active from about 10 - 12 m.y. B.P. or, alternatively, from about 20 m.y. 

 B.P. to the present time. 



The Sorol Trough (Fig. 2) is believed by Weissel and Anderson 

 (1978) to be an active extensional feature, forming the northern margin 

 of a Caroline Plate. 



As can be seen from the above synopsis, the interpretations of the 

 tectonic origin and development of the Caroline Basin differ signifi- 

 cantly. While there is a general agreement as to the mode of origin 

 (sea-floor spreading) of the basin, there is divergent opinion as 

 to the nature and age of the inception of spreading, and the direction, 

 continuity, and longevity of that spreading. The following sections 

 will attempt to arrive at a reasonable synthesis of these diverse 

 interpretations by a rigorous examination of the available geophys- 

 ical and geological data. 



