Download pdf - d’Errico, F., Vanhaeren, M., van Niekerk, K., Henshilwood, C.S. & Erasmus, R.M. 2013. Assessing the accidental versus deliberate color modification of shell beads. A case study on

ASSESSING THE ACCIDENTAL VERSUS DELIBERATECOLOUR MODIFICATION OF SHELL BEADS: A CASE STUDYON PERFORATED NASSARIUS KRAUSSIANUS FROM BLOMBOS

CAVE MIDDLE STONE AGE LEVELS*

F. D’ERRICO,1,2† M. VANHAEREN,1 K. VAN NIEKERK,2 C. S. HENSHILWOOD2,3 andR. M. ERASMUS4

1Université de Bordeaux, UMR 5199 PACEA, Equipe Préhistoire, Paléoenvironnement, Patrimoine,33405 Talence cedex, France

2Institute for Archaeology, History, Cultural and Religious Studies, University of Bergen, Øysteinsgate 3, 5007,Bergen, Norway

3Institute for Human Evolution, University of the Witwatersrand, Johannesburg, South Africa4School of Physics, University of the Witwatersrand, Johannesburg, South Africa

Colour plays an eminent role in beadwork. Colour modifications are reported on early shellbeads from Middle Stone Age sites. However, identifying the colouring agent and demonstrat-ing the intentional nature of the colouring process is not straightforward. Here, we provideanalytical data on colour and structural modifications observed on Nassarius kraussianus(Nk) collected in modern thanatocoenoses and on shells of the same species experimentallyheated in oxidizing and reductive atmospheres. Comparison with Nk shell beads from the72 ka old Middle Stone Age levels of Blombos Cave, South Africa, and contextual analysis ofother malacological remains from the same levels that were not used as ornaments identify themechanisms responsible for the change of colour in modern Nk thanatocoenoses and heatedshells, and show that although some Nk shell beads were heated, intentional heat treatment ofshell beads is not demonstrated.

KEYWORDS: ORNAMENTS, BEADWORK, SYMBOLISM, STILL BAY, HEAT TREATMENT,SEM–EDS, RAMAN, MICROSCOPY

INTRODUCTION

The earliest known evidence for the use of personal ornaments consists of perforated marine andestuarine shells found at sites from northern and southern Africa, as well as western Asia, datedto between 100 and 70 ka (Henshilwood et al. 2004; d’Errico et al. 2005, 2008, 2009; Vanhaerenet al. 2006, 2013; Bouzouggar et al. 2007; Bar-Yosef Mayer et al. 2009; Eiwanger et al. 2009).A characteristic trait of these ornaments is that they belong, at each site, to a single species(d’Errico and Vanhaeren 2009). This personal ornament tradition apparently disappears at the endof the last interglacial (c.70 ka). Around 44 ka, beads reappear almost simultaneously in Africaand Eurasia. In Africa, they take the form of ostrich eggshell beads (OESB) (Ambrose 1998;d’Errico et al. 2012; Gliganic et al. 2012); and in Eurasia, of dozens of discrete types identifyingregional patterns (Vanhaeren and d’Errico 2006).

Personal ornaments represent a behaviour specific to humans in which items are displayed onthe physical body to project meaning that can be interpreted by members of the same and possibly

*Received 13 August 2013; accepted 10 October 2013†Corresponding author: email [email protected]

bs_bs_banner

Archaeometry ••, •• (2013) ••–•• doi: 10.1111/arcm.12072

© 2013 University of Oxford

mailto:[email protected]

other groups. For this reason, early instances of bead use are commonly interpreted as evidencefor the existence of symbolic communication systems created by human societies comparableto ours (Ambrose 1998; McBrearty and Brooks 2000; Vanhaeren and d’Errico 2006; Kuhn andStiner 2007; Henshilwood and Dubreuil 2011). This argument is not universally accepted andit has been argued that due to their apparent simplicity, the earliest beads do not necessarilyreflect symbolic systems and a degree of cognitive sophistication qualitatively comparable tothose recorded in present-day and historically known human societies (Wynn and Coolidge2007; Botha 2008; Klein 2008; Dissanayake 2009; Coolidge and Overmann 2012; Klein andSteele 2013). The first beadworks may, however, be more complex than one could at first sightbelieve. Bead type is but one factor that plays a role in beadwork codes. Bead size, number,arrangement, colour and location on the body may convey meaning as much as bead type, andthese elements have only recently started to be investigated in the earliest beads. Experimentalreproduction of use wear recorded on Nassarius kraussianus shell beads from Blombos Cavehas recently shown that a clear change in the way of stringing beads and the visual appearanceof the resulting beadwork occurred between the lower and upper Still Bay layers (Vanhaerenet al. 2013). Also, the presence of pigment residues (Henshilwood et al. 2004; d’Errico et al.2005, 2008, 2009; Vanhaeren et al. 2006, 2013; Bouzouggar et al. 2007; Bar-Yosef Mayer et al.2009; Eiwanger et al. 2009) on many well-preserved shell beads from Middle Stone Age(MSA) and Middle Palaeolithic (MP) sites suggests that colour may have played a role in theway early beadworks conveyed meaning. Dark grey to black colouring, interpreted as due toheating, has been observed on marine shell beads from the MSA at Blombos Cave (d’Erricoet al. 2005) and Sibudu (d’Errico et al. 2008) in South Africa, the MP at Grotte des Pigeons,Rhafas and Ifri n’Ammar in Morocco (Bouzouggar et al. 2007; d’Errico et al. 2009; Nami andMoser 2010), on the ostrich egg shell beads (OESB) from the Early Later Stone Age levels atBorder Cave (d’Errico et al. 2012), the Later Stone Age of Geelbek in South Africa (Kandel andConard 2005) and the shell beads from the Upper Palaeolithic/Mesolithic site of Franchthi Cavein Greece (Lange et al. 2008; Perlès and Vanhaeren 2010). It has been suggested (Kandel andConard 2005; Lange et al. 2008, d’Errico et al. 2009; Perlès and Vanhaeren 2010) that darkbeads were submitted to heat treatment for intentional modification of their colour, possibly toenhance their visual impact or convey meaning through colour codes, similarly to what isknown from present-day beadwork (Schoeman 1983; Wickler and Seibt 1995). The identifica-tion of such technology in the MSA and the MP would come as no surprise. Intentional colourmodification of pigment through heating has been proposed for the MP sites of Qafzeh(Godfrey-Smith and Ilani 2004) and Skhul (d’Errico et al. 2010; Salomon et al. 2012). Heattreatment of silcrete for tool production is attested at Pinnacle Point site PP5/6 as early as164 ka and has been recently identified in the Still Bay levels of Blombos Cave dated to 72 ka(Brown et al. 2009; Mourre et al. 2010; Schmidt et al. 2013). Controlled use of fire was alsoinvolved in the production of adhesive to haft tools in Europe and Africa (Mazza et al. 2006;Wadley et al. 2009; Pawlik and Thissen 2011).

However, the question of whether controlled use of fire was applied to change the colour ofbeads remains open. Burnt or burnt-looking marine shells may result from darkening due todiagenetic processes, accidental burning (loss of shells in an active hearth, hearth affectingpre-deposited sediments containing shells), heating for subsistence activities (cooking of ediblespecies), heat treatment to purposely change the colour of the shells or to facilitate its manufac-ture, waste burning or a combination of these factors (Hartzell 1991; Claassen 1998; Stiner 1999;Kandel and Conard 2005; Lange et al. 2008; d’Errico et al. 2009; Perlès and Vanhaeren 2010).In this study, we analyse light and dark Nassarius kraussianus (Nk) shell beads from the Still Bay

2 F. d’Errico et al.

© 2013 University of Oxford, Archaeometry ••, •• (2013) ••–••

layers of Blombos Cave, modern dead Nk darkened by taphonomic processes, and modernexperimentally heated shells of the same species in order to reach a better understanding of themechanisms responsible for colour change in shells (Lange et al. 2008; Perlès and Vanhaeren2010), and to establish whether Blombos MSA shell beads were heated, and whether this processwas done deliberately to change their colour.

THE ARCHAEOLOGICAL CONTEXT

Blombos Cave is situated 300 km east of Cape Town (34°25′S, 21°13′E), and 100 m inland fromthe Indian Ocean (Fig. 1 (a)). Excavations conducted since 1991 (Fig. 1 (b)) by one of us (CSH)have identified a stratigraphic sequence (Fig. 1 (c)) with, from the top to the bottom, 80 cm ofLater Stone Age (LSA) deposit, an archaeologically sterile layer of aeolian dune sand, referredto as the BBC Hiatus, and four MSA phases (BBC M1, BBC M2 upper, BBC M2 lower and BBCM3) (Henshilwood et al. 2001a,b, 2011; Jacobs et al. 2003a,b, 2006, 2013; Jacobs 2004;Henshilwood 2008a,b; Henshilwood and Dubreuil 2009, 2011; Villa et al. 2009; Mourre et al.2010; Thompson and Henshilwood 2011). LSA layers have been radiocarbon-dated to c.2 ka bp.Multiple- and single-grain OSL and TL methods have provided dates for the sterile sand layerlying on top of the MSA layers and for each of the MSA phases (Fig. 1 (c)): c.70 ka for the sandlayer, c.78–72 ka for the M1 and upper M2 phase, c.84 ka for the lower M2 phase, andc.100 000 ka for the M3 phase (Jones 2001; Henshilwood et al. 2002, 2011; Jacobs et al. 2003a,b,2006, 2013; Tribolo 2003; Jacobs 2004; Tribolo et al. 2006; Thompson and Henshilwood 2011).Bifacial foliate points typical of the Still Bay technocomplex interpreted as spear points (Villaet al. 2009; Mourre et al. 2010), bone tools including awls and fully shaped spear points(Henshilwood et al. 2001a; d’Errico and Henshilwood 2007) are cultural markers of the M1 andupper M2 phases. The M2 lower phase is a low-intensity occupation in which no Still Baycultural markers are found. Ochre pieces, often with traces of utilization, are present in all MSAlayers and abundant in the M3 phase (Henshilwood et al. 2009). Ochre pieces engraved withgeometric patterns come from the M1, M2 and M3 phases (Henshilwood et al. 2009). Possibleengravings on bone (d’Errico et al. 2001; d’Errico and Henshilwood 2007) consisting of parallelstriations and sets of joining lines also come from the M1 and upper M2 phases.

Sixty-eight Nk shell beads (Fig. 2 and Table 1) were found in the Still Bay layers (Henshilwoodet al. 2004; d’Errico et al. 2005; Vanhaeren et al. 2013). All derive from the M1 phase (layersCA, CB, CC and CD), with the exception of two specimens from the upper M2 phase (layer CF)in an area where slumping of overlaying layers occurred. Fifty-six of the 68 Nk beads publishedso far (Vanhaeren et al. 2013) were found in seven groups (1–7) of 2–24 beads, each group beingrecovered in a single square (1 × 1 m) or in two adjacent sub-squares (50 × 50 cm each) duringa single excavation day (Table 1). This led us to propose that each group was originally part ofa single beadwork item, lost or disposed of during a single event (d’Errico et al. 2005). The 12remaining shell beads are isolated recoveries unearthed in different sub-squares or at differentdates (Table 1).

MATERIALS AND METHODS

To identify possible causes of colour variation in Blombos Nk, two heating experiments wereperformed on Nk collected alive, emptied of their meat and cleaned. In the first experiment, 60shells were equally distributed in 20 porcelain crucibles. In 10 crucibles, shells were sandwichedbetween leaves and humic soil. Shells were placed in the other 10 crucibles without additions.

Accidental versus deliberate colour modification of shell beads 3


Figure 1 (a) The location of Blombos Cave. (b) A map of the site, with excavated areas indicated in white. (c) The southsection of Blombos Cave, showing layers, phases and available OSL, TL and U/Th age ranges for the MSA (modified afterHenshilwood et al. 2011).



Step heating in a Vecstar furnace used 10 temperature intervals of 100°C, ranging from 100°C to1000°C. One crucible from each group was removed from the furnace at each step after the settemperature was reached for 10 min. In the second experiment, three groups of 10 shells wereheated in the soil underneath an open fireplace for approximately 1 h. Ten shells were stuck intothree capsules of Carpobrotus edulis fruits (South African sour figs), 10 shells wrapped in leaves

Figure 2 Perforated Nassarius kraussianus from the Middle Stone Age Phases M1 and M2 at Blombos Cave. Thenumbers refer to Table 1.



Tabl

e1

Con

text

ual

and

desc

ript

ive

data

onN

assa

rius

krau

ssia

nus

shel

lbe

ads

from

the

Mid

dle

Ston

eA

gele

vels

ofB

lom

bos

Cav

e

Num

ber

inF

igur

e2

Dat

eof

exca

vati

onM

SAph

ase

Lev

elSq

uare

and

sub-

squa

reG

roup

Dor

sal

side

colo

urVe

ntra

lsi

deco

lour

Surf

ace

feat

ure*

Bur

nt

102

/02/

1999

M1

CA

AF5

c†

Ora

nge

Lig

htbe

ige

PDD

no2

09/0

2/19

98M

1C

AE

5b1

Bei

geB

eige

Nno

309

/02/

1998

M1

CA

E5b

1L

ight

oran

geB

eige

Nno

409

/02/

1998

M1

CA

E5b

1B

eige

Bei

geN

no5

09/0

2/19

98M

1C

AE

5b1

Bei

geB

eige

Nno

609

/02/

1998

M1

CA

F5a

1O

rang

eB

eige

Nno

709

/02/

1998

M1

CB

AE

51

Dar

kor

ange

Bei

gePD

Dno

809

/02/

1998

M1

CB

AE

51

Ora

nge

Bei

geN

no9

09/0

2/19

98M

1C

BF5

a2

Lig

htor

ange

Bei

geN

no10

09/0

2/19

98M

1C

BF5

a2

Lig

htor

ange

Bei

geN

no11

28/0

1/19

99M

1C

BF6

b†

Dar

kbe

ige

Bei

geN

no12

05/0

2/19

99M

1C

BF6

a†

Dar

kbr

own

Lig

htgr

eyN

yes

1306

/02/

1998

M1

CB

E5b

†L

ight

oran

geB

eige

Nno

1405

/02/

1997

M1

CA

-CC

F3†

Dar

kgr

eyD

ark

grey

HC

,HD

yes

1506

/02/

1997

M1

CA

-CC

E2

†L

ight

oran

geB

eige

PDD

no16

11/1

1/19

97M

1C

A-C

CE

43

Lig

htor

ange

Bei

geN

no17

11/1

1/19

97M

1C

A-C

CE

43

Dar

kgr

eyD

ark

brow

nH

Dye

s18

07/0

2/19

97M

1C

A-C

CE

44

Lig

htbr

own

Lig

htor

ange

Nno

1907

/02/

1997

M1

CA

-CC

E4

4B

eige

Bei

gePD

Dno

2007

/02/

1997

M1

CA

-CC

E4

4B

eige

Bei

gePD

Dno

2107

/02/

1997

M1

CA

-CC

E4

4L

ight

beig

eB

eige

PDD

no22

07/0

2/19

97M

1C

A-C

CE

44

Bei

geB

eige

PDD

no23

07/0

2/19

97M

1C

A-C

CE

44

Lig

htor

ange

Bei

gePD

Dno

2407

/02/

1997

M1

CA

-CC

E4

4L

ight

brow

nB

eige

Nno

2507

/02/

1997

M1

CA

-CC

E4

4L

ight

brow

nB

eige

PDD

no26

07/0

2/19

97M

1C

A-C

CE

44

Lig

htbr

own

Bei

gePD

Dno

2707

/02/

1997

M1

CA

-CC

E4

4B

row

nL

ight

brow

nH

Cye

s28

07/0

2/19

97M

1C

A-C

CE

44

Ora

nge

Bei

geN

no29

07/0

2/19

97M

1C

A-C

CE

44

Bei

geB

eige

PDD

no30

10/0

2/19

97M

1C

A-C

CE

45

Bei

geL

ight

beig

ePD

Dno

3110

/02/

1997

M1

CA

-CC

E4

5B

eige

Bei

gePD

Dno

3210

/02/

1997

M1

CA

-CC

E4

5L

ight

brow

nB

eige

Nno

3310

/02/

1997

M1

CA

-CC

E4

5L

ight

brow

nB

eige

Nno

3410

/02/

1997

M1

CA

-CC

E4

5L

ight

brow

nB

eige

Nno



3516

/02/

2000

M1

CC

H5a

6D

ark

brow

nB

row

nH

C,H

Dye

s36

16/0

2/20

00M

1C

CH

5a6

Dar

kgr

eyD

ark

grey

HC

,HD

yes

3716

/02/

2000

M1

CC

H5a

6D

ark

grey

Gre

yH

C,H

Dye

s38

16/0

2/20

00M

1C

CH

5a6

Dar

kgr

eyG

rey

HC

yes

3916

/02/

2000

M1

CC

H5c

6D

ark

oran

geO

rang

eH

C,H

Dye

s40

06/0

2/19

98M

2C

FAE

4a†

Bei

geL

ight

beig

eN

no41

09/0

2/19

98M

2C

FE

5b†

Lig

htbr

own

Bei

geN

no42

16/0

2/20

00M

1C

CH

5c6

Dar

kor

ange

Bei

geH

C,H

Dye

s43

16/0

2/20

00M

1C

CH

5c6

Dar

kbr

own

Dar

kbr

own

HC

yes

4416

/02/

2000

M1

CC

H5c

6D

ark

beig

eB

eige

Nno

4516

/02/

2000

M1

CC

H5c

6D

ark

beig

eL

ight

oran

geH

Cye

s46

16/0

2/20

00M

1C

CH

5c6

Ora

nge

Lig

htor

ange

HC

yes

4716

/02/

2000

M1

CC

H5c

6D

ark

brow

nB

row

nH

Cye

s48

16/0

2/20

00M

1C

CH

5c6

Ora

nge

Ora

nge

Nno

4916

/02/

2000

M1

CC

H5c

6D

ark

beig

eB

eige

PDD

no50

16/0

2/20

00M

1C

CH

5c6

Lig

htor

ange

Bei

gePD

Dno

5116

/02/

2000

M1

CC

H5c

6D

ark

beig

eL

ight

oran

gePD

Dno

5216

/02/

2000

M1

CC

H5c

6D

ark

grey

Dar

kgr

eyN

yes

5316

/02/

2000

M1

CC

H5c

6D

ark

grey

Gre

yN

yes

5416

/02/

2000

M1

CC

H5c

6D

ark

grey

Dar

kbr

own

Nye

s55

16/0

2/20

00M

1C

CH

5c6

Ora

nge

Lig

htor

ange

PDD

no56

16/0

2/20

00M

1C

CH

5c6

Dar

kbr

own

Lig

htbr

own

HC

yes

5716

/02/

2000

M1

CC

H5c

6D

ark

brow

nD

ark

brow

nH

Cye

s58

16/0

2/20

00M

1C

CH

5c6

Dar

kbe

ige

Dar

kor

ange

Nye

s59

16/0

2/20

00M

1C

CH

5c6

Ora

nge

Lig

htor

ange

HC

,HD

yes

6016

/02/

2000

M1

CC

H5c

6O

rang

eL

ight

oran

gePD

Dno

6124

/04/

2002

M1

CC

H6b

7B

eige

Ora

nge

PDD

no62

24/0

4/20

02M

1C

CH

6b7

Gre

yB

row

nH

C,H

Dye

s63

24/0

4/20

02M

1C

CH

6b7

Gre

yB

row

nH

C,H

Dye

s64

24/0

4/20

02M

1C

CH

6b7

Dar

kbe

ige

Ora

nge

Nno

6522

/04/

2002

M1

CC

H6b

†L

ight

oran

geO

rang

ePD

Dno

6615

/04/

2004

M1

CC

I5c

†L

ight

oran

geO

rang

eN

no67

17/0

4/20

02M

1C

AH

6b†

Dar

kbr

own

Bro

wn

HC

yes

6820

/04/

2004

M1

CD

h2I5

c†

Bei

geB

eige

HC

,HD

yes

*PD

D,p

ost-

depo

sitio

nal

dam

age;

HC

,hea

tcr

acks

;H

D,d

esqu

amat

ion;

N,n

one.

†Iso

late

dre

cove

ry.



and 10 buried in the soil. The compact sticky flesh of the sour fig presents the advantage ofhomogeneously embedding the Nk shells with organic material, avoiding oxidation during theheating process.

Modern unmodified and experimentally heated specimens were prepared for analysis of theirchemical and microstructural composition as follows: the lateral aspect of the shell opposite tothe lip was abraded with an ESCIL 300 GTL lapping and polishing machine, using an 800 gritpaper, until a 3 × 2 mm perforation was created. The perforation edge was then polished using acloth covered with a fine diamond polishing solution. The resulting surfaces were examined withan optical microscope in reflected light and polishing was repeated until all visible scratches wereremoved. Shells were then etched in a 0.1 M solution of HCl in distilled water for 3 s, rinsed indistilled water and air dried.

Unetched and etched shells were analysed and photographed using a motorized Leica Z6APOA microscope equipped with a DFC420 digital camera and a Leica Application Suiteequipped with the Multifocus Module. To determine their elemental composition, five etchedmodern specimens were analysed using a JEOL 840A scanning electron microscope (SEM)equipped with an energy-dispersive X-ray system (EDAX). The modern shells included oneunheated specimen from the Goukou Estuary biocoenosis, one unheated specimen from athanatocoenosis of the same estuary showing a dark grey colouring, and six more specimens fromthe Goukou biocoenosis: one heated with leaves underneath an open fireplace and five heated ina furnace at temperatures of 400°C, 600°C and 800°C respectively, with leaves and soil, and300°C and 600°C as such.

To determine the structural composition in a non-destructive way, four unetched modern shellsas well as two archaeological Nk—a beige (Table 1, no. 42; Fig. 2, no. 42) and a dark grey(Table 1, no. 53; Fig. 2, no. 53) specimen from the Blombos Still Bay level CC—with fracturesshowing the internal shell structure, were analysed using a Jobin Yvon T64000 Raman spectrom-eter operated in triple subtractive mode. The 514.5 nm line of an argon ion laser was used as theexcitation source. Backscattered spectra were collected via an Olympus BX40 microscopeRaman attachment, and the light dispersed via 1800 lines per millimetre gratings on to a liquidnitrogen–cooled CCD detector. Power for the sample was kept fairly low (1.2 mW) to minimizelocalized heating effects. A narrow bandpass filter was used to remove laser plasma lines from thespectra. The modern shells included one specimen heated within a sour fig beneath an open fire,and three specimens heated in a furnace, two between leaves and humic soil at 400° and 800°Crespectively, the third as such at 300°C.

Three shades of beige, brown, orange and grey were used to account for colour variation on thedorsal and ventral sides of unmodified and experimentally heated modern Nk shells and Nk shellbeads from the MSA levels at Blombos Cave (Vanhaeren et al. 2013). For comparative purposes,colour variation was also recorded on a representative sample of malacofauna, not used asornaments, from the same MSA level (CC) that yielded most of the dark grey Nk shell beads. Thecomparative sample comes from four 50 × 50 cm sub-squares (H5a H5c, H6b and I5c). Thepresence of cracks and desquamations was systematically recorded using a Wild M3C micro-scope equipped with a Coolpix 995 digital camera.

RESULTS

The colour and shade of the Blombos MSA Nk shells varies between beige, orange, brown andgrey, depending on the observed shell aspect (Table 2) and the stratigraphic level in which theshell was found (Table 3). An opposition appears to exist within this variation between shades of



Tabl

e2

The

cont

inge

ncy

tabl

eof

colo

urva

riat

ion

onth

edo

rsal

and

vent

ral

aspe

ctof

Blo

mbo

sM

iddl

eSt

one

Age

Nas

sari

uskr

auss

ianu

ssh

ells

Dor

sal

colo

urVe

ntra

lco

lour

*

L.b

eige

Bei

geD

.bei

geL

.ora

nge

Ora

nge

D.o

rang

eL

.bro

wn

Bro

wn

D.b

row

nL

.gre

yG

rey

D.g

rey

Tota

l

L.b

eige

11

Bei

ge2

101

13D

.bei

ge3

21

17

L.o

rang

e8

19

Ora

nge

13

41

9D

.ora

nge

21

3L

.bro

wn

71

8B

row

n1

1D

.bro

wn

13

21

7L

.gre

y0

Gre

y2

2D

.gre

y2

33

8To

tal

334

07

51

25

41

33

68

*L,l

ight

;D

,dar

k.



Tabl

e3

The

freq

uenc

yof

colo

urva

riat

ion

onth

edo

rsal

and

vent

ral

aspe

cts

ofB

lom

bos

Mid

dle

Ston

eA

geN

assa

rius

krau

ssia

nus

shel

lsac

cord

ing

tole

vel

and

spat

ial

grou

ping

Dor

sal

colo

ur*

L.b

eige

Bei

geD

.bei

geL

.ora

nge

Ora

nge

D.o

rang

eL

brow

nB

row

nD

.bro

wn

L.g

rey

Gre

yD

.gre

yTo

tal

Lay

erC

A–

4–

11

––

––

––

–6

CA

A–

––

–1

––

––

––

–1

CB

––

13

––

––

1–

––

5C

BA

––

––

11

––

––

––

2C

C–

16

25

2–

–6

–2

630

CD

h21

––

––

––

––

––

–1

CF

––

––

––

1–

––

––

1C

FA1

––

––

––

––

––

–1

CA

-CC

16

–3

1–

71

––

–2

21To

tal

113

79

93

81

80

28

68

Gro

up1

–3

–1

21

––

––

––

72

––

–2

––

––

––

––

23

––

–1

––

––

––

–1

24

14

–1

1–

41

––

––

125

–2

––

––

3–

––

––

56

––

51

52

–5

––

–6

247

1–

––

––

––

––

2–

3Is

olat

ed–

32

31

–1

–2

––

113

Tota

l1

137

99

38

17

02

868



Vent

ral

colo

ur*

L.b

eige

beig

eD

.bei

geL

.ora

nge

Ora

nge

D.o

rang

eL

brow

nB

row

nD

.bro

wn

L.g

rey

Gre

yD

.gre

yTo

tal

Lay

erC

A–

6–

––

––

––

––

–6

CA

A1

––

––

––

––

––

–1

CB

–4

––

––

––

–1

––

5C

BA

–2

––

––

––

––

––

2C

C–

4–

65

11

53

–3

230

CD

h2–

1–

––

––

––

––

–1

CF

–1

––

––

––

––

––

1C

FA1

––

––

––

––

––

–1

CA

-CC

116

–1

––

1–

1–

–1

21To

tal

334

07

51

25

41

33

68

Gro

up1

–7

––

––

––

––

––

72

–2

––

––

––

––

––

23

–1

––

––

––

1–

––

24

–10

–1

––

1–

––

––

125

14

––

––

––

––

––

56

–4

–6

21

12

3–

32

247

––

––

1–

–2

––

––

3Is

olat

ed2

6–

–2

––

1–

1–

13

Tota

l3

340

75

12

54

13

368

*L,l

ight

;D

,dar

k.



beige, orange and light brown on the one hand and shades of darker brown and grey on the otherhand, as single shells may display various shades within these two broader groups but nevercombine shades from both (Table 2). The largest colour variation is observed on the ventralaspect of Nk shells from layer CC (Table 2). This layer also yielded all the brown- and grey-coloured shells, with the exception of one shell from the intermediate level CB that had a lightgrey ventral and a dark brown dorsal side (Table 2).

Colour variations of this type are not observed on modern Nk collected alive, as these displaya combination of green, khaki and yellow shades (Fig. 3). Shades of beige, orange, brown andgrey are, however, observed in modern Nk thanatocoenoses (Fig. 3). SEM observation andelemental characterization, through energy-dispersive X-ray spectroscopy (EDAX) of a modernshell collected alive and a modern dark grey shell collected dead, indicates that 5–10 μm longparticles of pyrite (iron sulphide), migrating through the more porous dorsal surface, probably as

Figure 3 Colour variation on the dorsal and ventral aspects of Nassarius kraussianus shells collected alive at theDuiwenhoks estuary, Cape Province, South Africa (a), dead at Goukou estuary, Cape Province, South Africa (b), andcollected alive and heated after cleaning them at different temperatures in an oxidizing (c) and reducing atmospherecreated by sealing the shells with organic material (d).



a result of bacterial activity (Silverman 1967), are responsible for the black colouring of Nk shellsfound in modern thanatocoenoses (Figs 4 and 5).

SEM observation and EDAX analysis did not identify particles of pyrite on MSA Nk shellbeads. In addition, Raman spectroscopy of a dark grey MSA shell did not show any evidence forthe presence of iron sulphide (peaks at 342 and 379 cm−1; McGuire et al. 2001) indicating thatthis diagenetic process is not responsible for the colouring of the MSA shells (Fig. 6).

Experimental heating of modern Nk produced shells that had colours and shades that differedrelative to temperature and atmosphere (Fig. 3). Heating shells in an organic compound within a

Figure 4 A polished and etched section of a dark grey Nassarius kraussianus from a thanatocoenois collected at theGoukou estuary, observed in optical (a) and SEM microscopy (b, c). Note in (a) the presence of black particlespenetrating the shell matrix from the dorsal outer surface, on the left of the photograph, and in (b, c) the sameparticles highlighted by the etching of the shell surface. The arrows indicate the particles analysed by EDAX inFigure 5 (d).



reductive atmosphere resulted in the shell colour changing into dark grey/black at temperaturesabove 300°C and produced a glossy black shell surface at temperatures above 500°C. The coatingof and penetration into the shell of amorphous carbon released by the leaves and humic soil isprobably responsible for the dark-grey/black colouring of the shells at temperatures above 300°C.The glossy metallic appearance of this black coating on shells heated above 500°C can possiblybe explained by structural modification of the layer due to release of O and H, previously reportedto occur between 450°C and 500°C (Ray et al. 2003). Heating in an oxidizing atmosphereproduced larger colour variation. The ventral sides of the shells became light beige, beige, light

Figure 5 SEM–EDAX spectra of the surface of a light-coloured unmodified Nassarius kraussianus (Nk) collected alivein the Duiwenhoks estuary (a), a dark-coloured Nk from the Goukou estuary thanatocoenosis (b), Nk heated at 300°C(c) and 600°C (d) in an oxidizing atmosphere, Nk heated at 400°C (e), 600°C (f) and 800°C (g) in a reducing atmospherecreated by sealing the shells with organic material, and of a Nk heated within the capsule of a South African sour fig inthe soil underneath an open fireplace (h). The peaks of gold, chlorine and sodium are due to etching and metal coatingfor SEM analysis. The aluminium, sulphur and iron peaks in (b) are most probably due to permineralization, replacementand weathering phenomena affecting shells in thanatocoenoses.



Figu

re6

Ram

ansp

ectr

aof

(a)

four

diff

eren

tshe

llla

yers

inm

oder

nun

mod

ified

Nas

sari

uskr

auss

ianu

s(1

,out

ersh

elll

ayer

;2,

3,m

iddl

esh

elll

ayer

s;4a

,4b,

inne

rsh

elll

ayer

);(b

)m

oder

nN

assa

rius

krau

ssia

nus

heat

edat

diff

eren

tte

mpe

ratu

res

inox

idiz

ing

(1,

300°

C,

inne

rsh

ell

laye

r;2,

300°

C,

mid

dle

shel

lla

yer;

3,30

0°C

,ou

ter

shel

lla

yer)

and

redu

cing

atm

osph

eres

(4,4

00°C

,inn

ersh

ell

laye

r;5,

400°

C,o

uter

shel

lla

yer;

6,80

0°C

),(c

)m

oder

nN

assa

rius

krau

ssia

nus

heat

edin

the

soil

unde

rnea

than

open

firep

lace

,an

d(d

:1a

,1b)

ali

ght(

Tabl

e1,

no.4

2)an

d(d

:2a

–c)

dark

(Tab

le1,

no.5

3)co

lour

edN

kfr

omM

iddl

eSt

one

Age

leve

lCC

ofB

lom

bos

Cav

e.T

hepe

aks

corr

espo

ndto

arag

onit

e(a

t20

5cm

−1),

calc

ite

(at

280

cm−1

)an

dca

rote

noid

pigm

ents

(at

1133

and

1526

cm−1

)pr

esen

tin

the

shel

l(U

rmos

etal

.199

1;W

ithn

all

etal

.200

3).



Figu

re6

Con

tinu

ed.



brown, grey and white at 200°C, 300°C, 400°C, 500°C and 800°C respectively. The black colourobserved on the dorsal aspect of shells heated at 300°C to 400°C in an oxidizing atmosphere, andon both shell aspects of shells heated at 400°C to 500°C in a reductive atmosphere, is due to asuperficial layer of soot obscuring the underlying shell colour.

Optical and scanning electron microscopy analysis coupled with EDAX and Raman spec-troscopy shows that heating Nk causes structural modifications. These analyses reveal that Nkshells are composed of four layers of aragonite crystals with a crossed lamellar layered micro-structure (Fig. 6) that degrade into calcite with an irregular prismatic microstructure at tem-peratures above 300°C (Figs 7 and 8). At 800°C in an oxidizing atmosphere, the calciumcarbonate is transformed in calcium oxide (lime), leading to the decomposition of the shell(Fig. 6). At the same temperature in a reducing atmosphere, the calcite undergoes adensification with elimination of porosity and net shrinkage (Fig. 8 (b)). Elemental analysis(Fig. 5) shows that Nk heated in a reducing atmosphere and in the presence of organic materialbecome enriched in carbon, probably in the form of amorphous carbon, which is responsiblefor the blackening of the shells.

Raman analysis shows that dark MSA Nk are composed of calcite and the light-colouredNk, found in the same stratigraphic levels, of aragonite (Fig. 6). The presence of heat crackson the surface of dark MSA Nk (Fig. 9) confirms that they have been heated. On the basis ofthe experimental results presented above, dark MSA Nk shells were heated in a reductiveenvironment at a temperature between 300°C and 500°C, a process responsible for theircolouring.

Burnt marine shells other than Nk do occur in the same sub-squares in which burnt and unburntNk were recovered (Table 4). The proportion of burnt shells increases with their degree offragmentation. The only difference between Nk and edible species is that unlike Nk, the lattersystematically include remains of calcined shells resulting from prolonged heating at hightemperature in an oxidizing environment. Like Nk, inedible species and water-worn shell frag-ments show evidence of burning but not of charring.

Finally, no clear correlation appears when examining the spatial distribution by layer ofburnt/unburnt Nk shell beads and the location of hearths in the same layers (Fig. 10). A consistentnumber of unburnt shells are present in areas in which large hearths were found, particularly inlayer CC, and burnt shells occur in sub-squares in which no hearths were recorded. Groups ofshells found together in a sub-square associated with a hearth include burnt and unburnt shells.Also, the shell distribution does not fit the hypothesis that shell burning is due to heatingproduced by overlying hearths.

DISCUSSION AND CONCLUSIONS

Microscopic, Raman and EDAX analyses of experimentally heated Nk shells, dark Nk shells frommodern thanatocoenoses and MSA Nk shell beads identified firm criteria to distinguish heatedfrom unheated Nk beads, and showed that the dark colouring of the latter is due to heating. Inorder to formally demonstrate that the heating of the Nk was the consequence of a deliberateprocess seeking to produce dark ornaments, one should either find no traces of burning on othershell remains found in the same squares/levels or record on the latter traces of burning inproportions significantly different from those observed on the shell beads. The Blombos data donot conform to the first expectation, and match the second with such a degree of ambiguity thatit is difficult, at present, to reach a firm conclusion. The absence of calcined Nk and the substantialpresence of calcined shells from other species are consistent with the intention of darkening the



300 µm300 µm

180 µm

40 µm 30 µm30 µm

(a)

(b)

(c)

(d)

(e)

(f)

70 µm70 µm

300 µm

180 µm

40 µm

Figure 7 Optical (a) and SEM (b–f) photographs of the cross-section of an unheated modern Nassarius kraussianus(Nk) shell (a–c), and of a Nk shell heated in a reducing atmosphere at 300°C (d), 400°C (c) and 600°C (f).



Nk in a controlled reductive environment, but cannot be considered, at this stage, as a convincingproof that Nk shells were intentionally heated. The spatial distribution of burnt and unburnt shellbeads supports, to some extent, intentional heating of the beads. If MSA Blombos Cave inhab-itants wore only unburnt shell beads and hearths were responsible for the blackening of lost shellbeads, one would expect to find all burnt shells in the hearths, which is not the case. On thecontrary, if MSA Blombos Cave inhabitants wore intentionally heated and unburnt shell beads,one would expect to find black and light shells in and outside hearths. This is due to the fact thathearths may have not been functional at the moment in which light beads were lost. This is thepattern that we observe at Blombos Cave. In order to verify this hypothesis, future research will

(a) (c)

(d)(b)

240 µm

30 µm30 µm

40 µm

40 µm40 µm

Figure 8 SEM photos of the cross-section of a Nassarius kraussianus (Nk) shell heated at 800°C in a reducingatmosphere (a, b) and of a Nk heated in the soil underneath an open fireplace (c, d).



need to focus on high-resolution analysis of the site formation processes to evaluate the degreeto which the spatial distribution of small items such as Nk shells may have been affected by syn-and post-depositional displacement.

ACKNOWLEDGEMENTS

We thank Gérard Blanc, Pierre Guibert, Kathrin Lange, Marlize Lombard, Renata GarciaMoreno, Catherine Perlès, Alain Queffelec, Ina Reiche and Jörg Schäfer for helpful discussions,Elisabeth Sellier for assistance with the SEM analysis, and Cécile Bossy and Alain Queffelec forgiving us access to the muffle furnace and the polishing machine. This research was funded bythe European Research Council (ERC) under the European Union’s Seventh Framework Pro-gramme (FP7/2007–2013)/ERC grant agreement no. 249587, the PROTEA French – SouthAfrican research programme, the Groupe de Recherche Internationale STAR of the CNRS, theWenner-Gren Foundation and the Projet Région Aquitaine Origines III. CSH was funded by aNational Research Foundation/Department of Science and Technology supported Chair at theUniversity of Witwatersrand, South Africa, and by a joint Norwegian Research Council/SouthAfrican National Research Foundation grant.

(a) (b)

(c) (d)

0.5 mm 0.5 mm

0.5 mm 0.1 mm

Figure 9 Heat cracks on experimentally heated Nassarius kraussianus (Nk) shells (a, b) and on Nk from the MiddleStone Age levels of Blombos Cave (c, d).



Tabl

e4

The

freq

uenc

yof

unbu

rnt

(‘U

nbur

.’),

burn

t(‘

Bur

.’)

and

calc

inat

ed(‘

Cal

c.’)

shel

lsan

dsh

ell

frag

men

tsof

mar

ine

shel

lsp

ecie

sfr

omla

yer

CC

.Lar

gefr

agm

ents

are

>2cm

,med

ium

frag

men

tsbe

twee

n1

and

2cm

,and

smal

lfr

agm

ents

are

<1cm

.Res

idue

sco

rres

pond

mai

nly

tom

icro

flake

sof

nacr

e,pr

obab

lyof

Pern

ape

rna

orT

urbo

sarm

atic

us.I

ncid

enta

lsh

ells

corr

espo

ndto

smal

lga

stro

pods

,and

wat

er-w

orn

shel

lsto

roun

ded

frag

men

tsof

unde

term

ined

shel

lsp

ecie

s

Sub-

squa

re

H5a

H5c

H6b

I5c

n(%

)n

(%)

n(%

)n

(%)

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Per

nape

rna

MN

I3

–3

84

264

––

15

9C

ompl

ete

oral

mos

t–

––

2–

––

––

––

–L

arge

frag

men

ts*

1–

–5

––

40–

–3

11

Med

ium

frag

men

ts†

1–

236

3–

104

4–

–8

17Sm

all

frag

men

ts‡

1815

284

432

268

114

–30

89(6

5)(3

3)(2

)(2

5)(7

5)

Turb

osa

rmat

icus

MN

I4

13

71

–13

2–

203

3C

ompl

ete

oral

mos

t–

––

––

––

––

––

–L

arge

frag

men

ts*

4–

313

1–

262

–24

511

Med

ium

frag

men

ts†

–3

–12

5–

122

–2

73

Smal

lfr

agm

ents

‡7

4–

121

46–

154

171

3134

65(7

2)(2

8)(9

0)(1

0)(<

1)(2

4)(2

6)(5

0)

Scut

alas

taar

genv

ille

iM

NI

1–

–1

––

1–

–2

––

Com

plet

eor

alm

ost

––

––

––

––

–2

––

Lar

gefr

agm

ents

*–

––

––

–1

––

––

–M

ediu

mfr

agm

ents

†–

––

––

––

––

––

–Sm

all

frag

men

ts‡

1–

–2

––

––

––

––

Cym

bula

ocul

usM

NI

1–

–0.

50.

5–

2–

–6

1–

Com

plet

eor

alm

ost

––

––

––

1–

–4

1–

Lar

gefr

agm

ents

*–

––

––

–3

––

41

1M

ediu

mfr

agm

ents

†7

––

2–

––

4–

68

–Sm

all

frag

men

ts‡

9–

–5

5–

82

–8

94



Tabl

e4

Con

tinu

ed

Sub-

squa

re

H5a

H5c

H6b

I5c

n(%

)n

(%)

n(%

)n

(%)

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Unb

ur.

Bur

.C

alc.

Din

opla

xgi

gas

MN

I0.

50.

5–

–1

–1

––

0.5

–0.

5C

ompl

ete

oral

mos

t–

––

––

––

––

Lar

gefr

agm

ents

*–

––

––

–3

––

1–

–M

ediu

mfr

agm

ents

†–

1–

–2

–7

––

––

1Sm

all

frag

men

ts‡

1–

––

9–

41

––

–1

Hal

ioti

ssp

.M

NI

1–

–1

––

––

–1

––

Com

plet

eor

alm

ost

––

––

––

––

––

––

Lar

gefr

agm

ents

*–

––

––

––

––

2–

–M

ediu

mfr

agm

ents

†1

––

––

––

––

––

–Sm

all

frag

men

ts‡

––

–2

––

––

––

––

Don

axsa

rra

MN

I–

––

––

–1

1–

––

–C

ompl

ete

oral

mos

t–

––

––

––

––

––

–L

arge

frag

men

ts*

––

––

––

––

––

––

Med

ium

frag

men

ts†

––

––

––

31

––

––

Smal

lfr

agm

ents

‡–

––

––

–2

––

––

–

Dil

oma

sp.

––

–1

––

1–

–1

––

Res

idue

s§13

050

–25

420

7–

n/a

n/a

n/a

n/a

n/a

n/a

(72)

(27)

(55)

(45)

Bar

nacl

es2

2–

91

–9

––

3–

–In

cide

ntal

s¶4

1–

32

–35

––

2–

–W

ater

-wor

n∥10

1–

414

–42

––

1–

–N

assa

rius

krau

ssia

nus

–4

–12

7–

12

–1

1–

*>2

cm;

†be

twee

n1

and

2cm

;‡

<1cm

;§

mic

rofla

kes

ofna

cre,

prob

ably

Per

nape

rna

and/

orTu

rbo

sarm

atic

us;

¶sm

all

gast

ropo

ds;

∥rou

nded

frag

men

tsof

unde

term

ined

shel

lsp

ecie

s.



Figure 10 The spatial distribution of Nassarius kraussianus shell beads recovered at Blombos Cave according tocontextual and descriptive data. The dark grey and grey sub-squares indicate the location of hearths and ash areas (dataon hearths from Haaland 2012).



REFERENCES

Ambrose, S., 1998, Chronology of the later Stone Age and food production in East Africa, Journal of ArchaeologicalScience, 25, 377–92.

Bar-Yosef Mayer, D. E, Vandermeersch, B., and Bar-Yosef, O., 2009, Shells and ochre in Middle Paleolithic Qafzeh Cave,Israel: indications for modern behavior, Journal of Human Evolution, 56, 307–14.

Botha, R., 2008, Prehistoric shell beads as a window on language evolution, Language & Communication, 28(3),197–212.

Bouzouggar, A., Barton, N., Vanhaeren, M., d’Errico, F., Collcutt, S., Higham, T., Hodge, E., Parfitt, S., Rhodes, E.,Schwenninger, J.-L., Stringer, C., Turner, E., Ward, S., Moutmir, A., and Stambouli, A., 2007, 82,000-year-old shellbeads from North Africa and implications for the origins of modern human behavior, Proceedings of the NationalAcademy of Sciences, USA, 104, 9964–9.

Brown, K. S., Marean, C. W., Herries, A. I. R., Jacobs, Z., Tribolo, C., Braun, D., Roberts, D. L., Meyer, M. C., andBernatchez, J., 2009, Fire as an engineering tool of early modern humans, Science, 325, 859–62.

Claassen, C., 1998, Shells, Cambridge University Press, Cambridge.Coolidge, F. L., and Overmann, K. A., 2012, Numerosity, abstraction, and the emergence of symbolic thinking, Current

Anthropology, 53(2), 204–25.d’Errico, F., and Henshilwood, C. S., 2007, Additional evidence for bone technology in the southern African Middle

Stone Age, Journal of Human Evolution, 52, 142–63.d’Errico, F., and Vanhaeren, M., 2009, Earliest personal ornaments and their significance for the origin of language

debate, in The cradle of human language (eds. R. Botha and C. Knight), 16–40, Oxford University Press, Oxford.d’Errico, F., Henshilwood, Ch., and Nilssen, P., 2001, An engraved bone fragment from ca. 75 kyr Middle Stone Age

levels at Blombos Cave, South Africa: implications for the origin of symbolism and language, Antiquity, 75, 309–18.d’Errico, F., Vanhaeren, M., and Wadley, L., 2008, Possible shell beads from the Middle Stone Age layers of Sibudu Cave,

South Africa, Journal of Archaeological Science, 35, 2675–85.d’Errico, F., Henshilwood, C. S., Vanhaeren, M., and van Niekerk, K., 2005, Nassarius kraussianus shell beads from

Blombos Cave: evidence for symbolic behaviour in the Middle Stone Age, Journal of Human Evolution, 48, 3–24.d’Errico, F., Salomon, H., Vignaud, C., and Stringer, C., 2010, Pigments from the Middle Palaeolithic levels of es-Skhul

(Mount Carmel, Israel), Journal of Archaeological Science, 37(12), 3099–110.d’Errico, F., Backwell, L., Villa, P., Degano, I., Lucejko, J., Bamford, M., Higham, T., Colombini, M.-P., and Beaumont,

P., 2012, Early evidence of San material culture represented by organic artifacts from Border Cave, South Africa,Proceedings of the National Academy of Science, USA, 9(33), 13 214–19.

d’Errico, F., Vanhaeren, M., Barton, N., Bouzouggar, A., Mienis, H., Richter, D., Hublin, J-J., Mcpherron, S. P., andLozouet, P., 2009, Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa,Proceedings of the National Academy of Science, USA, 106, 16 051–6.

Dissanayake, E., 2009, The Artification Hypothesis and its relevance to cognitive science, evolutionary aesthetics, andneuroaesthetics, Cognitive Semiotics, 5, 148–73.

Eiwanger, J., Mikdad, A., and Moser, J., 2009, Découverte de coquilles perforées de type Nassarius au site Ifri n’Ammar(Rif Oriental, Maroc), Bulletin d’Archéologie Marocaine, 22, 9–15.

Gliganic, L. A., Jacobs, Z., Roberts, R. G., Domínguez-Rodrigo M., and Mabulla, A. Z., 2012, New ages for Middle andLater Stone Age deposits at Mumba rockshelter, Tanzania: optically stimulated luminescence dating of quartz andfeldspar grains, Journal of Human Evolution, 62, 533–47.

Godfrey-Smith, D. I., and Ilani, S., 2004, Past thermal history of goethite and haematite fragments from Qafzeh cavededuced from thermal activation characteristics of 110°C TL peak of enclosed quartz grains, Revue d’Archéométrie,28, 185–90.

Haaland, M., 2012, Intra-site spatial analysis of the Still Bay Units in Blombos Cave, South Africa, Master’s dissertation,Department of Archaeology, History, Culture and Religion, University of Bergen, Bergen.

Hartzell, L. L., 1991, Archaeological evidence for stages of manufacture of Olivella shell beads in California, Journal ofCalifornia and Great Basin Anthropology, 13(1), 29–39.

Henshilwood, C. S., 2008a, Winds of change: palaeoenvironments, material culture and human behaviour in the LatePleistocene (c. 77–48 ka) in the Western Cape Province, South Africa, in Current themes in Middle Stone Ageresearch (eds. M. Lombard, C. Sievers and W. Ward), 35–51, Goodwin Series 10, South African ArchaeologicalSociety, Vlaeberg.

Henshilwood, C. S., 2008b, Holocene prehistory of the Southern Cape, South Africa: excavations at Blombos Caveand the Blombosfontein Nature Reserve, British Archaeological Reports International Series 1860, Archaeopress,Oxford.



Henshilwood, C. S., and Dubreuil, B., 2009, Reading the artifacts: gleaning language skills from the Middle Stone Agein southern Africa, in The cradle of human language (eds. R. Botha and C. Knight), 41–60, Oxford University Press,Oxford.

Henshilwood, C. S., and Dubreuil, B., 2011, The Still Bay and Howiesons Poort, 77–59 ka: perspective-taking and theevolution of the modern human mind during the African Middle Stone Age, Current Anthropology, 52(3), 361–400.

Henshilwood, C. S., d’Errico, F., and Watts, I., 2009, Engraved ochres from the Middle Stone Age levels at BlombosCave, South Africa, Journal of Human Evolution, 57, 27–47.

Henshilwood, C. S., d’Errico, F., Marean, C. W., Milo, R. G., and Yates, R., 2001a, An early bone tool industry from theMiddle Stone Age at Blombos Cave, South Africa: implications for the origins of modern human behaviour,symbolism and language, Journal of Human Evolution, 41, 631–78.

Henshilwood, C. S., d’Errico, F., Vanhaeren, M., van Niekerk, K., and Jacobs, Z., 2004, Middle Stone Age shell beadsfrom South Africa, Science, 304, 403.

Henshilwood, C. S., d’Errico, F., Van Niekerk, K. L., Coquinot, Y., Jacobs, Z., Lauritzen, S.-E., Menu, M., andGarcía-Moreno, R., 2011, A 100,000-year-old ochre-processing workshop at Blombos Cave, South Africa, Science,334, 219–22.

Henshilwood, C. S., Sealy, J. C., Yates, R. J., Cruz-Uribe, K., Goldberg, P., Grine, F. E., Klein, R. G., Poggenpoel, C.,van Niekerk, K. L., and Watts, I., 2001b, Blombos Cave, Southern Cape, South Africa: preliminary report on the1992–1999 excavations of the Middle Stone Age levels, Journal of Archaeological Science, 28(5), 421–48.

Henshilwood, C. S., d’Errico, F., Yates, R., Jacobs, Z., Tribolo, C., Duller, G. A. T., Mercier, N., Sealy, J. C., Valladas,H., Watts, I., and Wintle, A. G., 2002, Emergence of modern human behavior: Middle Stone Age engravings fromSouth Africa, Science, 295, 1278–80.

Jacobs, Z., 2004, Development of luminescence techniques for dating Middle Stone Age sites in South Africa, Ph.D.dissertation, University of Wales, Aberystwyth.

Jacobs, Z., Duller, G. A. T., and Wintle, A. G., 2003a, Optical dating of dune sand from Blombos Cave, South Africa:II—single grain data, Journal of Human Evolution, 44(5), 613–25.

Jacobs, Z., Wintle, A. G., and Duller, G. A. T, 2003b, Optical dating of dune sand from Blombos Cave, South Africa:I—multiple grain data, Journal of Human Evolution, 44(5), 599–612.

Jacobs, Z., Duller, G. A. T., Wintle, A. G., and Henshilwood, C. S., 2006, Extending the chronology of deposits atBlombos Cave, South Africa, back to 140 ka using optical dating of single and multiple grains of quartz, Journal ofHuman Evolution, 51, 255–73.

Jacobs, Z., Hayes, E. H., Roberts, R. G., Galbraith, R. F., and Henshilwood, C. S., 2013, An improved OSL chronologyfor the Still Bay layers at Blombos Cave, South Africa: further tests of single-grain dating procedures and are-evaluation of the timing of the Still Bay industry across southern Africa, Journal of Archaeological Science, 40(1),579–94.

Jones, H. L., 2001, Electron spin resonance dating of tooth enamel at three Palaeolithic sites, Ph.D. dissertation,McMaster University, Canada.

Kandel, A. W., and Conard, N. J., 2005, Production sequences of ostrich eggshell beads and settlement dynamics in theGeelbek Dunes of the Western Cape, South Africa, Journal of Archaeological Science, 32, 1711–21.

Klein, R. G., 2008, Out of Africa and the evolution of human behaviour, Evolutionary Anthropology, 17, 267–81.Klein, R. G., and Steele, T. E., 2013, Archaeological shellfish size and later human evolution in Africa, Proceedings of

the National Academy of Sciences, USA, 110(27), 10 910–15.Kuhn, S., and Stiner, M., 2007, Body ornamentation as information technology: towards an understanding of the

significance of early beads, in Rethinking the human revolution (eds. P. Mellars, K. Boyle, O. Bar-Yosef and C.Stringer), 45–54, McDonald Institute Monographs, Cambridge.

Lange, K., Perlès, C., Vanhaeren, M., and Reiche, I., 2008, Heat induced modification of marine shells as personalornaments at the prehistoric site of Franchthi Cave, Greece: first results of a multianalytical approach, in 9thInternational Conference on NDT of Art, Jerusalem, Israel, 25–30 May 2008, http://www.ndt.net/search/docs.php3?MainSource=65.

McBrearty, S., and Brooks, A. S., 2000, The revolution that wasn’t: a new interpretation of the origin of modern humanbehaviour, Journal of Human Evolution, 39, 453–563.

McGuire, M. M., Jallad, K. N., Ben-Amotz, D., and Hamers, R. J., 2001, Chemical mapping of elemental sulfur onpyrite and arsenopyrite surfaces using near-infrared Raman imaging microscopy, Applied Surface Science, 178,105–15.

Mazza, P. P. A., Martini, F., Sala, B., Magi, M., Colombini, M. P., Giachi, G., Landucci, F., Lemorini, C., Modugno, F.,and Ribechini, E., 2006, A new Palaeolithic discovery: tar-hafted stone tools in a European mid-Pleistocene bone-bearing bed, Journal of Archaeological Science, 33, 1310–18.



http://www.ndt.net/search/docs.php3?MainSource=65

http://www.ndt.net/search/docs.php3?MainSource=65

Mourre, V., Villa, P., and Henshilwood, C., 2010, Early use of pressure flaking on lithic artifacts at Blombos Cave, SouthAfrica, Science, 330, 659–62.

Nami, M., and Moser, J. (eds.), 2010, La Grotte d’Ifri n’Ammar. Tome 2. Le Paléolithique moyen, Forschungen zurArchäologie Außereuropäischer Kulturen 9, Dr Ludwig Reichert Verlag, Wiesbaden.

Pawlik, A. F., and Thissen, J. P., 2011, Hafted armatures and multi-component tool design at the Micoquian site ofInden-Altdorf, Germany, Journal of Archaeological Science, 38, 1699–708.

Perlès, C., and Vanhaeren, M., 2010, Black Cyclope neritea marine shell ornaments in the Upper Palaeolithic andMesolithic of Franchthi Cave, Greece: arguments for intentional heat treatment, Journal of Field Archaeology, 35(3),298–309.

Ray, S. C., Fanchini, G., Tagliaferro, A., Bose, B., and Dasgupta, D., 2003, Amorphous carbon films prepared by the ‘dip’technique: deposition and film characterization, Journal of Applied Physics, 94(2), 870–8.

Salomon, H., Vignaud, C., Coquinot, Y., Beck, L., Stringer, C., Strivay, D., and d’Errico, F., 2012, Selection and heatingof colouring materials in the Mousterian leves of Es-Skhul (c.100 000 years BP, Mount Carmel, Israel),Archaeometry, 54, 698–722.

Schmidt, P., Porraz, G., Slodczyk, A., Bellot-Gurlet, L., Archer, W., and Miller, C. E., 2013, Heat treatment in the SouthAfrican Middle Stone Age: temperature induced transformations of silcrete and their technological implications,Journal of Archaeological Science, 40(9), 3519–31.

Schoeman, S., 1983, Eloquent beads, the semantics of a Zulu art form, Africa Insight, 13(2), 5–25.Silverman, M. P., 1967, Mechanism of bacterial pyrite oxidation, Journal of Bacteriology, 94(4), 1046–51.Stiner, M., 1999, Palaeolithic mollusk exploitation at Riparo Mochi (Balzi Rossi, Italy): food and ornaments from the

Aurignacian through Epigravettian, Antiquity, 73(282), 735–54.Thompson, J., and Henshilwood, C. S., 2011, Taphonomic analysis of the Middle Stone Age large mammal faunal

assemblage from Blombos Cave, Southern Cape, South Africa, Journal of Human Evolution, 60, 746–67.Tribolo, C., 2003, Apports des méthodes de la luminescence à la chronologie de techno-faciès du Middle Stone Age

associés aux premiers hommes modernes d’Afrique du Sud, Ph.D. dissertation, Université Bordeaux 1, Talence.Tribolo, C., Mercier, N., Selo, M., Valladas, H., Joron, J.-L., Reyss, J.-L., Henshilwood, C., Sealy, J., and Yates, R., 2006,

TL dating of burnt lithics from Blombos Cave (South Africa) and the antiquity of modern behavior, Archaeometry,48, 341–57.

Urmos, J., Sharma, S. K., and Mackenzie, F. T., 1991, Characterization of some biogenic carbonates with Ramanspectroscopy, American Mineralogist, 76, 641–6.

Vanhaeren, M., and d’Errico, F., 2006, Clinal distribution of personal ornaments reveals the ethno-linguistic geographyof Early Upper Palaeolithic Europe, Journal of Archaeological Science, 33(8), 1105–28.

Vanhaeren, M., d’Errico, F., van Niekerk, K. L., Henshilwood, C. S., and Erasmus, R. M., 2013, Thinking strings:additional evidence for personal ornament use in the Middle Stone Age at Blombos Cave, South Africa, Journal ofHuman Evolution, 64(6), 500–17.

Vanhaeren, M., d’Errico, F., Stringer, C., James, S. L., Todd, J., and Mienis, H. K., 2006, Middle Palaeolithic shell beadsin Israel and Algeria, Science, 312, 1785–8.

Villa, P., Soressi, M., Henshilwood, C. S., and Mourre, V., 2009, The Still Bay points of Blombos Cave (South Africa),Journal of Archaeological Science, 36, 441–60.

Wadley, L., Hodgskiss, T., and Grant, M., 2009, Implications for complex cognition from the hafting of tools withcompound adhesives in the Middle Stone Age, South Africa, Proceedings of the National Academy of Sciences, USA,106, 9590–4.

Wickler, W., and Seibt, I., 1995, Syntax and semantics in a Zulu bead colour communication system, Anthropos, 90,391–405.

Withnall, R., Chowdhry, B. Z., Silver, J., Edwards, H. G. M., and de Oliveira, L. F. C., 2003, Raman spectra of carotenoidsin natural products, Spectrochim Acta A, 59(10), 2207–12.

Wynn, T., and Coolidge, F., 2007, Did a small but significant enhancement in working memory capacity power theevolution of modern thinking? In Rethinking the human revolution (eds. P. Mellars, K. Boyle, O. Bar-Yosef and C.Stringer), 79–90, McDonald Institute Monographs, Cambridge.

