Jökull - 01.01.2010, Page 155

Paleomagnetic observations in SW- and S-Iceland
Figure 4. Location of pro-
files in Stóra-Sauðafell and
its vicinity. A fault between
profiles KJ and KI (Sæ-
mundsson et al., 2010) is
shown. – Staðsetning sniða
í Stóra-Sauðafelli og um-
hverfis það í Kjósarskarði.
Figure 5. Stóra-Sauðafell
seen from road 48. Profile
KJ lies near the middle of
the photo and KI is to the
right of the shallow gully,
both beginning at the lowest
lava exposures. – Ljósmynd
af Stóra-Sauðafelli, snið KJ
er þar nálægt miðju og KI
til hægri.
The profile KP (Figures 4 and 6) begins at a sharp
bend in a stream west of the northern end of Stóra-
Sauðafell. The bottom flow KP 1 is well exposed but
highly cracked so that it was impossible to collect core
samples from it. However, fluxgate measurements in
the field gave a reversed polarity. The lithology of
this flow is characteristic of andesite although no such
rocks are shown at that locality in the geological map
by Sæmundsson et al. (2010). Some of the other flows
in profile KP have textures reminiscent of quartz-rich
tholeiite or even andesite. The top lava which is the
only normally magnetized unit in the profile, presum-
ably correlates with the normal-polarity series KJ 10A
to 16. Successive directions are in some cases seen to
be very similar, especially in KP 4–5 and 10–13.
Another two profiles KO and KN were sampled in
the hill Stóröxl across the Laxá river (Figures 4 and
6). The lower slopes of this hill are largely covered by
gravel with occasional exposures including acid tuff
and the acid or intermediate lavas KO 2A (where only
one reversely magnetized core sample was collected)
and KO 2B. It is likely to belong to the same volcanic
phase as KP 1. A layer of coarse tuff is encountered
at 265 m altitude underneath profile KN. On top of
the tuff there are several lava flows, the lowest one
petering out towards the north. Six were sampled in
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