20 THE OCEAN FLOOR 



schools of thought on these theories Rubey has coined 

 the expressive terms "the quick soaks," who prefer to 

 beheve that all the water was present from the very 

 beginning, and "the slow soaks," who think that it 

 increased by small increments over a much longer 

 period of time. The "excess volatiles," which the slow 

 soaks assume were released gradually from the earth's 

 crust, are supposed to have been retained within the 

 interior of the earth in quantities amounting to a fraction 

 of 1 % of the total weight of the solid matter. 



Starting from known geochemical data Rubey finds 

 the total quantity of water present in the primitive 

 atmosphere and ocean to have been not more than one- 

 sixth, probably a still smaller fraction, of the present-day 

 total, the rest having been gradually released from the 

 crust during the crystallization of complex silicate melts. 

 A large part of this magmatic water Rubey assumes to 

 have been released as "juvenile water" through hot 

 springs.* Even if the water which existing hot springs 

 are delivering to the surface consisted of only .8% of 

 juvenile water, in the course of two billion years they 

 could account for the entire volume of present ocean 

 water, without counting contributions of water from 

 volcanic eruptions! 



* Professor Eugen Wegmann has called my attention to the 

 fact that as defined by E. Suess the term "juvenile" should 

 be used for matter which has not participated in supracrustal 

 cycles, so that the excess volatiles released from the crust 

 should properly be called "juvenile" instead of "magmatic." 



