416 Noticca of Memoir's — Professor Alexander Agassiz — 



Mar^ is said by Pelatan to have five terraces of elevated coralliferous 

 limestone, and to be riddled with caverns,. Clark considers the 

 elevated coralliferous limestones of the Loyalty Islands probably to 

 be Pleistocene. 



" In the Solomon Islands Guppy has traced extensive elevated 

 reefs, which, however, he considers as belonging to the present 

 epoch. Elevated coralliferous limestones also exist in the New 

 Hebrides, as well as on the southern shore of New Guinea. 



" The time of this Fijian elevation we cannot at present ascertain. 

 It is not unnatural to assume that it was coincident with the elevation 

 of Northern Queensland, and that the area of elevation included New 

 Guinea, the islands to the east of it as far south as New Caledonia, 

 and as far east as the most distant of the Paumotus (Gambler 

 Islands), and extended northward of that line to include the Gilbert, 

 Ellice, Marshall, and Caroline Islands ; and that since this epoch of 

 elevation the islands within that area have been, like Northern 

 Australia, subject to an extensive denudation and erosion, many of 

 them being reduced to mei'e flats but a few feet above the surface of 

 the sea, others worn away to represent to-da}' but a small portion of 

 their former extent. It is upon the reef flats thus eroded, or around 

 the islands and islets which ai'e the remnants of a former period, 

 that the corals of to-day have obtained a foothold. And further, by 

 the mechanical action of the sea combined with that of the trade 

 winds, channels have been excavated out of the substratum under- 

 lying the coral reefs to form the lagoons of the barrier reefs and 

 atolls of Fiji. 



" So that, as far as we can judge from the case of the Fiji Islands, 

 the shape of the atolls and of the barrier reefs is due to causes which 

 have acted during a period preceding our own. The islands of the 

 whole group have been elevated, and since their elevation have, like 

 the northern part of Queensland, remained nearly stationary, and 

 exposed to a great and prolonged process of denudation and of aerial 

 and submarine erosion, which has reduced them to their present 

 height ; the submarine platforms upon which the barrier reefs have 

 grown being merely the flats left by the denudation and erosion of 

 the central island, while the atolls are similar flats from the surface 

 of which the islands have at first disappeared and the interior parts 

 of which have next been removed by the incessant scouring of the 

 action of the sea, the ceaseless rollers pouring a huge mass of water 

 into the lagoon, which finds its way out of the passages leading into 

 it or over the low outer edges of the lagoon. These atolls and 

 islands, surrounded in part or wholly by encircling and barrier reefs, 

 have not been built (as is claimed by Dana and Darwin) by the 

 subsidence of the islands they enclose. They are not situated in an 

 area of subsidence, but, on the contrary, in an area of elevation. 

 The theory of Darwin and Dana is therefore not aiDplicable to the 

 Fiji Islands. 



"The evidence of elevation is not limited to that furnished by the 

 remains of the elevated coralliferous limestone just mentioned, and 

 it is natural to assume that the elevation we have just traced was- 



