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

Abstract

Few microwear studies have been conducted on tools made from quartzite. Most rely on visual observation of microwear features using optical light microscopes and scanning electron microscopes. Quantification of microwear on quartzite tools is extremely rare, even though numerous methods to mathematically document surface roughness have been applied to other silicate tools. In this paper, laser scanning confocal microscopy (LSCM) was used to document surface roughness on four experimental scrapers made from two different subtypes of Mistassini quartzite that were used on either fresh or dry deer hide. Surface roughness data were analysed using area‐scale fractal complexity (Asfc). The results of this test case indicate that Asfc can effectively discriminate between the unused and used regions on the quartzite tools based on surface roughness, and that it can also discriminate between surface roughness produced by working dry versus fresh hides. Differences in the subtypes of Mistassini quartzite did affect surface roughness, but not significantly enough to prevent discrimination of the dry and fresh hide‐working tools. Although the use of the Asfc parameter for lithic microwear analysis requires further testing, these first results suggest it could be a reliable technique to mathematically document and discriminate wear patterns on archaeological quartzite tools.

Polish is quantitatively different on quartzite flakes used on different worked materials

“…Nonetheless, we think that more varieties of quartzite should be tested in the future to improve the classification power of the model tested in this study. This data is apparently in contrast with what was observed by Stemp et al [22,23] on the Mistassini variety, where significant variability decision tree; Fig 4) of the different worked materials. For simplicity, the schemes show X-Z profiles, in black, with furrows superimposed in red.…”

“…[17][18][19]. Similarly, quantitative methods have mainly been applied on chert surfaces [7,10,12,20,21], with few attempts done to assess their potential for the analysis of coarse-grained rocks [22][23][24]. Trials on other raw materials, such as obsidian or basalt, have also been performed in the past [14,[25][26][27].…”

“…Coarse-grained rocks such as quartzite have been less frequently investigated in conventional use-wear studies [ 41 – 43 and references therein], as well as in quantitative ones [ 22 , 23 ]. As a consequence, comparable quantitative datasets of these rocks are quite limited.…”

Rethinking Use-Wear Analysis and Experimentation as Applied to the Study of Past Hominin Tool Use

“…Since quantification methods have comparison and frames of reference as their main goals, researchers have realized that it is fundamental to define standards and protocols that improve data repeatability, reproducibility, and comparability (Adams 2014;Calandra et al 2019b;Dubreuil and Savage 2014;Evans et al 2014). This is of particular importance since different pieces of equipment are used by various researchers, and different settings can be applied during the analysis (Stemp et al 2013(Stemp et al , 2018. Nevertheless, these methods will not change the fact that the nature of wear formation is diverse and is consequently represented in different types (Stemp et al 2016).…”

Quantifying lithic surface alterations using confocal microscopy and its relevance for exploring the Châtelperronian at La Roche-à-Pierrot (Saint-Césaire, France)

“…Recent technological developments in the field of usewear analysis, such as surface textural imagery (Knutsson, 1988;Linton et al, 2016), interferometry (Dumont, 1982;Anderson et al, 2006), atomic force microscopy (Kimball et al, 1995;Faulks et al, 2011) and 3D scanning (Grosman et al, 2011;Benito-Calvo et al, 2017), have helped to better characterize and compare microwear on stone and bone tools. More recently, confocal microscopy has proven to be a successful tool for quantifying use-wear on stone tools (Evans and Donahue, 2008;Evans and Macdonald, 2011;Giusca et al, 2012;Stevens et al, 2010;Stemp and Chung, 2011;Bofill et al, 2013;Stemp et al, 2013Stemp et al, , 2017Evans et al, 2014;Ibáñez et al, 2014aIbáñez et al, ,b, 2016Key et al, 2015).…”