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very considerable subsidence, in many islands the proofs of recent 
very strong upheaval. In New Guinea tertiary deposits have been 
observed to oceur on the highest mountain tops (Carstensz-top, 4780 
m., and Wilhelmina-top 4750 m.) and in the group of the Fiji 
islands ') some regions have in recent times been raised 300 m., 
while parts only a few kilometres distant show traces of strong 
subsidence and submergence. 
As to the real or apparent subsidences of lesser or larger extent 
in true oceanic regions, not compensated by counter-movements, such as 
are generally assumed to have taken place in the Central Pacific as well 
as in the Indian Ocean and also in a small part of the Atlantic, no 
satisfactory explanation of their mode of origin has as yet been given 
and great uncertainty continues to prevail on this head. 
Now it is clear, that, before we try to suggest any explanation, 
the question has to be considered how far the assumption of the 
subsidence of true oceanic islands is supported by facts. Such consi- 
deration proves that although the assumption of subsidence is indi- 
rectly supported by the convergent evidence of many facts, yet until 
now, only one fact is known, which gives direct evidence of sub- 
sidenee and, consequently, disappearance below the sea-level of an 
oceanic island. 
This fact is the subsidence recently proved with certainty by 
boring on the island of Bermuda. Bermuda-Island is the only oceanic 
island in the Atlantic lying within the limits of the geographical 
distribution of the reef-building corals. Bermuda-Island, or the group 
of the Bermudas, is at the surface entirely composed of reef-limestone. 
It rises on a submarine bank or shoal which is strongly elongated 
in a south-east and north-west direction. This shoal is 51 km. long 
at a depth of 100 fathoms and is surrounded on all sides by a 
sea of an average depth of 4500 in. 
The deep boring referred to was made in the island in the 
year 1912 at a point situated 42 m. above sea-level. It proved that 
Bermuda Island consists of a volcanic mountain, built up of a series 
of superposed banks of basaltic volcanic material, the probably 
truncated top of which now lies somewhat more than 75 m. below 
sea-level. 
On this truncated cone or platform rests the so-called Bermuda 
limestone, a reef-limestone extending upwards to the surface of the 
sea, the portion of the island projecting above the ‘sea also consist- 
ing of it. 
1) E. G. Anprews. Relations of coral reefs to crust movements in the Fiji- 
islands. Amer. Journal of science. XLI. p. 141, 1916. 
