An Analysis of Folsom Projectile Point Resharpening Using Quantitative Comparisons of Form and Allometry

Journal of Archaeological Science 33 (2006) 185e199

http://www.elsevier.com/locate/jas

An analysis of Folsom projectile point resharpening usingquantitative comparisons of form and allometry

Briggs Buchanan*

University of New Mexico, Department of Anthropology, Albuquerque, NM 87131, USA

Received 22 April 2005; received in revised form 7 July 2005; accepted 11 July 2005

Abstract

A sample of Folsom points from the Southern Plains of Texas and New Mexico is analyzed quantitatively in order to assesspatterns of point resharpening in relation to distance to raw material source area and evaluate models of how resharpening wasaccomplished in terms of point design. A newly developed digitizing method is used to capture 12 interlandmark characters from

coordinate data to describe point form. Principal components analysis is used to investigate size and shape variation in point form,and the symmetry and allometry of characters are used to explore the effects of resharpening on point dimensions. Size allometryillustrates the degree of association of relative point proportions, and other aspects of point form, with point size. Blade length, theleading edge of the weapon, was found to be isometric with point size, suggesting that this character was critical to the proper

functioning of weapon tips. The regulation of blade length to point size supports a fixed-in-haft model for Folsom point resharpening.Multivariate analyses show that reduction in point forms do not correlate with distance-to-source but are more consistent with themodel of the cyclical resharpening and replacement of points. This research illustrates that multivariate and allometric analyses are

useful methods for investigating models of technological organization and the effects of resharpening on point form.� 2005 Elsevier Ltd. All rights reserved.

Keywords: Southern Plains; Paleoindian; Folsom; Resharpening; Digitizing; Multivariate analysis; Allometry

1. Introduction

The recognition and analysis of Folsom point metricand raw material variation has held a significant role inthe formulation and development of Early Paleoindianmodels of adaptation in the Great Plains and RockyMountain regions of North America [4,6,7,14e19,21,26,44e47,53,75,79]. Considerable efforts also have beenexpended toward determining how and why Folsompoints were manufactured and fluted [2,3,20,26,29,31,33,34,36,56,83,87,91]. This attention to a particularartifact type, however, is not unwarranted consideringthe limited nature of the Folsom archaeological record

* Corresponding author. 102-6385 Hawthorn Lane, Vancouver,

British Columbia, V6T 1Z4, Canada. Tel.: C1 604 221 5647.

E-mail address: [email protected]

0305-4403/$ - see front matter � 2005 Elsevier Ltd. All rights reserved.

doi:10.1016/j.jas.2005.07.008

(e.g., [30,42,48,54]), the apparent care and technicalsophistication in the manufacture of such points (e.g.,[29]), and the implicit importance of this weapon type ina highly mobile hunting culture [6,17,46,64,68].

Uniformity in Folsom point dimensions has beenrecognized as evidence for similarity in the manufactur-ing of points throughout western North America andas a result of satisfying strict requirements imposed bythe hafting technique [5,63:47,64:164e176,88]. Folsompoint dimensions are used to infer resharpeningassociated with the staged reduction of points betweenraw material source visits. Models of Folsom techno-logical organization predict that as overall raw materialsupplies are degraded, and points made at the quarryare broken during use, replacement points are manu-factured from flakes detached from bifacial cores andeventually from the core itself [17,45,46,55]. Point

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186 B. Buchanan / Journal of Archaeological Science 33 (2006) 185e199

resharpening analyses focus on point length and theproportion of reworked points within assemblages inrelation to linear distance to raw material source, knownas the retooling index [12,13,18:105e111,45,46], wherepoint length and resharpening are the primary indicatorsof use, and within-assemblage variation acts as a mea-sure of the state of lithic stores at any given position onthe landscape [14].

The identification of projectile points modified byreworking and resharpening, however, can be animprecise enterprise for archaeologists. Lanceolateprojectile points, such as Folsom points, functionedprimarily as weapon tips [65] and to keep them properlyworking after use, the tip and exposed edges had to bekept sharp [2,14,27:26,28:110e111]. Evidence of multi-ple attempts to sharpen edges in the form of overlappingflake scars often is obliterated by the last episode offlaking. In cases of breakage and reworking, evidence ofprevious flake scarring may have been removed entirely.To compound these problems, recovered projectilepoints were deposited or lost from varying stages intheir use-lives, ranging from unused to what appears insome cases to be completely exhausted, and it is difficultto ascertain where along the use-continuum a particularartifact is without knowledge of the original form ofa particular point.

It has been suggested that Folsom points weredesigned to facilitate resharpening. Ahler and Geib [2]have argued that Folsom points were designed towithstand breakage and to be used in the manner ofa snap blade, in that points were made with expendablebasal length and when the tip dulled or fragmented itcould be repositioned in the haft and the newly exposededges made sharp through removal of small flakes.Others have argued [14] that the rehafting of points forresharpening was impractical and that point tips mostlikely were resharpened while fixed-in-the-haft. Theinterrelationship between the characters describingpoint form is used in this analysis to evaluate thesespecific resharpening models.

The present research uses statistical methods toanalyze projectile point size and shape in the investiga-tion of Folsom point resharpening. Quantitative anal-ysis of points offers an objective method to discoverpatterns of size-related shape changes made to pointsthroughout their use-lives. A sample of Folsom pointsfrom the Southern Plains of Texas and New Mexico isanalyzed using 12 morphometric characters derivedfrom landmark data. Only points made of Edwardschert were included in the analysis in order to simplifythe examination of variation in point form in relation todistance from source area. Principal components anal-ysis is used to explore point size and shape variation.The symmetry and allometry of characters also is usedto analyze the effects of resharpening on points.Bilateral asymmetry in point blade dimensions is used

in the identification of resharpening [18:106,35]. Sizeallometry is used to explore morphometric variation todetermine the degree of association of relative pointproportions, and other aspects of point form, with pointsize. Allometry provides a method to examine resharp-ening, which essentially is a problem of identifyingshape-related changes to points that are sequentiallyreduced in size.

The objectives of this research are twofold: (1) toquantitatively identify the effects of resharpening onFolsom points and provide a more precise evaluation ofthe effects of distance-to-source on point form, and (2)to evaluate models of how resharpening was accom-plished in terms of the design of Folsom points, i.e., thesnap-blade model [2] opposed to the fixed-in-haft model[14]. The results have implications for models of Folsomtechnological organization as well wider application inthe study of resharpening within other point types.

2. Folsom assemblages in the analysis

Folsom points from five Southern Plains assemblageswere used in the analysis (Fig. 1). Folsom sites on theGreat Plains generally date between 10,900 and 10,30014C years BP [39,41,51:266,86]. More precise chronolog-ical ordering of assemblages within this period is difficultgiven the statistical error ranges associated with thedates. The five assemblages are from Blackwater Draw(including the Mitchell Locality), Cooper, Lake Theo,Lubbock Lake, and Shifting Sands. The sites are located

Fig. 1. Orthophotograph of western Oklahoma, Texas, and eastern

New Mexico showing the location of sites in the analysis and the

Edwards Plateau region.

187B. Buchanan / Journal of Archaeological Science 33 (2006) 185e199

on the Southern High Plains (Blackwater Draw andLubbock Lake), the adjacent dissected Rolling Plains(Cooper and Lake Theo), and dune fields on the westernedge of the Southern High Plains (Shifting Sands). Ofthe 47 points in the sample, 43 are Folsom points andfour are described as Midland points (Table 1).

The sample of points from Blackwater Draw(LA3324; also known as Blackwater Draw LocalityNo. 1, or the Clovis site) is derived from various kill andcamp localities, as well as from spring conduits,throughout the site [16,18,40,43]. Blackwater Draw islocated on the High Plains of eastern New Mexicobetween the cities of Portales and Clovis. The site issituated in an ancient basin that is connected toBlackwater Draw by a small channel that runs for2 km south of the basin [50:57e75]. Folsom materialshave been recovered from three primary geologic units:the diatomite, Brown Sand Wedge, and spring conduits[43]. Several Folsom bison kills are located in ponddeposits (the diatomite) within the basin, and Folsomcampsites are located along the basin margins in thebrown-sand deposits that interfinger with pond depositsand along the adjacent uplands (e.g., the MitchellLocality [16,84]). Several spring conduits containingdiagnostic Folsom artifacts are located along thewestern basin margin [50:70].

Lubbock Lake (41LU1) is located within an ancientmeander of the Yellowhouse Draw on the northwesternoutskirts of Lubbock, Texas, on the Southern HighPlains [57,58]. Folsom bison kills occur along the edges ofpond margins in stratum 2A at Lubbock Lake [58]. Morethan half the points in the sample were recovered fromstratum 2A, although only one point (from Area 18) wasdocumented in association with bison remains [25].

Table 1

General provenience information associated with the sample of

Folsom points included in the analysis

Site No. of points Provenience References

Blackwater

Draw

4 Gravel pit and surface

of back dirt piles during

original excavations

[18]

8 1962 excavations

conducted by

Jim Warnica

[43:122e123]

2 Mitchell locality [16:70e71]

Lubbock

Lake

3 Surface [58:104e107]

3 Found in situ in stratum

2A along reservoir walls

[58:104e107]

1 Area 18 [25]

Cooper 6 Middle Kill [12,13]

1 Upper Kill [12,13]

1 Slump block [12,13]

Lake Theo 2 Bone bed [23,37,38]

1 Surface [23,37,38]

Shifting

Sands

15 Surface of dune blowouts [8,48]

Cooper (34HP45) is located in northwest Oklahomain the dissected Rolling Plains region northeast of theSouthern High Plains [11e14]. The site contains threestratified Folsom bison kills within the fill of a smallarroyo that drains into the North Canadian River.

Lake Theo (41BI70) is located near the easternescarpment of the Southern High Plains in CaprockCanyons State Park [23,37,38,59]. A bison kill andadjacent occupation surface were uncovered withina stratified terrace above Holmes Creek, a tributary ofthe Red River.

Shifting Sands (41WK21) is located in the AndrewsDunes of western Texas on the western edge of theSouthern High Plains. Over 5000 artifacts have beenmapped and recovered from the surface of the site [8,48].Several areas of artifact concentration have beenidentified. Although most of the concentrations maybe attributable to differential exposure, evidence ofdistinct activities at different areas has been noted, inparticular, Area 2, represented by tool manufacturingdebris and fragmented tools, and Area 3, a probablebison kill and processing area [48]. The Shifting Sandsassemblage consists of points identified as Folsom(n Z 3), Midland (n Z 4), and points that have beendescribed as both (n Z 3) [48].

The validity of the unfluted Midland type, however,has attracted considerable debate and remains un-substantiated [1,5,63,78]. Midland points generally aredescribed as thinner, unfluted typological variants ofFolsom points [89]. It has been suggested that Midlandand unfluted Folsom pointsdwhich may be typolog-ically indistinguishabledwere left unfluted in responseto having limited raw materials on hand when groupswere far from suitable lithic source areas [5,46].Differences in the size and shape of Midland andFolsom points are examined. Also included in thesample from Shifting Sands are several diminutive, orminiature, Folsom points (n Z 5; less than 3 cm inlength) made on thin flakes with only marginal retouch[48:228e231].

3. Folsom use of Edwards Chert

Edwards chert was selected as the single source inwhich to measure distance-to-site because it is thepredominate raw material found at Folsom sites onthe Southern Plains [6,45,46,48,49,72] (Table 2). Ed-wards chert is found in situ within deposits of limestonefrom the Edwards Formation found throughout theEdwards Plateau region of central Texas [9] (Fig. 1).Owl Creek, a black to dark-gray variety of Edwardschert, has been identified as a subtype that occurs northof Fort Hood, Texas [12:94], although further identifi-cation of subtypes within the Edwards Formation hasbeen largely unsuccessful [32].


Chert of similar appearance to materials from theEdwards Formation has been identified in eastern NewMexico [9,80] and in gravels of the Antler SandsFormation of southeastern Oklahoma and along theeastern escarpment of the Southern High Plains [9,52].These Edwards chert look-alikes are assumed not tohave been used extensively by Folsom groups because oftheir inferior quality and small nodule size [47:396,71],although the degree to which this material is identified inassemblages is not known. It is assumed for this analysisthat the material identified as Edwards chert was derivedfrom somewhere within the Edwards Plateau region andnot from look-alike sources.

Another operating assumption for this analysis is thatEdwards chert was procured directly at the outcropsource and not through trade, an assumption bolsteredby the inferred highly mobile bison hunting adaptationmaintained by Folsom groups and indirect evidence ofembedded procurement of stone for tools [12,17,23,45:305e306]. A strict distance-decay model, where thequantity of raw material diminishes as a function ofdistance traveled from source, which would indicatea direct correlation with movement or down-the-linetrade of raw material from the source area, does notappear to fit the distribution of Edwards chert on theSouthern Plains [45,72]. Instead, there is a lack ofcorrelation with distance-to-source and measures oftoolstone resources, such as the proportion of resharp-ened points, in Folsom assemblages [17,45,46,55]. Thissuggests that linear-distance measures from site tosource will not necessarily be accurate predictors ofthe distance raw materials have moved, but they areused as a baseline for comparative purposes in thisanalysis.

4. Methods

4.1. Digitizing projectile points and the definition ofinterlandmark distance characters

Measurements were taken from digital images ofprojectile points following methods described in detailelsewhere [24]. Digital images of artifacts were imported

Table 2

Approximate straight-line distances (km) from assemblage locations to

the Edwards chert source area

Assemblage Approximate straight-line

distance to Edwards Chert

source area (km)

References

Blackwater Draw 360 [43,45:393]

Lubbock Lake 180 [45:393,58]

Cooper 410 [11e14,45:393]

Lake Theo 200 [45:393]

Shifting Sands 160 [45:393,48]

into the tpsDIG program (version 2.02) created byRohlf [77] for two-dimensional outlining. A cursorplaced over landmark positions was used to capturecoordinate data, which then were saved to a file. ThetpsDIG program can be used to magnify images andtherefore permit close inspection of the form that isbeing digitized. Thirty-six coordinate pairs were used foreach projectile point in the analysis. Four coordinatepairs were used to define the scale. Two lengths (2 cmand 4 cm) were digitized with each image and theaverage used as the scale to compute interlandmarkdistances.

Thirty-two landmarks (positions directly comparableamong forms) and pseudolandmarks (positions usedto record margins) were used to define point boundaries(Fig. 2). Thirteen landmarks define each edge and ninedefine the base (with overlap). Three landmarks, oneat the tip and two at the base, are considered

Fig. 2. Folsom point from Shifting Sands (catalog number 34) showing

the approximate location where 11 of the 12 characters (character

point area not shown) are measured and the location of the tip and

basal landmarks. Character initials: EL, edge boundary length; TB, tip

to base length; TW, width of tip to base length to maximum inflection

position; BL, blade length; MW, maximum width; BB, base boundary

length; LB, linear measure of base; ML, midline length; OL, overall

length; BW, basal width across first third of point; LT, length from

base to 1/3 along opposite edge.


‘‘homologous’’ (type I) landmarks [22]. In biologicalterms, a homologous landmark is fully comparable inhistological and topological characteristics from speci-men to specimen. The term is used here to identifypositions that can be directly comparable across pro-jectile point forms used in the analysis. Several land-marks represented maximum and minimum positionsalong the point outline (type II), and the remainder wereused to define the rest of the point outline (the pseudo-or type III landmarks). The same sequence for digitizingprojectile point outlines was followed for each artifact.The tip landmark followed by the basal landmarks wasdigitized first and then the edges and base. The edgesand base were digitized sequentially by approximatinghalf of each length to be digitized and moving from thebase toward the tip. Pairs of Cartesian coordinatesassociated with the landmarks were converted toEuclidean distances in Matlab 6.0 (release 12) to createthe characters for the analysis.

The 12 characters based on the interlandmarkdistances were used to delineate the general shape ofpoints (Table 3; Fig. 2). Point area (PA) was taken bycalculating the morphospace within the digitized outlineof a point. For the analyses the square root of PA istaken to render it dimensionally equivalent to all othercharacters. The other characters are used to describeaspects of blade width (TW, BL, and MW), basal shape(BB, LB, BW, and LT), and aspects of length (EL, TB,ML, and OL). The term blade is used to refer to theportion of the point distal of the maximum width (MW).This definition uses an objective criterion to definewhere the blade begins, in contrast to studies where theblade is defined as the portion of the point distal to thehafting area. The hafting area usually is defined bythe limits of edge grinding (e.g., [2]; see also [66]). Theabsolute limit of edge grinding, however, can be difficult

to identify and may not actually represent the entire haftarea, as demonstrated from high-power use-wearanalyses on Folsom points (analyses by Kay as citedby Bement [14]). In addition to the 12 characters,maximum thickness measurements were taken directlyfrom points using digital calipers or obtained frompublished sources, although these measurements areexamined only in the univariate analyses.

4.2. Statistical and allometric analyses

Prior to statistical analyses, data were transformed tothe natural log scale to make differences in size relativerather than absolute [67]. Univariate statistical analyseswere conducted in SPSS 10.0 (release 10.0.1) andmultivariate analyses were carried out using functionswritten for Matlab 6.0 (release 12). Univariate analysesinclude analysis of variance (ANOVA) with multiplecomparisons to identify where significant differencesoccur [82:179e219]. Multiple comparisons were madeby controlling the experimentwise type I error rate usingthe Bonferroni alpha correction [10:84]. In such cases analpha value equal to 0.05/n, where n is the number oftests conducted, was used.

Principal components analysis (PCA) is used toexplore patterns of size and shape variation in points.PCA is an exploratory data-reduction technique used toidentify a small set of uncorrelated variables (compo-nents) that account for a large proportion of the totalvariance in the original variables [73]. Because PCA isexploratory, homoscedasticity (i.e., the assumption thatthe variance in scores for one variable is roughly thesame at all values of the other variable) and normality ofthe data are not required [73,82]. Eigenvectors andeigenvalues indicate the polarity and magnitude ofvariation in each variable and the relative percentages

Table 3

Characters used in morphometric analyses of projectile points

Characters Description

PA Square root of the point area. Calculated as the area enclosed by the 32 landmarks outlining the point. PA, point area

EL Average of edge boundary lengths. Calculated as the sum of interlandmark distances along the 13 landmarks that define an

edge. EL, edge boundary length

TB Average of the linear lengths from the tip landmark to each of the base landmarks. TB, tip landmark to base landmark length

TW Average of the distance from tip landmark to base landmark (character TB) to calculated maximum edge inflection position along

point edge. TW, width of tip-to-base length to maximum inflection position

BL Average of the distance from the calculated maximum edge inflection position (character TW) to the tip landmark. BL, blade length

MW Average of the distance from the calculated maximum edge inflection position to the midline. MW, maximum width

BB Base boundary length. Calculated as the interlandmark distances along the nine landmarks that define the basal concavity

situated between the two base landmarks. BB, base boundary length

LB Base linear length. Calculated as the distance between the two base landmarks. LB, linear measure of base

ML Midline length. Calculated as the distance from the tip landmark to the midpoint of the basal concavity (character BB).

ML, midline length

OL Overall length. Calculated as the distance from the tip landmark to the midpoint of the linear length between the base landmarks

(character LB). OL, overall length

BW Width at 1/3 total length above base landmarks. BW, basal width across first third of point

LT Average of length from base landmark to 1/3 total length point along opposite edge of point. LT, length from base to first third

distance along opposite edge


of variation accounted for in each component. Principalcomponent scores of a projectile point on a componentare weighted averages of all the character states of thatparticular projectile point. Principal components (PCs)are computed from the covariance matrix of distancemeasures.

Size allometry (opposed to growth allometry) ofpoint form is examined using bivariate and multivariateapproaches. For bivariate analyses of size allometry, thesquare root of point area (PA) is used as a proxy ofoverall point size. The more traditional measure of pointsize used in resharpening models (e.g., [45]) has beenoverall length, however the allometry of this character isof particular concern here and therefore is evaluatedindependently against size. One model of allometricshape change (Huxley’s model) is yZ bXk, where X andY are the sizes of two forms and k (the allometriccoefficient) is an exponential factor that relates the sizes.The allometric equation yZ bXk in logarithmic form isa simple linear relationship logeYZ logeb C k logeX,where Y is the character examined in relation to size, k isthe slope or allometric coefficient, and b is the y-intercept [69]. Using a linear regression model, theregression coefficient of logged Y on logged X is a directestimate of k, the allometric coefficient [70]. Allometriccoefficients indicate the manner in which given charac-ters change in relation to point size. Values greater thanunity (kO 1) indicate positive allometry (charactersdisproportionately larger relative to size), and values lessthan unity (k ! 1) indicate negative allometry (charac-ters disproportionately smaller relative to size). Isometryis a property of characters that increase at the samerelative rate with proportions remaining constant(kZ 1) [62].

Allometry is used to investigate size-related shapechanges; and because shape cannot be defined uniquely,it must always relate to particular size variables [76,81].Therefore, the choice of size variable in allometricstudies will always affect results [74]. A multivariategeneralization of the allometry equation attempts toalleviate this problem using PCA and examination ofthe isometry hypothesis for all variables simultaneously[61]. PC1, the size vector, is used as the best approx-imation for a composite measure of point size (given thesimilar sign and magnitude associated with PC1dseebelow). Multivariate allometric coefficients are derivedby normalizing loadings from PC1. The resultingbivariate and multivariate allometric coefficients areused to investigate point form variation in the sample ofFolsom points.

5. Results

Examination of untransformed overall length (OL)data for the sample of Folsom points shows two points

in the right tail (Fig. 3). These longest points in thesample include a point from Blackwater Draw (36-19-16; [18:77]) and a point from Lubbock Lake (TTU 40-36-136; [58:107]). These two points are good examples ofpossibly unresharpened points. The log-transformedoverall length (OL) and point area data (PA) byassemblage does not correlate with distance to sourcearea (r2 Z 0.022, P Z 0.325 and r2 Z 0.000, P Z 0.997,respectively). The lack of a relationship between overalllength and point area with distance to the Edwards chertsource area is clear in the boxplots of these data byassemblage (Fig. 4). Analysis of variance (ANOVA) ofoverall length and point area (using the log-transformeddata that better approximate normality) indicate nosignificant difference between assemblages (P Z 0.566and P Z 0.724, respectively).

Blade length (BL), measuring the linear length fromthe point of maximum inflection along the edge to the tiplandmark, serves as a good proxy measure for remainingutility of a point. This portion of a point, described asthe leading edge by Ahler and Geib [2:804], is most oftensubject to breakage and dulling and consequentlyreceives successive resharpening attempts. ANOVA ofblade length also shows no significant difference betweenassemblages (P Z 0.663; Fig. 5). Regression of bladelength on distance to source exhibits no significantcorrelation (r2 Z 0.001, P Z 0.820), nor is there a sig-nificant correlation between blade length variance orsample size and distance to source (r2 Z 0.04, P Z 0.739and r2 Z 0.01, P Z 0.853, respectively).

ANOVA of the remaining nine characters by assem-blage reveals that the only significant differences are inbasal characters (BB, LB, and BW). Multiple compar-ison of basal characters using the Bonferroni adjustmentindicates that point bases from Shifting Sands aresignificantly smaller than all of the other points in basallength (LB), smaller than Cooper, Blackwater Draw,and Lubbock Lake points in basal boundary length

Overall Length (mm)42.038.034.030.026.022.018.014.0

10

8

6

4

2

0

Fig. 3. Histogram of untransformed overall length (OL) data (mm) for

Folsom points in the analysis (n Z 47).


(BB), and smaller than Blackwater Draw points in widthat one-third-length above the base (BW). If the fivediminutive points [48] from Shifting Sands are removedfrom the ANOVA, no significant differences are found inbasal characters between assemblages (LB, P Z 0.087;BB, P Z 0.146; BW, P Z 0.691).

8143715 8143715N = Cooper(410)

Blackwater Draw(360)Lake Theo(200)

Lubbock Lake(180)Shifting Sands(160)

mm

(nat

ural

log)

5.0

4.5

4.0

3.5

3.0

2.5

PA

OL

Fig. 4. Boxplots of point area (character PA) and overall length

(character OL) by assemblage (linear distance in kilometers to

Edwards chert source area in parentheses after assemblage name, the

correlations between OL and PA and distance to source are not

significant [P Z 0.325 and P Z 0.997, respectively]). Boxes represent

the interquartile range containing 50% of the values, the line across the

box indicates the median, and the whiskers are lines that extend from

the box to the highest and lowest values.

8143715N =Cooper(.21)

Blackwater Draw(.31)Lake Theo(.16)

Lubbock Lake(.22)Shifting Sands(.26)

Blad

e Le

ngth

(mm

[nat

ural

log]

)

3.6

3.4

3.2

3.0

2.8

2.6

2.4

2.2

2.0

Fig. 5. Boxplot of blade length (character BL) by assemblage (standard

deviations in parentheses; the correlation between BL and distance to

source is not significant [P Z 0.820]). Boxes represent the interquartile

range containing 50% of values, the line across the box indicates the

median, the whiskers are lines that extend from the box to the highest

and lowest values excluding outliers, the open circles indicate outliers,

and the asterisk indicates an extreme outlier.

ANOVA of maximum thickness using most of thepoints in the sample (thickness was not available for twoLubbock Lake points that are now missing [58] and wasnot published for two of the points from the MitchellLocality at Blackwater Draw [16]) exhibited no signif-icant difference between assemblages (P Z 0.684). Atwo-sample t-test, testing the hypothesis that the meanthickness is statistically different between points identi-fied as Folsom and Midland, showed no significantdifference (P Z 0.653; with equal variances assumed).This result is in agreement with Amick’s [5] comparisonof thickness using a much larger sample of Folsom andMidland points (n Z 626; PO0.05 [5:31]).

Examination of overall mean variation by character(normalized from the covariance matrix) demonstratesthat basal and width characters (TW, MW, BB, LB,BW, and LT) are the least variable (Table 4). Lengthcharacters (EL, TB, BL, ML, and OL) exhibit relativelymore variation and the highest mean variation isexpressed in midline and overall length characters.

Bilateral asymmetry in point dimensions is anattribute considered useful in determining if pointresharpening has been undertaken, along with reducedlength, sinuous blade edges, and invasive overlappingnegative flake scars [18:106,35]. In an effort to examinebilateral asymmetry related to resharpening, blade length(BL) is examined in detail. BL is averaged whenemployed in all subsequent analyses, but here the leftand right blade lengths of each point are examinedindependently. A plot of the left blade length against theright blade length shows the degree of asymmetry foreach point (Fig. 6). Because it was arbitrary which face ofa point was analyzed, the direction of deviation from thefit line for the total population (below or above the line) isnot of interpretative relevance; however, the absolutedistance from the line is an indication of greater bladeasymmetry.

Ninety-five-percent confidence bands are used todetermine which points fell close enough to the fittedline to be considered symmetrical; again, the results donot correlate with linear distance to source. Points from

Table 4

Overall mean variation by character

Character Variation

PA 0.215

EL 0.281

TB 0.289

TW 0.193

BL 0.236

MW 0.159

BB 0.171

LB 0.150

ML 0.302

OL 0.300

BW 0.157

LT 0.186


Shifting Sandsdthe closest site to the Edwards chertsourcedhowever, exhibit the lowest incidence of asym-metrical blades (6/11; 54.5%). All of the blades fromLake Theo are asymmetrical (3/3; 100%), nearly all ofthe blades from Lubbock Lake are asymmetrical (6/7;85.7%), close to half the blades from Blackwater Draware asymmetrical (9/14; 64.3%), and more than halffrom Cooper are asymmetrical (5/8; 62.5%). It isinteresting to note that the expectation that longerblades should be more symmetrical and that asymmetryis introduced during resharpening is not demonstratedhere. Points with longer blades plotted in the upper rightof Fig. 6 are more divergent from the fit line comparedwith points with shorter blades in the lower left of Fig. 6.

Principal components analysis of all the charactersand the total sample of points indicate that the first twoprinciple components account for 93.3% of the varia-tion. The plot of PC scores from the first two principalcomponents shows significant overlap of points from theCooper, Blackwater Draw, Lake Theo, and LubbockLake assemblages (Fig. 7). The Shifting Sands points aredifferentiated along the PC2 axis. When the ShiftingSands assemblage is divided into subcomponents basedon descriptions of the different points [48] (R. Rose,2003, personal communication), the points that are mostdifferentiated from the other points can be identified(Fig. 8). Four of the five diminutive points made fromthin flakes [48] are distributed in the lower left-handcorner of Fig. 8 (the fifth diminutive point clusters withpoints from the other assemblages). Three of the fourMidland points as well as two of the Folsom/Midland

Right Blade Length (mm [natural log])3.63.43.23.02.82.62.42.22.0

Left

Blad

e Le

ngth

(mm

[nat

ural

log]

)

3.6

3.4

3.2

3.0

2.8

2.6

2.4

2.2

2.0

Shifting SandsLake TheoLubbock LakeBlackwater DrawCooperTotal Population

Fig. 6. Left blade length plotted against right blade length by assem-

blage. Points plotted outside of the 95% confidence bands are

considered to have significantly asymmetrical blade lengths (absolute

distance from fit line is an indication of asymmetry; whether a point is

plotted above or below the fit line is arbitrary).

points also are differentiated from the main cluster ofpoints.

The loadings for PC1 are all positive, and most are ofsimilar magnitudedbasal characters BB and LB areslightly lower than the other charactersdindicating thatoverall this component accounts for the majority of sizevariation (Table 5). Loadings for PC2 indicate juxtapo-sition between length characters (EL, TB, ML, and OL)and width characters (TW, MW, BB, LB, BW, and LT)describing point-shape variation. Loadings for PA andBL on PC2 have relatively small (in magnitude) loadingsand therefore can be disregarded in the interpretation ofPC2. A vector plot (cf. [60,85]) graphically displayingeigenvalues for PC1 and PC2, illustrates the delineationof basal and width characters from length characters(Fig. 9). PC3 accounts for only a limited portion of theoverall variation (4%) contrasting width (primarily TWand MW) and basal characters (BB and LB; Table 5).

ANOVA of PC1 scores indicates no significantdifference between assemblages (P Z 0.551), whereasANOVA of PC2 scores indicates a significant differencebetween assemblages (P Z 0.000). Multiple comparisonof PC2 scores using the Bonferroni adjustment revealsthe source of difference is between Shifting Sands and theother assemblages. If the diminutive points from ShiftingSands are removed from the comparison of PC2 scores,the only difference found is between Cooper and ShiftingSands. If the diminutive, Midland, and Folsom/Midlandpoints are removed from the comparison of PC2 scores,then there is no significant difference between assemb-lages (P Z 0.150).

9 9.5 10 10.5 11 11.5 12 12.5

0.6

0.8

1

1.2

1.4

1.6

1.8

CP

BW

LL

LT

SS

PC1 (78.6%)

PC2

(14.

7%)

Fig. 7. Plot of the first principal component (PC1) scores against the

second principal component (PC2) scores for points by assemblage

showing centroids indicated by crosses and corresponding convex

polygons that minimally enclose sets of points (PC scores) for each

assemblage (SS, Shifting Sands; LL, Lubbock Lake; LT, Lake Theo;

BW, Blackwater Draw; CP, Cooper).


Bivariate allometry of each character regressed onpoint area (PA, the single character proxy for overallpoint size) is used to examine point size and shaperelationships among the total sample of points. Resultsof the regression analyses show that most charactersdescribing different length measures (EL, TB, ML, andOL) are positively allometric with slopes greater than 1.0(Table 6). Width and basal characters (MW, BB, LB, andBW) are negatively allometric with slopes less than 1.0.An exception to this pattern is LT, which is in oppositionto the other length characters with a slope of less than1.0. BL is the only isometric character with a slope notsignificantly different from 1.0 (Table 6; Fig. 10).

Multivariate allometry scales eigenvalues from thefirst principal component to derive allometric coefficients.The multivariate allometric coefficients are similar tothose derived from the bivariate analyses for all thecharacters (Table 7), suggesting that PA was a good

9 9.5 10 10.5 11 11.5 12 12.5

0.6

0.8

1

1.2

1.4

1.6

1.8

CP

BW

LL

LT

SSmid

SSF

SSf-m

SSmn

PC1 (78.6%)

PC2

(14.

7%)

Fig. 8. Similar plot as shown in Fig. 7, but with the Shifting Sands

assemblage identified by subassemblage (SSF, Shifting Sands Folsom;

SSf-m, Shifting Sands Folsom-Midland; SSmid, Shifting Sands Mid-

land; and SSmn, Shifting Sands miniature points).

Table 5

Loadings for the first four principal components

Character PC1 PC2 PC3 PC4

% variation 78.57 14.65 4.01 1.97

PA 0.993 �0.013 0.012 0.083

EL 0.965 �0.240 �0.052 0.026

TB 0.960 �0.264 �0.084 0.021

TW 0.822 0.195 0.480 0.221

BL 0.905 �0.010 0.132 �0.404

MW 0.808 0.468 0.347 �0.049

BB 0.639 0.705 �0.277 �0.030

LB 0.565 0.751 �0.305 0.072

ML 0.930 �0.349 �0.076 0.054

OL 0.952 �0.291 �0.081 0.017

BW 0.796 0.554 0.148 0.002

LT 0.957 0.259 �0.087 0.037

proxy for point size in the bivariate allometric analyses.Length characters (EL, TB, ML, and OL) are positivelyallometric, whereas width and basal characters (TW,MW, BB, LB, BW, LT) are negatively allometric and,again, BL is nearly isometric.

The regression of blade length (BL) on point areademonstrates that the slope of blade length is nearlyisometric (with a slope of 0.99). Ahler and Geib’sresharpening model [2] predicts that there should be nocorrelation between blade length and point size (b1 Z 0).In their model the basal section of points are shiftedupward and rehafted for resharpening; therefore, bladelengths should remain relatively constant regardless ofpoint size or length and not proportional across points

-1 -0.5 0 0.5 1

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

PA

ELTB

TW

BL

MW

BBLB

ML OL

BW

LT

PC1 loadings

PC2

load

ings

Fig. 9. Vector correlations of the 12 characters within the plane of the

principal components shown in Fig. 7 (PA, point area; EL, edge

boundary length; TB, width of tip to base length to maximum

inflection position; BL, blade length; MW, maximum width; BB, base

boundary length; LB, linear measure of base; ML, midline length; OL,

overall length; BW, basal width across first third of point; LT, length

from base to 1/3 along opposite edge).

Table 6

Linear regression results of each character regressed against point size

(PA) for the total sample of points and results of testing the isometric

null hypothesis (H0: b1 Z 1)

Character y-intercept r2 SE ka H0: b1 Z 1

EL �0.07 0.914 0.055 1.19 0.000

TB �0.24 0.913 0.056 1.22 0.000

TW �0.89 0.691 0.084 0.84 0.000

BL �0.38 0.778 0.085 0.99 0.065b

MW �0.06 0.635 0.080 0.71 0.000

BB 0.73 0.378 0.124 0.65 0.000

LB 1.09 0.306 0.115 0.51 0.000

ML �0.42 0.873 0.071 1.26 0.000

OL �0.39 0.903 0.062 1.26 0.000

BW 0.66 0.632 0.080 0.71 0.000

LT 0.32 0.905 0.042 0.86 0.000

a kZallometric coefficient.b Not significantly different from a slope of 1.


of different sizes. Although the blade length characterdoes not correspond directly to the most distal portionof the tip that Ahler and Geib suggest is designed tofracture, blade length (equivalent to Ahler and Geib’sleading edge described as ‘‘the portion of the pointforward of its maximum width . that part which cutsand enters the target’’ [2:809] and part of the bladeshown above the haft bindings in their Figs. 5a, 5b,and 7) is assumed to have been adjusted when pointswere reset in the haft in proportion to the length of tipthat was lost. Indeed, Ahler and Geib suggest accordingto their model that the length of blade elementsdtheportion exposed above the bindings or the leadingedgedshould exhibit the lowest variability when com-pared to other point dimensions and thereby themeasurement of these dimensions should provide a testof their model [2:813e814].

Regression of blade length on point area and overalllength, testing the null hypothesis of no slope (H0:b1 Z 0), exhibited significant correlations in both cases

2.8 3 3.2 3.4 3.6 3.8

2.2

2.4

2.6

2.8

3

3.2

3.4

PA mm (ln)

BL m

m (l

n)

Fig. 10. Regression analysis of blade length (BL) on point area (PA)

testing the isometry hypothesis (P Z 0.065). Solid line is the best-fit

line for data and dashed line is the hypothetical isometric line (see

Table 6 for results).

Table 7

Multivariate allometric coefficients for each character

Character Multivariate allometric

coefficient

PA 1.06

EL 1.28

TB 1.31

TW 0.89

BL 1.10

MW 0.76

BB 0.72

LB 0.56

ML 1.33

OL 1.35

BW 0.75

LT 0.92

(P Z 0.000; see Table 6 for regression statistics) in-dicating that blade lengths do not conform to the Ahlerand Geib model. Because blade lengths are isometricwith point area, a more plausible model may be that asthe length of points was reduced through resharpening,the expendable blade portion of the point was reducedaccordingly. This could have been done while the pointwas fixed in the haft, thereby sparing the need to theremove the point from the haft for each resharpeningevent.

6. Discussion

Size and shape variation in point form linked toresharpening was evident in the sample. The relativelylimited number of longer points in the distribution ofFolsom point lengths in the sample (Fig. 3) indicatedthat unresharpened points are rarely recovered. Theprevalence of point resharpening was noted in thevariation of length characters, particularly in overalllength, compared to width and basal characters. Closerexamination of blade length showed there was consider-able within-assemblage variation in this character butthat the variation did not correlate with linear distanceto the Edwards chert source area. This evidencesupports current resharpening and point-replacementmodels that suggest raw-material use is not simplya function of distance to source but most likely resultsfrom the number of resharpening events undertakensince the last lithic-quarry visit [17,45,46].

Investigation of bilateral asymmetry in blade lengthsdemonstrated the high degree of asymmetry present ineach assemblage. Asymmetry in blade length is assumedto be a result of focused resharpening on dull orfragmented blade edges or through the use of one edgefor cutting tasks. The unexpected result of bladeasymmetry associated with the longest points in thesample, however, suggests that even the longest points inthe sample may have been resharpened at least once orthat symmetry was rarely achieved in Folsom pointblades. However, without having an adequate compar-ative sample of points presumed to be at the beginningstages of use (such as from a cache), it is unknown towhat tolerance Folsom points were permitted to beasymmetrical and the effect that asymmetry may haveon the aerodynamic properties of points.

A primary objective of this research was to determineif projectile-point size reduction resulting from theresharpening of dull and broken edges could be detectedsolely on the basis of quantitative characters. Newlymanufactured projectile points do not begin their use-lives at the same size, but if similar sets of rules ortolerances are followed during point production, re-gardless of initial blank size, it is assumed that theresulting points will be morphologically similar. With


comparable starting forms, regardless of size, it isassumed that subsequent changes created by resharpen-ing can be monitored using quantitatively measuredcharacters.

Principal components analysis demonstrated that themajority of variation in the 12 characters was attribut-able to size. The primary juxtaposition in point shapewas between base and width characters and lengthcharacters. As length increases, basal and widthcharacters decrease resulting in relatively narrow, longpoints. This relationship describes what can most likelybe attributed to simple design criteria and the physicsrelated to proper hafting and aerodynamic capabilitiesof points. If width characters were isometric orpositively allometric, long points would quickly becometoo wide to haft, lose aerodynamic qualities, and likelybe able to fracture easily.

In fact, allometric analyses showed that Folsompoints might well have been constrained to be dispro-portionately longer. Characters describing length haveallometric coefficients that generally are around 1.2.This attribute, or perhaps functional constraint, mayreflect not only the need for certain length to widthratios for proper hafting and weapon delivery but theneed for disposable blade length while the point is still inits haft [14]. A significant finding of the allometricinvestigation is the isometry of blade length. Bladelength describes the leading edge of the point, the sectionof the point that penetrates the hide of prey targets. Theconformity to proportionality of blade length with pointsize suggests the vital role that blade length played inkeeping points functional. If blade edges were fracturedor dulled through use, resharpening would be conductedand perhaps deliberately geared toward producinga sufficiently proportioned tip.

The manner in which the resharpening of points wasconducted, however, has been a matter of debate. Thesnap-blade model, proposed by Ahler and Geib [2] forthe hafting and resharpening of Folsom points, wherepoints are hafted to allow basal proportions to beexpendable when more blade length is needed, is notsupported by the findings in this analysis. Ahler andGeib [2:813] note that blade length (what they describeas the portion of the point that extends beyond thedulling of the edges that indicate the limits of hafting; inthis analysis blade length is described as the distancefrom the maximum inflection point to the tip) should bethe portion of the point that was under strict control.The isometry of blade length found in this samplesuggests that the blade portion of the point was expend-able and not the base as is predicted in the Ahler andGeib model.

The potential for broken point tips to be rebaseddthat is, the removal of flakes to form new basal ears anda basal concavity on the fractured proximal edge of a tipfragmentdwas not specifically identified in this analysis.

However, the relationships identified in the allometricanalyses show that even if tip fragments were rebased,blade lengths were made proportional to size. On thewhole, points in this sample do not exhibit dispropor-tionately longer blade lengths, as would be expected ifrebasing simply put a new concave base on a generallytriangular tip fragment. Bement [14] has suggested thatFolsom point dimensions and the hafting technique usedmay have been designed expressly to avoid fractures thatwould result in tip fragments that were long enough tobe reworked. In his model, Bement [14] proposes thatpoints were bound almost entirely in the haft leavingonly enough exposed tip to do the penetrating andcutting function of the weapon. This arrangement wouldlikely produce only snap fractures to the tip that couldbe resharpened while in the haft by cutting throughthe distal most haft bindings if needed. In this scenario,the potential for the rebasing and consequentially therehafting of fractured point tips is minimized throughthe hafting mechanismdan implication not at odds withthe findings of the analysis presented here.

Most of the diminutive points and Midland pointsfrom Shifting Sands clearly were different with respect tosize and shape in relation to the other points. Thediminutive points were made by the retouching ofsmall, thin flakes (and in one case from a channel flake[48:228]) and are pseudo-fluted (marginal retoucharound ventral flake surfaces). The distinctiveness ofthese points is a result of a different mode ofmanufacture not found in the other assemblages in thisanalysis, although, similar diminutive points have beenrecovered at the Lindenmeier site in Colorado [90] andthe Adair-Steadman site in Texas [87]. Because thisdifferent method of manufacture is found along withother typical Folsom points and may be related toa functional response to limited availability or stores ofraw material [46,48], it is assumed that the production ofdiminutive points was an alternative mode of pro-duction that does not follow typical productionmethods. Models of Folsom technological organizationpredict that as flakes detached from bifacial coresbecome increasingly smaller, so will the size of thepoints made from them. However, other small pointsnot specifically identified as diminutive are found in theother assemblages (for example, the complete pointA917-40 from Lake Theo is less than 3 cm long [23:132])but they are not significantly different in shape fromlarger points suggesting the diminutive points fromShifting Sands are different. Alternatively, diminutivepoints may have been used to hunt for smaller game orused by children as toys. The lack of diminutive pointsfrom other assemblages on the Southern Plains suggeststhat the unique production of diminutive points wasseldom done.

The majority of the Midland and Folsom-Midlandpoints also were differentiated from the other points


along with the diminutive points. A number ofresearchers have suggested that Midland points donot represent a type distinct from Folsom based on theco-occurrence of Midland and Folsom points atexcavated sites and the overall similarities in pro-duction and form [5,46,48,63]. At Shifting Sands,Folsom and Midland pointsdas well as points de-scribed as having characteristics of both Folsom andMidlanddwere recovered together. Some of the Mid-land points, however, exhibited distinctly differentshapes compared with the entire sample of points.These points, together with the diminutive points, mayreflect a lack of raw-material provisions held by groupsvisiting the site. If replacement points were needed butonly a limited amount of raw material was available,a solution could have been to alter the manner inwhich Folsom points were made, using lateral thinninginstead of fluting in the case of Midland points or bypseudo-fluting small flakes as was the case for di-minutive points [5,46,48,63].

The use of morphometrics to describe the size andshape of Folsom projectile points in this study is notoffered as a replacement for qualitative assessments ofpoint resharpening that rely on the presence of attributessuch as the sinuosity of blade edges and invasiveoverlapping negative flake scars, but as an additionalmethod that can be used to investigate if changes in pointform are the result of resharpening. The charactersdefined in this study can be used in conjunction withmultivariate techniques to monitor shape differencesobjectively across a range of points of different sizes. Theallometry of point characters in particular proved to bea useful technique to investigate proportional changes invarious characters describing point form across a widerange of points at different stages in their use-lives andfrom different assemblages.

The results presented here, although based ona relatively small sample (nZ 47), demonstrate thatFolsom point dimensions are inconsistent with the snap-blade hypothesis proposed by Ahler and Geib [2].Ahler and Geib formulated specific expectations forthe manner in which Folsom point-dimensions shouldchange over the course of successive point resharpeningepisodes. Quantitative testing of those expectationsrevealed that their model was unlikely for the sampleof points studied here. Quantitative analyses of pointdimensions did provide additional support for thecurrent models of Folsom technological organization.Reduction in point forms did not correlate withdistance-to-source but was more consistent with themodel of the cyclical resharpening and replacement ofpoints after sequential use episodes. This researchoutlines how allometry can be used to investigate thesources of variation that potentially effect the form ofprojectile technologies and to quantify functionalconstraints of points of all types.

7. Conclusions

Variation in point form is fundamental evidence inthe inference of Folsom technological organization andmobility. This variation however, previously has beenmonitored using only point length and qualitativedescriptions of resharpening to interpret patterns amongpoint assemblages. The analysis presented here de-veloped a quantitative approach to the investigation ofFolsom point form. Twelve interlandmark distancecharacters were used to describe point form. The sourceof most point size variation was determined to be relatedto the resharpening of point blades. None of the variouslength characters examined correlated with lineardistance to raw material source supporting models ofFolsom technological organization that propose pointsupplies were managed carefully with broken andexhausted points intermittently replaced after use andresharpening episodes. Allometric analyses showed thatblade length was isometric with point area and lengthcharacters were positively allometric. In terms of the twoobjectives of this paper, it was found that variation inthe sample of Folsom points from the Southern Plainsprimarily was a result of resharpening and the correla-tion of blade length with point size supports the fixed-in-haft model for Folsom resharpening. This research hasdemonstrated that multivariate and allometric analysesare useful methods for investigating models of techno-logical organization and the effects of resharpening onpoint form.

Acknowledgments

The author is grateful to Richard Rose for allowingaccess to the Shifting Sands collection and for sharing hisknowledge of the site and region. Leland Bement(Oklahoma Archeological Survey) provided digital pho-tographs of the Cooper points. The points from LakeTheo were examined while on loan from the Panhandle-Plains Historical Museum, Canyon, Texas (Jeff Indeck,Curator), and photographed and analyzed at theMuseum of Texas Tech University. One of the LubbockLake points (TTU-A1000000) was photographed at theLubbock Lake Landmark. Point TTU-A1000000 wasgenerated during fieldwork under TAC permit No. 36.The Lubbock Lake Collection is a state-associated held-in-trust collection. Thanks to Leland Bement, MarcusHamilton, DavidMeltzer, Michael O’Brien, and RichardStrauss for providing very helpful comments and advicethat considerably improved the content of this work,although any errors solely are the responsibility of theauthor.


References

[1] G. Agogino, The Midland complex: is it valid? American Anthro-

pologist 71 (1969) 1117e1118.[2] S.A. Ahler, P.R. Geib, Why flute? Folsom point design and

adaptation, Journal of Archaeological Science 27 (2000) 799e820.

[3] K.Akerman, J.L.Fagan,Fluting theLindenmeierFolsom: a simple

and economical solution to the problem and its implications for

other fluted point assemblages, Lithic Technology 15 (1986) 1e6.

[4] D.S. Amick, Folsom diet breadth and land use in the American

Southwest, PhD dissertation, Department of Anthropology,

University of New Mexico, Albuquerque. University Microfilms,

Ann Arbor, MI, 1994.

[5] D.S. Amick, Patterns of technological variation among Folsom

and Midland projectile points in the American southwest, Plains

Anthropologist 40 (1995) 23e38.

[6] D.S. Amick, Regional patterns of Folsom mobility and land use in

the American southwest, World Archaeology 27 (1996) 411e426.

[7] D.S. Amick (Ed.), Folsom Lithic Technology, Explorations in

Structure and Variation, International Monographs in Prehistory,

Archaeological Series 12, Ann Arbor, MI, 1999.

[8] D.S. Amick, J.L. Hofman, R.O. Rose, The Shifting Sands

Folsom-Midland site in Texas, Current Research in the Pleisto-

cene 6 (1989) 1e3.

[9] L.D. Banks, From Mountain Peaks to Alligator Stomachs, A

Review of Lithic Sources in the Trans-Mississippi South, the

Southern Plains, and Adjacent Southwest, Oklahoma Anthropo-

logical Society Memoir 4, Norman, OK, 1990.

[10] K.G. Beal, H.J. Khamis, A problem in statistical analysis: simul-

taneous inference, Condor 93 (1991) 1023e1025.[11] L.C. Bement, The Cooper Site: a stratified Folsom bison kill in

Oklahoma, in: L.C. Bement, K.J. Buehler (Eds.), Southern Plains

Bison Procurement and Utilization from Paleoindian to Historic,

Plains Anthropologist Memoir 29, 1997, pp. 85e99.[12] L.C. Bement, Bison Hunting at Cooper Site, Where Lightning

Bolts Drew Thundering Herds, University of Oklahoma Press,

Norman, OK, 1999.

[13] L.C. Bement, View from a kill: the Cooper site Folsom lithic

assemblage, in: D.S. Amick (Ed.), Folsom Lithic Technology,

Explorations in Structure and Variation, International Mono-

graphs in Prehistory, Archaeological Series 12, Ann Arbor, MI,

1999, pp. 111e121.

[14] L.C. Bement, Pickin’ up the pieces: Folsom projectile point re-

sharpening technology, in: J.E. Clark, M.B. Collins (Eds.),

Folsom Technology and Lifeways, Special Publications No. 4,

Lithic Technology, University of Tulsa, Tulsa, OK, 2002,

pp. 135e140.

[15] J.M. Blackmar, Regional variability in Clovis, Folsom, and Cody

land use, Plains Anthropologist 46 (2001) 65e94.

[16] A.T. Boldurian, Lithic Technology at the Mitchell Locality of

Blackwater Draw: A Stratified Folsom Site in Eastern New

Mexico, Plains Anthropologist Memoir 25 (1990).

[17] A.T. Boldurian, Folsom mobility and organization of lithic

technology: a view from Blackwater Draw, New Mexico, Plains


[18] A.T. Boldurian, J.L. Cotter, Clovis Revisited, New Perspectives

on Paleoindian Adaptations from Blackwater Draw, New

Mexico, University Museum Monograph 103, The University

Museum, University of Pennsylvania, Philadelphia, PA, 1999.

[19] A.T. Boldurian, S.M. Hubinsky, Preforms in Folsom lithic

technology: a view from Blackwater Draw, New Mexico, Plains


[20] A.T. Boldurian, P.T. Fitzgibbons, P.H. Shelley, Fluting devices in

the Folsom tradition: patterning in debitage formation and

projectile point basal configuration, Plains Anthropologist 30

(1985) 293e303.

[21] A.T. Boldurian, G.A. Agogino, P.H. Shelley, M. Slaughter,

Folsom biface manufacture, retooling, and site function at the

Mitchell Locality of Blackwater Draw, Plains Anthropologist 32

(1987) 299e311.

[22] F.L. Bookstein, Morphometric Tools for Landmark Data: Geom-

etry and Biology, Cambridge University Press, Cambridge, 1991.

[23] B. Buchanan, Folsom lithic procurement, tool use, and re-

placement at the Lake Theo site, Texas, Plains Anthropologist 47

(2002) 121e146.

[24] B. Buchanan, Cultural transmission and stone tools: a study of

Early Paleoindian technology in North America, unpublished

PhD dissertation, Department of Anthropology, University of

New Mexico, Albuquerque, 2005.

[25] B. Buchanan, E. Johnson, V.T. Holliday, The 1948 and 1999

excavations of stratum 2 Paleoindian bone beds in Station E

(Area 18) at Lubbock Lake, Current Research in the Pleistocene

18 (2001) 13e14.

[26] J.E. Clark, M.B. Collins (Eds.), Folsom Technology and Life-

ways, Special Publications No. 4, Lithic Technology, University

of Tulsa, Tulsa, OK, 2002.

[27] M.B. Collins, Clovis and Folsom lithic technology on and near

the southern Plains: similar ends, different means, in: D.S. Amick

(Ed.), Folsom Lithic Technology, Explorations in Structure and

Variation, International Monographs in Prehistory, Archaeolog-

ical Series 12, Ann Arbor, MI, 1999, pp. 12e38.

[28] S.L. Cox, A re-analysis of the Shoop site, Archaeology of Eastern

North America 14 (1986) 101e170.

[29] D.E. Crabtree, A stoneworkers approach to analyzing and

replicating the Lindenmeier Folsom, Tebiwa 9 (1966) 3e39.

[30] J. Dawson, W.J. Judge, Paleo-indian sites and topography in the

middle Rio Grande Valley of New Mexico, Plains Anthropologist

14 (1969) 149e163.

[31] J.J. Flenniken, Reevaluation of the Lindenmeier Folsom:

a replication experiment in lithic technology, American Antiquity

43 (1978) 473e480.

[32] C.D. Frederick, C. Ringstaff, Lithic resources at Fort Hood:

further investigations, in: W.N. Trierweiler (Ed.), Archaeological

Investigations on 571 Prehistoric Sites at Fort Hood, Bell and

Coryell Counties, Texas, Archeological Resource Management

Series Research Report No. 31, United States Army, Fort Hood,

1994, pp. 125e181.

[33] G.C. Frison, B.A. Bradley, Folsom Tools and Technology at the

Hanson Site, Wyoming, University of New Mexico Press, Albu-

querque, 1980.

[34] G.C. Frison, B.A. Bradley, Fluting Folsom projectile points, in:

G.C. Frison, D.J. Stanford (Eds.), The Agate Basin Site, Acad-

emic Press, New York, 1982, pp. 209e212.

[35] A.C. Goodyear, The Brand Site: A Techno-Functional Study of

a Dalton Site in Northeast Arkansas, Arkansas Archaeological

Survey Publications on Archaeology, Research Series 7 (1974).

[36] E.M. Gryba, A stone age pressure method of Folsom fluting,

Plains Anthropologist 33 (1988) 53e66.

[37] B.R. Harrison, K.L. Killen, Lake Theo: A Stratified, Early Man

Bison Butchering and Camp Site, Briscoe County, Texas,

Panhandle-Plains Historical Museum, Special Archeological Re-

port 1 (1978) 1e108.[38] B.R. Harrison, H.C. Smith, A test excavation of the Lake Theo

site Briscoe County, Texas, Panhandle-Plains Historical Review

48 (1975) 70e106.

[39] C.V. Haynes Jr., Clovis-Folsom geochronology and climate

change, in: O. Soffer, N.D. Praslov (Eds.), From Kostenki to

Clovis: Upper Paleolithic-Paleo-Indian Adaptations, Plenum

Press, New York, 1993, pp. 219e236.

[40] C.V. Haynes Jr., Geochronology of paleoenvironmental change,

Clovis type site, Blackwater Draw, New Mexico, Geoarchaeology

10 (1995) 317e388.


[41] C.V. Haynes Jr., R.P. Beukens, A.J.T. Jull, O.K. Davis, New

radiocarbon dates for some old Folsom sites: accelerator technol-

ogy, in: D.J. Stanford, J.S. Day (Eds.), Ice Age Hunters of the

Rockies, University Press, Colorado, Niwot, 1992, pp. 83e100.[42] J.J. Hester, A Folsom lithic complex from the Elida site,

Roosevelt County, N.M, El Palacio 69 (1962) 92e113.

[43] J.J. Hester, Blackwater Draw Locality No. 1: A Stratified Early

Man Site in Eastern New Mexico, Southern Methodist Univer-

sity, Fort Burgwin Research Center Publication 8, 1972.

[44] J.J. Hester, J. Grady, Paleoindian social patterns on the Llano

Estacado, in: E. Johnson (Ed.), Paleoindian Lifeways, The

Museum Journal, West Texas Museum Association, Texas Tech

University, Lubbock, 1977, pp. 78e96.

[45] J.L. Hofman, Folsom land use: projectile point variability as a key

to mobility, in: A. Montet-White, S. Holen (Eds.), Raw Material

Economies Among Prehistoric Hunter-Gatherers, University of

Kansas, Publications in Anthropology 19 (1991) 335e355.

[46] J.L. Hofman, Recognition and interpretation of Folsom techno-

logical variability on the Southern Plains, in: D.J. Stanford,

J.S. Day (Eds.), Ice Age Hunters of the Rockies, University Press,

Colorado, Niwot, 1992, pp. 193e224.

[47] J.L. Hofman, Unbounded hunters: Folsom bison hunting on the

Southern Plains circa 10,500 BP, the lithic evidence, in: J. Jaubert,

J.-P. Brugal, F. David, J.G. Enloe (Eds.), Le Bison: Gibier et

Moyen de Subsistance des Hommes du Paleolithique aux Paleo-

indiens des Grandes Plaines, Editions APDCA, Antibes, France,

1999, pp. 383e415.[48] J.L. Hofman, D.S. Amick, R.O. Rose, Shifting Sands: a Folsom-

Midland assemblage from a campsite in western Texas, Plains


[49] J.L. Hofman, L.C. Todd, M.B. Collins, Identification of central

Texas Edwards chert at the Folsom and Lindenmeier sites, Plains


[50] V.T. Holliday, Paleoindian Geoarchaeology of the Southern High

Plains, University of Texas Press, Austin, 1997.

[51] V.T. Holliday, The evolution of Paleoindian geochronology and

typology on the Great Plains, Geoarchaeology 15 (2000) 227e290.

[52] V.T. Holliday, C.M. Welty, Lithic tool resources of the eastern

Llano Estacado, Bulletin of the Texas Archeological Society 52

(1981) 201e214.

[53] B.B. Huckell, J.D. Kilby, Folsom point production at the Rio

Rancho site, New Mexico, in: J.E. Clark, M.B. Collins (Eds.),

FolsomTechnology and Lifeways, Special Publications No. 4, Lithic

Technology, University of Tulsa, Tulsa, OK, 2002, pp. 11e29.

[54] B.B. Huckell, J.D. Kilby, B. Buchanan, M.J. Hamilton, S. Ruth,

2001 excavations at theBocaNegraWashFolsomsite, north-central

NewMexico, Current Research in the Pleistocene 19 (2002) 39e40.

[55] E.E. Ingbar, The Hanson site and Folsom on the northwestern

Plains, in: D.J. Stanford, J.S. Day (Eds.), Ice Age Hunters of

theRockies,University Press Colorado,Niwot, 1992, pp. 169e192.

[56] E.E. Ingbar, J.L. Hofman, Folsom fluting fallacies, in: D.S.

Amick (Ed.), Folsom Lithic Technology, Explorations in

Structure and Variation, International Monographs in Prehistory,

Archaeological Series 12, Ann Arbor, MI, 1999, pp. 98e110.

[57] E. Johnson, Paleoindian bone expediency toolsdLubbock Lake

and Bonfire Shelter, Canadian Journal of Anthropology 2 (1982)

145e157.

[58] E. Johnson (Ed.), Lubbock Lake, Late Quaternary Studies on

the Southern High Plains, Texas A&M University Press, College

Station, 1987.

[59] E. Johnson, V.T. Holliday, R.W. Neck, Lake Theo: late Quater-

nary paleoenvironmental data and a new Plainview (Paleoindian)

date, North American Archaeologist 3 (1982) 113e137.

[60] P. Jolicoeur, Multivariate geographic variation in the wolf Canus

lupus L. Evolution 13 (1959) 283e299.

[61] P. Jolicoeur, The multivariate generalization of the allometry

equation, Biometrics 19 (1963) 497e499.

[62] P. Jolicoeur, Principal components, factor analysis, and multi-

variate allometry: a small-sample direction test, Biometrics 40

(1984) 685e690.

[63] W.J. Judge, Systems analysis and the Folsom-Midland question,

Southwestern Journal of Anthropology 26 (1970) 40e51.

[64] W.J. Judge, Paleoindian Occupation of the Central Rio Grande

Valley in New Mexico, University of New Mexico Press, Albu-

querque, 1973.

[65] M. Kay, Microwear analysis of some Clovis and experimental

chipped stone tools, in: G.H. Odell (Ed.), Stone Tools: Theo-

retical Insights into Human Prehistory, Plenum Press, New York,

1996, pp. 315e344.[67] O.N. Keene, The log transform is special, Statistics in Medicine 14

(1995) 811e819.

[68] R.L. Kelly, L.C. Todd, Coming into the country: early Paleoindian

hunting and mobility, American Antiquity 53 (1988) 231e244.

[69] B. Kuhry, L.F. Marcus, Bivariate linear models in biometry,

Systematic Zoology 26 (1977) 201e209.

[70] L. Leamy, D. Bradley, Static and growth allometry of morpho-

metric traits in randomized house mice, Evolution 36 (1982)

1200e1212.

[71] P.D. LeTourneau, Folsom use of eastern New Mexico look-alike

cherts on the Llano Estacado, Current Research in the Pleistocene

15 (1998) 77e79.

[72] P.D. LeTourneau, Folsom toolstone procurement in the

Southwest and Southern Plains, unpublished PhD dissertation,

Department of Anthropology, University of New Mexico, Albu-

querque, 2000.

[73] B.F.J. Manly, Multivariate Statistical Methods, A Primer, second

ed., Chapman and Hall, London, 1994.

[74] J.E. Mosimann, Size allometry: size and shape variables with

characterizations of the lognormal and generalized gamma distri-

butions, Journal of the American Statistical Association 65 (1970)

930e945.[75] P.J. Munson, Folsom fluted projectile points east of the Great

Plains and their biogeographical correlates, North American

Archaeologist 11 (1990) 255e272.

[76] J.T. Richtsmeier, V.B. Deleon, S.R. Lele, The promise of geo-

metric morphometrics, Yearbook of Physical Anthropology 45

(2002) 63e91.

[77] F.J. Rohlf, Thin plate spine digitizing program, SB Morpho-

metrics Web Page, State University of New York at Stony Brook,

!http://life.bio.sunysb.edu/morph/index.htmlO, (accessed 2002).

[78] I. Rovner, G. Agogino, An analysis of fluted and unfluted

Folsom points from Blackwater Draw, The Masterkey 41 (1967)

131e137.

[79] F. Sellet, Beyond the point: projectile manufacture and

behavioral inference, Journal of Archaeological Science 31

(2004) 1553e1566.

[80] P.H. Shelley, Paleoindian movement on the southern High Plains:

a re-evaluation of inferences based on the lithic evidence from

Blackwater Draw, Current Research in the Pleistocene 1 (1984)

35e36.[81] R.J. Smith, On the definition of variables in studies of primate

dental allometry, American Journal of Physical Anthropology 55

(1981) 323e329.[82] R.R. Sokal, F.J. Rohlf, Biometry, The Principles and Practice of

Statistics in Biological Research, third ed., WH Freeman and

Company, New York, 1995.

[83] J.B. Sollberger, A technique for Folsom fluting, Lithic Technol-

ogy 14 (1985) 41e50.

[84] D. Stanford, F. Broilo, Frank’s Folsom campsite, The Artifact 19

(1981) 1e11.

[85] R.E. Strauss, L.A. Fuiman, Quantitative comparisons of body

form and allometry in larval adult Pacific Sculpins (Tele-

ostei:Cottidae), Canadian Journal of Zoology 63 (1985)

1582e1589.

http://life.bio.sunysb.edu/morph/index.html


[86] R.E. Taylor, C.V. Haynes Jr., M. Stuiver, Clovis and Folsom age

estimates: stratigraphic contexts and radiocarbon calibration,

Antiquity 70 (1996) 515e525.

[87] C. Tunnell, Fluted projectile point production as revealed by lithic

specimens from the Adair-Steadman site in northwest Texas, in:

E. Johnson (Ed.), Paleoindian Lifeways, The Museum of Texas

Tech University, The Museum Journal 17 (1977) 140e168.

[88] C. Tunnell, L. Johnson, Comparing Dimensions for Folsom

Points and Their Byproducts from the Adair-Steadman and

Lindenmeier Sites and Other Localities, Texas Historical Com-

mission Archeological Reports Series No. 1, 1991.

[89] F. Wendorf, A.D. Krieger, New light on the Midland discovery,

American Antiquity 25 (1959) 66e78.

[90] E.N. Wilmsen, F.H.H. Roberts, Jr., Lindenmeier, 1934-1974:

Concluding Report on Investigations, Smithsonian Contributions

to Anthropology No. 24, Smithsonian Institution Press, Wash-

ington, DC, 1978.

[91] J. Winfrey, An event tree analysis of Folsom point failure, Plains


Further reading

[66] L.H. Keeley, Hafting and retooling: effects on the archaeological

record, American Antiquity 47 (1982) 798e809.

Documents

An Analysis of Folsom Projectile Point Resharpening Using Quantitative Comparisons of Form and Allometry