SECT. 3] PELAGIC SEDIMENTS 717 



Fig. 39 shows data for both oceans based on protactinium/ionium dates at 

 approximately the 100,000-year level in both cases, and on extrapolation of the 

 age below this level. A higher resolution is obtained in the Atlantic sequences 

 owing to the higher total rate of deposition, which protects the record more 

 efficiently from the smoothing effects of animal burrowing and post-depositional 

 dissolution. The higher Atlantic resolution indicates a bij)artition of the Pacific 

 productivity maximum 3.2 and confirms the bipartition of the Pacific maxima 

 2 and 4, only vaguely indicated in most Pacific sequences. A cumulative error 

 from extrapolation might account for the difference in apparent age between 

 the Pacific maximum 6 and the Atlantic 14. The suggested interoceanic cor- 

 relation is summarized in Table VIII. The climatic implications of the strati- 

 fication are discussed in detail elsewhere (Emiliani, 1955; Arrhenius, 1959a; 

 Emihani and Flint, Chapter 34 of this volume). 



Table VIII 



Suggested Correlation between Productivity Stratification in Equatorial Pacific 

 Sediments (Arrhenius, 1952) and Paleotemperature Stratification in Atlantic 

 and Caribbean Sediments (Emiliani, 1955) 



Stages and substages 

 Equatorial Equatorial Atlantic 



Pacific and Caribbean 



The marked effects on circulation and organic production, and ultimately 

 on sediment deposition, caused by the vanishing of the Coriolis force at the 

 equator, open a promising possibility for determining its position in the past. 

 Any displacement of the geographic equator should be accompanied by a 

 corresponding displacement of the thickness maximum of the strata (cf. Fig. 36) 

 and of the maximum in concentration of bio tic sedimentary components, 

 resulting from the high productivity in the Equatorial Divergence. If the 

 position of the equator at a given time were established at two points, less than 

 180° and preferably 90° apart, the position of the poles would also be deter- 

 mined. The estimated possible resolution of this method is of the order of a few 

 degrees of meridional displacement. The sediment cores now existing at the 



