W. M. Davis — Shaler Memorial Study of Coral Reefs. 251 



deposition of the limestones upon them, and not to represent 

 the boundaries either of intrusive igneous masses — as some 

 observers have supposed — or of unworn submarine volcanic 

 cones. Similar indications of unconformity between the lime- 

 stones of elevated reefs and their volcanic foundations were 

 noted in three other Fiji islands. Several important con- 



Fig. 1. 



Fig. 7. Successive stages in the development of an uplifted and dissected 

 reef, enclosed by a new barrier reef. 



sequences follow, particularly in the case of Yanua Mbalavu, 

 where the old reef as well as the volcanic mass has a dissected 

 surface and an embayed shoreline within the lagoon of a well 

 developed barrier reef. The volcanic island, block 3, fig. 7, 

 must have stood at least as high as it does now before the 

 limestones were deposited upon it, in order that its surface 

 should have suffered erosion down as low as present sea level. 

 The island must then, during the formation of the reef-lime- 



