Rit (Vísindafélag Íslendinga) - 01.07.1962, Page 148

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Fig. 77. Breccia cap on Skálafell.
S = Stardalshnúkur.
figure is in part perspective). The section around (x) is
shown in Fig. 78. At 620 m is an erosion surface cutting the
tuff (t) and the intrusive basalt (b). On this rests a coarse
weathering debris from the intrusive basalt (b). This is part
of a thick mostly finer sediment (s) in which one lava flow
(1) occurs. On a new erosion surface rests the tillite m, finally
covered by reversely polarized breccia cap (B).
Fig. 78. Section in Skálafell.
Explanation in the text.
Kjölur has a quite similar cap of reverse breccia above
about 650 m, and although lower rocks have a regional dip
of about 5°, and even 10—12° on the south side between
Hækingsdalur and Stíflisdalur, the cap is horizontal as far as
can be seen. But the contact is not well exposed. It is probable
that by a fault an easternmost part dropped by about 150 m.
At any rate it seems to be the same breccia that here rests on
a surface at about 500 m on the south side of Búrfellsdalur.
Súlur. The main tuff-breccia of Súlur may conveniently
be reconsidered here. We have seen that it is an erosional
remnant of an extensive layer, older than the valley topo-
graphy at Hvalfjörður. It seemed possible that this layer is
a topmost member of the Plateau and thus older than the