NARRATIVE OF THE CRUISE. 
925 
“ Regions situated similarly to enclosed and shallow seas and the borders of the present 
continents appear to have been, throughout all geological ages, the theatre of the greatest 
and most remarkable changes ; in short, all, or nearly all, the sedimentary rocks of the 
continents would seem to have been built up in areas like those now occupied by the 
terrigenous deposits. During each era of the earth’s history, the borders of some lands 
have sunk beneath the sea and been covered by marine sediments ; while in other parts 
the terrigenous deposits have been elevated into dry land, and have carried with them a 
record of the organisms which flourished in the sea of the time. In this transitional or 
critical area there has been throughout a continuity of geological and biological pheno- 
mena. 
“ The small extent occupied by littoral formations, especially those of an arenaceous 
nature, shown by deep-sea investigations, is important. In the present state of things 
there does not appear to be anything to account for the enormous thickness of the clastic 
sediments making up certain geological formations, unless the exceptional cases of erosion 
which are brought into play when a coast is undergoing constant elevation or subsidence 
are taken into consideration. Great movements of the land are doubtless necessary 
for the formation of thick beds of transported matter like sandstones and con- 
lomerates. 
“ The debris carried away from the land accumulates at the bottom of the sea before 
reaching the abysmal regions of the ocean. It is only in exceptional cases that the 
finest terrigenous materials are transported several hundred miles from the shores. In 
place of layers formed of pebbles and clastic elements with grains of considerable 
dimensions, which play so large a part in the composition of emerged lands, the great 
areas of the ocean basins are covered by the microscopic remains of pelagic organisms, 
or by the deposits resulting from the alteration of volcanic products. The distinctive 
elements that appear in the river and coast sediments are, projjerly speaking, wanting in 
the great depths far distant from the coasts. To such a degree is this the case that in 
a great number of soundings, from the centre of the Pacific for example, mineral particles 
on which the mechanical action of water has left its imprint cannot be distinguished, and 
quartz is so rare that it may be said to be absent. It is sufficient to indicate these facts 
in order to make apparent the profound differences which separate the deposits of 
the abysmal areas of the ocean basins from the series of rocks in the geological 
formations. 
“ The continental geological formations, when compared with marine deposits of 
modern seas and oceans, appear to present no analogues to the red clays, Racliolarian, 
Globigerina, Pteropod, and Diatom oozes. If it do not follow from this that deep and 
extended oceans like those of the present day cannot formerly have occupied the areas 
of the present continents, and as a corollary that the great lines of the ocean basins and 
continents must have been marked out from the earliest geological ages, it is, never- 
