Perdigoes, Portugal
The co-called central area of the enclosure of Perdigoes consists
according to the test for cs-magnetometry (June 2009) of the following features
(see fig. 1b with numbers 1-16):
Remarks about a course
interpretation for the “central area”
1 The “black spot”, well visible in the first aerial photo
from the site after plugging as soil-mark
(oblique view from 199x). This is also visible in the magnetogram, but
more grayish with internal structures. Also in the magnetogram there is a rim
around the “black spot” partly visible with a positive magnetization contrast
(dark gray to black). This could be caused by a biogenic magnetization of a wooden
construction. The diameter is about 22 m.
2 A double palisade shown
as a positive magnetization contrast (also biogenic). The dark trace is less
than one meter wide. Well visible in the southern part, but also more
fragmented around the interior of the enclosure ditch (3). The double palisade
(2) is clearly cut by the “black spot” (1) in the SW part. The double palisade
(2) is only visible outside of the “black spot” on both sides.
3 The enclosure ditch
(3) has a width of about 2–3 m; on the NE side the ditch is straight over a
length of 50 m (on this side is also the strongest magnetization contrast and
the greatest width). The double palisade follows the trace of ditch (3) on the
interior side. At the northern end of the linear part there is an entrance
(interruption of the ditch).
4 Another enclosure ditch (4) with a “bastion like” shape is
also almost linear on the SE side like ditch (3) – the ditches (3) and (4) are
forming a passage like feature (a cursus?). At the end of this linear segment (NE)
there is an interruption in the ditch that could mark an entrance. The ditch
(4) is 3 to nearly 5 m wide (at the northern side) and has a very strong
positive magnetic contrast, which mabe caused again by a burnt filling. This
also causes a strong magnetic “shadow” to the north (white band). In some of
the so-called bastions little circles are visible (positive magnetic contrast)
with an diameter of about 5 m – possibly little round houses.
5 Another enclosure ditch
(5) was found almost at the same distance than (3) to (4) on the north side,
but the main part may be outside of the measured area. This ditch is about 3 m
wide and has no bastions. Possibly this ditch (5) also belongs to the central
enclosure, but further measurements are need to mapping the full extend. The
ditch (5) ends on the NE side, but there are some pits, which could also belong
to this ditch system (5).
X1 There is a big number of
pits all over the place and also in the central area. But in the central area
the distribution of pits is less compared with the “pit-belt” between ditch (9)
and (11). Some of the bigger pits in the central area are marked in fig. 1.
About 20 m west from the “black spot” (1) there is another positive magnetic
anomaly with an magnetic shadow going round, which could be a congregation of
pits or a underground structure made from magnetic stone (slate or shists?).
The size of this structure is about 8 x 8m.
Conclusions:
The
“black spot” (1) certainly does not belong to the other enclosures in the
central area. It cuts the double palisade (2) and must be therefore later. Also
the location hard at the side of ditch (3) is an argument against the “black
spot” as the central feature. It could be much younger or even modern (small
water basin).
The
planned trench in the central area for the excavation in summer 2009 is mainly
set on this “black spot”. Therefore it would fail the verification of the
double palisade (2). It would be more adequate to shifting the trench about 15
m to the SE (the exact measure should be taken from the AutoCad map). Then it
would be possible to see the ditch (3), the double palisade (2) and a smaller
section of the “black spot”.
