Microwear Patterns on Experimental Cache Creek Basalt Tools

Abstract

This thesis ls a contributlon to middle range research and involves the analysis of mlcrowear on experimentally used tools for the purpose of investigating the relatlonshlps between tool-use behaviour and mlcrowear patterns. One hundred and thirteen chipped stone tools manufactured from vitreous and non-vitreous basalts were used In controlled experiments replicating the Aboriginal tool-use behaviour of the Interior Salish peoples and their prehistoric ancestors who occupied the southwestern interior of British Columbia. The ultimate qoal of the research was to provide an interpretive framework for basalt tools found at late prehistoric sites in this area. Microwear traces on the used basalt tools were studied with the aid of a stereomicroscope (up to 100 x), an incident light microscope {up to 600 x) and a scanning electron microscope. The observed wear traces are documented In the text, on tables and In photomicrographs . Microflake scar attributes on 90 vitreous basalt tools were subjected to statistical analysis, including cluster analysis and discriminant function analysis. Four blind tests were undertaken to Identify strengths and weaknesses In a preliminary interpretive framework. Objective functional classification on the basis of microflake scar attributes has been achieved using cluster analysis and discriminant function analysis. Successful classifications were obtained in the area of use-actions only. Discriminant function analysis has proven to have a high potential for further achievements In this area and the addition of variables derived from other classes of mlcrowear should improve the results . As a result of the present study the relationship between mlcroflake scar attributes, use action and contact material hardness are more clearly understood. In addition, mlcropolish characteristics have been related to contact material, duration of use and tool action in a seven-stage developmental model. Distinctive microwear patterns resulting from important prehistoric activities , including butchering, hide scraping and wood working, have been identified on the experimental tools.