X THEOCEANFLOOR 



taken together, is covered by water masses from one to 

 six miles thick. Only the uppermost surface of this 

 enormous lowland has so far been accessible to in- 

 vestigation, and a relatively small number of sediment 

 samples have been raised from great depths. It seems 

 likely that the new science of submarine geology will 

 be much advanced during the latter half of this cen- 

 tury. Many problems concerning the deep-sea deposits 

 — their structure, their composition, and their origin — • 

 will be elucidated through future international efforts 

 in deep-sea research. 



I owe a debt of gratitude to David H. Home for 

 clarifying the English of the manuscript, making the 

 index, and helping to see the book through press. 



HANS PETTERSSON 



Goteborg, 1954 



