years ago. Rivalling European cave art, the illustrations of hunting scenes and mystical beings are thought to be the oldest evidence of figurative art and artistic creativity on the planet.
Upon investigating the chemistry of the limestone rock face, Huntley and colleagues were surprised to find pervasive evidence of salt crystallisation (haloclasty). The salts chemically weaken the rock and mechanically separate the surface of the panels from the limestone wall and ceiling, causing the rock art to flake off the walls.
“These processes are accelerated by increasing temperatures and more extreme weather,” Huntley explains.
Next to extensive quarrying of limestone, the weathering poses the greatest threat to preservation of the cave art, the authors say.
“The amount we have learned from studying this rock art just in the last few years is staggering,” says Huntley. “It houses the earliest yet known animal depiction and the first complex narrative scene yet found. These are important markers of people’s cognitive and social capacities.
“We are in a race against time to learn from this rock art before it is irrevocably damaged.”