Archaeologia Islandica - 01.01.2002, Blaðsíða 30

Timothy J. Horsley & Stephen J. Dockrill
Figure 7 reveals that many of these
anomalies have a regular form, with
some linear and rectilinear features visi-
ble. These are interpreted as being the
responses to buried stone foundations for
structures originally in these locations.
As stated above, one of the aims of
the surveys in this area was to locate any
features associated with a church, and
this has been achieved. A high resistance
anomaly has been detected to the east of
the main cluster, and in the area where
the church was expected. Almost rectilin-
ear, this anomaly could be structural in
origin, but with anomalies only detected
on three of the four sides. Although ori-
ented east-west and about 6m x 4m, on
its own this rather amorphous anomaly
cannot be confidently identifíed as a
church. However this anomaly is seen to
be situated at the centre of a circular
anomaly of low resistance, about 30m in
diameter. This ring of low resistance
might be due to an infilled boundary
ditch or bank, and is consistent with a
medieval Icelandic church. This was later
confirmed by excavation when a number
of graves were discovered within the area
(Gestsdóttir 1999, 44). It does not appear
that either method has detected these
graves.
A very subtle positive linear anomaly
can be made out in the northeastem cor-
ner of the survey area, and might be due
to the buried remains of a bank, possibly
a field boundary.
Two linear low resistance anomalies
have been detected to the west of the
track, which could be interpreted as
infilled ditches. However, these coincide
with the positions of the ferrous pipe
anomalies seen in the gradiometer sur-
vey, and can be positively identified as
the response to these modern pipe trench-
es.
Within the survey area to the east of
the track, a number of linear high and
low resistance stripes are visible. These
are real anomalies, not survey defects,
and can be seen to be on a slightly differ-
ent orientation to the survey grid. During
the data collection, a number of linear
depressions were noticed on the farm
mound, probably be caused by tread
marks of a bulldozer employed to level
buildings on the farm in the 1970s. These
would certainly produce anomalies like
those detected.
When the results of both geophysical
surveys over the farm mound are com-
pared, it can be seen that the gradiometer
survey has successfully detected the
church anomaly as one of the areas of
intense dipole anomalies. Other anom-
alous areas can then also be confidently
interpreted as being due to buried struc-
tural remains, as they too coincide with
areas of high resistance.
Geophysical surveys within the farm
of Hofstaðir have proved successful not
only for the detection of anomalies, but
also for the interpretation and assessment
of buried remains at the site, therefore
improving the archaeological under-
standing of the site.
Anomalies detected during the earth
resistance surveys and subsequently con-
firmed by excavation indicate that this
technique has the potential to Iocate and
identify cut features into sediments, in
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