DETAILS CONCERNING FIJI REEFS 505 



drews observed them over 17 years ago, consist of the maturely dissected 

 strata of a slanting marine coastal plain, as will be further explained in 

 a later paragraph; and as snch they constitute a moderate submarine 

 slope of rather uneven surface, but not a "platform" in any proper sense 

 of the word. As to the northwestern side of the island, where the barrier 

 reef incloses an exceptionally broad lagoon interspersed with volcanic 

 islands, no one knows what the shape of the reef foundation is; its outer 

 part is imperfectly charted. The only geological observer who has lately 

 visited that district is Foye, who writes: "In general the present coral 

 reefs [of Viti Levu] are developing on platforms which originated dur- 

 ins^ the deposition of the coastal series" (1917, 306) ; but the word "plat- 

 form" is here used in a very general sense, inasmuch as it applies to the 

 uneven surface of the formerly uplifted, then dissected, and now sub- 

 merged coastal plain on the south, as well as to the extensive lagoon area 

 of the northwest, regarding the foundation of which no details are at 

 hand. 



All the facts that I noted in Fiji confirm the opinion that the barrier 

 reefs of those islands have grown up from submerged insular slopes, 

 whatever form the slopes happened to have when they were submerged. 

 They were presumably less inclined beneath the broad lagoon northwest 

 of Viti Levu than beneath the narrow lagoon on the south ; the same state- 

 ment may apply to the second largest island of Vanua Levu. The larger 

 the land area concerned, the larger its rivers and the better the oppor- 

 tunity for the formation of sloping offshore deposits, to which the term, 

 "platform," may perhaps apply: it is probably for this reason that the 

 two largest islands of Fiji lend some color of support to Vaughan's view. 

 The submerged slopes are pretty surely of moderate inclination around 

 the small Exploring Isles also, for there a worn-down barrier reef of 

 earlier origin, now submerged, appears to furnish the foundation for the 

 present barrier reef ; but the earlier reef was formed on a strong volcanic 

 slope (1916, b). Around all the other Fiji Islands that I saw — Mbengha, 

 Kandavu, Ono, Matuku, Totoya, Moala, Ngau, Ovalau, Nairai, Makongai, 

 Wakaya, Eambe, and a few more, all smaller than the two larger ones — 

 there is no indication that the submerged volcanic slopes were signifi- 

 cantly less steep than the strongly inclined visible slopes. I must there- 

 fore conclude that submerged platforms "formed by other than coral-reef 

 agencies" are unessential to the formation of barrier reefs in Fiji. 



NEGLECT OF PHYSIOGRAPHIC EVIDENCE 



A paragraph may be given to inquiring why considerations so manifest 

 as those presented above regarding the submarine slope and other features 



