Santander, February 19th-22nd 2008 - Aranzadi

Molluscs as sedimentary components. Another perspective of analysis
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order to relate those data with the location of every
subunit in the site and more concrete, in relation to
the hut, we divide the area in three categories: F
(outside the hut); CU (inside the hut); T (last subunits
of each occupation units). A non random relation
between the positions of the subunits is established
depending on the density of molluscs contained.
75% of the subunits, which have higher
content of valves than the mean (89.56 individuals/dm3)
are concentrated outside the hut, whereas
at the same place are located only 21.74% of
the subunits with lower valves content than the
mean. On the contrary, 52.17% of subunits with
lower content of valves than the mean in the sediment
are in the centre of the hut, whereas just
16.67% subunits with higher content of molluscs
are located in this place (fig. 6).
Figure 6. F= Fuera (Outside); CU= Centro Unidad (Inside); T= Tapa (last subunities
of each ocupation unity).
To work with samples allows us to make estimates
about the MNI consumed to the whole of
each stratigraphic subunit. During the excavation
we recorded the whole volume of sediment of
each stratigraphic subunit; on the other hand, the
fragments of shell were separated from the other
components of the samples, they were identified
taxonomically and the MNI counting was based on
identifiying characteristics and discriminative parts
between individuals.
The total MNI was calculated extrapolating the
results obtained from each sample (4 dm³), to the
total volume of their corresponding subunit
(Orquera and Piana 2000). In general, the results
obtained from the 35 samples analysed show that
the most important consumed species in the settlement
were mussels (Mytilidae) (92.4% of the
total MNI); limpets (Nacella (P.) magellanica,
Nacella (P.) deaurata) (5%) and whelks: Trophon
geversianus (0.3%) and Acanthina monodon
(2.3%) (Verdún 2006).
Thinking about the results obtained from the
inferential statistic and those obtained from the calculation
of the valves density in the sediment, we
can observe a clear difference on the location of
the stratigraphic subunits in the site in relation to its
composition. To explain this phenomenon we have
two possibilities. They can be due to taphonomic
factors or to social activities.
Related to taphonomic factors we could think
that inside the hut, where the site is busier, actions
like trampling could have caused a high level of
fracture in molluscs. This could explain the loss of
molluscs in this area compared to the area outside
the hut. Nevertheless, this explanation was rejected
for two reasons: the first one is that, in this
case, we should record a high level of calcium carbonate
inside the hut but it is not like this. The
second reason is that activities such as butchering
were recorded out of the hut (Estévez and
Clemente unpublished). This supports the idea
that the area out of the hut is also busy; therefore it
must be affected by trampling too.
Taking this data into consideration it is empirically
proved by statistic analysis that the differences
in the matrix composition constitute evidence
of the management and differential use of space
in Yamana society. Those differences are materialized
in the valves, pebbles and soil content in
every stratigraphic subunit and, on the other
hand, can also be evidence of the carrying out of
activities related with it, such as setting up and
maintenance.
On the other hand, the valves and residue
accumulation around the hut can have a double
function, as some reports suggest. Some ethnographic
testimonies report the use of the valves as
a constructive element and also as a protection
against the wind. The presence of residues, valves
and others, around the hut is described by some
authors such as C. Wilkes (1844), G. P. Despard
(1859, 1863), P. Hyades (1885), L. F. Martial
(1888), R. Dabbene (1911) (references cited in
Orquera and Piana 1989-1990; Orquera and Piana
1999). Moreover some of them suggested that this
is a skirting board against the wind (L. F. Martial
1888; L. Bridges 1947; P. Hyades and J. Deniker
1891; M. Gusinde 1937; G. P. Despard 1863) (references
cited in Orquera and Piana 1999) (Fig. 7).
Those data reinforce the hypothesis of the
space management and residue distribution while
adapting zones depending on the activities or
MUNIBE Suplemento - Gehigarria 31, 2010
S.C. Aranzadi. Z.E. Donostia/San Sebastián