166 



WORZEL AND HARRISON 



[chap. 9 



of Cruiser Bank. Some seismic data (Bentley et al., iinpiil)lislied) exist on the 

 seamount and in the nearby flanking regions to provide control on the upper 

 parts of the sections. A two-dimensional analysis was used to compute the 

 variations of the M-discontinuity which would be required to accoinit for the 

 gravity anomaly (Worzel and Talwani, 1959a). Fig. 24 shows the resulting 

 section. Since this feature is not perfectly represented by a two-dimensional 





Observed grovity 



Topography 



-2.3km/sec;2.lg/cm' 

 ^3.6 km/sec; 2.5g/cm' 



r4.6km/sec; 2.5g/cm' 



Vertieol exoggerotion 20:1 



2^0 !iTl%Sil2J gZcm'_ 

 6.2 km/sec; 2. 84g/cm' 



CRUISER SEAMOUNT 



DISTANCE 



755 7W' 



K I LOUETERS 



Fig. 24. Cnistal section of Cruiser Bank computed to fit the seismic anil gra\ity data. 

 (After Worzel and Talwani, 1959a.) 



form, being 50 miles wide and 150 miles long, this represents a maximum 

 estimate of the fluctuations of the M-discontinuity. 



Perhaps the most detailed study of a seamount has been made of Caryn Peak, 

 a small peak located where the Hudson submarine canyon enters the Sohm 

 abyssal plain. While no seismic data exist on the peak, there are stations in the 

 deep areas around the peak. Core A- 158 taken at a depth of 3970 m was on 

 the flank of Caryn Seamount. Upper Cretaceous fossils, altered by replacements 

 or recrystallization of the original CaCOa in a way considered due to vulcanism, 

 were foimd in the core (Miller and Ewing, 1956). This makes it most probable 

 that the vulcanism responsible for this feature must have ended toward the 

 end of the Upper Cretaceous. 



Fig. 25 shows the computations for nine different mass distributions for the 

 north-south and east-west crossings of this feature (Worzel and Talwani, 



