BOTTOM WATERS 145 



only warmer than at present but much more stagnant. 

 That is, the lime-dissolving power of the deepest water 

 layers, which is at present attributed to the cold Ant- 

 arctic bottom current, should have been absent or at 

 least much less intense during the Tertiary Age. As- 

 suming the production of calcareous shells from the 

 surface plankton to have been as intense then as now 

 (in fact, it should have been greater because of the 

 higher surface temperature), there is no reason why 

 red clay should have been produced at all in Pre- 

 Quaternary time! 



This is one reason I was so moved when our first 

 long core of typical red clay was raised from the bottom 

 of the central Atlantic Ocean during the first crossing 

 with the "Albatross." For even if we ascribe as high a 

 figure as 10 millimeters in 1,000 years to the rate of 

 sedimentation of that core (the probable average is 

 only 7 millimeters), its lowest parts would have the 

 respectable age of 1^-: million years, thus taking them 

 definitely back into the Pliocene, when the great 

 deterioration of climate characteristic of the Quater- 

 nary had not yet set in. Still older red clay was sub- 

 sequently obtained from the central Pacific Ocean. 



How to explain the occurrence of Pre-Quaternary 

 red clay, therefore, seems a baffling task to oceanog- 

 raphers, who have wholeheartedly adopted Wiist's 

 theory of the Antarctic bottom current as the main lime- 

 dissolving factor in great depths. 



My own views, which may seem rather heretical to 



