Archaeologia Islandica - 01.01.1998, Síða 137

Archaeological Sediments and Site Formation at Hofstaðir, Mývatn, NE-Iceland
lenses, some no more than 0.5 cm
thick, which were composed of either
tephra from the Landnám sequence,
peat ash or windblown silt, or are
mixed layers containing variable a-
mounts of silt, charcoal, ash and black
organic material. No two turves
contained the same lenses, indicating
that they had been of variable origin,
and that their history was probably
more complicated than that of wall or
roof collapse. Also, turves containing
such fine, variable layers have not been
found in any of the turf structures that
have been excavated on the site so far.
Five micromorphology samples (Pr.
1/1 -1/5; fig.l) were taken in the hopes
of determining whether they had first
been used as building materials, or
whether they had been freshly dug out
of the ground and thrown into the
threshold with the rest of the soil fill.
This interpretation may be difficult
but it will be aided by comparing
these samples to those from the intact
turf wall and the in situ Landnám
tephra sequence. If it proves to be
possible to detect features indicative of
exposure, weathering, shrinkage, and/
or loss of structural integrity prior to
burial, it may be interpreted that these
turves were used as building materials
in a house that has not yet been
excavated on the site, or at least that
they were stockpiled prior to their use
as fill in the doorway.
The uppermost micromorphology
sample in this sequence (Pr. 1/5) is
especially interesting because it con-
tains the boundary between the
doorway fill and the post-abandon-
ment layer of windblown silt that also
caps the turf wall. Because it is pos-
sible that the walls and roof were in-
tentionally dismantled in order to fill
in the structure, it will be interesting
to see if there is any evidence for the
intentional truncation of the doorway
fill at this time. It may be difficult to
interpret this, however, because the
upper surface of both the wall and the
fill will have been exposed, possibly
for some time, before the windblown
silt began to accumulate in sufficient
amounts to protect them from degra-
dation.
3) Floors of the Structure in Area D:
The turf structure in Area D had been
investigated by Daniel Bruun in 1908,
but the 1997 excavation revealed that
Bruun had not completely removed
the interior of the structure on its
north end. On either side of Bruun’s
north-south trench through the
structure, floor layers were found pre-
served in situ under post-abandon-
ment fill, which was composed of long
horizontal turves and soil. Once again,
the original floor surface was on the
undulating Hekla-3 tephra layer and
associated soil (silt loam; 5YR 3/4
dark reddish brown). At the time of
construction, these layers had been
reached by removing the overlying
soil, prehistoric tephra layers and the
ubiquitous C4, to a depth of 25-30cm
below the ground surface. Ten micro-
morphology samples were taken from
the floor layers in Area D, of which
seven include the original floor surface
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