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Show 82 NEWER PLTOCENE PERTOD· [Ch. VII. se this volcanic action explosions. We may, therefore, suppo f E . d f th modern vents o ~ tna, as to have been as mdepen en~ 0 e . . . h . 1 . t the analocrous formatwns m the Val dt that w 1c 1 gave rise o o 1 . . I Noto. tI.S qui' t e ev ident that the lavas of the. Cyc op1an tsles are not t h e 1o wer extremities of currents which flow. ed down from t1le h1. g h es t crater of Etna' or from .t he regton wh.e re 1a tera1 erup tt.o ns are now frequent,-lavas w.h ich, after ente. r.m g t 11 e sea, were af tern..r ards upraised into their present position. It is more probable that the basalts of the Bay of Trezza, and h l tl Southern foot of Etna, at La Motta, Aderno, t ose a ong 1e Paterno, Licodia, and other places, originated in the same sea in which the eruptions of the Val di Noto took place. . There are, however, as we have observed, no scctwns to prove that the central and oldest parts of Etna repose on similar submarine formations. The modern lavas of the volcano arc continually extending their area, and covering, from time to time, a larger portion of the marine strata; but we know not where this operation commenced, so that we cannot demonstrate the posteriority of the whole cone to these newer Pliocene strata. We might imagine that ·when the volcanos of the Val di Noto were in activity, and when the eruptions of the Bay of Trezza were taking place, Etna already existed as a volcano, the upper part only of the cone projecting above the level of the waters, as in the case of Stmmboli at present. By such an hypothesis, we might refer the origin of the older part of Etna to the same period as that of the sedimentary strata and volcanic rocks of the Val di N oto. But, for our own part, we see no grounds for inclining to such a theory, since we must admit that a sufficient series of ages has elapsed since the limestone of the Val di N oto was deposited, to allow the same to be elevated to the height of from two thousand to three thousand feet, in which case there may also have been sufficient time for the growth of a volcanic pile like Etna, since the newer Pliocene strata now seen at the base of the volcano originated, Ch. VII.] E'fNA. 83 INTERNAL STRUCTURE OF THE CONE OF ETNA. In our first volume we merely described that part of Etna which has been formed during the historical era; an insignificant portion of the whole mass. Nearly all the remainder may be referred to the tertiary period immediately antecedent to the recent epoch. We before stated, that the great cone is, in genera], of a very symmetrical form, but is broken, on its eastern side, by a deep valley, called the Val del Bove *, which, No. 17. Great valle!J on the east side of Elna. a, highest cone. b, Montagnuola. c, Head of Val del Bove. d, d, Serre del Solfizio. e, Zaffarana. f, One of the lateral cones. g, Monti Rossi. commencing near the summit of the mountain, descends into the woody region, and is then continued, on one side, by a second and narrower valley, ca1led the Val di Cal anna. Below the latter another, named the Val di St. Giacomo, bcgins,-a long narrow ravine, which is prolonged to the neighbourhood of Zaffarana ( e, No. 17), on the confines of the fertile region. These natural incisions, into the side of the volcano, are of such "' In the provincial dialect of the peasants called 'Val del Bue,' for here the herdsman -- ' in reduct.t valle mugienliwn Prospectat errantes greges.-' D.r. Buckl~nd was, I believe, the first English geologist who examined this valley With ~~teuho~1'. and I am indebted to him for having described it to me, l1efore my VISit to Sicily, as more worthy of attention than any single spot in that island 01' perhaps in Europe. I have already stated, that the vi<:w of this valley whid~ I hav. e given in the f ron t1',s p1· cce of tl 1e second volume, does not pretend to 'c onvey any Idea of the grandeur of the scene. G 2 |