Jökull - 01.12.1982, Page 9

in the Reykjavík area show an ice movement from
the south-southeast, while in the Akranes area they
are oriented from the northeast.
Another conclusion, once again based on much
experience from Scandinavia and exemplified by
the situation on Grímsey, is that in coastal areas
with irregular topography both above and below
sea level the direction of the receding ice front and
thereby also of the glacial striae changed contin-
uously. This is the reason why double sets of striae
appear now and then. VVell known examples are
from Arbaer on the outskirts of Reykjavík and from
the surroundings of Borgarnes.
BREIDAFJÖRDUR (Fig. 5)
Thoroddsen (1906, p. 327) having observed traces
of glaciation both on the northern side of Snaefells-
nes and on the southern side of the Vestfirdir pen-
insula as well as in the innermost tributary fjords to
Breidaljördur (Hvammsfjördur and Gilsfjördur),
considered it „very interesting to know if the islands
tn Breidaljördur south of Bardastrandarsýsla were
glacially striated and, ifso, what was the direction of
the striae“. He mentions that these islands never
had been visited by geologists.
Kjartansson (1955) states that he had great difli-
culty in finding glacial striae on the islands of
Breidafjördur, because ofwave abrasion which has
attacked all the islands, forming a beautiful strand-
flat. However, he made a few observations of striae
on Látralönd and Skáleyar, showing ice movements
from northeasterly directions.
I was able to visit some of the outer islands of
Breidafjörduron June 29—30, 1973. OnHeigilsey a
bedrock surface was uncovered from under 0.5 m of
humus and pebbles. It did not show any clear striae
but was most probably affected by glacial activity,
as the outcrop exhibited a stoss side to the north-
northeast and a small crescentic gouge was present.
On the eastern part of Flatey I found two sites with
bedrock surfaces bearing definite glacial striae from
the east-northeast; both sites were covered by a thin
mantle of till. In the Svefneyar complex of islands I
found well preserved glacial striae, coarse and thin,
at several sheltered places about 2 km northeast of
the farm. They showed ice movements from the
northeast and east-northeast.
These observations show that the ice sheet reach-
ed far into theopen sea. In this connection reference
should be made to a paper dealing with the same
problent. In a B.S. thesis at the University of Ice-
land Olajsdóttir (1974) demonstrated the existence
of a long ridge, 25 to 30 m high and 800 m wide,
situated outside of Breidafjördur and 140 km west of
Snaefellsnes at a depth of 250 m. She believed this
ridge to be an end moraine showing the outermost
position of the ice sheet front during the VVeichsel or
Saale glacial period.
VESTFIRDIR (Fig. 5)
Thoroddsen (1906) observed numerous traces ofan
inland ice sheet over Vestfirdir, which he believed
was separate from the main ice sheet of Iceland,
although the two ice sheets were believed to be in
contact at Gilsfjördur— Bitrufjördur. From the inn-
er part of the peninsula outlet glaciers extended
down the valleys and into the fjords. How far they
extended was an open question tohim. Between the
Fig. 6. Drumlinized till plateau, at
Keflavík, Vestfirdir.
Mynd 6. Oldóttur hjalli úr j'ókul-
ruðningi í Kejlavík á Vestjjórbum.
JÖKULL 32. ÁR 7