146 G. F. BECKER RELATIONS OF RADIOACTIVITY TO COSMOGONY 



tion of the conditions of the formation of primeval granite. The only 

 origin compatible with known facts seems to be the action of superheated 

 aqueous vapor on solid nearly anhydrous rhyolitic or trachytic rocks, pro- 

 ducing aqueo-igneous fusion immediately after the consistentior status. 

 This would apparently imply that the granitic shell is not more than a 

 few miles in thickness and is consistent with the inference as to the thick- 

 ness of the radioactive shell. The thermal relations seem to indicate that 

 the formation of granite must have been excessively slow, unless by some 

 means energy was potentialized. Now the formation of uranium poten- 

 tialized an enormous amount of energy. Hence it is reasonable to believe 

 that the formation of uranium took place at this time and at the expense 

 of the heat of compression of the terrestrial nebula. 



