734 



GRIFFIN AND GOLDBERG 



[CHAP. 26 



recourse will not be made to such considerations. Nonetheless, one a 'priori 

 expects a greater relative contribution of land-derived material to the North 

 Pacific as compared to the South Pacific. 



Experimentally derived data give strength to this deduction. Goldberg and 

 Koide (1962) using the ionium/thorium chronology (Goldberg and Koide, 



^^. 



^' 



« 



lliije 



Fig. 5. Electron micrograph of halloysite tubes I'roni the core Capricorn BG 9, 19° Ol'S, 

 177° 46'E. (By courtesy of Shell Development Corporation, Houston, Texas.) 



1958) found a rather uniform rate of build-up of the sea floor in the South 

 Pacific of 0.4 mni'/lO^ years, whereas values of the rate of sedimentation in 

 the North Pacific vary between 0.5 and 10 mm/lO^ years with an overall 

 average around 1-2 mm/lO^ years. These rates of accumulation are for the 

 non-calcareous components of the deposits. 



Detrital quartz attains values of 25% by weight in sediments from the mid- 

 ocean North Pacific and falls off" in concentration toward polar and equatorial 



