Rit (Vísindafélag Íslendinga) - 01.07.1962, Side 161

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Hreppar that the group n2 is separated by an angular un-
conformity from the lower groups that contain vestiges of
cold climate. This suggests that here must be a gap in the
paleomagnetic record.
Further, it seems likely that the Young rocks in Middle
Northern Iceland do not correspond to such a deep and tilt-
ed group as n4 in the Ok or Hreppar areas. Rather, they
would correspond to a later period enclosing n2 (N2).
It is striking that between the Valagil normal group, with
its cold climate vestiges, and the deeper groups containing
Lower Tertiary lignite (cf. Einarsson 1957) there is no an-
gular unconformity, nor other unconformity as far as is
known. Also in Skorradalur, which has not been described
in this paper, one comes to the same conclusion. There the
lowest cold climate groups dip 10° SE. Only in the Esja moun-
tain one finds a clear sign of erosion at the base of R3. This
suggests that the vestiges of cold climate range far back into
the Tertiary. The lignite at Sleggjulælkur is considered as
Oligocene by Pflug (1959). Between this and n4 in the Ok
area are found 9 magnetic groups (cf. Einarsson 1957) with
a total thickness of about 2500 m. On this basis it would seem
likely that n4 is not younger than Miocene. For lack of suit-
able fossils this important question of the age of the oldest
cold climate vestiges in Iceland cannot be settled before abso-
lute dating has been undertaken.
Further studies of erosion-levels.
We shall now extend our studies of erosion-levels beyond
the areas considered in Chapters I and II.
1. The strandplane.
Leaving the Snæfellsnes peninsula we come to the exten-
sive erosion plane of the Mýrar and Borgarfjörður area, cut
into dipping Plateau basalts. It is of similar dimensions as
the Breiðafjörður plane and we can also apply quite similar
arguments to explain it, namely that it is mainly the work of