Use-polished stone flakes from Liang Bua, Indonesia: Implications for plant processing and fibrecraft in the Late Pleistocene

Abstract

Edge-glossed flakes, usually recognised as stone tools with macroscopically visible polish from use, have been documented in parts of Southeast Asia from contexts spanning the past 12,000 years and possibly more than 30,000 years. It has been proposed that the edges of these flakes were polished by cutting, splitting or otherwise processing siliceous and fibrous plants for matting, basketry and bindings, and possibly by the reaping of cereals such as rice. Previous studies of use-wear on edge-glossed flakes in Southeast Asia have suggested several tool functions, including the cutting, splitting and scraping of plants with few or no phytoliths (e.g., Pandanaceae) and highly siliceous plants, with high phytolith content, such as Arecaceae palms (e.g., rattan) and Poaceae grasses (e.g., rice, bamboo and cattail reeds). Our study of the use-wear on 16 edge-glossed flakes from layers spanning the past 18,000 years at Liang Bua, a limestone cave on the Indonesian island of Flores, Indonesia, indicates processing of various plant taxa, including Poaceae grasses, Arecaceae palm and wood. The edge-glossed flakes from Liang Bua have features of micropolish that indicate they were probably linked with fibrecraft. Eleven of the 16 Liang Bua artefacts with edge-gloss are between about 18,580 and 11,750 years old, from artefact assemblages associated with modern humans; they currently represent the earliest evidence of these behaviours on Flores. No edge-glossed flakes have yet been identified in the 190,000–50,000-year-old artefact assemblages associated with Homo floresiensis.