Rit (Vísindafélag Íslendinga) - 01.07.1962, Síða 150

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300 m valley stages although, as we have seen, other solu-
tions are possible. The question must here be left open but
the new possibility leads to a promising outlook.
Summarizing, we come to the conclusion that after N2 at
Hvalfjörður (which is probably identical with n2 of Hrepp-
ar) there followed a long denudation interval and we must
assume that this left a considerable gap in the paleomagne-
tic record.
Following this, we find two magnetic groups (Kjölur and
Súlur) which are older than the uplift period and the 300 m
valley stages. These rocks had probably a wide distribution.
In Hvalfjörður we have recognized the same Plateau groups
with vestiges of cold climate as in the Hreppar area, with
the exception that the correspondence to n4 is not yet certain.
It is interesting that N3 is very thin at Hvalfjörður and n3 is
mostly absent in Hreppar. This group would seem not to have
occurred generally.
The Ok area.
The group N2 of the Hvalfjörður area is especially pro-
minent on the north side of Hvalvatn, where it forms the
area Veggir with southeast dip of 2—3°. A little farther east,
at Kvígindisfell, it becomes nearly horizontal and now ex-
tends northeast until it is covered by the tuff-breccia masses
at the southern foot of the Langjökull socle. From its eastem-
most limit here to the western limit of n2 (Gullfoss group)
near Sandvatn there is a gap of about 30 km, occupied largely
by post-glacial lavas. There can hardly be any doubt, how-
ever, that N2 and n2 are the same group and it seems pro-
bable that it is found everywhere at a shallow depth below
post-glacial lavas and loose surface debris in the hidden zone.
We shall now study the lavas and tuff-breccias which rest
on N2 in Kvígindisfell and at the foot of Thórisjökull. Then
we consider sections on the north side of Ok where we can
once more study the Plateau Basalts and in some respects