Rit (Vísindafélag Íslendinga) - 01.06.1967, Page 111

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Öræfajökull to Snæfellsnes would be more or less similar to
the profiles of the Reylcjanes Ridge southwest of Iceland. One
would expect at least 4 strong positive anomalies of Rrunhes
age, i.e. over Öræfajökull, the Laki—Veidivötn area, the Laug-
ardalur—Thingvellir area and the crest of the Snæfellsnes
peninsula.
According to this hypothesis it would he impossihle to cor-
relate the magnetic anomalies of the Reykjanes Ridge with
the geomagnetic time scale, and some few hundred meters
of the surficial rocks of the ridge, which have heen produced
during the two last geomagnetic-epochs (including the two
normal geomagnetic events of the Matuyama), could cause
the magnetic anomalies. The regularity of the magnetic ano-
malies on the Reykjanes Ridge would then be a coincidence
only and not a proof of spreading ocean floor.
In this connection I would like to point out that in my
opinion the magnetic anomalies in Ljósavatnsskard provide
a good example of magnetic anomalies caused by a dipping
lava succession as Ljósavatnsskard is at the edge of the so-
called “central graben” where the basalt series have been
flexed and dip now between 10 and 30°.
References: See paper by G. Gudmundssori.
Th. Sigurgeirsson:
The evidence given in Vine’s paper (Vine 1966) seems
to indicate that profiles of magnetic field intensity across
ocean ridges can be transformed mathematically one into an-
other with a transformation which only depends on orienta-
tion of the geomagnetic field relative to the ridge and one
or two parameters characteristic for each ridge system. If
this turns out to be applicable in general, even for ridge
systems located on opposide sides of the earth, I think it is
very difficult to account for it without using the universal
reversals of the geomagnetic field as a basis for the explana-
tion. I am therefore inclined to consider the Vine and Mat-