232 



PRINCIPLES OF STRATIGRAPHY 



3, the configuration of the basins. It is this latter, /. c, the presence 

 of continental masses in the path pi the currents, which causes a 

 piling up of the waters on the coast against which it is driven by 

 the primary causes, and a potential depression of the surface from 

 which it flows away. In the one case, then, the heaped-up water 

 must flow away, and in the other compensating streams originate, 

 drawing the water into the space whence removal has taken place. 

 In a symmetrical ocean reaching from pole to pole and covering 



Fig. 2)6. Schematic representation of ocean currents in an ideal ocean. (After 

 Kriimmel.) 



a meridional distance of 90°, we would have a symmetrical ar- 

 rangement of currents as shown in the annexed diagram repro- 

 duced from Kriimmel (Fig. 36). On both sides of the equator, 

 at 10° north and south latitudes, the equatorial streams would flow 

 westward and on approaching the western shores, bending respec- 

 tively northward and southward and crossing eastward again in 

 50° north and south latitude, would approach the equator again 

 along the eastern border of the sea, thus constituting the principal 

 north and south circulation. Between the equatorial currents set- 

 ting westward is an eastward-setting equatorial counter current, 



