Archaeologia Islandica - 01.01.1998, Blaðsíða 141

Archaeological Sediments and Site Formation at Hofstaðir, Mývatn, NE-Iceland
internal laminae. These fine layers
ranged in colour from 5YR3/3 and 3/4
dark reddish brown to 7.5YR 4/6
strong brown and seemed to contain
small white fibrous inclusions, but
field observations could not determine
the cause of its laminated appearance.
It is possible that this layer contains a
high proportion of decomposed grass.
In order to determine the precise com-
position of Context 51 and to interpret
its mode of deposition and any post-
depositional disturbances, it was tar-
geted for micromorphological analysis
(Pr. 2/1; Pr. 3/1, 3/2, 3/3, 3/5; Pr. 4/3;
figs. 1, 2 & 3), geochemistry analysis
(bulk sample no. 8) and archaeobotan-
ical analysis (by Garðar Guðmunds-
son). In addition, Pr. 2/2 is a very large
undisturbed block, which was taken
for the purpose of micro-excavation in
the laboratory. This combination of
techniques should allow us to de-
termine whether Context 51 re-
presents a change in the function of
the structure over time or the early
phases of abandonment. This layer was
in turn capped by the horizontal pieces
of turf and mixed soil that filled in the
structure after its abandonment. The
boundary between these phases will be
visible in six micromorphology sam-
ples (Pr. 2/1; Pr. 3/1, 3/2; Pr. 4/1-4/3;
figs. 1, 2 & 3). It may be possible to
interpret whether the turf fill is a
result of intentional collapse of the
roof or collapse due to neglect, if the
intentional collapse was done immedi-
ately following the abandonment of
the structure.
4) The Landnám Issue: Beneath the
western wall of the structure in Area
D, the so called Landnám tephra
sequence was preserved in situ. Bear-
ing in mind the important question of
the earliest phase of settlement at Hof-
staðir, and in Iceland in general, it was
decided to compare the soils immedi-
ately above and below the tephra, in
an effort to determine whether or not
there were any signs of disturbance in
the immediate vicinity prior to 871 ±2
A.D. Two micromorphology samples
were taken (Ref. 1/1 and Ref. 2/3;
fig.l) and two samples for geochem-
istry analysis were taken, one from
below the Landnám tephra (bulk
sample no. 11) and one from above it
(bulk sample no. 12). The impact of
humans on the natural soil sequence
can take many forms, including
changes in the structure of the soil
(certain activities can cause it to
become compacted and platy), and the
input of anthropogenic materials such
as fragments of charcoal and bone,
plant matter and animal excrement.
The latter two will decay, leaving only
recalcitrant compounds in the soil,
such as lipids, and phosphorus which
is readily retained in andisols. In addi-
tion, the translocation of clay down
the soil profile, which can be triggered
by disturbances in the upper A hori-
zon, may indicate that the surface of
the ground has been cleared of vegeta-
tion. At the moment there is con-
siderable debate about the strengths
and weaknesses of using these soil
characteristics to interpret the pres-
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