Rit (Vísindafélag Íslendinga) - 01.06.1967, Page 80
76
Geoloqical formgtions
(J Rasmussen,l963)
Upper bosolt sequence,
upper zone
Upper bosalt sequence,
lower zone
Cool - bearing series
Lower basolt sequence
Unknown
Fig. 7. Correlation of P-wave velocities and geological formations
in the Faeroe Islands. (Pálmason, 1965).
There is no evidence, similar to what is given here for
layers 0, 1 and 2, to indicate a stratigraphic interpretation
of the boundarv between layers 2 and 3. This is simply be-
cause layer 3 has not been found at the surface anywhere.
If, however, a stratigraphic interpretation is accepted for the
1—2 boundary, there appears to be no difficulty in accepting
the 2—3 boundary also as a stratigraphic horizon, although
the nature of layer 3 still remains largely unknown. This
layer is found at depths varying between about 1.5 km and
about 4.5 km, and direct pressure effects are therefore not
likely to be very important in bringing about the increase
in velocity. The velocities observed are usually in the range
6.0 to 6.7 km/sec, and there are indications that two diffe-
rent layers with average velocities 6.2 and 6.5 km/sec may
exist. The lower value is close to that which is commonly
found in the upper part of the continental crust, while the
higher value is closer to the value for the main oceanic layer.
It has been argued (Einarsson, 1965) that the seismic
boundaries cannot be interpreted as stratigraphic horizons
P velocity