340 



Hans Pettersson 



sediment and the surrounding layers of the nodule may have occurred. With due 

 reserve for the limited number of samples investigated, one may say that there is 

 strong evidence for a transfer of radium from the sediment via the bottom v^ater to 

 the nodule, whereas the accretion of radium from the water column above is not 

 likely to have occurred to a notable extent. 



By what kind of chemical action the solution of radium and other elements has 

 taken place is unknown, owing to our ignorance regarding the chemical reactions, 

 proceeding with immense slowness, in the contact region between sediment and 

 bottom water. 



Table III 

 Station Albatross A65%. Lat. 14° 29'. Long. f^81°24'. Depth 4960 m 



It does not seem unlikely that submarine volcanic activity, which has undoubtedly 

 played a dominant part in the building up of the islands and the "guyots" in the Pacific 

 Ocean, may have given rise to magmatic acids, converting calcareous sediments into 

 Red Clay and, at the same time, dissolved also other sediment components, thus 

 facilitating their transfer into manganese nodules, manganese crusts and other 

 concretions. It seems reasonable to assume that this acidulation has been con- 

 centrated to a relatively thin bottom layer over low-lying parts of the ocean floor. 



