NVESTIGATING THE FLOOR 



73 



results from the Atlantic part of the cruise were mostly 

 obtained in the region of Bermuda and show the second 

 type of structure, that is, with a layer of volcanic mate- 

 rial interposed between the sediments and the basement 

 rock. 



During the "Albatross" cruise the extensive lava beds 



Fig. 26. Corer bent against lava bed 



in great ocean depths were forcibly brought to our 

 notice through lost or bent coring tubes (Figure 26). 

 The interference of such sediment-covered lava beds 

 with the echoes from WeibulFs exploding depth charges 

 was at first suggested as a possible explanation for the 

 missing echoes from still deeper reflecting surfaces. The 

 influence of submarine volcanic action on the com- 

 position of the sediments and especially on the solution 



