(Table 1) Permanent currents in the Campeche Bank area based on data of 24-hour stations

Data of twenty buoy stations were used to compile a new chart of permanent currents in the surface layer (10 m depth) for the region of the Yucatan shelf (Campeche Bank). It was found that vertical variations in direction of the currents are insignificant within the shallow plateau of the banks.

Composition of bottom sediments from the Campeche Bank

A complete section of an unconsolidated sedimentary sequence about 5 m thick was sampled in the western margin of the Campeche Bank with use of gravity cores. The sequence forms a flat sea bottom at depth of 51-53 m and rests on a consolidated basement composed of coral limestones and carbonate sandstones. Initiation of deposition of unconsolidated sediments in this area is related to a sea transgression caused by sea level rise that followed the Würm glaciation stage about 10-11 ky ago. Analysis of grain size and chemical compositions of sediments and study of biogenic carbonate remains made it possible to outline environmental changes in this region during the last 10 ky.

Magnetic and gravity measurements on North-South profiles across the Grosse Meteor Bank, North Atlantic

During the first section of the "Meteor" cruise No. 2 a profile was run from the Azores to the south across the flanks of the Mid-Atlantic Ridge with a chain of seamounts. The profile extended between the Cruiser (living) and the Hyeres seamounts, which, according to our soundings, form a connected massif, and across the centre of the Grosse Meteor Bank (30°N, 28.5 °W). These seamounts rise from a depth of more than 4000 m up till close to the surface of the sea forming there a large almost flat plateau. In the case of the Grosse Meteor Bank, this plateau has a N-S extension of approx. 30 nautical miles and an E-W extension of approx. 20 nautical miles and reaches a height of 275 m in water depth. The gravity measurements yielded a density of the topographic masses of 2.6 g/cm**3 for the Grosse Meteor Bank. Magnitude and shape of the measured free-air anomaly are very well shown in a model computation with this density. The theoretical gravity effects of the seismically detected swell of cristalline rock and of the Moho depression (mountain root) are not indicated by the observational data. It can, therefore, be assumed that the latter two neutralize each other. It seems, accordingly, that there is no local isostatic compensation of the topographic masses. Hence, the density of 2.6 g/cm**3 obtained would be about the true density of rock. In connection with the mean velocity of P waves (Aric et al., 1968) obtained by seismic refraction methods it must be concluded that the material of the 1200-4000 m thick surface layer of the Grosse Meteor Bank consists of consolidated sediments. This finding is supported by the total intensity of the Earth's magnetic field over the Grosse Meteor Bank. On the assumption of a homogeneous magnetization in the direction of the present Earth's field, the computed anomaly of the massif deviates considerably from the measured anomaly while the magnetic field of the seismically detected crystalline body is capable of interpreting the observed data. Deviating from the prevailing interpretation of the seamounts' plateau as a volcanic cone with submarine abrasion, the Grosse Meteor Bank and the seamounts in the vicinity are assumed to be of continental origin. The questions whether these seamounts submerged later on or whether the sealevel has risen subsequently are, therefore, largely nonexistent.