Rit (Vísindafélag Íslendinga) - 01.07.1962, Page 170

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Cardium Groenlandicum zone as defined by Bárðarson (1925).
It seems to me that a somewhat greater age is more likely,
for the following reasons.
The Cardium Groenlandicum zone is characterized by the
invasion of a great number of northern forms which seems
to mark a definite step towards the Pleistocene, if, by defini-
tion, this invasion is not even taken as the beginning of the
Pleistocene (Einarsson 1959 a, Áskelsson 1960). But of the 45
species in the C. Gr. zone which do not occur below this zone
in Tjörnes only 3 or 4 occur in the Skammidalur fauna.
Whereas in the C. Gr. zone this new fauna is % of the total
in the zone, it is only !/10 iii Skammidalur; and in this small
percentage none of the typically northern species occurs.
This seems to indicate rather clearly that the northern in-
vasion is later than the Skammidalur fauna. This fauna can
therefore with good reasons be considered as Pliocene.
Eyjafjöll. Vestiges of the 300 m base level have mostly been
destroyed in this area, only on Steinafjall they are clear. On
the east and west sides of this 810 m high mountain there are
deep valleys, partly coalescing on its north side, which isolate
the mountain so well that its south facing surface has been
very largely, if not completely sheltered from main glaciers.
On this surface there are two valleys, rather smoothly graded
to a nearly 300 m base level. Here weathering and frost ac-
tion have very severely broken up the surface and it seems
practically certain that the valleys were unglaciated during
the last (Wurm) glaciation. Clear signs of older glaciations
are not seen. This place can be considered as a refugium and
in accordance with this I found the relict Helix hortensis in
the steep slope in front of the Varmahlíðardalur.
Vestmannaeyjar. In earlier papers on the geology of the
Westman Isles I considered the cluster of mountain on the
north part of Heimaey as an uplifted part of a more general
tuff-breccia layer. Later, I have ascertained that these moun-
tains are remnants of heavily destroyed craters. It is remark-
able that these mountains, one of them flat-topped, have