Quantifying the Reduction Intensity of Handaxes with 3D Technology: A Pilot Study on Handaxes in the Danjiangkou Reservoir Region, Central China.

Hao Li,Chaorong Li,Kathleen Kuman,Michael D Petraglia

doi:10.1371/journal.pone.0135613

Abstract

This paper presents an approach to analyzing the reduction intensity of handaxes with the aid of 3D scanning technology. Two quantitative reduction indices, the Scar Density Index (SDI) and the Flaked Area Index (FAI), are applied to handaxes from the third terrace of the Danjiangkou Reservoir Region (DRR), central China, dated to the Middle Pleistocene. The results show that most of the DRR handaxes in this sample show moderate reduction, which also reflects a least-effort reduction strategy and a generally short use-life for these tools. Detailed examination of the DRR handaxes by sector reveals that the tips generally show the most reduction, while the bases show the least shaping, with cortex often preserved on the base to facilitate handling. While western Acheulean assemblages in this regard are variable, there are many examples of handaxes of varying age with trimming of the bases. We also found no significant differences in the levels of reduction between the two main raw materials, quartz phyllite and trachyte. However, the type of blank used (large flakes versus cobbles) and the type of shaping (bifacial, partly bifacial and unifacial) do play a significant role in the reduction intensity of the DRR handaxes. Finally, a small number of handaxes from the younger (the early Late Pleistocene) second terrace of the DRR was compared with those from the third terrace. The results indicate that there is no technological change in the reduction intensity through time in these two DRR terraces.

Highlights

Since the 1980s, lithic researchers have worked to develop a series of methods to measure reduction intensity, as a tool for interpreting curation or re-sharpening of tools and morphological variability, and they have applied them to both experimental and archaeological assemblages
The Danjiangkou Reservoir Region (DRR) handaxes can be confirmed to be made from similar size cobbles, and we suggest that the size-independent Scar Density Index (SDI) used in this study is appropriate for measuring the reduction intensity of handaxes
The extensive application of reduction intensity indices in the past three decades has remarkably improved the ability of lithic analysts to interpret human behaviour

Summary

Introduction

Since the 1980s, lithic researchers have worked to develop a series of methods to measure reduction intensity, as a tool for interpreting curation or re-sharpening of tools and morphological variability, and they have applied them to both experimental and archaeological assemblages. The quantitative reduction indices proposed by Dibble [1] (the ratio of the remaining surface area to platform area), and Kuhn [2]

Objectives

Methods

Results

Conclusion