Árbók Hins íslenzka fornleifafélags - 01.01.1943, Page 65

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is the same as devastated Stöng and other farms in Þjórsárdalur.
7'hus ÞórarinsstaSir was devastated at the same time as the settlement in
Þjórsárdalnr.
In the soil profiles round Þórarinsstaðir a sharply marked strata of
charcoal, about 1 cm thick, was found between ash layers VI and Vlla.
Similarly deposited charcoal was found around tlie excavated farms in
Þjórsárdalur. Obviously this charcoal is the result of burning the birch
forest or brushwood in order to clear the land. The author thinks it proljable
that summer dairies were iocaled in Hrunamannaafréttur prior to its settle-
ment, and that around these summer dairies tlie brushwood was burnt in
order to improve tlie pasture.
In all measured soil profiles in Hrunamannaafréttur and in the northern
part of Ytri-Hreppur the soil layer between ash layers VI and Vlla consists
of clayish soil, which has grown very slowly in thickness and bears little
or no signs of wind accumulation. This indicates that during the first
ccnturies after the colonization of Iceland, the cover of vegetation extended
all the way north to Kjölur. After the deposition of the light pumice layer
the rate of deflation has rapidly increased. The resistance of the soil and
vegetation also liad been previously weakened by fire clearing and grazing.
The ruins of Laugar and Rógsliólar also were inspected by the author.
The ruin al Laugar is Imdly destroyed. Tbere are, however, indications
tiiat this farm was deserted at tlie same time and for the same reason
as Þórarinsstaðir. Tlie ruin at Rógshólar is still more completely
destroyed, the only remains being scattered stones from the walls.
\s no such stones could be found above layer VI it may be regarded as
nearly certain, tliat tliis farm never was inlialiited after tlie forma-
tion ol' layer VI. The author thus comes to the conclusion that the enlire
otd settlement in Ilrunamannaafréttur was devaslaled when the licjht piímice
layer VI fell, which means — provided the author is right about the age of
that layer — that it was devaslatecl by tlic eruption of Mt. Hekla in 1300 A. D.
Finally the author discusses professor Jón Steffensen’s opinion, based
c.n his study of the slceleton material from Skeljastaðir, that the settle-
nient in Þjórsárdalur was abandoned about the middle of tlie llth century
(a tlieory originally propounded by professor Ólafur Lárusson), not sudd-
enly, because of volcanism, but gradually, because of climatically unfavour-
alile years. The autlior finds, tliat altliough Steffeusen’s skeleton studies are
of great value, liis arguments regarding tlie fate of the Þjórsárdalur settle-
rcent are not tenable and cannot influence the conclusion, that the seltle-
rcenl was devastated by tlie Hekla eruption of 1300.
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