Science News

Western Australian rock art could represent chaos that followed at the end of the ice age

The examples of rock art from Gwion in Western Australia, discovered in 1891, may date back 10,000-12,000 years according to a team of archaeologists. The researchers used an unusual dating method: they dated the tiny grains of coal in the fossilized wasp nests created by these insects on the painted walls.

Dating rock art is always difficult since the substances that are used to paint, mostly ocher minerals, cannot be dated to radiocarbon. The researchers, therefore, thought of using the nests made by the so-called “mud wasps,” flying insects that build their nests from the mud, in this case on a rock substrate.

The researchers measured how long the grains of quartz sand that wasps from the past used to create their nests were present on the rock where the paintings were. These are nesting wasps whose nests, made of mud, petrify after abandonment. These remains can be analyzed through various complex optical techniques and it is also possible to date the traces of pollen contained in them. With this method, they established that Gwion’s rock art examples date back over 10,000 years ago.

It is a period that coincides with the end of an ice age, a period during which the level of the oceans rose and there were floods in northern Australia.

This led the Aboriginal people who lived near the coasts to take refuge inland and precisely these forced emigrations could be the object of the meaning of many drawings that often depict human figures moving with bags and headdresses.