36 J- STANLEY GARDINER. 



never able to approach a typical part of the reef from seaward', but in the Maldives at 

 about three fathoms the bottom consists of great buttresses and masses with branching 

 Madrepora and Pocillopora, massive corals here and there, and a considerable nullipore 

 growth between. These coral colonies are for the most part small, the branches short and 

 stout,— the usual condition near the surface, or in any strong current, — and somewhat re- 

 sembling those of the conglomerate masses. Between the buttresses sand and a few boulders 

 of coral, broken off the higher parts of the reef and rolled smooth, are seen, themselves 

 perhaps to be built into the reef Such boulders I have not found in the conglomerate, and 

 their absence would indicate that the latter was formed both deeper and before the existence 

 of any reef-flat to the atoll. Indeed the conglomerate would seem to have constituted part 

 of the original reef {which by subsequent growth fashioned the atoll of Minikoi) at a time 

 antecedent to the formation of any definite reef-flat, and at a depth of at least three fathoms. 

 The conglomerate then may be considered to prove conclusively an elevation of the atoll. Its 

 .mmmits are 6 feet above the reef-flat (the loiv-tide level) and, allowing 18 feet for the 

 depth at which it was formed, there must have been an alteration of level of at least 

 24 feet. 



Returning to the condition of the whole reef at the time of elevation, if there were 

 a broad reef-flat, no additional upheaval to that suggested above would be required to 

 explain the height of the island in different positions. The boulders, which form the rocky 

 area, lie more or less horizontally on one another, and are much rain-worn. If they had 

 been piled up by the waves, they would show a definite dip, but their position is more 

 in accordance with theii- being formed by the simple sinking of the surface owing to the 

 solvent action of the rain, removing nullipores, sand and the softer parts. The height of 

 the land-sections D and F is about 14 feet-, and the elevation based on other considera- 

 tions 2'1 feet, giving a sinking of 10 feet to the surface. Considering the heavy rainfixll, 

 the spongy nature of a reef, and the almost complete absence of evidence of nullipore 

 growth in the boulders, this erosion of the surface wmild seem to me but reasonable. 

 Allowing an average loss of half an inch in a century, ample even if the original reef were 

 not solid, only 24,000 years since the elevation would be required. This period is perhaps 

 more than sufficient for all the changes which have taken place in the atoll since its elevation, 

 but is not synchronous with any known upheaval, such as might naturally be expected 

 in the Hindustan continent, if such a change of level has taken place, as I believe, more 

 or less at the same time throughout both the Laccadives and Maldives. 



Let us proceed however to an examination of the sandy areas, so as to see whether 

 they lend any support to the changes that have so far been deduced. I have already 

 described the surface characters of this area with the exception of a small patch at Boni- 

 Kodi, similar sand to which indeed forms a belt everywhere against the rocky area. It 

 consists of coarse particles of all the organic skeletons, which a.ssist in forming a reef, with 

 larger rounded pieces of coral. It thus differs entirely from the fine sand of the lagoon 

 shore elsewhere, resembling somewhat closely the sand at the base of the sea-beach of the 

 south half of the island. I investigated its distribution by digging pits in section across 



1 For the reef characters in different positions see Sec. III. foniid in section G, as I consider that there may have been 



Such reef as exists between Mou-Rambu and Kodi points is alonf; the ridge here a piling up of boulders, even land, at a 



not typical. tirue antecedent to the elevation. 



- I have not taken the greater elevation — 19 feet — as 



