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Journal of Archaeological Science 40 (2013) 3475e3491

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Journal of Archaeological Science

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Functional insights into the innovative Early Howiesons Poorttechnology at Diepkloof Rock Shelter (Western Cape, South Africa)

Marina Igreja a,*, Guillaume Porraz b,1

a LAMPEA UMR 7269 (Aix-en-Provence, France) UNIARQ, University of Lisbon (Portugal), Rua gonçalves lobato n3, 2d, 2720-264 Lisbon, PortugalbCNRS, UMR 7041-ArScAn-AnTET, Maison de l’Archéologie et de l’Ethnologie, Université de Paris X, France

a r t i c l e i n f o

Article history:Received 7 September 2012Received in revised form15 February 2013Accepted 16 February 2013

Keywords:Middle Stone AgeEarly Howiesons PoortBacked toolsBladesHaftingUse-wear analysis

* Corresponding author. Tel.: þ351 969302453.E-mail addresses: dearaujo.igreja@mmsh.univ-aix

(M. Igreja), guillaume.porraz@mae.u-paris10.fr (G. Po1 Tel.: þ33 (0) 146692655.

0305-4403/$ e see front matter � 2013 Elsevier Ltd.http://dx.doi.org/10.1016/j.jas.2013.02.026

a b s t r a c t

The Howiesons Poort (‘HP’) is characterized by a set of technological innovations that mark a rupture inthe Southern African Middle Stone Age. However perspectives regarding its origin and emergenceremain speculative. The recent identification of an Early HP phase at Diepkloof Rock Shelter provides theopportunity to characterize the initial stage of this technology and to discuss various mechanisms behindits innovative characteristics.

This study provides a technological characterization of the Early HP lithic industry of Diepkloof thatfocuses on micro-wear analysis. These results suggest that the Early HP contained the full spectrum ofinnovations found in later expressions of the HP in terms of raw material provisioning strategies andtechno-typological rules. Use-wear analyses support the suggestion that a wide range of activities wereperformed on site and show that geometric backed tools (predominantly composed of truncated forms)were 1) not devoted to specific tasks and 2) used predominantly as knives, not as projectiles. Theinnovative driver at the origin of the HP is likely not related to the adoption of new hunting weapons butto a novel way of conceiving and hafting tools, based on standardized and interchangeable products. Therapid adoption of this new hafting technique may explain the sudden appearance of the HP technologicalsystem in the archaeological record.

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1. Introduction

The Howiesons Poort (HP) is indicative of a break within thesouthern African Middle Stone Age (MSA) (Singer and Wymer,1982; Deacon and Deacon, 1999; Wurz, 2002). The HP lithic tech-nology, in terms of raw material selection as well as blank pro-duction and tool manufacture, argue for a fundamental change inthe way hunter-gatherer populations were organized and inter-acted. Apart from technology, various avenues of evidence supportthe innovative character of the HP (Deacon and Deacon, 1999;Lombard, 2005a). The earliest expression of a graphic tradition,articulated through geometric patterns engraved on ostricheggshell containers (Texier et al., 2010), is one of these spectacularmanifestations associated with the HP. These various avenues ofarchaeological evidence explain why the HP has been directly

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compared to the southern African Later Stone Age (once consideredas its earliest expression) and to the Eurasian Upper Paleolithic.

The HP is well documented in southern Africa. Its recognitionrests on evidence for the exploitation of fine-grained rocks, theproduction of blades and bladelets with soft hammer stone per-cussion and the manufacture of backed pieces (Singer and Wymer,1982; Volman, 1984; Deacon, 1995; Wurz, 2002; Soriano et al.,2007; Porraz et al., 2008). HP sites are indicative of the occupa-tion of different regions, south of the tropic of Capricorn, from theAtlantic to the Indian Ocean (Fig. 1). In spite of a large number ofsites, only a few of them (e.g. Klasies River, Rose Cottage, Sibudu,Pinnacle Point 5/6, Diepkloof) provide long sequences that allow usto discuss diachronic variability within the HP. However only asmall number of studies have interrogated its spatial variability.Many aspects of the HP history still remain unexplored. Since itsdiscovery (Stapleton and Hewitt, 1927) the chronology and themechanisms involved in its emergence and disappearance remaincontroversial (Lombard, 2005a).

Several archaeological studies have recently investigated thedisappearance of the HP (Soriano et al., 2007; Villa et al., 2010;MacKay, 2011; Porraz et al., 2013a). The results of these studiessuggest a gradual disappearance, ruling out the hypothesis of

Fig. 1. Location of Diepkloof Rock Shelter and of main Howiesons Poort sites.

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cultural discontinuity between the HP and the post-HP (Jacobs andRoberts, 2009). The existence of several phases within the HP isnow accepted (Harper, 1997; Soriano et al., 2007; Porraz et al.,2013a). However its initial appearance has not yet been docu-mented and the interpretation of its origin remains speculative (seeMellars, 2006; Jacobs and Roberts, 2009).

Most lithic studies on the HP focus generally on geometricbacked pieces. Indeed, this fossile directeur synthesizes differentlevels of technological transformation that define the HP (rawmaterial selection, blank production, hafting technology, typolog-ical corpus) (Porraz, 2009). These backed pieces are often assumedto be the composite parts of projectiles, and are often equated withmicroliths, despite substantial confusion as to what microlithismactually comprises (see Elston and Kuhn, 2002; Wadley andMohapi, 2008; Brown et al., 2012). It is occasionally assumed thatthese backed pieces were part of the equipment of the hunter, asocial figure with a new status among Pleistocene societies(Ambrose and Lorenz, 1990). Geometric backed pieces would havebeen part of a new system of exchange andwould have helped formsolidarity between groups (Ambrose and Lorenz, 1990; Deacon,1995), and would also provide additional evidence for the exis-tence of a complex symbolic system during this period (Wurz,1999). Therefore, the appearance and adoption of these new toolswould have been decisive in the evolutionary process of anatomi-cally modern human societies. Recent research (Lombard, 2011)supports the idea that geometric backed pieces were used as stone-tipped arrows during the HP at Sibudu. Therefore, the question ofthe appearance of the HP cannot be explored without discussingtheir function. However, the assumption that the origin of the HPmight be linked to the adoption of a new hunting system (McCalland Thomas, 2012) has to be tested and integrated in a broadtechnological analysis.

The recent identification of an Early HP phase at Diepkloof(Porraz et al., 2013a) offers the chance to describe what is the initialstage of this lithic tradition. Here we provide a technologicaloverview of this Early HP lithic industry paying specific attention touse-wear analysis. To a certain extent, this paper echoes therecently published SADBS industry from Pinnacle Point 5/6 dated at

ca. 71 ka (Brown et al., 2012) and which presents techno-typological similarities with the Early HP of Diepkloof. However,the SADBS industry, composed of fine-grained rocks, blades andbacked pieces, has not been assigned to the HP, presumablybecause it pre-dates the expected chronology of the HP (accordingto Jacobs et al., 2008) and because the “SADBS microlithic backedbladelets differ in form from the previously described HP” (p. 592,Brown et al., 2012).

2. The Early Howiesons Poort at Diepkloof Rock Shelter(Western Cape, South Africa)

2.1. The Howiesons Poort sequence

The rock shelter of Diepkloof (Western Cape, South Africa) islocated 14 km from the current Atlantic coast line and approxi-mately 180 km north of Cape Town (Parkington et al., 2013). SeveralMSA sites have been excavated in the area, most of them locatedalong the coast (e.g. Elands Bay Cave, Hoedjiespunt, Ysterfontein,Peers Cave) or within the Cederberg mountains (e.g. Klein Kliphuis,Hollow Rock Shelter, Klipfonteinrand). Among these sites, HP oc-cupations have been recorded at Diepkloof, Klipfonteinrand, KleinKliphuis and Peers Cave (Fig. 1).

The site exposes today a long MSA archaeological sequence(3.1 m deep) which includes an HP represented by over 24 strati-graphic units (SU) (ca. 1.5 m deep). This long HP sequence has beenrecently revisited and subdivided into 3main technological phases:an Early, an Intermediate and a Late HP (Porraz et al., 2013a). These3 phases share a similar technological pattern characterized by theselection of fine-grained silcrete, laminar core reduction and themanufacture of backed pieces (Porraz et al., 2013a). In this paper,we will focus on the earliest phase.

The Early HP at Diepkloof has been presently excavated overless than 4 m2. 6 SUs have been assigned to this technologicalphase (Fig. 2), for a thickness of approximately 70 cm, and nosignificant change or hiatus are recorded within the sediments ofthis phase (Miller et al., 2013). The preservation of remains is quiteexceptional and comprises various faunal species (Steele and

Fig. 2. Frontal section (N/O6) of Diepkloof Rock Shelter and location of the Early HP stratigraphic units.

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Klein, 2013), botanical remains in the form of charcoals and seeds(Cartwright, 2013), macro-residues on tools (Charrié-Duhautet al., 2013) as well as ochre finds (Dayet et al., 2013). Whileengraved ostrich eggshells are mostly confined to the Intermedi-ate and Late HP, the earliest examples of engraving appear at theend of the Early HP (Texier et al., 2013). In the chronoculturalsuccession, the Early HP immediately follows the Still Bay (‘SB’)type ‘Larry’ and precedes the technologically distinct MSA-Jack(Porraz et al., 2013a).

In previous publications (Jacobs et al., 2008; Tribolo et al.,2009), absolute TL and OSL dating falsely attributed these strati-graphic units to the SB. At that time, the study and excavation ofthe Diepkloof sequence was ongoing and the presence of bifacialpieces in the SUs Jess and Kate (the top of the Early HP), below aquartzite flake-based industry (MSA-Jack), was considered as ev-idence of an SB tradition. However, technological analysis showsclearly that this phase belongs to the HP (Porraz et al., 2013a). NewOSL dating (Tribolo et al., 2013) confirms the previous TL dates andthe age of the HP at Diepkloof (Tribolo et al., 2009). The TL datingindicates the appearance of the Early HP after 110 � 9 ka, with anaverage age of 106 � 10 ka (SUs Kerry-Kate), while the OSL datingprovides an age of 109 � 10 for the top of the Early HP (SU Jess)(Tribolo et al., 2013). Using the OSL dating published by Jacobset al. (2008), the Early HP of Diepkloof (sample DRS 13 e SUsKate-Kenny) would date to 70.9 � 2.3 ka, suggesting a contem-poraneity with the SADBS industry of Pinnacle Point 5/6 (Brownet al., 2012). Both data sets confirm an early appearance for theHP and argue in favor of a long duration for this technology(Tribolo et al., 2013).

2.2. The Early Howiesons Poort lithic technology

This first study focuses on the M6 and N6 squares and the SUsKegan, Kenny, Kerry, Kate, Julia and Jess. Instead of studying theEHP in independent units (Porraz et al., 2013a), this paper aims todescribe the technology in its overall characteristics. All plotted andnon-plotted pieces together, the collection encompasses about5000 lithic finds, including about 2000 pieces larger than 20 mm(Table 1).

2.2.1. Raw material acquisitionRocks of different origins compose the lithic assemblage of the

Early HP of Diepkloof. Concerning the local raw materials, themedium- to coarse-grained quartzite from the Table Mountaingroup formation (the host rock of the shelter) corresponds to 29%of the lithic assemblage (>20 mm). But a noticeable increase inquartzite occurrence is noticed toward the end of the Early HP.Quartz pebbles, originating from the conglomerate of theTable Mountain formation, are abundantly available in the vicinityof the shelter. Quartz pebbles compose 20% of the lithologicalspectrum (>20 mm) and their proportion also increases towardthe end of the Early HP. This higher contribution of local rocks inthe upper part of the Early HP might indicate the existence of 2distinct sub-phases within this lithic tradition (Porraz et al.,2013a). In addition, few pieces of coarse-grained yellowish-brown silcrete (‘Y-B silcrete’) suggest the use of an outcrop locatedca. 10 km east from Diepkloof (Porraz et al., 2013a). Local and sub-local rocks (<20 km) contributed up to 54% of the raw material(Table 1).

Table 1Technological classification by raw material of lithic artifacts from the Early HP from Diepkloof Rock Shelter (squares M6, N6).

Local rocks Sub-local rocks Non-local rocks Total

Quartzite Quartz Fine-grainedquartzite

Y-B silcrete Silcrete Hornfels Others

Flakes 347 133 4 29 193 46 3 755Bipolar flakes 5 80 0 1 29 0 1 116Irregular blades 70 45 3 19 179 12 4 332Regular blades 2 5 0 8 92 4 3 114Bladelets 1 9 1 6 167 4 3 191Cores 3 18 0 3 41 0 0 65Shaping flakes 17 1 1 1 21 0 0 41Bifacial pieces 3 1 0 3 5 0 0 12Manuports 3 3 1 1 1 0 0 9Chunks >20 mm 112 92 0 7 87 6 1 305Sub-total (N) (%) 563 (29%) 387 (20%) 9 (0.5%) 78 (4%) 815 (42%) 72 (3.7%) 15 (0.8%) 1940 (100%)Chips 156 344 2 28 334 34 2 900Shaping flakes <20 mm 8 9 0 1 23 5 1 47Chunks <20 mm 137 1381 1 9 499 35 6 2068Total (N) 864 2121 12 116 1671 146 24 4955

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But this assemblage is also characterized by a selection offine-grained rocks. In the geological context of Diepkloof, thisselection takes the form of a transport of medium to fine-grainedsilcrete over distances greater than 20 km. These fine-grainedexotic materials compose approximately 42% of the lithicassemblage (>20 mm, Table 1). A few other exotic rocks werealso selected, notably hornfels and various cherts. The silcretewas collected predominantly in (sub)primary contexts but asmall number of occurrences with cobble cortex suggest that thismaterial was also collected on terraces. The other fine-grainedrocks mostly originate from secondary deposits (exhibitingpebble cortex). Our geological survey suggests that the selectionof exotic rocks HP occupants of Diepkloof exploited were avail-able in various different geographic areas. For example at dis-tances exceeding 50 km (north of Diepkloof) for the acquisitionof the hornfels and for some of the silcrete cobbles (Porraz et al.,2013a).

Heat treatment of silcrete has been suggested by Brown et al.(2009) in an MSA context at Pinnacle Point, in the Still Bay ofBlombos Cave by Mourre et al. (2010) and more recently in theSADBS industry at Pinnacle Point 5/6 (Brown et al., 2012). In theEarly HP of Diepkloof, numerous silcretes have been modified byheating processes. The case is especially visible on some HP coreswhere natural or cortical surfaces clearly contrast with thebrightness of the removals (e.g. n�1, 2, 4, Fig. 3). It seems that someproduction strategies were effectively applied after heating theblock and/or the core. However, in the archaeological context ofDiepkloof where combustion features are numerous (Miller et al.,2013), the technological process of heating needs to be better un-derstood in order to properly assess the degree of control and ofintentionality (Schmidt et al., 2013).

2.2.2. Blank productionThe chaînes opératoires on silcrete are oriented toward the

production of blades and bladelets (�11mm). The core geometry ofthe main reduction system resembles to what has been describedby Villa et al. (2010) based on the HP collection of Klasies River(Fig. 3). We will refer to this reduction strategy as the ‘HP type’.

At their final stage, the Early HP cores of Diepkloof havegenerally a rectangular section and a surface of quadrangularmorphology, occasionally triangular (n�1e3, Fig. 3). The core isoriented along its length axis and is exploited through a series ofunidirectional removals. The exploitation involves one single sur-face (the widest) while the back of the core is generally raw (oftencortical) and flat. The geometry of the volume is controlled by thedetachment of flakes from the back of the core (used as a platform)

and/or by the removal of the blades themselves. Different technicalproducts can therefore be identified. For example, the flakesremoved to control the lateral convexities show blade removalsthat are perpendicular to their axis of percussion (lateral prepara-tion flakes: Fig. 3).

With regard to the first stage of core preparation, little infor-mation is directly available from our lithic collection and severalmodalities of initialization are plausible. However, some bladeswith a cortical side attest to the exploitation of the bloc withminimal preparation (n�10, Fig. 3). No entame crest was used tostart the blade production. Actually, the crested blades present inthe HP lithic assemblage correspond to side-preparations (Fig. 3).These postero-lateral crests (Inizan et al., 1995) have always oneversant and were mainly (if not exclusively) realized during theproduction, on one or two sides of the core in order to control itsgeometry. Occasionally, the blade production goes from thewidest to the narrowest surface of the core (to manage thetransversal convexity), leading to the detachment of a crest withone versant and one cortical side (when the back of the core israw) (postero-lateral crested blades: Fig. 3). The presence and/orthe detachment of these crested blades are not systematic butfrequently observed on the cores. Alternatively (and/or at an earlystage), the production exploits the natural geometry of the blocwhich led to the detachment of blades with a cortical back (n�8,Fig. 3).

Regarding the longitudinal convexity, HP cores and productsattest to a control ensured mainly by the detachment of over-plunging blades (n�1, 8, 18, Fig. 3). This production is alwaysunidirectional and the opening of an opposite platform seemsdevoted to some specific technical operations (e.g. correction of anaccident), or to a final operation before discard. The platform ofthe blades is generally plain (79%) and the overhang oftenabraded, sometimes rounded. These technical attributes supportthe hypothesis of direct and marginal percussion with a softhammer. The use of a soft hammer stone, as recognized in theIntermediate HP at Diepkloof (Porraz et al., 2008) and in other HPcontexts (Soriano et al., 2007) is likely but remains to be properlydemonstrated.

The transformation of the core geometry during its exploitationneeds generally to be better documented. But the rhythm of theproduction likely explains the variability of the cores abandoned atDiepkloof. Indeed, some small blocs have been exploited on theirwidest and narrowest surfaces and no longer have traces of thetypical lateral preparation of the HP core type. However, with re-gard to the whole Early HP lithic assemblage, these cores likelybelong to the HP reduction system.

Fig. 3. Geometry of HP blade cores and archaeological examples from the Early HP of Diepkloof Rock Shelter (n�1e3: HP blade/bladelet cores; 4e6: bladelet cores; 7e21: blade/bladelets. Drawings by M. Grenet).

M. Igreja, G. Porraz / Journal of Archaeological Science 40 (2013) 3475e3491 3479

The regular blades, with parallel edges and ridges, are dominantover the irregular ones. They have a triangular or trapezoidal sec-tion, and often present a rectilinear profile. Unbroken blades arevery rare, due to the low elasticity of the silcrete (85% of the blades

are broken). Therefore, the mean length of the blades (27 mm) doesnot represent a good indicator of intended production but ratherreflects a threshold above which breaking occurs. Blade width has anarrow dispersion (85% of the blades have a width bracketed

M. Igreja, G. Porraz / Journal of Archaeological Science 40 (2013) 3475e34913480

between 7 and 13 mm, Graph 1) with a mean size of 10 mm. Bladeshave a mean thickness between 2 and 3 mm. A small number ofthem show residues likely related to their hafting (Charrié-Duhautet al., 2013).

In addition to the HP core reduction strategy, we observe thepresence of a second independent chaîne opératoire initiating withthe selection of flakes or small blocs (n�4e6, Fig. 3). While the HPcore reduction is based on the exploitation of the wider surface,these cores are exploited on the narrowest face of their volume, in aburin-like manner when the production is on a flake. These re-movals are always unidirectional and oriented toward the pro-duction of small blades and bladelets (n�20, 21, Fig. 3). Theinitialization of the production occasionally starts with the pro-duction of a crest, generally partial, with one or two sides. A fewproducts also show preparation of crests during the sequence ofproduction. Eventually, the geometry of the cores is controlled byremovals detached from the back of the core (n�6, Fig. 3). Thisreduction strategy suggests a distinct and complementary trajec-tory of production than for the HP core type, with a productionoriented toward narrowest and smallest bladelets.

The production of blades and bladelets are carried out throughthe application of two central reduction strategies that were pref-erentially applied to fined-grained rocks, especially silcretes(Table 1). Very few regular blades were made on quartzite andquartz, whereas unidirectional production remains dominant forthese 2 raw materials. A few centripetal flakes on quartzite are alsopresent. However these originate predominantly from the top ofthe Early HP, immediately below MSA-Jack (characterized by aquartzite flake-based industry). Generally speaking, the exploita-tion of quartzite and quartz represents short sequences of pro-duction, a low degree of core preparation and the use of internal

Fig. 4. Examples of (bi)truncated pieces (1e3, 5, 7e17) and segments (4, 6)

hard hammer stone percussion. A small number of products onquartz and silcrete also document the use of bipolar percussion.However these products are presently been grouped together withthe pièces esquillées (cf. infra).

2.2.3. The typological corpusEarly HP formal tools compose ca.12% of thewhole studied lithic

collection (>20 mm). One of the main typological characters of theEarly HP lithic assemblage is the presence of geometric backedpieces, which have been subdivided into 2 main typological cate-gories: the truncated or bi-truncated pieces (truncation oblique tothe axis of the tool edge) and the segments (curved backed shapedparallel to the axis of the tool edge) (Fig. 4). In the Early HP lithicassemblage, the truncated pieces (n ¼ 28) are clearly the dominantform and the small number of segments (n ¼ 4) (Table 2) likelydocument an adaptation to the blank rather than an independentformal tool type. These backed pieces were produced predomi-nantly on regular blade blanks. These blades usually presentrectilinear or convex edges, which are not retouched. The trunca-tion is always made on the dorsal surface, rectilinear or concave,and always oblique, often at an extremely acute angle (<to 45�,Fig. 4). The consequences of the truncation, besides blunting theedge, were the creation of a sharp point at one or both extremitiesof the tool, and the manufacture of a desired morphology, mostlytrapezes and triangles. In terms of size category (Graph 2), themean width of the backed pieces is 11 mm, with a minimum of6 mm and a maximum of 17 mm. Their mean length is 29 mm, butthe data have to be considered with caution regarding the lowpercentage of complete implements (25% in squares M6eN6); theirmean thickness is 3 mm. In sum, the geometrics present a distri-bution similar to the blades, but mean dimensions suggest that the

from the Early HP of Diepkloof Rock Shelter (drawings by M. Grenet).

Table 2Typological classification of the Early HP collection from Diepkloof Rock Shelter (squares M6, N6).

Local Sub-local Non-local Total

Quartzite Quartz Fine-grainedquartzite

Y-B Silcrete Silcrete Hornfels Others

Marginal retouch 1 0 1 1 10 0 0 13 (5.4%)Scrapers 5 4 0 0 5 5 0 19 (7.9%)Convergent scrapers 0 0 0 0 2 0 0 2 (0.8%)End-scrapers 0 0 0 1 1 0 0 2 (0.8%)Bifacial pieces 4 1 0 3 4 0 0 12 (5%)Dentic./Notch 3 2 0 1 14 1 2 23 (9.6%)Strangulated notched pieces 0 0 0 0 3 1 0 4 (1.7%)Truncated pieces 0 1 0 1 25 0 1 28 (11.7%)Segments 0 1 0 0 3 0 0 4 (1.7%)Piéces esquillées 5 66 0 1 41 1 1 115 (47.9%)Burins 1 0 0 0 5 0 0 6 (2.5%)Fragments 0 2 1 0 7 1 1 12 (5%)Total 19 (7.9%) 77 (32.1%) 2 (0.8%) 8 (3.3%) 120 (50%) 9 (3.8%) 5 (2.1%) 240 (100%)

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selection of the blanks might have been oriented toward thelongest blades and/or the unbroken blades. This typological pop-ulation has been made on fine-grained rocks, preferentially onsilcrete blades/bladelets. Yet the significance of the internal vari-ability of the geometric backed pieces (in size and shape) requiresfurther investigations and the study of a bigger sample. Somebacked pieces exhibit a black residue laterally distributed over theshorter edge (n�10, Fig. 4). This residue is likely related to the lateralhafting of the tools (Charrié-Duhaut et al., 2013).

The dominant formal tool category in the Early HP assemblage ispièces esquillées (Table 2, Fig. 5). While their function is oftendebated (Langejans, 2012; Le Brun-Ricalens, 2006) and may varyaccording to technological and geographical context, preliminaryuse-wear results at Diepkloof show indisputable evidence of use asa tool (cf. infra). At this stage of our analyses, we therefore consider

Fig. 5. Examples of pièces esquillées (1e10) and bipolar products (11e18) f

all the pièces esquillées as one single tool population. But we cannotexclude that some of them correspond to bipolar cores. Thesepieces have generally a short or elongated quadrangular form andare splintered (often bifacially) at both extremities. These piecespresent removals generally on both faces, often invasive, related tobipolar percussion (n�1e10, Fig. 5). The products, due to theirbreakage, have a typical triangular or trapezoidal section, andgenerally present the impact traces of bipolar percussion (n�11e18,Fig. 5). No natural blank (e.g. pebble, slab) seems to have beenselected and used as pièces esquillées; but the archaeologicalcollection represents the selection of various products, cortical,laminar, or neither, with a maximum dimension of 30 mm. Withinthis tool category, silcretes and quartz were equally used (Table 2).

A number of other formal tools occur (Table 2), mostly in theform of lateral or double scrapers. These scrapers were produced on

rom the Early HP of Diepkloof Rock Shelter (drawings by M. Grenet).

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various types of blanks and exhibit direct and regular un-invasiveretouch. A few notches and denticulates are documented as wellas a small number of strangulated-notched pieces, which are thedominant formal tool characterizing the Intermediate phase of theHP (Porraz et al., 2013a). We also identified the presence of onemacro-tool with a denticulate retouch, occurring on a quartziteslab.

Finally, there are a small population of bifacial pieces that arepresent until the top units of the Early HP (Fig. 6). These bifacialpieces are rare, even absent in the SUs Kerry and Kate, but occa-sional shaping flakes (n�5, Fig. 6) are documented throughout thesequence. These bifacial elements cannot be interpreted as aconsequence of post-depositional mixture (Miller et al., 2013).Indeed, geometric backed pieces and bifacial pieces overlap over 7SUs (from SU Kegan to SU Jess). The question of the nature of thesebifacial pieces, relative to those within the SB units, is not easy torecognize due to the small sample of the Early HP. Nonetheless, ifwe exclude SU Kegan (immediately above the SB), the observationbased on finished implements is of interest. Indeed, the 2 finishedbifacial pieces within the Early HP (n�1, 3, Fig. 6) differ from those ofthe SB in the sense that they are morphologically atypical (one isoff-centered, the other is oval) and techno-economically different(they are both complete while no complete, finished bifacial pieceshas been found within the SB at Diepkloof). Interestingly, these 2Early HP bifacial pieces differ from each other, which would suggesta lower degree of standardization than during the SB. We considerthis bifacial tradition as part of the technological repertoire of theEarly HP inhabitants of Diepkloof.

3. A functional insight into the Howiesons Poort technology

3.1. What we know

Functional studies of MSA stone tools have gained favor over thepast few years. For the HP, these studies chiefly focus on the geo-metric backed tools, focusing on the question of their use, insertion,morphology and dimensions. Nonetheless, the interpretation of theHP backed tools has long been extrapolated by comparisons withLater Stone age microliths. The HP backed tools are often consid-ered to be similar to those of the Later Stone Age, despite cleardimensional differences (Wadley and Mohapi, 2008).

Fig. 6. Examples of bifacial pieces (1e4) and of bifacial shaping flakes (5)

The HP backed pieces form a heterogeneous class (Wadley andMohapi, 2008; Wurz, 1999), varying in terms of morphology, di-mensions and raw material. The significance of this variability,whether it reflects distinct functional purposes, different adaptiveforms (to different blanks or to rawmaterial), or different regionalor temporal expressions, requires further examination. Recentstudies on the HP of Sibudu have highlighted these questions,showing that variability of segments (in shape and size) is linkedto rock types and functional purposes (Wadley and Mohapi, 2008;Lombard, 2008). Quartz was used to produce small and stan-dardized segments probably used as transversal arrowheads,while hornfels and dolerite were transformed into more elon-gated forms that were probably used as weapon tips or barbs. Inthis case, the authors hypothesize a complex level of technologicalorganization based on different raw material economies (sensuPerlès, 1992).

At Sibudu, recent analysis suggest that the backed tools werelikely butchery knives as well as components of hunting weapons,implying the use of bow and arrow technology (Lombard, 2011).The HP backed tools from Klasies River similarly were used asprojectile elements (Villa et al., 2010). Closely linked to the questionof function is the question of the type of handling. Evidences ofhafting in the form of adhesive imprints have been found at Sibudu(Gibson et al., 2004; Lombard, 2008), Umhlatuzana (Lombard,2007) and Diepkloof (Rigaud et al., 2006; Charrié-Duhaut et al.,2013). This evidence clearly supports a lateral hafting of thesetools, but several positions in the shaft have been hypothesized(Lombard and Pargeter, 2008; Villa et al., 2010).

3.2. A word on the methods

Until recently functional interpretations onMSA industries havefocused predominantly on the analysis of macroscopic edge dam-age, such as fractures (Bird et al., 2007; Villa et al., 2010). Themorphology of fracture helps to establish a distinction betweenpost depositional damage (like trampling) and a human use (Odell,1978, 1980; Kamminga, 1982; Bergman and Newcomer, 1983;Fisher et al., 1984; Geneste and Plisson, 1990; Cattelain and Knecht,1997; Andrefsky, 2005). However, the factors affecting impactfracture formation are extremely variable (Gonzales Urquijo andIbanez Estevez, 1994; Pargeter, 2011).

from the Early HP of Diepkloof Rock Shelter (drawings by M. Grenet).

M. Igreja, G. Porraz / Journal of Archaeological Science 40 (2013) 3475e3491 3483

In some cases, macroscopic analyses have been combined withthe study of mineral and organic residue morphology preserved ontools (Gibson et al., 2004; Lombard, 2005b, 2011; Byrne et al., 2006;Langejans, 2012). Interpretations are based on the morphologicalidentification of the residues and on the differential distribution ofresidues on the surface of tools. In comparative experiments resi-dues are interpreted to be indicative of the function of tools as wellas the materials worked, but risks of contamination have to becorrectly controlled (Monnier et al., 2012).

By contrast, microscopic use-wear traces such as polishes andstriae have never been systematically applied in this context. High-power microwear analysis was initially developed in Europe byKeeley (1980) based on the Russian Semenov’s work (Semenov,1964). This method involves the use of magnifications >100�,normally characterizing use-wear traces at 200�, and occasionallyusing up to 400�. The information gained through the use of highermagnification centers on polishes and striae, which are reliableindicators of the material worked and of the gestures performed.Interpretations on the function of tools rest on the comparisonsbetween the archaeological materials and an extensive experi-mental collection of use-wear traces.

A polish is defined as the visible alteration of the rock surface sothat the reflectivity of the rock surface increases when viewedthrough a microscope (Keeley, 1980). A polish is the result ofrepeated friction of the tool against theworkedmaterial: its patternand distribution on the tool vary in accordance with the nature andhardness of the raw materials, the type of motion executed, andwith the duration the tool has been used. But the process involvedin the formation of polished edges is still disputed. Studies havefocused on determining whether the “polish” observed opticallyafter use can be attributed to a plastic deformation exclusively, or toa silica gel layer formation through a process of hydrolysis and silicadissolution. The first hypothesis suggests that traces result frommechanical action, by progressive loss of tool surface and itsconsequent regularization occurring during work (Kamminga,1979; Masson et al., 1981; Levi-Sala, 1988; Yamada, 1993). Thesecond attributes the polish formation to a process of silica disso-lution. As the result of the heat (deriving from friction), abrasion(from the extraneous particles), the hardness of the worked ma-terial and the presence of water, an amorphous layer of silica gelincluding residues of worked material is formed (Anderson-Gerfaud, 1981; Mansur-Franchomme, 1986). In addition, residuessuch as phytoliths from plants, can be trapped in this silica gel layer(Anderson, 1980). Other studies suggest that polishes are depositsof worked material within the irregularities of the tool’s surface(Christensen, 1998).

High-power analyses also center on striae. Striae (in the sense ofgrooves in the polished surface) are formed when small chips areremoved from the used edge during work or when other extra-neous particles are dragged across the surface of the tool or thepolished area. Their length, orientation and distribution dependupon the hardness of the material being worked, the extent ofabrasion that is present and the type of working motion. Striae canalso occur through post-depositional soil movement, but they areeasily distinguishable from those resulting from use, by theirrandom distribution, usually restricted to the interior of the tool’ssurface and not affecting the edge.

3.3. Present use-wear analysis

Progress has been made over the last decade regarding ourunderstanding of HP technology, however two methodologicaloversights should be mentioned. Firstly researchers have focusedon HP backed pieces and have neglected the other tool categories,suggesting the existence of possible biases of interpretation. As a

noticeable exception, we have to mention the recent publication ofG. Langejans (2012) on the pièces esquillées from Sibudu. Secondly,analytical descriptions and functional interpretations have focusedon macro-traces and on residues, but microscopic use-wears (pol-ishes and microscopic striae) have not been considered. Yet suc-cessful interpretations of stone tool use depend on as many lines ofevidence as possible, and must rely on the observation of bothmacroscopic and microscopic use-wear (Plisson, 1985; GonzalesUrquijo and Ibanez Estevez, 1994). The present study combinesthe analysis of macroscopic features (scarring, edge rounding, andfractures e seen with low-power microscopy), with microscopicuse-wear (polishes and striae e observed with high-power mi-croscopy), and with comparisons with experiments that have beencompleted on a wide range of rocks (flint, silcrete, quartz).

Bright-field microscopy is inappropriate for the study of non-flint stone tools, since, because of the composition and structure,this method cannot sense low-amplitude defects on the polishedsurface. This study, therefore, employs Differential InterferenceContrast Microscopy (DIC) combined with the use of high-resolution epoxy casts of the tool edges to interpret the functionof Diepkloof artifacts, which are partly made on coarse-grainedrocks with bright surfaces (Igreja, 2009). Slopes, valleys, andother discontinuities on the surface of the specimen create opticalpath differences, which are transformed by reflected light DIC mi-croscopy into amplitude or intensity variations that reveal a topo-graphical profile. Unlike the situation with transmitted light andsemi-transparent phase specimens, the image created in reflectedlight DIC can often be interpreted as a true three-dimensionalrepresentation of the surface geometry, provided a clear distinctioncan be realized between raised and lowered regions in the spec-imen. This technique is ideal for use-wear studies on highlyreflective materials because it provides a high resolution, con-trasting and three-dimensional view of microtopography, superiorto conventional binocular microscopy commonly used to examineuse-wear (Igreja, 2009).

4. The use-wear study of the Early Howiesons Poort ofDiepkloof Rock Shelter

4.1. The sample

For the Early HP, 135 artifacts have been analyzed (Table 3). Thesample includes 20 truncated and bi-truncated pieces, 4 segments,5 bifacial pieces, 8 pièces esquillées, 1 denticulate, 1 strangulated-notched piece, 1 end-scraper, 73 blades and bladelets, 20 flakes,as well as 2 cores. Studied artifacts were made on silcrete (118),hornfels (2) or on quartz (15). The sample covers a wide range ofproducts and represents the techno-typological diversity identifiedin the collection, with a central focus on silcrete.

The lithic pieces were first examined under low magnification(40�) followed by an analysis under a standard reflected lightmicroscope (BH Olympus) equipped with Differential InterferenceContrast (DIC) at 100�, 200� and 400� magnification, followingthe standard procedures used in use-wear analysis (Plisson, 1985;Gonzales Urquijo and Ibanez Estevez, 1994). Photomicrographswere taken using a digital camera Nikon 4500.

4.2. Results of the use-wear analysis

Scars, striae and polishes affecting stone tool edges and surfacesas result of natural weathering (mechanical and chemical) can beeasily distinguished from those caused by tool use. They arerandomly organized all over the tool, whereas use-wear tracesmainly develop along the used edge of the tool (Levi-Sala, 1986,1988). Post-depositional polishes are usually flat (when caused by

Table 3Inventory of the use-wear results from the Early HP collection from Diepkloof Rock Shelter.

Typo-techno. Raw material Preservation Use-wear Transversal Longitudinal Impact Percussion Total

Animal Animal

Silcrete Quartz Hornfel Total Weathered Good Soft Bone Wood Hard Soft Hard Wood Impact Hard

Retouched(bi)Truncated 18 1 2 21 9 12 10 1 1

11 3 1 2 e e 10

Segments 4 e e 4 2 2 1 e e e e e e e 1 e 1Bifacial pieces 5 e e 5 4 1 e e e e e e e e e e e

Piéces esquillées 5 3 8 2 6 5 e e e e e e e e 5 5Denticulates 1 e e 1 1 e e e e e e e e e e e e

SN pieces 1 e e 1 1 e e e e e e e e e e e e

Endscrapers 1 e e 1 e 1 e e e e e e e e e e e

UnretouchedBlades/bladelets 67 6 e 73 24 49 10 e e e e 5 4 1 e e 10Flakes 15 5 e 20 18 2 e e e e e e e e e e e

Cores 2 e e 2 e 2 e e e e e e e e e e e

Total 119 15 2 136 61 75 26 1 11

1 8 5 3 1 5 26

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mechanical factors) or very bright (when caused by chemicalagents, showing a white patina that is macroscopically visible),covering the whole microtopography of the tool’s surface, some-times associated with chaotic striae. In contrast, polishes resultingfrom use are limited to the used edge or surface, whose features(aspect, density, texture) vary according to the nature of theworkedmaterial and gesture, while the striae distribution along the usededge of the tool is organized in terms of direction. At Diepkloof, inspite of some evidence of post-depositional damage of the edgesand surfaces of the stone tools caused by chemical (patina) andmechanical phenomena, the Early HP lithics present in general anexcellent state of preservation (Table 3). This high level of preser-vation provides reliable analytical conditions. Surprisingly, while75 pieces present good preservation (i.e. absence of post-depositional polishes and striae), only 26 of them show recogniz-able use-wear traces (Table 3).

4.2.1. The geometric backed piecesThis class of tools includes (bi)truncated pieces and segments.

They exhibit mostly transversal and longitudinal striae on theirlateral edges (Table 3). Nine (bi)truncated pieces show edge scar-ring associated with polish on both sides of the opposite edges tothe backing. These use-wear traces suggest that the implementswere used to cut or work soft animal tissues (n ¼ 2), hard animalmaterials (n ¼ 1) and wood (n ¼ 2) (Fig. 7). Some of these tools alsopresent use-wear related to use as a scraping implement to processsoft animal tissues (n ¼ 1), bone (n ¼ 1), hard materials (n ¼ 1) andwood (n ¼ 1).

Thesegeometricbacked toolswereusedmainlyas cutting tools forprocessing activities rather than used as projectile elements. Indeed,most of these artifacts have extremities that are intact or presentfractures that are non-diagnostic of a projectile function. Only twoartifacts (a segment, a truncated piece) show an impact fracture (n�7,8, Fig. 7) that could be related to use as a projectile according to thediagnostic impact fractures defined by Fisher et al. (1984).

The presence of a blunted edge is directly related to the haftingprocess. Indeed, isolated bright spots are visible on some ridges ofthe backed edges and are also associated with the rounding of thesame edges (n�2, 3, Fig. 7). This cannot be attributed to post-depositional processes, as they are not randomly distributed onthe stone tools. The occurrence of polishes on the ridges indicates acontact with a hard material (Rots, 2002) where polishes are likelyto form. This is consistent with the presence of macroscopic resi-dues found on HP artifacts (Charrié-Duhaut et al., 2013).

4.2.2. The pièces esquilléesThe pièces esquillées usually present two opposite used zones,

showing distal hinged and abruptly ended scars which are visiblemacroscopically. To date, very little evidence on the function of thepièces esquillées have been published in the literature, especially inMSA contexts (for an exception: Langejans, 2012).

Within the Early HP collection of Diepkloof, use-wear traceshave been found on 5 pièces esquillées (4 pieces are on silcrete, 1 onquartz; Table 3). These micro-wear traces are related to a percus-sion on small length of hard material, probably wood (Fig. 8). Use-wear traces have exclusively been found on one extremity of thepieces, never on the two splintered edges. The nature of the use-wear traces on these types of artifacts, and their consistent occur-rence, suggests that this tool had a specific function. These resultsare interesting when considering the recent residue analysis per-formed on the material of Sibudu (Langejans, 2012) where a smallsample of pièces esquillées from the HP were interpreted as beingused mostly for animal processing. Some macro- and microscopicfunctional evidence are also documented in South African LaterStone Age (Binneman, 1984) and European Upper Paleolithic sites(Dewez, 1985; Schmider and Valentin, 1994; Lucas and Hays, 2004)where pièces esquillées have been used to percuss wood or hardanimal tissues, such as bone and antler.

4.2.3. Other formal toolsAmong the 5 bifacial pieces that have been analyzed, only 1

presents a good state of preservation. However no use-wear tracehas been found. Regarding the suggestion that their use may havebeen as projectiles, no macroscopic tip damage (impact fracture)has been observed thus far.

Unfortunately, no trace has been found on the denticulate andon the strangulated-notched piece, due to post-depositional pro-cesses, nor on the end-scraper despite its good preservation.

4.2.4. Blades and flakesThe blades and the bladelets are exceptionally well preserved,

with ca. 70% of the sample (n ¼ 49/73) exhibiting good preser-vation. However, only 10 of them show evidence of a use (ca. 20%).The use-wear identified on these blades consists mainly of edgescarring, located on both sides of the used edge, in associationwith polish (Fig. 9). These artifacts were exclusively used in alongitudinal motion, to cut soft animal tissues (most probably inthe process of butchering) (n ¼ 5), hard materials (n ¼ 4) andwood (n ¼ 1) (Fig. 9). All the used blades present regular edges

Fig. 7. Examples of Early HP backed pieces from Diepkloof Rock Shelter with macroscopic and microscopic use-wear. (1): intense edge scarring related to use associated withlongitudinal motion; (2a) and (3b): polish from cutting soft animal tissue; (2a): parallel striae (yellow arrow) associated with polish, whose orientation is typical of a longitudinalmotion; (2b) and (3a): rounded ridge likely resulting from hafting; (4): polish related to scraping of hard material; (5): polish related to scraping of wood; (6): polish related toscraping of bone; (7, 8): possible impact fracture. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

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Fig. 8. Examples of Early HP pièces esquillées from Diepkloof Rock Shelter used as intermediary tools to percuss hard materials. (1a), (1b), (3a) and (4a): detail of splintered edgesshowing microwear; (1c), (3b), (4b) and (2): polishes likely related to wood working.

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that were suitable for cutting purposes. The use of the bladesseems to have been restricted to a single working edge, as sug-gested by the presence of traces on only one edge of the blade,corroborating the hypothesis of lateral handling of the blades assuggested by the macro-residue distribution (Charrié-Duhautet al., 2013).

Various flakes have been analyzed, including flakes attributed tosome stages of preparation or control of the core geometry. Un-fortunately the small sample size exhibits poor preservation of thesurface and no use-wear traces have been found, nor on the corethat was analyzed.

4.3. Main results of the functional analysis

The use-wear traces indicate the processing of different organicmaterials such as soft animal tissue (n ¼ 8), wood (n ¼ 4) and bone(n ¼ 1). The work of animal soft materials likely corresponds tobutchering activity, as suggested by the morphology of the scars onthe tools edges. Surprisingly, we observe evidence of bone workingon one truncated piece (n�6, Fig. 7) while no evidence of bonetechnology has yet been identified within the archaeologicalcollection. This piece presents a typical polish characterized by itsbrightness and compact matrix, and its distribution close to thetools edge (Plisson, 1985; Gonzalez Urquijo and Ibanez Estevez,1994). The small size of the truncated piece and the restrictedsurface of the polish could imply that the tool was used at an earlystage of bone tool manufacture, possibly to smooth the bone’ssurface (see Averbough, 2000).

The use-wear analysis allows us to recognize different func-tional actions, such as cutting (longitudinal motions), scraping(transversal motions) and percussion. However, evidences ofhunting activities (implying propulsion) are scarce. Indeed, onlytwo artifacts show a fracture that could be related to a projectiletechnology.

The presence of a single working edge per artifact and the in-tensity of the use-wear show that the tools were not intensivelyused. Among the pieces with use-wear traces, many are still func-tionally viable with regard to the preservation of their edges.Moreover, a large proportion of products (52 out of a total of 77)

show no use-wear traces but a good state of preservation, sug-gesting that they were not used or only for a short period of time.The absence of use-wear traces cannot be related to rock propertiesas our functional experiments show that silcrete and quartz bothdevelop visible polishes when they are used. However, polish onsilcrete seems to develop after a longer period of use than on otherrock, such as flint (Igreja, in progress). Nonetheless, these pre-liminary observations suggest a low intensity of blank consump-tion, which may be surprising considering the exotic origin ofsilcrete.

The use-wear analysis documents an interesting pattern interms of tool specialization. The study of the pièces esquillées sug-gests a strict use for percussion and the study of the blades in-dicates an exclusive use for longitudinal actions. Unlike these tools,the study of the backed pieces suggests diversified types of actions(transversal, longitudinal and also projectile), implying a widerrange of actions. In addition, they also show a greater use in termsof intensity and frequency. Indeed, if we compare the blades(dominant in the collection) and the backed pieces (dominantlymade on blades), we notice that only 15% of the blades shows use-wear traces compared to 50% for backed pieces. This observation isnot related to post-depositional effects, as blades exhibit a goodstate of preservation (67% of the blades present a good state ofpreservation, Table 3). In sum, the backing appears as a techno-logical transformation that allowed the user to extend the life of theblades and diversify their use.

5. Discussing the Early Howiesons Poort technology and themechanisms of its appearance

5.1. The Early Howiesons Poort occupations at Diepkloof RockShelter

Early HP inhabitants at Diepkloof based their raw materialprovisioning strategies on the introduction of non-local fine-grained rocks (mostly silcrete), suggesting the frequent circulationof populations over distances greater than 20 km. These rocks werelikely introduced in the form of small blocks or cores, thenexploited directly on the site, and were mostly used for blades and

Fig. 9. Examples of Early HP blades from Diepkloof Rock Shelter: (1a) and (2a): edge scarring located on both sides of the used edge; (1b) and (2b) polish related to contact withhard materials; (3) polish from sawing wood.

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backed piece production. While no refits were found, the diversityof the products -indicating the presence of different phases of thereduction sequence- support this interpretation. But some rawmaterials suggest that a few end products may have also beenintroduced directly. In parallel, local rocks such as quartzite andquartz appear to have been exploited mostly for immediate needs,without a rigid preparation of the core.

The activities of the Early HP inhabitants at Diepkloof wereoriented toward the processing of wood and animal resources.The use-wear analysis shows that these resources were processedin different ways (cutting, scraping and percussive technologies),

suggesting different types of activities. Evidence for hunting ac-tivities is minimal, perhaps as a result of the type of occupation.Indeed, the range of activities and the resources exploited duringthe Early HP at Diepkloof (Cartwright, 2013; Dayet et al., 2013;Steele and Klein, 2013; Texier et al., 2013) support the hypothesisof site occupations with a residential signature. Depending on theterritorial organization of these populations, hunting activitiesmight be under-represented at Diepkloof. Alternatively, othertechnologies that are under-represented in the archaeologicalrecord might have contributed to the acquisition of animalresources.

Graph 1. Width of blades from the Early HP (squares M6eN6, Diepkloof Rock Shelter).

M. Igreja, G. Porraz / Journal of Archaeological Science 40 (2013) 3475e34913488

Interestingly, raw materials were frequently introduced fromnon-local areas but do not reflect a high rate of consumption.Indeed, the sheer number of blades contrasts with the low amountshowing use-wear traces, which supports the idea that most ofthese blades were used for very short-term activities or were notused at all but produced in advance. The case is different for backed(blade) pieces which were used with a higher intensity and fordiversified usages.

Blades and backed pieces were nonetheless both part of acomplex hafting technology, implying the use of glue to maintainand fix the tools, as documented by the use-wear observations andmacro-residues (Charrié-Duhaut et al., 2013). Distribution of theresidues is similar between the backed and unretouched blades,which were both likely hafted laterally (as compared to axially).However, the differences in the way backed pieces and blades wereused suggest there was some variation in the way they were haftedand/or inserted.

5.2. The Early Howiesons Poort of Diepkloof and its implications

The HP of Diepkloof shows diachronic variability over time.Three main phases have been identified (Early, Intermediate, LateHP) and the present use-wear analysis contributes to the discussionof the significance of these phases. The functional analysis showsthat the Early HP lithic assemblage is not task related, but reflects awide range of activities. Preliminary observations from the laterphases of the HP suggest a similar pattern, implying that a func-tional argument does not explain the technological variabilityobserved through time.

Graph 2. Box plot visualizing the dimensions of the Early HP backed pieces fromDiepkloof Rock Shelter. The box plot includes all the pieces from squares M6 and N6, aswell as 3 complete pieces from square N7.

The laminar reduction sequence associated with the Early HPpersists throughout the sequence of Diepkloof and is similar towhat has been recently identified as the HP of Klasies River (Villaet al., 2010). This HP laminar core reduction reveals the existenceof similar roots between the different sites. Regarding the distri-bution and the chronology of the HP sites across southern Africa,Diepkloof provides to date the oldest evidence of an HP technol-ogy (Jacobs et al., 2008; Tribolo et al., 2009; 2013). The dating andthe techno-typological analysis suggest that the Early HP of Die-pkloof could represent an initial stage of the HP technology. Ourdata also suggest that the Early HP should be distinguished fromthe classic HP (Soriano et al., 2007; Porraz et al., 2008; 2013a),which includes the Intermediate and the Late HP phases atDiepkloof.

The Early HP lithic assemblage of Diepkloof presents similar-ities with the SADBS industry of Pinnacle Point 5/6 (Brown et al.,2012). The SADBS lithic assemblage is composed of fine-grainedrocks, regular blades and bladelets detached with soft hammerpercussion and with abraded and plain platforms, as well asbacked pieces made on blades. Unlike Brown and colleagues, weare inclined to affiliate the SADBS industry to the HP tradition onthe basis of its techno-typological peculiarities. However, thedating between the Early HP of Diepkloof (Tribolo et al., 2013) andthe SADBS industry of Pinnacle Point 5/6 (Brown et al., 2012)diverge substantially.

At Diepkloof, the Early HP immediately succeeds a bifacialtechnology, without significant sedimentary hiatus (Miller et al.,2013). The Early HP appears suddenly and already contains all thetechnological innovations found in later manifestation of the HP.Despite the modest persistence of a bifacial technology throughoutthe Early HP, this new technology introduces a distinct rupturewithin the Diepkloof sequence. But whether the appearance of theEarly HP represents an intrusive phenomenon or a regionaldevelopment and whether its appearance was gradual or suddenrequires more discussion.

The hypothesis that the HP might be related to a populationexpansion is based on a large set of luminescence dates thatsupports the idea of 1) a contemporaneous appearance of the HPacross southern Africa, 2) a similar age of appearance of the HP tothat of the expected period of the anatomically modern humans(L3) dispersal within Africa (Jacobs and Roberts, 2009). This rapiddispersal of the anatomically modern humans would have beenfavored by a new set of behavioral innovations granting behav-ioral advantages to these populations. But the dating of the HPfrom Diepkloof (Tribolo et al., 2009; 2013) together with thetechnological analysis, disputes this model. The HP in southernAfrica is older than previously thought and does not appeareverywhere at the same time. This implies a period of contem-poraneity between groups of different technological traditionsacross southern Africa (Tribolo et al., 2013) and also a temporalgap between when the HP first appeared and when it presumablyexpanded across southern Africa. Considering the age of the HP atDiepkloof and the absence of convincing archaeological equiva-lents in the northern part of southern Africa, the HP should beconsidered a regional expression that originated somewhere insouthern Africa and potentially in the south-western Cape coastalregion (Porraz et al., 2013b).

The challenge associated with the question of the regionalappearance of the HP is to explain the sudden appearance of thistechnology. We can assume that some transitional stages are notdocumented at Diepkloof (which is possible), but the dating as wellas the micromorphological and technological analyses (with thepresence of bifacial implements) do not document any significanttemporal gap between the SB and the HP (Tribolo et al., 2013;Milleret al., 2013). According to the TL and OSL dating (Tribolo, 2013), the

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HP appears at Diepkloof during OIS 5d or 5c and would thereforenot be linked to any sudden climatic change.

The inventiveness of the HP is documented by a set of techno-logical innovations expressed by the pattern of selected raw ma-terials, the blade reduction strategy and the typological corpus.Geometric backed pieces, because they share similarities withmorerecent ones, are often considered as a key innovation related to theadoption of a new hunting equipment (Ambrose and Lorenz, 1990;Shea, 2006; McCall and Thomas, 2012). These tools are oftencategorized as microliths and are assumed to have been used tocreate composite tool components as part of advanced projectileweapons (Brown et al., 2012). Size-classes to define microlithismvary with authors and with archaeological collections. For example,Brown and colleagues follow Clark’s technological definition andinclude all small flakes and bladelets less than 50 mm in maximumlength as being microlithic. But microlithism is not only a dimen-sional character but it is also related to the functional prerequisiteof the tool (Delagnes et al., 2006; Chesnaux, 2008), meaning thatvariation in size is restricted. However, the HP backed pieces arecharacterized by dimensional diversity (Wadley and Mohapi, 2008;Wurz, 1999) and were used for various purposes. Therefore, weurge caution to establish a distinction between the significance of“geometrization” (the shape) and “microlithization” (the size).

Our results provide strong arguments against a functionalspecialization of the backed tools, supporting previous studies(Wadley and Mohapi, 2008). The Early HP backed pieces 1) werenot devoted to specific tasks, and 2) were primarily involved indomestic activities and not in hunting tasks: they were used for theproperties of their edge (as knife elements) rather than for their tip.Therefore, the appearance of the HP technology cannot be directlyrelated to the adoption of a new projectile technology (such as thebow).

On the other hand, backed pieces introduce an innovative idearegarding hafting. This hafting technology was based on the se-lection and production of standardized pieces that were theninterchangeable, probably within the framework of composite tools(Deacon, 1995; Lombard, 2005a). This advantagemight be linked tothe production and curation of standardized hafts in their mode ofinsertion and, likely, in their morphologies. This notion of inter-changeability implies a strong standardization of the tools whichwas possible because of a good control of the fracture (selection offine-grained rocks), a system of production with strict rules (HPcore reduction system with soft percussion), and a control of theshape and dimension of the tools (backing of the blades). We arguethat a new hafting concept necessitating the use of glue may havetriggered the transformation of the technological system and mayexplain the sudden change observed in the archaeological record.

6. Conclusion

The sequence at Diepkloof records the succession of differenttechnological phases which contribute to clarifying the techno-logical evolution of MSA southern African societies. The site in-cludes a long HP sequence that has been subdivided into 3 maintechnological phases (Porraz et al., 2013a,b). The present techno-logical and functional analysis focused on the earliest phase of theHP and has benefited from the excellent state of preservation of thelithic artifacts.

The Early HP is characterized by a core reduction system and bytypological characteristics which display similarities with morerecent phases of the HP at Diepkloof and other sites, suggestingthe existence of common roots between these industries. On thebasis of our current set of observations (including dating andtechno-typological comparisons), we contest the model of acontemporaneous appearance of the HP all across southern Africa,

support the hypothesis of an older origin of the HP, and argue infavor of a southern African origin of the HP.

The HP appeared suddenly, as a new system, implying that theeconomic, the production and the typological spheres were inter-related. We hypothesize that the adoption of a new way tohandle and fix tools might represent the key innovation. This newhafting technology would have been based on interchangeability,requiring standardized tools. Standardization would explain thedesign of backed pieces (control of the tools’ shapes and di-mensions), the production of HP blades (control of the thicknessand regularity of the blanks’ edges) and the subsequent selection offine-grained rocks to ensure the control of rock breakage duringproduction.

The use-wear analysis shows that the appearance of backedpieces is not directly connected to hunting practices related to anew projectile technology but, on the contrary, seems linked tovarious domestic activities. This transformation is not a result of asudden climatic change and does not reflect any kind of rapidadaptation or specialization. The occurrence of the HP follows abifacial technology at Diepkloof and introduces a clear technolog-ical change as well as a new system of territorial organization. Thesuccess of the HP, and its underpinnings, should be understoodwith closer reference to paleoenvironmental and demographicdatasets, but should also refer to theories on technological inno-vation (e.g. Simondon, 2005).

Acknowledgments

The scientific project and excavation at Diepkloof has beenfunded by the French Ministry of Foreign Affairs (MAE), theAquitaine region, the Provence-Alpes-Côte-d’Azur region and bythe Centre National de la Recherche Scientifique (CNRS). We arealso thankful to the Paleontological Scientific Trust (PAST) and theNational Research Foundation (NRF) of South Africa for funding.The University of Cape Town has been of great support inproviding space, facilities and other logistical help. Our extendedthanks to the Fundação para a Ciência e Tecnologia from thePortuguese government of Science and Technology for fundingthe post-doctoral research grant of the author M. De Araujo Igreja.G. Porraz has also benefited from the support of the Fyssenfoundation, thanks to Prof. John E. Parkington (University of CapeTown) and of the Alexander von Humboldt foundation thanks toProf. Nicholas J. Conard (University of Tübingen). We finally like tothank L. Purdue and C.E. Miller for providing help with the writingof the English.

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