A geophysical study of the Atlantis-Meteor seamount complex

The depth of the ocean floor in general increases systematically
with increasing crustal age (e.g. Sclater and Francheteau, 1970;
Parsons and Sclater, 1977). This increase of depth further away from a
mid-ocean ridge crest can be explained by thermal models for the
evolution of the oceanic lithosphere. There are, however, large portions
of oceanfloor whose depth deviate from the predicted depth-age
relation (depth anomalies, Menard, 1973). Cochran and Talwani (1977)
examined depth anomalies throughout the world's oceans and noticed a
relation between "the intermediate wavelength positive features (both
gravity and depth) and areas of extensive off-ridge volcanism (c.f.
Menard, 1973; Anderson et aI, 1973; Sclater et aI, 1975). The
volcanism which is not associated with plate margin processes is
called intra-plate volcanism (Turcotte and Oxburgh, 1978).
The Atlantis-Meteor seamount group forms a large volcanic complex
in the central North Atlantic ocean, situated some 700 km south of the
Azores. The whole area around this complex is too
shallow in terms of the depth-age curve and constitutes a positive
depth anomaly. It actually forms the most southern part of the North
Atlantic Gravity High (Cochran and Talwani, 1978), which extends from
Iceland to about 300 N and which comprises areas of different plate
tectonic setting. The study of Cochran and Talwani (1978) was based
upon 1°*1° averages. In the area around the Atlantis-Meteor complex
there was not enough gravity data to calculate 1°*1° averages (see
Cochran and Talwani, 1978)