Santander, February 19th-22nd 2008 - Aranzadi

52
BÁRBARA AVEZUELA
Figure 6. Direct pressure. 1a-1b, from the inside of gastropod. 2a-2b, from
the outside of gastropod.
The rest of the perforations were made externally
by semicircular rotation using perforators of different
sizes. The obtained holes were circular and the
cross-section conical. Only in one case was the
cross-section not conical: that made from the inside
of the Littorina, Horea perhaps because from that
position it is not possible to control the movement. We
observed striae left by lithics in the walls of the perforation
and rises in the active and opposing surfaces.
And finally, the last technique used was sawing
(Fig. 8), used on the back of two gastropods with the
edges of two flakes. The result is two extended
furrows, conical-rectums, with striae from lithics in the
walls of the perforation and rises in the opposite face.
The lithic tools used were perforators of different
sizes and a burin. In the 13 units in which we
obtained the perforation successfully, twice the
contour tended to a rounded form, nevertheless in
the rest of units the form was polygonal, almost
triangular, always conditioned by the cross-section
of the end of the lithic tool that we used.
Sometimes the perforation follows the structural
lines of the shell. We found fissures and rises in the
attack surface as well as in the opposite one and
the cross-section is always irregular.
The fourth technique, semicircular rotation (Fig.
7), was employed on 7 gastropods and two bivalves.
We were able to make a perforation with this
technique from the inside of the aperture of a
Littorina litorea but the technique is not easy to
execute from this position due to a lack of manoeuvrability
inside the aperture.
Figure 7. Semicircular rotation. 1a, from the outside of gastropod, circular
with striae left by lithic tool. 1b, from de inside of gastropod, rotation with
pressure, we can see the cross- section of the tool used in the morphology
of the perforation.
Figure 8. Sawing. Furrow conical-rectum with striae from lithics in the walls
of the perforation.
4. STUDY OF THE ARCHAEOLOGICAL COLLECTION
This small collection of personal ornaments is
made up of six species of marine molluscs, one
freshwater mollusc and three red deer atrophied
canines (Fig. 3). For the technological study we
apply the results of our experiments and those
from other authors (D'errico et al. 1993, Alvarez-
Fernández 2006, Taborin 1993).
The first specie represented is the Cyclope
neritea (Fig.9); we have 16 perforated specimens.
The perforations vary in size depending on the
wear that they have suffered, including specimens
with perforations broken from use.
From the contours of the perforations we
recognize several wear stages
1. Rectangular perforations are those that have
limited wear.
2. Next are perforations that are rounded
towards the ring of the peristome… (Fig. 9. 1)
3. …until making contact and fusing with the
peristome. Then, the perforation begins to fracture
in the opposite direction (Fig. 9. 3).
MUNIBE Suplemento - Gehigarria 31, 2010
S.C. Aranzadi. Z.E. Donostia/San Sebastián