INVESTIGATIONS OF STRATIGRAPHY 103 



time levels. He was especially interested in titanium.* 

 Between localities within the eastern part of the area 

 investigated he found perceptible variations of titanium 

 accumulation, whereas in the Pleistocene strata of the 

 open, topographically regular part of the ocean only a 

 small fraction of the accumulation showed regional 

 variations. The deviations from uniformity in space 

 were given quantitative expression, and from the re- 

 gional uniformity a corresponding uniformity in time 

 within the area and the time interval in question was 

 inferred. The Pleistocene strata display a marked 

 homogeneity, on which Arrhenius has based a tentative 

 chronology on the assumption of a uniform rate of 

 minerogenous accumulation during the Pleistocene 

 within the east eupelagic area. Arrhenius checked these 

 data against a radiocarbon dating on one core, using 

 the method developed by Libby.- 



To the view of a constant rate of accumulation of 

 minerogenous matter within the area in question ex- 

 ception has been taken by Kullenberg. For the discus- 

 sion of these and other aspects of Arrhenius' work the 

 reader may be referred to his rejoinder to various 

 criticisms in Tellus (1954). 



3. The amount of biogenetic silica in the eupelagic 

 sediments of the eastern Pacific has also been cal- 

 culated by Arrhenius. He finds the maximum rate of 



* That titanium is less likely to undergo postdepositional 

 changes than other chemical elements has been urged by vari- 

 ous eadier authors such as Correns, Wiseman, and Koczy. 



