Ch. VIII.] 
DILUVIAL WAVES. 
101 
There seems nothing in the deep sections of the Val del 
Bove, to indicate that the lava currents of remote periods 
were greater in volume than those of modern times ; and 
there are abundant proofs that the countless beds of solid 
rock and scoria? were accumulated, as now, in succession. 
On the grounds,, therefore, already explained, we must infer 
that a mass, eight thousand or nine thousand feet in thick- 
ness, must have required an immense series of ages anterior 
to our historical periods, for its growth ; yet the whole must 
be regarded as the product of a modern portion of the newer 
Pliocene epoch. Such, at least, is the conclusion that we 
draw from the geological data already detailed, which show 
that the oldest parts of the mountain, if not of posterior date 
to the marine strata which are visible around its base, were at 
least of coeval origin. 
Whether signs of Diluvial Waves are observable on Etna. — 
Some geologists contend, that the sudden elevation of large 
continents from beneath the waters of the sea, have again and 
again produced waves which have swept over vast regions of 
the earth, and left enormous rolled blocks strewed over the 
surface*. That there are signs of local floods of extreme 
violence, on various parts of the surface of the dry land, is 
incontrovertible, and in the former volumes we have pointed out 
causes which must for ever continue to give rise to such phe- 
nomena ; but for the proofs of these general cataclysms we 
have searched in vain. It is clear that no devastating wave 
has passed over the forest zone of Etna, since any of the lateral 
cones before mentioned were thrown up ; for none of these 
heaps of loose sand and scoriae could have resisted for a moment 
the denuding action of a violent flood. 
To some, perhaps, it may appear that hills of such incoherent 
materials cannot be of immense antiquity, because the mere 
action of the atmosphere must, in the course of several thou- 
sand years, have obliterated their original forms. But there is 
no weight in this objection, for the older hills are covered with 
* Sedgwick, Anniv. Address to the Geol, Soc, p. 35. Feb, 1831. 
