This material has been published in Lithic Technology: LITHIC TECHNOLOGY: Measures of Production, Use, and Curation edited by William Andrefsky, Jr. This version is free to view and download for MEASURES OF personal use only. Not for re-distribution, re-sale or use in derivative works. © PRODUCTION, USE, http://www.cambridge.org/gb/academic/subjects/archaeology/ AND CURATION prehistory/lithic-technology-measures-production-use-and- curation?format=PB&isbn=9781107646636

Edited by WILLIAM ANDREFSKY, JR. Washington State University

.:.:·:.,, CAMBRIDGE ::! UNIVERSITY PRESS Q.DO~ EXPLORING RETOUCH ON BIFACES 87

4 JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. However, assessing retouch amount may not be as universal as we might initially believe. We define retouch as the deliberate modifi­ cation of a stone tool edge created by either percussion or pressure­ EXPLORING RETOUCH ON BIFACES: flaking techniques (Andrefsky 2005). As such, retouch takes place in UNPACKING PRODUCTION, the beginning production stages of a tool as well as in the subsequent episodes of resharpening and reshaping of a tool's cutting edge. There­ RESHARPENING, AND HAMMER T"'(~E fore, we would expect the amount of retouch to progressively increase throughout the production and the use-life of a tool. To evaluate retouch in terms of degree of curation, analysts have created indices that quantify retouch for comparisons of storie tools. Previous retouch measures have been effective for different kinds of stone tool forms. Barton (1988) and Clarkson (2002) measure retouch on flake tools based upon progressive use of the original flake blank. Abstract Kuhn (1990) measured retouch on scraper edges. Andrefsky (2006) and Measuring retouch amounts on stone tools has been helpful for under­ Hoffinan (1985) measured retouch on hafted bifaces (see also Eren and standing human organizational strategies. Multiple retouch indices Prendergast; Hiscock and Clarkson; Quinn et al., this volume). We geared toward assessing retouch amounts on flake tools and unifaces feel that North American bifaces represent a different tool type than have been developed, but few have been developed to evaluate retouch some bifaces from other parts of the world. Bifaces are stone tools exclusively for bifaces. For this study, a retouch index was developed that have two surfaces (or faces) that meet to form an edge around and evaluated on an experimental assemblage of bifaces. It is shown the entire perimeter and usually have flake scars that extend from the that reduction activities on bifaces may create extensive amounts of retouch that are contingent upon a number offactors from both the pro­ edge to the midline of the surface (Andrefsky 2005). North American duction and resharpening events that must be taken into consideration bifaces tend to undergo a production phase and a subsequent use-life before understanding a biface's life history. phase (Callahan 1979; Whitaker 1994). In some areas of the world, bifaces are produced from flake blanks as a result of their being used and resharpened extensively (cf. Clarkson 2002). However, we feel that some bifaces do not become bifaces as a result of this use and INTRODUCTION resharpening process. We feel that some bifaces are shaped by extensive Tool curation has been defined as the relationship between a tool's retouch before they are even used. Some bifaces, particularly those potential utility and its actual usage (Andrefsky 2005; Bamforth 1986; in parts of North America, are extensively retouched during their Shott 1996), or its "life history" (Eren et al. 2005). This curation production phase, and thus, the retouch amount on the biface has concept has been linked to studies of hunter-gatherer organizational little or no meaning with regard to curation. We suggest that retouch strategies in understanding issues ofland use, economy, ar:d, mobility. indices should be specifically tailored to different kinds of tools and For stone tools, retouch amount has been used as an effective measure that we need to consider the differences between bifacial production to assess the degree to which a tool has been curated (for discussion of and bifacial resharpening after use. curation see Andrefsky 2006; Barton 1988; Binford 1973, 1979; Blades To gather information on biface retouch, we conducted a series of 2003; Clarkson 2002; Davis and Shea 1998; Dibble 1997; Nelson 1991; production and use experiments attempting to replicate bifaces sim­ Shott 1989, 1996). ilar to those recovered from Chalk Basin, a chert quarry workshop area on the Owyhee River in southeastern Oregon. Our experiment

86 88 JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES

systematically gathered attribute information from both the bifaces were done by just one of the authors throughout the experiment. being produced and used and the debit;,tge resulting from the experi­ Initially, all three bifaces were reduced using a quartzite hard hammer ment. to remove most of the cortex from the objective piece. After the first half-life, a siltstone hard hammer and a soft hammer (i.e., antler billet) were used to shape and thin the bifaces. Gradually, throughout the THE EXPERIMENT experiment, the percentage of hard hammer flakes decreased whereas Our experimental study involved the production of three "quarry the percentage of flakes made by a soft hammer increased. bifaces" made from high-chipping-quality chert. Information op each biface was recorded after six arbitrary production and use-life events. DEBITAGE PATTERNS WITH BIFACE PRODUCTION The first two events were arbitrary production events and the last four AND RESHARPENING were associated with resharpening episodes after tool use events. When the biface was reduced by approximately half of its starting weight In a previous study (Wilson afid AndrefSky 2006), we explored the during the production process, we arbitrarily stopped and collected variability found in debitage characteristics between biface production debitage shatter for that production event. Resharpening episodes and biface resharpening events from the experiment. From 256 prox­ occurred when the edges of the biface were retouched enough so imal flakes analyzed, we found that debitage characteristics were sig­ that it could be used as a tool with a cutting edge around the entire nificantly associated with differences in production and resharpening perimeter. The biface edges were then dulled and resharpened again events. Metric variables sensitive to these different retouch activities to create a series of resharpening episodes of each biface. include maximum length, width, thickness, weight, and platform area One of the authors performed all of the flintknapping over a (maximum platform width multiplied by maximum platform thick­ drop cloth using either a hard hammer or a soft hammer percussor, ness) (Table 4- I). Nominal attributes that were sensitive to retouch while the other author recovered and numbered each flake as it was activities were platform type and presence of cortex. removed. All production and resharpening were done with percussion Using platform types previously defmed (AndrefSky 2005), we flaking (no pressure flaking). The greatest number of flakes collected found that flakes made from biface production exhibit more flat was from the first production event, which yielded an average of or cortical platforms than flakes made during resharpening events twenty-nine flakes per biface. This makes intuitive sense, because the (Figure 4- I). Most ofthe flakes also had dorsal cortex and have a smaller biface was reduced by the greatest amount during this episode. The width-to-thickness ratio, heavier weight, and larger platform area smallest number of flakes collected was from the first resharpening (Table 4- I). event, with an average of I2 flakes collected for each biface. The In contrast, flakes that are the by-products of resharpening events resharpening events had the greatest amount of variability amongst all tend to have more complex and abraded platforms. The flakes pro­ three bifaces. The average number of flakes collected for each biface, duced from resharpening events also weigh relatively less, with a after the first resharpening event, was nineteen flakes per event. The smaller platform area, and have a higher width-to-thickness ratio. cores chosen for the experiment were all roughly the same shape and Even though the two comparative groups in the debitage study did size (approximately weighing I,ooo g each). However, one biface had have some overlap, the average sizes of the two groups were signifi­ about twenty more flakes removed from it during the experiment than cantly different. the other two bifaces. This was due to the presence of material flaws Given the results of differences noted in the debitage attribute that had to be removed in order to maintain an effective cutting tool. analysis, we could expect to see a positive correlation between flake After each event, all of the shatter was collected and the biface was weight and platform area, and also between flake weight and width­ photographed and measured. For consistency, all of the measurements to-thickness ratio. Intuitively, if the weight increases, there should 90 JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES 91

Table 4. r. Comparison of attributes recorded from proximal flakes 120

Attribute Max Min Mean Std. deviation

Production Weight (g) 99-5 0.7 I2.784 IS-935 100 Width (mm) 93.8 1.5 41.245 r6.63 5 c .t. Resharpening Length (mm) I I3. I 4-6 42.I32 I7.9I6 o Production 80 Thickness (mm) 26.9 2.8 7-870 4-2~2 - Unear (Resharpenlng) Platform width (mm) 58.8 7-4 I9-499 I0.622 s -Unear (Production) Platform thickness (mm) I6.I r.o 5.852 3.085 .::::.. Cl Platform area (mm) I33.822 138.8oi 'ii 60 946.7 7-4 ' :::: Width to thickness (mm) I5-37 0.48 s.BB59 2.5206 Resharpening Weight (g) 5-3 5-3 l.I93 1.054 Resharpening: y = 0.0231x + 0.7878 Width (mm) 44-4 7-2 I8.736 7-054 40 R2 = 0.1151 Length (mm) 65.2 8.5 24.3 I 5 I 1.237 Thickness (mm) 7-5 0.7 2.308 .873 Platform width (mm) 20.5 2.1 8.]63 3-729 20 Production: Platform thickness (mm) 5-3 0.4 I.892 .852 y = 0.0785x + 2.2111 Platform area (mm) 91.2 !.7 I7.60] IS -556 ~=0.4671 Width to thickness (mm) 22.50 3.8s 8.60I9 3.o6so

Platform Area (mm2) FIGURE 4.2. Platform area of proximal flakes plotted against their weight.

60 also be an increase in platform area, given that bigger flakes us.ually have larger platforms, and there should also be a decrease in the 50 width-to-thickness ratio, assuming that the more a flake weighs the larger it should be in size, which is expressed as a ratio. Figure 4.2 displays a scattergram that shows a strong and significant (R2 = .4671, cQ) 40 ~ Q) F = 94-979, p < .oor) relationship between increasing flake weight and c.. platform area with production flakes. From the resharpening episodes, 30 flakes clustered together around the lower weights and smaller platform areas. This relationship was not as strong (Pearson's r = 0.336) as with 20 production flakes but was still statistically significant (R2 = .1151, F = 18.027, p <.ooo5). 10 When flake weights were plotted against the width-to-thickness D Production ratio, it appeared that the weight of the flake increased as the ratio 0 • Resharpening began to decrease (Figure 4.3). On closer examination, however, this abraded cortical crushed complex flat was a significant (R2 = .0403, F = 6.781, p =.oro) but weak correla­ Platform Types (Andrefsky 2005) tion for resharpening flakes. For the production events, there was an insignificant relationship between the variables, where only o. 7% of FIGURE 4.1. Platform types identified on proximal flakes. the variance could be explained (R2 = .0074, F = o.88o, p = -350). JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES 93

400 25~------, Production Resharpening 350 --- {:;' E 300 - .e -~'\ I A Resharpening ta ' I!! 250 c Production

160 It Production l Resharpening 140 ..,._ . ' iii 120 '\\ . 0 ' - ..J 1100 ~ : 2 ~ : .. 80 ~ ' . u "'ca 60 "t: ' 4 :I ""'~ ' (/) 40 '""'..~ ' ' ' 20 ~ ...... : -r 6 0 -- 0 2 3 4 5 6 Use·lile Event

1-+-Biface 1--it-Biface 2 _.....,_Biface sl

FIGURE 4.6. Surface area lost for each biface throughout the reduction sequence. 16

Biface 1 Side A Biface 1 Side B little lost surface area; the average surface area lost for each biface is FIGURE 4-7· Illustration of Clarkson's (2002) grid used to calculate his index of inva­ 2 2 siveness with numbered squares on each side of the biface. The gray areas on _the roughly 50 cm , compared to about 200 cm lost during production. biface figure indicate the midpoint between the midline of the biface and the edge. This pattern also suggests that there may be some observable differ­ Flake scars originating from the edge that do not reach the midpoint would receive a ences in biface characteristics between production and resharpening o.s and flakes that extend past the midpoint would score a r for that segment. events. However, lost surface area is only effective for discriminating such events in a controlled experimental setting. It is not possible to Each side of the biface was partitioned into eight equal segments effectively use such a measure on excavated assemblages, because sur­ (cf. Clarkson 2002), each one accounting for 12.5% of the total area face area lost can only be calculated based upon knowing the original (Figure 4.7). After a reduction event, each segment was given a score size of the biface. However, like the change in debitage attributes, it of either o, 0.5, or 1. Segments exhibiting no retouch would receive does suggest that other biface characteristics might help assess differ­ a score of o. If the flake patterning was evident but did not reach ences between production and resharpening events. the midpoint area of the artifact, defined as the arbitrary line from the midline of the biface to the edge, that square would have a value of 0.5. A score of I was given to squares where retouch extended from RETOUCH INTENSITY the edge of the biface and past the midpoint area. The scores from Other studies have shown that retouch intensity has been an effective each square were added up and then divided by I6 for the average measure of curation on stone tools (Clarkson 2002; Eren and Pren­ retouch amount, which was the index of invasiveness score. If the dergast, this volume, Quinn et al., this volume; Hiscock and Clarkson invasiveness score was close to o, the biface would be considered to 2005; Kuhn I990). We suggest that bifaces have a unique produc­ exhibit little to no retouch. When the invasiveness score approached tion life and use life and thus, retouch amount has to account for I, the tool is classified as being completely retouched. these two phases of a biface life cycle. To assess our assumption, we We found that retouch amount using this technique is not sensi­ applied Clarkson's (2002) index of invasiveness to our experimentally tive to resharpening after the production phase. Using this index, the produced bifaces. bifaces were scored as heavily retouched after the second use-life event JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES 97

9 : - . /__ l 0.95 I ., ! 3 iii" 2 > / : 0.9 )(., , l .E .t 4 0.85 . Production l Resbarpeniog -:---+ . 6 0.8 2 3 4 5 6 Use-life Event

1-+-Biface 1 ...... aiface 2 __.,_Biface 31

FIGURE 4.8. Results of applying Clarkson's index of invasiveness (2002) to our exper­ imental bifaces. Biface 1 Side A Biface 1 Side B

(Figure 4.8). One of the bifaces even reached a value of one (maxi­ FIGURE 4.9. The analysis grid adapted from Clarkson (2002) and used to count ridges systematically for our study. The squares on the biface are I x I em in size and mum retouch amount) after the first use-life event. This is interesting indicate the locations where ridge counts were analyzed throughout the experiment. because we know the bifaces were never used. However, the index reveals a maximum level of retouch and subsequently a maximum level of curation. This suggests that the index of invasiveness may not be a flake removal scars from early production events to final resharpening good indicator ofbifacial retouch as it relates to curation, and also that events. To explore flake removal scar counts, we developed a retouch bifaces are produced, used, and resharpened differently than artifacts index based upon a sample of the flake removal patterns found on the such as flake tools (cf. Andrefsky 2006). The outcome of this method surface of each biface. The average number of ridge counts was used is not surprising, as Clarkson (2002: 72) does warn about the potential as a proxy for flake removals to derive this index. shortcomings of the index of invasiveness when applied to artifacts To test this retouch index, we collected biface data after each biface that have been "fully retouched." Clarkson's index was intended for use-life event (weight, maximum length, width, thickness, and flake application to bifacially retouched flakes. ridge count). The flake ridgesrwere recorded in a systematic way that involved scanning the biface at a high resolution (6oo dpi) and then sampling the bifacial surface image using Deneba's Canvas 8 drafting RIDGE COUNT RETOUCH INDEX program. The analysis ofeach biface image was partitioned using Chris Clarkson's index of invasiveness does not adequately segregate biface Clarkson's grid for evaluating retouch invasiveness, which partitioned production from biface resharpening after use. These two use-life each side of the biface into eight segments. Once the grid was digitally events are important in measuring retouch on bifaces. One of the superimposed on the biface, six I X I em squares were drawn on the things that intuitively appear to be occurring on the surface of biface and positioned in the same location after each use-life event our experimental bifaces is a progressive increase in the number of (Figure 4.9). Three I x I em squares were sampled on each face of JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES 99

4.5,------,------,

0 2 3 4 5 6 Use-life Event

1-+-Bilace 1 ...... Biface 2 -+-Biface 31 Biface 2 After Production FIGURE 4. r r. Average ridge count for each biface throughout the experiment.

FIGURE 4.10. Image of one of the analysis squares from one of the experimental bifaces, showing how flake ridges were counted. light and contrast. The ridges identified on the scanned image were checked on the actual biface to ensure that the lines observed were not biface fissures or ripple marks but actual flake ridges. Once the the specimen. By using a standardized size (I x I em) box, the same number of ridges for each square was confirmed, all six ridge counts amount of surface area was evaluated from the beginning production were added up and divided by six. This resulted in an average ridge stages through the usage and resharpening episodes, regardless ofbiface count for each biface after each use-life event. shape. This retouch index was applied to our assemblage of replicated Dorsal flake ridges, or arrises, were counted in each of the sampled bifaces, with expectations that there would be significant differences boxes. Dorsal ridges were defined as the raised areas that form between between production and retouch use-life events, as seen in the deb­ the intersections of flakes that were removed from the biface (Fig­ itage data, and in the amount of surface area lost on the experimental ure 4. IO) . Flake ridges that form as a result of platform preparation, bifaces. The average ridge count associated with each experimen­ which were present around the biface edge, were not included in tally produced biface use-life event illustrates that the ridge counts this analysis. Flake ridges were identified with the aid of a magnifica­ increase throughout all of the use-life events before dropping at use­ tion lens (I 6 x) and by examining the scanned image of the biface. By life event 5 during resharpening (Figure 4. I I). This pattern reveals using the scanned image of the biface to supplement the analysis, it was some interesting aspects of biface production and resharpening after easier to determine the number of ridges present in the analysis square use. First, the ridge count measure seems to work as an effective tool by focusing in on a particular grid and by adjusting the brightness and to assess use-life events from the beginning of the production cycle contrast of the i~age. Because the biface surface is not smooth, chang­ through the fourth use-life event, and retouch seems to increase as ing the brightness and contrast levels of the image allowed particular each use-life event increases. However, this progressive pattern ends ridges to become more pronounced with different combinations of at use-life event 5, where there is a drop in the retouch index. We roo JENNIFER WILSON AND WILLIAM AND REF SKY, JR. EXPLORING RETOUCH ON BIFACES IOI

100% .------7------,4 ., Production Resbarpening Q. --+ ?: 80% 3.5 Q; ... 100% E Q) E E 3 .. 60% E :r OS .Q"' J: 80% >< "D "E 2.5 ~ 8 01 .5 40% J: "D" +------:--+ >- c e . .a 60% 2 :I Q. 0 .' "C (.) j 20% u.. Q) :I "C 1.5 :E i! 2 40% a: D.. 0% (/) Q) 2 3 4 5 6 ... OS Use-life Event u:: 20% 0.5 j-Hard Hammer --Soft Hammer j 0% 0 FIGURE 4. 12. Graph of the percentages of flakes produced by soft and hard hammer 2 3 4 5 6 percussion. Use-life Event

~ % Hard Hammer Flakes -Ridge Count Index also see that the retouch progression is not markedly different between FIGURE 4 .13. Graph of the average ridge count and of the percentage of flakes made biface production and biface resharpening, as noted in the debitage by hard hammer percussion. data. Since this was not what we had expected, we began exploring our experimental data to determine what might account for the ridge To explore this relationship further, we plotted the ridge count count drop at use-life event 5. One immediate pattern discovered index and hammer type along with the use-life events (Figure 4.I3). was that the type of hammer used during the replication experiments The ridge count index for use life events 4-6 is indeed similar to gradually changed from hard hammer percussion to soft hammer per­ the relative percentages of hard hammer percussion. However, it is cussion as the bifaces were progressively retouched. Other studies also apparent that the ridge count index is sensitive to previous flake also suggest that hammer type and density can be important for flake removals on the biface. For instance, use-life events I-3 have high removal (Andrefsky 2007; Cotterell and Kamminga 1987; Dibble I995; values for hard hammer percussion, yet the ridge count index shows Hayden and Hutchings 1989). Figure 4.I2 charts our experimentally a steady increase from less than I.O to over 3.3 . Essentially, the ridge derived use-life events against the relative proportion ofhard and soft count index is increasing as the original nodule is being progressively hammer percussion used to remove flakes. The first three events are worked, even though the there is minimal change in the percussion primarily hard hammer percussion; this changes to approximately .p% technology. during event 4 and down to 2% during event 5, and then it goes back However, we also feel that the ridge count index is related to the up to close to 30% during event 6. The steep drop in hard hammer existing flake removal pattern on the biface and not solely associated percussion from events 3 through 5 and the subsequent rise at event 6 with the type of percussion technology used. For example, Biface mirrors the ridge count pattern, and suggests to us that the ridge count 2 in event 5 and Biface 3 in event 3 both have steep drops in the index is sensitive to the type of hammer used in biface production and average ridge count (see Figure 4· I I) . During these particular times of resharpening technology. the experiment, these bifaces had irregular flaws in the material that 102 JENNIFER WILSON AND WILLIAM ANDREFSKY, JR. EXPLORING RETOUCH ON BIFACES 103

had to be removed in order to continue to use the biface for usage Finally, it is also apparent from our data that flake removal amount is and resharpening episodes. In doing so, a large portion of the biface not sensitive to changes in biface production events vs. biface resharp­ surface was removed, including the previous flake ridges, which may ening events. Even though these events are clearly visible with debitage have greatly affected the number of flake ridges for particular analysis characteristics, they are not evident from the surface ofbifaces, because grids. the flake removal pattern of bifacial surfaces is produced by a series of multiple technological factors. As previously discussed, these can include flintknapper skill and technique, raw material quality, hammer SUMMARY AND DISCUSSION type, and reduction strategy. Although incomplete at this point, our analysis shows some interest­ In summary, retouch indices created for flake tools may not be ing trends and potential avenues for further exploration with regard suitable for understanding curation strategies for bifaces. As noted in to retouch on bifaces. First, it appears that retouch on bifaces may everal other papers in this volume, retouch is particular to different not be the same as retouch on flake tools. Bifaces are retouched mol types (Andrefsky· Eren and Prendergast; Quinn et al.) and to throughout the reduction sequence, even during the production phase. different tool functions (MacDonald). Retouch does not always equate The biface core has to be reduced in a fashion where the edge is to tool curation. Retouch is a technique used to shape a tool within continually being modified or retouched. Thus, traditional measures the context of tool production, use, and resharpening. All of these linking retouch amount to curation amount may not be effective for contexts must be considered in attempting to quantify tool curation. bifaces, because they may have a high retouch score without ever hav­ ing been used, as illustrated with the application of Clarkson's (2002) index of invasiveness. REFERENCES CITED

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