Fróðskaparrit - 01.01.1971, Síða 18

26
Magnetic Anomalies Around The Faeroe Islands
end, and this fact might give rise to a discussion of the connec-
tion of the geological main profile. The course of the A-hori-
zon, combined with the strike and dip measurements on land,
indicates that the deepest part of the lower series should be
exposed west of the town Vágur, and not at the southern end
of Suðuroy as usually assumed.
The profiles crossing the A-horizon in the north do not have
the same good resemblanoe to the calculated curve (Plate 1 and
Fig. 3). This may be explained partly by thickness variations
of the different polarization zones and partly by oblique
crossings.
Geological Theories
The course of the A-horizon around the islands shows (Fig.
1) that besides the general eastward dip of the layers the
most prominent tectonical features are two dome-structures,
one with its center north of Mykines and a smaller one, of
which Suðuroy is the eastern half. There seems to be a good
correlation between the course of the A-horizon and the isogals
of the Bouguer anomaly map published by Saxov (1969); a
similar correlation between Bouguer anomalies and the C-hori-
zon has been demonstrated earlier (Noe-Nygaard 1966).
A gravimetric survey in the waters between the Faeroe
Island and Iceland has recently been performed by Deutsches
Hydrographisches Institut and the results are going to be
published in the near future (Fleischer 1971).
From a preliminary gravity anomaly map, which Dr.
Fleischer kindly has put at my disposal, it seems that the
general level of Bouguer anomalies around the Faeroe Islands
is 40 mGal, and further it is seen that the big minimum over
the northern islands (Saxov 1969) has its lowest value, — 15
mGal, about 15 km north of Mykines.
While only land measurements were available it was thought
that the gravity gradient in the eastern part of the islands was
regional and that the local minimum on the north western
islands was about — 7 mGal, only. The sea measurements