DEEP-SEA RADIUM 123 



equilibrium value of uranium-supported radium in 

 10'^- gr Ra / gr, and the fifth the radium concentration 

 actually found. The cores numbered 69 to 87 are from 

 the equatorial region of the Pacific Ocean, core 238 

 was raised from the Romanche Deep in the equatorial 

 Atlantic Ocean, and core 251 was taken near the 

 equator in the same ocean but farther west. 



With the exception of two outstandingly high 

 amounts of uranium in core 76 at depths of 40 centi- 

 meters and 200 centimeters respectively below surface, 

 and one in core 87B at 41 centimeters, all the uranium 

 amounts found are moderate, ranging from .76 to 4.0 

 of the sixth decimal place. The corresponding equilib- 

 rium values for radium range from .27 to 1.4 units 

 of the twelfth decimal place, whereas in the case of the 

 three outstanding uranium values before mentioned, 

 the figures for uranium-supported radium are 2.5, 4.0, 

 and 10.8 units of the twelfth decimal place. Comparing 

 these latter radium values with those actually found 

 near the surface with maxima of up to 50 units, we 

 may say that at least in the upper levels of the cores 

 and especially in the central Pacific Ocean uranium- 

 supported radium accounts for only a small fraction 

 of the radium actually present. 



These results definitely contradict Joly's second ex- 

 planation for the high radium values found in the upper 

 levels of the red clay: that they are due to an accumula- 

 tion of uranium in great depths. Obviously the high 

 radium values found near the sediment surface must 



