Alternative Methods for Dating Rock Varnish at Murujuga, Western Australia

Summary

This is an abstract from the "New approaches to the intractable problem of dating rock art" session, at the 90th annual meeting of the Society for American Archaeology.

Placing robust age constraints on the production of rock art is difficult because the lack of suitable material for sampling. This is especially true in the case of petroglyphs where ‘paints’ are unavailable. The ARC-funded project ‘Dating Murujuga’s Dreaming’ faces this challenge by trying to identify a chronology for rock varnish that is abundant in the landscape. Many petroglyphs have been carved or pecked into the dark varnish, occasionally varnish has grown back onto the motifs, bracketing the time of production for the rock art, therefore dating the varnish could provide a minimum and maximum age. Along investigating the microbiome on rock surfaces associated with varnish formation, we are exploring the potential of uranium-series and radiocarbon for direct dating. The porous nature of the varnish raises questions regarding the ‘closed-system’ of these coatings, crucial for radiometric dating. While varnish can be 200µm thick, it presents technical challenges for radiometric dating as the thin layers are irregular and contaminants likely within. Organic carbon is another avenue being pursued. Indirect dating approaches include reconstructing the paleoclimate records to match varnish laminations. Rock varnish on dated meteorites in the Pilbara could provide suitable age calibration for the varnish on rock art at Murujuga.

This Resource is Part of the Following Collections

• Society for American Archaeology 90th Annual Meeting, Denver, CO (2025)   •
• New approaches to the intractable problem of dating rock art

Keywords

Record Identifiers

Abstract Id(s): 51233