Rit (Vísindafélag Íslendinga) - 01.07.1962, Page 61

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nevertheless some serious difficulties. The erosion of an ex-
tensive thick plate of the Young Reverse group into such a
remnant as existed when the Normal group was formed
seems extremely difficult to refer to the 100 m stage. Topo-
graphically, this part of the peninsula is likely to be of a si-
milar age as its eastern part and probably pre-tectonic. Thus
at least the entire Younger 300 m stage and possibly also the
Older 300 m stage are likely to be younger than the Young
sediments of the Búlandshöfði area. This question will be
further discussed when more insight has been gained by the
study of Southern Iceland.
It is quite clear that a large part of the southem strand-
plane was developed after formation of the normally magne-
tized group in Böðvarsholtshyma, in Rnararfjall, Hestur and
Kambsheiði. But just this impedes a clarification of the posi-
tion of this group here. Only in Böðvarsholtshyrna the Nor-
mal group extends down to the 160 m level; farther south
it reached possibly a deeper level. In the north, near Ólafs-
vík, the Normal group rests on marine sediments and on the
basement of Old rocks at quite a low level. Here it seems
most natural to assume that the Normal group rests on a low
strandplane and is younger than the 100 m stage. We can-
not, perhaps, fully exclude that this low position of the base
is due to later subsidence but it seems on the whole accept-
able that the level is practically undisturbed and that we are
concerned with the normal Pleistocene group NUX.
In the south the Normal group has then probably also
rested on this low terrace a few kilometres south of the pre-
sent escarpment. The front of Kambur shows a steep original
southwards fall of the lavas, perhaps because of the neigh-
bourhood of a lowland of the 100 m stage.
We are then led to the view that marine erosion during
the Pleistocene period of normal magnetism led to a wide
strandplane on the south side of the peninsula.
The subaerial erosion of the Normal group is on quite a
large scale. This is best seen around Fróðárheiði; Hestur