Árbók Hins íslenzka fornleifafélags - 2015, Page 101

ÁRBÓK FORNLEIFAFÉLAGSINS100
huts belonged to two distinct phases which were dated by tephrochronology. The
first phase was dated between AD 940 and 1104 and the second between AD 1104
and 1300.
The main difference between the two huts was that the older one had a water
duct running through the building. The duct showed evidence of rebuilding
and maintenance over an extended period of time but no signs were found of
a similar setup in the later hut. Four relatively well-preserved furnace bottoms
were excavated within these buildings with evidence of repeated rebuilding and/
or repairing. There were two sets of furnaces, one on each side in both huts.
Additionally, one less distinct furnace was excavated in the older hut and three
possible furnace remains in the northern part of the later one. The better-preserved
furnace remains as well as the slag found at the site indicate a type of furnace with
a slag outlet, where the slag is tapped out of the furnace resulting in slabs with a
ropy top surface.
The slag heap showed the same phase division as the huts, with clear evidence
of a halt in production for quite a few decades around AD 1100. It is estimated that
three-quarters of the slag was produced in the 10th and 11th centuries and the rest
sometime in the 12th-13th centuries. The slag heap covered an area of 10x15 m
and was 120 cm high with a relatively f lat top. Its volume was cautiously estimated
to be between 60-70 m3. Sieving with 7 mm mesh indicated slag content of 12-
13%. A portion of the slag was smaller than 7 mm and the slag percentage therefore
somewhat higher. Estimations of yield are elusive but an attempt was made based
on the findings from Skógar and analysis of iron, slag and ore from nearby sites
(Espelund 2004a). In accordance with the given premises around 7200-9100 kg of
iron may have been produced at the site.
Test trenches and coring in the area revealed small traces of occupational debris
in and around the farm mound as early as the 10th century. Substantial occupation
was evident between the AD 1104 and AD 1477 tephra layers. Above that were
mixed layers due to 20th century disturbance. The earlier and more productive
phase of the iron production therefore predates signs of substantial occupation and
farming activity on site, while the later phase was shown to be situated within the
contemporary 12th-13th century home field of the farm.