58 



HERSEY 



[chap. 4 



MeCliire, Nelson and Huckaby (1958) report comparisons of reflections with 

 l)orings in several structures in shallow waters of the Gulf of Mexico. They 

 obtained reflections from well known formations, and from deposits of shells 

 (Fig. 7). Other similar correlations with l>ottom cores have been reported 

 privately from work by Knott and Officer in the CJulf of Mexico, 



B. Continental Shelves 



These intriguing mor-i)h()logical features are receiving detailed attention off 

 California from D. G. Moore of the U.S. Naval Electronics Laboratory (see Fig, 8) 



HUNTINGTON BEACH 



1000 2000 3000 



I ■■ i J 



SCALE ■. r. : r 



200 



400 



UNLITHIFIEO SEDIMENT- 

 BEDROCK SURFACE- 



PALOS VERDES 



1000 2000 3000 



I 



SCALE IN FEET 



WAVE CUT SURFACE 

 OF SEAWARD DIPPING 

 M lOCENE ? BEDROCK ■ 



200 



400 



600 



Fig. 8. Sonoprobe recording of the continental shelf off California. (After Moore. 19(H), 

 Plate 3. ) 



and C. B, Officer (Fig. 9), off the coasts of New Jersey, New York, and southern 

 New England separately b_y John Ewing and S. T. Knott, and in Cape God 

 Bay by Hoskins and Knott (1961). Profiles taken independently by 

 Fwing and Knott across the shelf east of New Jersey are shown in Fig. 10. 

 Recordings were made by the writer and R, Waller over the edge of the Spanish 

 shelf south of Cartagena which are similar to those of Ewing and Knott, 

 Thus far, little or no velocity information is available to support these 

 profiles. However, it seems apparent that the present method can be used 

 to increase our understanding of the processes that form the continental 

 shelves. 



