With the exception of those anomalies on the extreme eastern side, 

 the identification of magnetic anomalies in the East Caroline Basin 

 was even more difficult than the identification of those in the West 

 Caroline Basin. The only clear-cut identifications that extend across 

 the entire basin are those on the southern side (Figs. 9; 12). However, 

 working north from the clearly established anomalies, and considering 

 the geometry of the area as well as the seismic reflection evidence, 

 reasonable inferences as to anomaly sequences can be made. 



One of the most striking aspects of Figure 12 is the 325 km left- 

 lateral offset of the spreading axes in the east and west basins along 

 an inferred fracture zone (F.Z. 4) at the western margin of the Eauripik 

 Rise. This is by far the greatest axial offset in the entire Caroline 

 Basin. 



The eastern basin is characterized bj' short, discontinuous fracture 

 zones in contrast to the proposed continuous offsets in the western 

 basin. These discontinuous fractures are characteristic of asymmetrical 

 spreading (Hayes, 1976), and evidence of asymmetry may be seen in the 

 varying distances from the extinct axis to certain key anomalies on 

 either side of the axis across these fractures. A mean increase of 

 15 - 20% in the northern limb spreading rate relative to the southern 

 limb is indicated. Note that the arguments given earlier as to the 

 difficulty of distinguishing asymmetrical spreading from discrete 

 ridge jumps still apply. In this instance it would be particularly 

 difficult to recognize any small-scale additional or partial anomalies 

 caused by ridge jumps, although none are readily apparent. 



44 



