Extracting residues from stone tools for optical analysis: towards an experiment-based protocol

摘要

The identification of residues is traditionally basedon the distinctive morphologies of the residue fragments bymeans of light microscopy. Most residue fragments are amorphous,in the sense that they lack distinguishing shapes oreasily visible structures under reflected light microscopy.Amorphous residues can only be identified by using transmittedlight microscopy, which requires the extraction of residuesfrom the tool’s surface. Residues are usually extracted with apipette or an ultrasonic bath in combination with distilled water.However, a number of researchers avoid residue extractionbecause it is unclear whether current extraction techniques arerepresentative for the use-related residue that adheres to aflaked stone tool. In this paper, we aim at resolving thesemethodological uncertainties by critically evaluating currentextraction methodologies. Attention is focused on the variationin residue types, their causes of deposition and their adhesionand on the most successful technique for extracting arange of residue types from the stone tool surface. Based on anexperimental reference sample in flint, we argue that a stepwiseextraction protocol is most successful in providing rep-resentative residue extractions and in preventing damage, destructionor loss of residue.