Lithic Technology & Tool Curation Strategies: Deep-Time Material Science

1. Behavioral Economics of Lithic Raw Material Transport

The spatial distribution of stone tool industries across Southwest Western Australia was governed by deliberate behavioral economic calculations that balanced raw material transport costs against functional utility.¹ In Bibbullmun country, geological availability varied drastically between the crystalline bedrock of the Darling Range (rich in quartz and dolerite) and the sandy, stone-poor Swan Coastal Plain, which is devoid of hard lithic outcrops save for buried alluvial gravels and coastal calcarenites.² To maintain functional toolkits while moving across extensive clan estates, Bibbullmun hunter-gatherers implemented sophisticated transport strategies, optimizing core geometries, carrying multi-functional implements, and deploying differential curation protocols depending on distance from quarry sources.³

2. Curated Versus Expedient Tool Technologies Across Southwest Biomes

Archaeological assemblages demonstrate a sharp technological dichotomy between curated and expedient lithic systems.⁴ Expedient technology—characterised by unstandardized, rapidly knapped quartz flakes produced via bipolar reduction on local pebbles—dominated domestic camp sites where quartz gravels were abundant.⁵ In contrast, curated technologies were reserved for high-value raw materials, notably fine silcrete, exotic chert, and dolerite.⁶ Curated implements, such as the composite kodj axe, backed geometric microliths, and formalised steep-edged scrapers, were manufactured in advance of anticipated tasks, transported across long distances, continuously resharpened, and maintained through careful replacement of adhesive balga resin haftings.⁷

3. Resharpening Trajectories, Edge Rejuvenation, and Exhaustion Morphologies

The life history (chaîne opératoire) of high-value tools reveals systematic resharpening trajectories that progressively altered implement morphology.⁸ Silcrete scrapers recovered from coastal plain occupation sites exhibit multiple generations of invasive retouch along their working margins, demonstrating that dull edges were systematically rejuvenated rather than discarded.⁹ As tools reached the end of their functional utility, reduction often transitioned into bipolar smashing to extract tiny final cutting slivers, resulting in microscopic exhaustion cores.¹⁰ This thrifty maintenance regime highlights the immense value placed on high-quality stone and illustrates the deep technological efficiency of Bibbullmun foraging economies.¹¹

4. Spatial Distribution of Exotic Toolstones and Custodial Trade Reciprocity

The geographic dispersal of exotic lithic raw materials provides conclusive evidence of extensive inter-subnation trade and alliance networks across Southwest Australia.¹² Dolerite from specific quarry dykes in Whadjuk country has been documented in archaeological sites across Binjareb and Wardandi territories, while coastal chert flakes penetrated deep into inland Balardong estates.¹³ These raw materials were transferred during seasonal inter-clan assemblies (Boonaroo gatherings) under formal customary protocols that regulated access to quarries as sovereign estate property.¹⁴ The material circulation of curated stone tools thus reinforced social treaties and genealogical alliances, anchoring Bibbullmun regional confederacies in enduring legal and material relationships.¹⁵