Santander, February 19th-22nd 2008 - Aranzadi

Shell beads in the Pre-Pottery Neolithic B in Central Levant: Cypraeidae of Tell Aswad (Damascus, Syria)
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technological patterns have been only described
for little perforations (Francis 1989, d’Errico et al.
1993, Bar-Yosef 1997). In the case of cowrie dorsum
removal by sawing, archaeological and experimental
data are not available. The personal experimentations
I made using sharp flint blades as
tools indicate that sawing could be easily distinguished
from grinding technique. Indeed, this
technique leaves series of striations on the shell
section as well as around the edge (Fig. 4a). The
striations show clearly the direction of the sawing
movement during the operation. When the blade
slips, fine and isolated striations sometimes mark
the lateral surfaces of the cowrie (Fig. 4b). Once
removed the dorsum, a regular but not entirely flat
opening edge results due to the frequent disruptions
occurring during the motion. On the experimental
specimens, deep sawing grooves are
systematically noticed (Fig. 4c).
Hammering is another technique attested for
making holes on shells (Ibidem). With this technique,
removing the cowrie dorsum implies the shaping
of the original shell by direct or indirect percussion.
The large hole obtained shows irregular,
rough, chipped and sharp edges.
For the two latter techniques (sawing and hammering),
the operation can be finalized by rubbing
the dorsal face in order to flatten the irregularities
of the surface (Francis 1989). Thus, grinding can
be used in a final step and then erase the diagnostic
traces made by the preceding methods.
Because of the smooth aspect of the circumference,
no tool marks or striations directly related to
the dorsum removal were observed microscopically
on the cowries of Tell Aswad. At least, two
techniques can be deduced from the morphological
features of the edge surface: grinding and
hammering. Eight items could witness the first
technique (n°11, 33, 35, 132, 144, 176, 180 and
CM-57) because of the flatness and regularity of
the dorsal surface (e.g. Fig. 2a, 2b, 2c, 2f, 2g, 2i,
2k). For two other cowries, the hammering technique
is suggested: the small specimen of
Monetaria moneta (n°CM-30a) found during the
previous excavations (Maréchal 1995: fig. 115c)
and an incised columellar part (n°143). For the first
item, the hypothesis was made by C. Maréchal
without precise description (Maréchal 1995: 135).
According to my observations, the second element
shows a tortuous transversal section with
irregular but relatively smooth ridge (Fig. 2d). This
pattern could have resulted from the hammering
method. Sawing technique was not evidenced but
combination including hammering plus grinding or
sawing plus grinding cannot be totally excluded.
3.2. Perforations
Small holes are present on five complete or
fragmentary cowries at Tell Aswad. In the absence
of striations, only the shape and size of the orifice
have been taken in account to identify the nature
of the perforations as well as the techniques used
to make them.
To obtain small perforations on shells, various
techniques can be employed: gouging, hammering,
sawing, drilling, scratching or grinding (e.g.
Francis 1989).
Some families of marine gastropod predators
such as Naticidae and Muricidae make holes in
the test of gastropod and bivalve shells which can
Figure 4. Experiment of sawing technique made on a modern cowrie to remove the dorsum part (magnification x10). a: striations on the shell section; b: isolated striations
caused by the slipping of the blade on the lateral side; c: regular but not entirely flat opening edge due to the frequent disruptions occurring during the motion.
MUNIBE Suplemento - Gehigarria 31, 2010
S.C. Aranzadi. Z.E. Donostia/San Sebastián