144 THEOCEANFLOOR 



along the bottom in all three oceans. They are largely 

 responsible for the low temperatures characteristic of 

 the deeper ocean waters. These so-called Antarctic 

 bottom currents, the trend of which is considerably 

 affected by the bottom configuration, have been held 

 responsible, especially by German oceanographers like 

 G. Wiist, for the disappearance of lime from sediments 

 of great depths, that is, for the conversion of Glohi- 

 gerina ooze into red clay. 



According to climatologists the present polar ice 

 caps were characteristic of Quaternary time and are 

 relicts of the extensive glaciations which at their 

 maxima heaped up millions of cubic miles of water in 

 the shape of inland ice over the continents in higher 

 latitudes. On the other hand, most of the Tertiary Age 

 is assumed to have had a much warmer climate, polar 

 ice being nearly or totally absent. During part of that 

 favored era subtropical vegetation grew on Greenland, 

 Spitzbergen, and probably the Antarctic. With the great 

 ice caps removed from our globe, the main driving 

 power behind the Antarctic and Arctic bottom currents 

 was also removed. Hence one is forced to assume that 

 at that time the vast ocean water masses below the 

 6,000-foot level must have had a temperature about 

 10° centigrade higher than at present, that is, compara- 

 ble to that of the bottom water in the Mediterranean, 

 which is totally cut off from polar influences by the 

 threshold at Gibraltar. Granting this to be true, the 

 bottom water during the Tertiary should have been not 



