SUBSIDENCE IN PACIFIC CORAL REGIONS. 365 
reefs and islands of the Pacific? It is very evident that the 
sinking of the Society, Samoan, and Hawaiian Islands has 
been small compared with that required to submerge all the 
lands on which the Paumotus and the other Pacific atolls rest. 
One, two, or five hundred feet, could not have buried the 
many peaks of these islands. Even the 1,200 feet of depres- 
sion at the Gambier Group is shown to be at a distance from 
the axis of the subsiding area. The groups of high islands 
above mentioned contain summits from 4,000 to 14,000 feet 
above the sea; and it is not probable that throughout this 
large area, when the two hundred islands now sunken were 
above the waves, there were none of them equal in altitude 
to the mean of these heights, or 9,000 feet. Hence, however 
moderate our estimate, there must still be allowed a sinking 
of many thousand feet. Moreover, whatever estimate we 
make that is within probable bounds, we shall not arrive at 
a more surprising change of level than the continents show 
that they have undergone; for since the Tertiary began (or , 
the preceding period, the Cretaceous, closed) more than 10,000 
feet have been added to the Rocky Mountains, parts of the ~' 
Andes, and Alps, and 19,000 feet to part of the Himalayas. ~ 
Between the New Hebrides and Australia, the reefs and 
islands mark out another area of depression, which may have 
been simultaneously in progress. The long reef of one hun- 
dred and fifty miles from the north cape of New Caledonia, 
and the wide barrier on the west, cannot be explained with- 
out supposing a subsidence of one or two thousand feet at the 
least. The distant barrier of Australia is proof of great sub- 
sidence, even along the border of that continent. But the 
ereatest amount of sinking took place, in all probability, over 
the intermediate sea, called the “‘ Coral Sea,’”’ where there are 
now a considerable number of atolls. fae 
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