Jökull - 01.12.1964, Blaðsíða 12

Fig. 6. Section Cf 16a on Kringilsárrani. Visible
length of ruler 95 cm.
Photo: S. Thorarinsson, Sept. 4, 1962.
THE THORLÁKSMÝRAR STAGE
Todtmann has described old-looking end
moraines between Saudá ancl Kringilsá about
2.5 km north of the 1890-moraines. She re-
gards these moraines as corresponding to old
terminal moraines in front of some of the
southern outlets of Vatnajökull—Öræfajökull,
such as Stóralda in front of Svínal'ellsjökull
(Todtmann 1960, pp. 47—49). The Stóralda
moraine is regarded both by Todtmann and
myself as early Subboreal. Having proved de-
finitely that the “hraukar” on Kringilsárrani
mark the maximum extension of Brúarjökull
in that area since the recession of the Wiirm
ice I found it unlikely that any subboreal ad-
vance could have brought the margin of the
glacier between lvringilsá and Saudá as far
north as to the Thorláksmýrar moraines. In
order to get some tephrochronological evidence
pro or contra Todtmann’s opinion I walked
over the ridge south of Saudafellsalda Sept.
5th, 1962, and dug a hole in a grass-covered
loessial soil-spot sliort east of Saudá, about
300 m north of the 1890 moraines (Cf 13
on fig. 1). I found Ö 1362 at 70 cm depth and
loessial soil below to more than 1.4 m depth.
Altliough I could not study the profile beneath
Ö 1362 in detail, and dicl not notice layers
H3 and H4, I felt rather certain that this soil
profile represented more than 3000 years of soil
formation.
July 21st, 1964, I dug a section on the west-
ern bank of Saudá, 130 m in front of the
“hraukar”. There I found, besides Ö 1362, both
H 1104 and H4. As H4 dates back to the first
half of the Subboreal Time it is definitely prov-
ed that the Thorláksmýrar stage cannot be suL
atlantic. It certainly goes back to the time of
the Wúrm ice recession.
Summing up we fincl that the series of ter-
minal, mainly thrust moraines and partly vege-
tation coverecl “hraukar”, which stretches from
Kverká to Maríutungur, was formed by two
catastrophic advances of Brúarjökull, in 1810
and 1890. In most places, but not everywhere,
the 1890 advance brought the ice margin some-
what farther than the 1810 advance, but on the
whole there seems to have been small difference
between the position of the ice margin after
those two advances. By these advances Brúar-
jökull reaches its maximum extension since the
withdrawal of the Wúrm ice.
THE TERMINAL MORAINES
OF HÁLSAJ ÖKULL
In July 1964 I pardcipatecl in the Iceland
Glaciological Society expedition to Brúarjökull.
Towards the end of this expedition we spent a
few days, July 24th—27th, in the surroundings
of the extinct cone volcano Snæfell, the highest
mountain in Iceland outside Vatnajökúll, 1833
m. The morphology of Snæíell and the state
of its glaciers has been described by J. N. Jen-
nings (1952), who surveyed this mountain in
1937 when participating in an expedition led
by W. V. Lewis. On the mountain there are
four true glaciers (fig. 7), three of which are
on the W side, one on the ENE side. All these
glaciers are without a name, but the glacier
on the ENE side (Cf. fig. 8) I have given the
name Hálsajökull. From Jennings (op cit., p.
Fig. 7. J. N. Jennings’ map of Snæfell. The glaciers are designated by block letters. A is
Hálsajökull. Addecl to the map by the author is the old terminal moraine in front of Hálsa-
jökull to which the short arrow points.
70
JOKULL 1964