THE OLDEST KNOWN ROCK PAINTING IN AUSTRALIA:

17,300 year old kangaroo dated with mud dauber wasp nests. Illustration from Finch et al.

Back on 20 June 2020, I wrote a column titled “Dating Australian Rock Art With Mud Wasp Nests” about using small samples of mud wasp (or mud dauber) nests that overlay old pictographs to date them using optically stimulated luminescence dating. This practice has now produced dates for an image in the Kimberly region in Australia as old as 17,300 BCE.

17,300 year old kangaroo dated with mud dauber wasp nests. Illustration from Finch et al.

“In two of the most extensive provinces for painted rock art in Australia, the Kimberley and Arnhem Land, naturalistic animals are the most common subjects in the oldest stylistic period on the basis of superimposition analysis, but there is debate about their antiquity and the adequacy of the definitions of these earliest styles. The same or similar animals are also depicted in more-recent art periods, but using different stylistic techniques (for example, solid or regular infill rather than irregular infill, and solid infill of the extremities of the head, tail and limbs); further evidence is therefore required to test these ideas as no old, radiometric age constraints have been published for any of these motifs. In the Kimberley region, it is now known that paintings from the superimposed and inferred to be more-recent Gwion stylistic period proliferated around 12 ka18, so the generally agreed relative rock art sequence predicts that the earlier paintings of naturalistic animals should be older than this.” (Finch et al. 2021)

12,700 year old kangaroo pictograph. Ian Waina nspecting the painting. Photo via Peter Veth, Balanggarra Aborigina Corporation. Illustration by Pauline Heney and Damien Finch.

Optically stimulated luminescence (OSL) dating relies on the transfer of energy from cosmic rays to crystalline materials. If these materials are in the light the energy bleeds back out but, if they are in complete dark the energy accumulates and is stored up until it can release. If this small piece of material is hidden underground (or incorporated into a mud wasp nest) it can be taken back to the archeologists lab and handled under controlled conditions. Then, when hit with a pulse from a laser the energy is released at once, its intensity indicating how much had built up and thus how long it was in the dark. If the mud wasp nest was taken from the surface of a rock art image, the date found in it represents the possible minimum age of the image. It can be older, but not younger, then the OSL date.

The team recording rock art. Image from www.bbc.com.

“In the Kimberley rock art stylistic sequence, these naturalistic animals belong to the earliest known phase of painted rock art, the Irregular Infill Animal Period (IIAP). Notwithstanding the abovementioned debate about the classification of similar motifs in the Arnhem Land region (some 700 km to the east), we adopt the comprehensive definition of the Kimberley IIAP by Walsh and Welch as a starting hypothesis. This definition of IIAP motifs includes some styles of hand stencils, hand prints, stencils of boomerangs and other objects, and some freehand depictions of plants (such as yams), animals (particularly kangaroos but also echidna, birds, goannas, fish and possum) and, more rarely, anthropomorphs. Here we report radiocarbon ages determined from 27 mud wasp nests, which were collected from 8 separate sandstone rock shelters, that constrain the ages of 16 IIAP motifs. Fifteen nests overlay ten IIAP motifs and six nests were underneath a further five motifs. Importantly, three overlying and three underlying nests were dated from one further IIAP motif, thereby providing a bracketed age constraint for that individual painting.” (Finch et al. 2021) These bracketed ages give maximum and minimum ages for that particular image narrowing down its date.

“The age estimates for 27 mud wasp nests in contact with 16 different rock paintings of the Kimberley IIAP style suggest that these motifs were painted between 17.2 and 13.1 cal kBP. The age of one IIAP macropod motif is well-constrained by six radiocarbon dates on three overlying and three underlying wasp nests to be between 17,500 and 17,100 years old, corresponding to the middle of the age range for the European figurative motifs.

Rock shelter containing the 17,300 year old painting. Image from University of Melbourne, Australia.

This is a period during which sea levels in the nearby Joseph Bonaparte Gulf began to rise from a low of ~125 m below present sea levels during the Last Glacial Maximum (21±3 ka) but mostly before the rapid rise in sea levels between 14.6 and 8 ka. By 12 ka, the coastline to the northwest had advanced by around 300 km over the continental shelf toward the area in which our study was undertaken. Many generations of Kimberley coastal Aboriginal populations experienced a continuing loss of territory over these millennia. At around the same time, from 14 to 13 ka, a paleo-environmental record from a nearby mound spring and other Kimberley climate proxies indicate an improving climate with an increase in monsoonal activity and precipitation.”  (Finch et al. 2021) With a 300 kilometer advance of the coast during that period one has to wonder how many wonderful sites have disappeared.

In summary, the study found what they are pronouncing as the oldest rock art yet discovered in Australia. “These Pleistocene ages for naturalistic animal motifs from the earliest known period of Australian rock painting position this creative human activity at the end of the Last Glacial Maximum. The initial results from eight rock art sites in the northeastern Kimberley suggest an extended period for the Irregular Infill Animal style, from 17 to 13 ka. Many more dates from this period are required before the full chronological extent of the paintings still visible today can be determined. For now, a robustly dated, approximately 17,300-year-old painting of a kangaroo is the oldest in situ rock painting radiometrically dated in Australia.” (Finch et al. 2021) This is such a fortuitous and clever way to date rock art, working in a team with an insect to learn marvelous facts.

NOTE: Some images in this posting were retrieved from the internet with a search for public domain photographs. If any of these images are not intended to be public domain, I apologize, and will happily provide the picture credits if the owner will contact me with them. For further information on these reports you should read the original reports at the sites listed below.

REFERENCES:

Faris, Peter, 2020, Dating Australian Rock Art With Mud Wasp Nests, 20 June 2020, https://www.blogger.com.

Finch, Damien et al., 2021, Ages for Australia’s oldest rock paintings, March 2021, Human Nature Behavior, doi.org/10.1038/s41562-020-01041-0. Accessed online 17 June 2023.