14 Proceedings of the Royal Physical Society. 
SupposED ABSENCE OF DEEP-SEA DEPOSITS IN THE 
Dry LAND. 
We come now to what is really the crucial argument in 
the whole question at issue—namely, the argument that we 
cannot point, in the existing dry lands, to any rocks which 
can be compared to the known deep-sea deposits at present 
in course of formation; but that, on the contrary, the dry 
lands are essentially formed of shallow-water deposits of 
clearly terrigenous origin. This view has been forcibly 
expressed by Sir A. Geikie in the 5rd edition of his “Text- 
Book of Geology,” from which I may quote the following 
passage :— 
“It follows from these conditions of sedimentation that 
representatives of the abysmal deposits of the central oceans 
are not likely to be met with among the geological formations 
of past times, Thanks to the great work done by the 
‘Challenger’ Expedition, we know what are the leading 
characters of the accumulations now forming on the deeper 
parts of the ocean-floor. So far as we yet know, they have 
no analogues among the formations of the earth’s crust. 
They differ, indeed, so entirely from any formation which 
geologists have considered to be of deep-water origin, as to 
indicate that from early geological times the present great 
areas of land and sea have remained on the whole where 
they are, and that the land consists mainly of strata formed 
of terrestrial debris laid down at successive epochs in the 
surrounding comparatively shallow seas.” 
As the views expressed in the above quotation really reach 
the core of the whole question at issue, and as I am unable 
to accept them as representing our actual knowledge on the 
subject, I may be allowed to treat the point with a little 
detail. In the first place, however, let me remind you what 
are the characteristic deep-water deposits of the present 
day, as brought out by the researches of the officials of the 
“Challenger” Expedition and others. In the deepest abysses 
of the ocean we meet with variously coloured impalpable muds 
—often spoken of as ‘red clays”—produced by the decomposi- 
tion of volcanic materials (ashes and scori), and containing 
