Jökull - 01.12.1956, Síða 5

Fig. 2. Stóralda view-
ed from N.
Photo S. Thorarinsson
14 Sept. 1955.
probably formed by a glacier advance during
the first centuries of the Subatlantic Time
(Thorarinsson 1946, p. 260—261) Todtmann
has, in my opinion rightly, identified this mor-
aine in a thrust moraine (Stauchmoráne)
found beneath recent moraine cover in front of
SE Breidamerkurjökull (Todtmann 1936). In a
paper 1952 Todtmann regards this thrust
moraine as prehistoric. She mentions in the
same paper that she has found the 1362-tephra
on the moraine Stóralda in front of Svínafells-
jökull, which would mean that this moraine
also was prehistoric, ancl she says further about.
Ivvíárjökull that “vielleicht ist auch der Kern
der hohen Seitenmoránen von sehr hohem
Alter” (1952, p. 407). As the age of these
moraines and that of Stóralda is of great interest
from a climate historic point of view, I found
it necessary to try to fix their age more de-
finitely by means of tephrochronology, and
during a short stay in Öræfi in the autumn of
1955 I visited both Svínafellsjökull and Kvíár-
jökull for a further study, the result of which
I shall now relate.
SVÍNAFELLSJ ÖKULI,
AND SKAFTAFELLSJÖKULL
When travelling along the road from the
Svínafell farm in Öræfi towards the farm Skafta-
fell and having travelled ab. 1.5 km over the
sandur plain west of the river Svínafellsá, one
has on the right a plain patch of grassland
called Svínanes. Above this grassland rises a
curved higli moraine ridge and in front of it
there are some lower, í'lat concentric ridges.
This moraine complex as a whole is called Stór-
alda and I refer here to the innermost and
highest ridge as Stóralda proper. Its relative
height on the steep proximal side is 20 m, that
of the less steep distal side 16 m. The max.
absolute height of Stóralda proper is 115 m and
its length ab. 0.5 km. The ridges iir front, at
least six in number, are flat gravel ridges, 50—
80 m broad. These ridges are rather like the
flat folds in front of the thrust moraine formed
by the sudden advance of Eyjabakkajökull
in 1890 (Thorarinsson 1938, fig. 2). Whether
the ridges in front of Stóralda proper are also
folded by a rapidly advancing glacier (cf. Helga-
son 1935, p. 15) or possibly formed as “Scher-
fláchen” moraines has to be decided definitely
by more detailed studies. The Stóralda proper,
however, gives the impression of being a thrust
moraine (cf. Todtmann 1952, Hoppe 1953).
Information on the oscillations of Skaftafells-
jökull and Svínafellsjökull until Eythórsson
started measurements of their frontal variations
in 1932 has been collected by Bárdarson (1936,
p. 2) and supplemented by Thorarinsson (1943,
pp. 32—33). It seems likely, from information
I have got in Öræfi, that these glaciers have
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