Archaeological dig reveals over 35,000 years of occupation in the Pilbara

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Australian Cultural Heritage Management Media Release

Archaeological dig reveals over 35,000 years of Aboriginal occupation in the Pilbara

Martidja Banyjima Aboriginal traditional owners and archaeologists from Australian Cultural Heritage Management (ACHM) have excavated a rockshelter site with a sequence of radiometric dates ranging from 2766 ±32 years BP (before present) to 35,159 ±537 BP. Further radiocarbon dating is in progress to better refine the cultural sequence, which extends further below the 35,159 ±537 BP site layer. The rockshelter is located on the Hope Downs RTIO/Hancock Prospecting joint venture mine site approximately 100km north of Newman, in the eastern Pilbara region of Western Australia. The archaeological excavations form part of a larger cultural heritage management program, which has been running for over two years.

The Martidja Banyjima people have named this site ‘Djadjiling’, in honour of the Ancestral Dreaming Track, which includes the hill in which the rockshelter is located. The Djadjiling site (field name HD07-1A-04) is the earliest dated archaeological site in the Pilbara upland region, where previously about 20,000 years had been documented for Aboriginal occupation.

Charcoal samples were submitted to the University of Waikato (NZ) dating laboratory for express analysis of key features throughout the 2 metre deep excavations. The upper-most date of 2,766 ±32 BP comes from a well-preserved hearth in the upper layer of the site. A heat-shattered retouched flake was recovered atop of the hearth. The retouched flake is morphologically a blade, measuring approximately 10cm in length and 2.5cm in width.

Resting approximately 45cm below this cultural feature is a prominent yellow sediment horizon that extends throughout the excavation profile. This yellow horizon averages 25cm in thickness and extends roughly 65‑90cm below datum. Charcoal recovered from the middle of this yellow layer yielded an age estimate of 17,975 ±72 BP. The age of this distinctive layer corresponds with the peak of the Last Glacial Maximum (LGM), when much of the Australian arid zone was subject to drier, colder, and windier climatic conditions. Preliminary results from the excavation suggest a much-reduced human presence at this rockshelter during this period.

Further beneath the LGM layer, at approximately 105cm below the datum, artefact density begins to increase. A date of 24,522 ±129 BP was obtained from a charcoal sample collected at 128.5cm below the datum, and several artefacts were present at this depth, including a white chert core. Artefact density again increases beneath this layer, with numerous flaked stone artefacts and a conjoin set consisting of a core with two flakes. An in situ charcoal sample adjacent to these conjoining artefacts yielded a date of 35,159 ±537 BP (148cmbd).

An additional 12 flaked artefacts were recovered in situ from depths up to 10cm below the 35,159 ±537 BP site layer. Considering that approximately 10cm of sediment separates the 25kya and 35kya age-estimates, one can only speculate at this stage on the maximum antiquity of the lowest cultural deposits. The site is potentially amongst the oldest investigated in Australia, and further radiocarbon determinations will undoubtedly resolve this issue. Substantial amounts of charcoal were also found in these Pleistocene layers. These finds indicate the excellent preservation of the site.

The excavations were directed by ACHM senior archaeologist W. Boone Law. Other ACHM archaeologists on the excavation team included Dr. Dawn Cropper, Duncan Wright, Graham Houghton, and Stephen Damhuis. Additionally, a team of Martidja Banyjima men including Alistair Parker, Cedrick Hicks, Jarren Stevens, Kim Hicks, Luke Parker, Ainsley Parker, Revis Hicks, Garry Parker, and Nathan Black participated with all facets of the excavation. Together the heritage team spent more than 30 field days at the site between December 2007 and March 2008, excavating nearly 11 tonnes of sediment.

Sorting and analysis of the finds will continue for several months. In the meantime, at least a dozen more rockshelters at the Hope Downs mine site will be excavated. Some of these are known to be archaeological sites, while others remain unknown – just as Djadjiling was an unknown quantity just a few months ago.

Negotiations among RTIO, Traditional owners and ACHM heritage managers are continuing towards insuring the preservation of this significant Aboriginal heritage site for future generations of Banyjima people, and for further scientific research.

For further information contact
W. Boone Law, Dr Dawn Cropper or Dr Neale Draper on 08 8340 9566.

Additional Information:

1. http://www.theage.com.au/news/national/archaeological-finds-dated-to-35000years/2008/04/06/1207420202548.html

2. http://www.theage.com.au/news/national/win-for-prehistoric-rocksite/2008/04/07/1207420278231.html

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