for the observed magnetic anomalies. Figure 1 shows that a 

 portion of the survey track connecting points C and D passed 

 directly over Baltimore Canyon. Similarly, the track connect- 

 ing points E and F passed directly over Norfolk Canyon. In 

 neither case was there any magnetic field change to correspond 

 with these prominent topographic features. 



Using the data shown on Profiles G-G', H-H', and I-I', 

 depths to the source of the large magnetic anomalies that were 

 found near the continental slope were estimated. These depth 

 estimates were made in accordance with empirical slope methods 

 of Vacquier et al (1951). The average depth estimates to 

 magnetic sources for these profiles are as follows: 



Profile G-G' 19000 feet 



Profile H-H' 18900 feet 



Profile I-I' 19980 feet 

 Depth estimates made from magnetic data from a single 

 survey track are at best only approximate. It was found, 

 however, that the "magnetic depths" estimated above are in 

 reasonable agreement with the depth to the crystalline basement 

 complex, as determined from seismic and drilling data by Ewing 

 et al (1950). It appears that the top of the magnetic source 

 is probably closely coincident with the basement surface. 



