Archaeologia Islandica - 01.01.2002, Blaðsíða 24

Timothy J. Horsley & Stephen J. Dockrill
susceptibility. (594 compared to a back-
ground value of 170 xl0"8m3kg"').
Linear anomalies, composed of many
discrete magnetic dipoles and running
along and parallel to the southem edge of
the survey area, coincide with the stone-
lined sunken lane in this area, and are
therefore interpreted as the responses to
individual rocks used in its construction.
Earth resistance results
The earth resistance survey has been very
successful, clearly locating a great num-
ber of linear high resistance anomalies
interpreted as being due to the buried
stone foundations for a great number of
buildings.
The results, presented in Figure 5,
clearly show a wealth of archaeological
detail in this small 60m x 60m area. A
large number of rectilinear anomalies are
visible, the majority of which are inter-
preted as the responses to buried structur-
al remains. Other less intense anomalies
may be due to compacted floor features
or paths
The mound on which the Cathedral
sits is seen as an area of higher resist-
ance, probably indicating its compacted
nature, yet there are anomalies visible
within it, which might be due to its con-
struction. (The intense linear anomaly is
due to the re-roofed tunnel, the top of
which is only a few centimeters below
the surface.)
The southern survey grids are also of
a higher resistance, coinciding with the
area of long grass, although it is not clear
if this is related in any way.
A full and detailed archaeological
interpretation will be included in the
forthcoming geophysics report for
Skálholt.
While these results can be compared
directly with the site plan of 1784 (Fig.
3), it should be remembered that the geo-
physical techniques are not detecting a
single phase, as represented in the map.
The survey results will detect all the
physical contrasts in the soil within the
limitations of the technique, which may
be due to many archaeological phases.
However, comparison with the plan does
reveal a remarkable correlation between
the buildings and the high resistance
anomalies, although on a slightly differ-
ent orientation to that implied by the
plan.
Geophysical surveys at Skálholt have
demonstrated that these techniques are
very successfu! in detecting buried fea-
tures at the site, for which there is no sur-
face evidence. It appears that intense
geological and geomorphological effects
seen at many of the other sites in Iceland
are less dominating here, allowing the
more subtle archaeological anomalies to
be identified.
Interpreted on their own, the earth
resistance data reveals a number of
anomalies typical of stone wall founda-
tions, and when combined with the docu-
mentary evidence for the approximate
location of farm buildings, this interpre-
tation can be confírmed.
The results of the fluxgate gradiome-
ter are less clear, however a number of
magnetic anomalies have been detected
which are attributed to archaeological
sources. Not only does an area of mag-
netic noise roughly coincide with the
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