Learning the Lithic Landscape in the Ivane Valley, Papua New Guinea: modelling colonisation and occupation using lithic sources and stone tool technology

Abstract

Modern humans first moved into the Ivane valley between 43,000 – 49,000 years cal BP, placing it within the initial colonisation stage of Papua New Guinea. At 2000 metres above sea level, this montane valley also marks the first time that modern humans move into a high altitude area in the Sahul region. This study addresses the question of how modern humans colonised and occupied new landscapes in the Sahul region by using the Ivane valley as a case study.

To investigate this question, a landscape learning framework was employed to demonstrate how people learnt and familiarised themselves with the lithic landscape. Lithic source use and stone tool technological organisation were expected to change due to two factors linked to landscape learning: (1) as people became more familiar with the properties of the specific lithic landscape itself; and (2) as a result of the particular technological responses utilised by people in exploiting their local environment.

The results of this study demonstrated both changes and continuities in raw material selection and stone tool technology in the Ivane valley over time. These were attributed to both the nature of the lithic landscape available and accumulations in landscape learning. Importantly, this study noted that while there was no evidence for risk minimisation in the initial stages of colonisation, overall raw material selection and technological organisation trend towards resource maximisation.

All periods of occupation were characterised by three factors: (1) only locally available raw materials were used; (2) specific raw materials were used for particular technological trajectories; and (3) technology was organised expediently, where sourcing, manufacture, use and discard of tools occurred on site, with no apparent evidence for curation.

The overall structure of the technology was considered to be a result of the nature of the lithic landscape, where the availability of abundant high quality raw materials negated the need to carry or curate mobile tool kits. A fundamental result of this thesis has therefore been the identification of the influence that the local lithic landscape has on shaping how technology is organised.

Changes in raw material selection and technology over time point to increases in landscape learning of both lithic and non-lithic resources. Right from initial colonisation, only local raw materials were used and these were used selectively, being associated with particular technological trajectories. Over time, raw material selection changes, developing towards an optimal use of the lithic landscape, where high quality raw materials were selected over others. At the same time, an increase in diversity of tool types suggests new familiarity with non-lithic resources in the Ivane valley.

In terms of stone technology, this thesis challenges the usual depiction of Pleistocene Sahul stone technology as a static amorphous tradition, with few defined tool types. Instead, it demonstrates that a dynamic technology existed in the Ivane valley, with formally modified tools present during all periods of occupation, as well as changes in raw material selection, technological trajectories and tool types occurring over time.