Discrimination of surface wear on obsidian tools using LSCM and RelA: pilot study results (area‐scale analysis of obsidian tool surfaces)

Abstract

This pilot study tests the reliability of laser scanning confocal microscopy (LSCM) to quantitatively measure wear on experimental obsidian tools. To our knowledge, this is the first use of confocal microscopy to study wear on stone flakes made from an amorphous silicate like obsidian. Three-dimensional surface roughness or texture area scans on three obsidian flakes used on different contact materials (hide, shell, wood) were documented using the LSCM to determine whether the worn surfaces could be discriminated using area-scale analysis, specifically relative area (RelA). When coupled with the F-test, this scale-sensitive fractal analysis could not only discriminate the used from unused surfaces on individual tools, but was also capable of discriminating the wear histories of tools used on different contact materials. Results indicate that such discriminations occur at different scales. Confidence levels for the discriminations at different scales were established using the F-test (mean square ratios or MSRs). In instances where discrimination of surface roughness or texture was not possible above the established confidence level based on MSRs, photomicrographs and RelA assisted in hypothesizing why this was so.

Testing Area‐Scale Fractal Complexity (Asfc) and Laser Scanning Confocal Microscopy (LSCM) to Document and Discriminate Microwear on Experimental Quartzite Scrapers

“…, ; Evans and Donahue ; Stevens et al . ; Evans and Macdonald ; Stemp and Chung ; Stemp et al . , ; Evans et al .…”

Old stones' song: Use-wear experiments and analysis of the Oldowan quartz and quartzite assemblage from Kanjera South (Kenya)

“…These protocols were followed here in the analysis of Oldowan quartz and quartzite artifacts from Kanjera South. There has also been an attempt to quantify use-wear, utilising technologies derived from the material sciences (e.g., Stemp and Stemp, 2003;Evans and Donahue, 2008;Stevens et al, 2010;Stemp and Chung, 2011;Evans and Macdonald, 2011). These approaches have had some success and may ultimately provide useful experimental protocols for use-wear analysts.…”

Quantifying Microwear on Experimental Mistassini Quartzite Scrapers: Preliminary Results of Exploratory Research Using LSCM and Scale‐Sensitive Fractal Analysis

“…Although some lithic use‐wear research has focused on various techniques that rely on two‐dimensional image analysis of worn stone tool surfaces, such as work by Barceló and Pijoan‐López (), Pijoan et al (), Barceló et al (), Dumont (), Gonzalez‐Urquijo and Ibañez‐Estevez (), Grace et al (), and Vila and Gallart (), among others, there has been recent interest in the application of methods that rely on documentation of surface roughness or texture using metrology, specifically laser profilometry (Stemp et al , , , ; see Stemp and Stemp, , ), atomic force microscopy (AFM) (Kimball et al , , ; Faulks et al , ), laser scanning confocal microscopy (LSCM) (Evans and Donahue, ; Evans and MacDonald, ; Stemp and Chung, ; Stevens et al , ), optical interferometry (Anderson et al , , ), and differential contrast microscopy (e.g., Alicona Infinite Focus) (Evans and MacDonald, ). Advantages associated with metrological study of stone surfaces include the production of data in three‐dimensions and the micro‐ to nanoscale level of surface measurement possible.…”