Visible Archaeology

Archaeology has a natural bias towards those parts of prehistory that are best preserved. Shell middens and stone tools do not decay with exposure and burial, but their resilience as signs of the past can skew subsequent interpretations about diet and technology. When a site reveals more perishable materials like wood or bone it is cause for celebration.

Situated in the lower southeast of South Australia, Koongine Cave and Wyrie Swamp are two such places. Just 40 kms apart, both were occupied by Aboriginal people during the Terminal Pleistocene - Holocene Transition. A limestone cave and a peat swamp are different sorts of occupation site, but together they provide the earliest and most complete "tool kit" for subsistence survival along this part of the Australian coast.

Radiocarbon dates for the use of Koongine Cave extend from 11,750-10,350 ybp to 10,250-8,200 ybp. Highest deposit rates are concentrated in the early phase of 11-10,000 ybp. Occupation during the later phase of 10-9,000 ybp was more intermittent. After inhabiting it for 2,000 years, the cave was abandoned.

At Wyrie Swamp, radiocarbon dates cover the period from 10,200 +/-150 ybp to 7,930 +/-160 ybp, with the main artefact emphasis between 10 and 9,000 ybp. The swamp was used as a camp for 2,000 years in total, at a time when it was smaller than it is today. The bank of dry ground around its western edge is now beneath 1.5 to 2.0 metres of fibrous and decomposing peat, formed since a much wetter weather pattern forced its abandonment by Aborigines around 8,000 ybp.

Koongine and Wyrie share the same stone tool technology. The raw material was flint. Substantial deposits occur along the shoreline. Chert, or "white cortex covered clastics", are eroded in the coastal shallows. The "freed silica nodules" left over are sometimes adopted by kelp as anchors. During storms the seaweed's flat leathery leaves cause these cobbles to be pushed towards the highwater line. 

Grey flint can also be mined from veins in cave walls or along the limestone ridges that run parallel to the seashore. In any event, this hard stone is in abundance, which may help explain, to some degree, the "low retouch-to-mass ratio" of local artefacts.

At Wyrie Swamp, 120 identified implements are described as "large core flakes" or "large primary flakes". The bulk of these tools were not "retouched". Only the cutting edges received minute chipping and trimming to produce "remarkably sharp edges in usable condition even now". 

The emphasis of the toolmaker was therefore clearly on the "maintenance of the tool edge". Excavating archaeologist RA Luebbers believed these sharp but otherwise unrefined tools were used for woodworking; planing and debarking timber or chiselling and carving barbed spearheads.

At Koongine Cave too, archaeologists Bird and Frankel have described "large flake scrapers" and "large cortical flakes". Comments are made on short steep angles and minimal evidence of re-sharpening. 

They classify the style as Gambieran (after Mount Gambier), with the representative type being "finely retouched scrapers made on large flakes". The "knappers" are said to have been making "hand-held wood-working tools", for the "on-site manufacture and maintenance of a wooden tool-kit".

Evidence of that wooden tool-kit has been found at Wyrie Swamp. The preservation qualities of natural peat are responsible for the recovery of a whole suite of wooden tools from this era. All are made from Drooping Sheoak (once called Casuarina stricta, now known as Allocasuarina verticillata). Three items dominate the Wyrie inventory.

     "The most common are short straight sticks with one end sharpened to a point and the other slightly rounded. Of the four complete specimens, all are covered with bark from end to end, are uniform in diameter throughout their length, and deviate only slightly from 39 cm in length". These were probably used "to dig plants and tubers from the soft shoreline muds".

     "Boomerangs are the second most common implements and are represented by three complete and six fragmentary specimens. Each exhibits the classical properties of a well designed aerodynamic missile. Wing cross-sections are bi-convex, with the top curvature decidedly greater than the latter, while in the more complete specimens a distinct rotation of the wing around its axis gives a twisted configuration".

     "The smallest complete boomerang has a wingspan of only 29 cm...The widest boomerang span is 41 cm...Another specimen is designed with one end resembling a wooden club...[Two specimens had] shallow incisions executed in a cross-hatch pattern..." In a swamp context, the purpose of boomerangs was possibly to down water-fowl such as swan, ibis, duck etc.

     "The third most common tool is the spear, and it is represented by three remarkable specimens. The most complete of these is a fragment of the leading tip of the spear including a barb, shoulder and main-shaft section. The delicate barb is carved from the shaft of the spear".

     "A second spear fragment is an exact duplicate of this find except that the existence of the barb is indicated only by opposed incisions carved into the shaft near the tip. A third spear was uncovered in the peat with its central shaft missing as a result of excavation damage. Both ends are shaped into slender points with no evidence of a hole to receive the hook of a spear-thrower...Measured in situ the spear was 1.2 metres long".

Note that of these three spears, two had a single barb each. These carefully crafted barbs are fashioned directly from the weapon main-shaft. The expense of this design is that when damaged in hunting, the entire front end of the spear must be reproduced. From an already short spear, with acute sensitivity to changes in weight and balance, the broken barb and excess wood behind it had to be removed, before cutting a new barb and sharpening the tip. 

In two of the retrieved examples, the shoulder behind barb appears to have been maintained at a diameter equal to the height of the barb to allow sufficient timber to repair and adjust the balance. This costly shortening process will not be overcome until their closely related stone tools industry begins to create "microliths" ― small "backed" blades that could be stuck and re-stuck to spearheads with resin.

The lack of "composite construction" in the Wyrie Swamp tool kit may simply be a sign of regionalism, of where the people in this particular locality were at. They had developed the miraculous engineering of the boomerang, but the efficiencies of replacement barbs, or the woomera, (spearthrower), were yet to be acquired. However, archaeology from elsewhere suggests that the appearance of microliths does not generally take place until the middle of the Holocene. These people were probably very much up to date.

One last element of the "complete tool-kit" emerges at Koongine Cave. It is animal bone. The main food types that could be identified from bone fragments included Wallaby, Wombat, Pademelon, Potoroo, Possum, and Kangaroo. A precious dozen of these remains showed human modification.

     "All of the artefacts were made from medium or large macropod fibulae. Manufacturing techniques involved snapping the fibula before shaping, which was mostly done by grinding...Apart from one spatula shaped end, all the points exhibit very fine tips, with a mean angle of 20.4⁰."  The length of these needle-like implements is from 45 mm to 165 mm, their thickness from 3 mm to 7 mm. 

Striations along the shafts suggest a variety of uses, from piercing fresh and dry animal skins, to similar functions with kelp and bark. The working of animal skin is the most strongly indicated use, which suggests the adoption of "simple apparel" like wrap-around cloaks or blankets to combat the cold.

In conclusion, it seems probable that the inhabitants of Koongine Cave and Wyrie Swamp camp were closely related. The radiocarbon dates for occupation are overlapping and the sites are not far apart. They were either the same extended family group or at least the same ancestor―descendant line.

What makes their "visible archaeology" so interesting is the completeness of their collection of artefacts. Wood and bone tools are rarely recovered from sites as old as Koongine and Wyrie. In fact the boomerangs and barbed spears from the swamp are the earliest actual examples of these weapons in Australia. Their uniqueness is enhanced by the likelihood that the people who made them were the first humans to settle this part of the continent in any permanent sense.

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REFERENCES

C Bird & D Frankel, 2001, 'Excavations at Koongine Cave: Lithics & Land-use in the Terminal Pleistocene & Holocene of South Australia', Proceedings of the Prehistoric Society, 67, 49-83

RA Luebbers, 1978, 'Meals and Menus: A Study of Change in Prehistoric Coastal Settlements in South Australia',

Unpublished PhD Thesis, Australian National University

P Hapgood & N Franklin, 2008, 'The revolution that didn't arrive: A review of Pleistocene Sahul', Journal of Human Evolution, 55, 187-222