Árbók Hins íslenzka fornleifafélags - 01.01.1943, Page 64

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A map showing the distribution and thickness of tlie light coloured,
rhyolitic ash layer which destroyed the settlement indicated that tliis asli
layer also would he rather thick in Hrunamannaafréttur. Tlie author, there-
fore, made a trip to that district in June 1945 in order to determine the
position of this ash layer in relation to the farm ruins there and found
that the farm ruin Þórarinsstaðir was partly filled by a light pumice layer
and was well preserved. In August that suminer tlie ruin was excavated by
Mr. Kristján Eldjárn, and the author tlien again visited Hrunamannaafréttur
and measured some sections at Þórarinsstaðir.
The old settlement on Hrunamannaafréttur is situated on the highland
piane east of Hvítá (cf. map fig 1), 15—20 km north of Tungufell, the
northernmost farm now existing in Ytri-Hreppur, and 270—350 m above
sca level. From old references one may conclude, that at least 5 farms have
been located in Hrunamannaafréttur in olden days, namely Þórarinsstaðir,
i.augar, Mörþúfur, Stangarnes and Rógshólar. From ecclesiastical deeds
(,,máldagar“) we know, that tlie settlement must have been abandoned lie-
fore the end of the 14th century. Two different traditions concerning the
íate of the settlement have survived. According to one it was deserted he-
cause of a plague; according to tlie otlier it was devastated hy an eruption
of Mt. Hekla.
Fig. 2 shows 4 soil profiles witli asli layers. Layers I and IV in
these profiles are from the Katla eruption 1918 and 1721 respectively,
layers II, III and V from the Hekla eruptions 1845, 176G/68 and 1693. The
eruptions 1766/68 and 1693 caused a great damage on many farms in tlie
Hreppar districts. Fig. 3 shows a profile on the liomefield at Tungufell,
where V is the light ash (pumice) layer VI, which devastated Þjórsárdalur.
The grayish-black ash layer VHa was formed shortly before the colonization
of Iceland, as lias ljeen shown by means of pollen analysis. Between it and
laver V is the light asli (puinice) layer VI, wliich devastated Þjórsárdalur.
The map in fig. 1 shows the distribution and thickness of the proximate part
of this ash layer, wliich proves, that the ash originated from Mt. Ilekla
proper. According to the author’s investigations in northern Iceland
during the past summers, the dispersal of tliis ash in northern Iceland
is not in accordance with that shown on his and Bjarnason’s map. The asli
layer is tliickest in the Skagafjörður district, which agrees very well with
statements made in the annals ahout tlie Hekla eruption of 1300.
Fig. 4 shows some sections from Þórarinsstaðir. The floors of the farm,
prior to any accumulation of soil, were immediately covered by a layer
(d’ light-coloured pumice of quite varying thickness. Flag-slones from
tlie roof rested upon this layer. In the soil profiles round Þórarinsstaðir
the corresponding pumice layer is 12 cm tliick and douhtless lias been at
least 20 cm thick when freshly fallen. Tlie sections from Þórarinsstaðir and
ihe thickness distribution of the pumice in tlie rooms prove, that the roofs
were still standing when the pumice fell and that the farm must have been
abandoned immediately after tlie pumice-fall. Thus it is certain, that the
farm Þórarinsstaðir was devastated by pumice-fall. Furthermore tlie soil
profiles prove, that the light pumice that devastated Þórarinsstaðir