Hutt— On the Geological Age of the North Atlantic Ocean. 517 
stl must have lain the lands formed of more ancient rocks (Archzean and others), 
which produced the sediments of which the Carboniferous formation is built up. 
This brings us towards the borders of the Central Atlantic plateau, or ridge; and 
here, as it seems to me, we have a clue to its origin and history. 
Speaking with all due reserve on a subject, regarding which our means for 
observation are so restricted, may we not fairly surmise that the central plateau 
of the Atlantic has some connexion, at least, with that ancient continental 
land of which we have been speaking? It seems to occupy somewhat of the posi- 
tion which this continent must have occupied, stretching from the Arctic regions 
southwards, embracing Greenland of the present day, and lying in a position 
between the Carboniferous submerged tracts stretching into the American area on 
the one hand, and into those of the British Isles and Western Europe, on the 
other. 
Again, let us inquire what would be the effect of the uprising of the 
Alleghanies on the parallel tract now under the waters of the Atlantic. It seems 
to me absolutely certain, on mechanical principles, that the uprising of the former 
must have been accompanied by a depression of the latter; in other words, that 
the formation of the ridge must have been accompanied by the formation of the 
furrow, complex though each may have been. The proverb, ‘‘every ridge has 
its furrow,” holds good in terrestrial mechanics; and the furrow in this case 
corresponds with the oceanic valley eastward of the American coast. 
The mode of formation of the eastern side of the North Atlantic is a question 
not so evident, or simple, as that of the western. Still I believe the same prin- 
ciples and course of reasoning are applicable to this case also. The originally 
horizontal sheets of Carboniferous strata of the British Isles, the north of France 
and Spain, which reach the Atlantic shores with a thickness of several?thousand 
feet vertical, must have extended far away westwards into the region now covered 
by the Atlantic waters. I have already shown that in this direction also lay the 
originating lands; and here we catch a glimpse (as it were) of the eastern margin 
of the central continental area, the western margin of which we have already 
mentally visited. We know also, that at the close of the Paleozoic era terrestrial 
movements involving the flexuring and folding of the Carboniferous beds took 
place over Western Europe as over Eastern America, and} the ultimate results 
would be somewhat of the same kind. Deep depressions, with corresponding 
elevations, were formed over the area once occupied byy wide-spread tracts of 
horizontal Carboniferous strata. Thus we might infer that the depression of the 
Bay of Biscay was contemporaneous with the tilting of the Carboniferous beds of 
Asturias. But I desire to refrain from particulars in a questionjwhich{can only be 
handled safely in a general manner. The general result of all these movements 
over the Atlantic area at the close of the Palzeozoic era would, we‘may'safely infer, 
have been to depress the central continental area, and to produce deep basins or 
