326 



THE GEOLOGIST. 



estuarine formations, and e^'idence is not wanting to snppoi-t the 

 inference that a large portion of the mountain is even of posterior 

 date. 



The marine tertiaiy strata of Cefali and Nizzeti are considered by 

 Sir C. Lyell as slightly younger than the Nor^^-ich Crag, and " if so, 

 the great mass of Etna, or all that is of sub-aerial origin, being newer 

 than the IS'izzetti clays, must be, geologically speaking, of extremely 

 modem date. Its foundations were probably laid in the sea, and 

 were in all likelihood contemporaneous with the basalts and other 

 igneous products of the Cyclopean Isles and Aci Castello, which 

 belong to the period of the fossil shells of ISTezzeti and Cefali. When 

 that fauna flourished, the area where Etna now rises was probably a 

 bay of the sea, afteiTwards converted into land by the outpouring of 

 lava and scorise, as well as by the slow and simultaneous upheaval of 

 the whole territory. Dming that gradual rise the ancient river-plain 

 of the Simeto, in which were embedded the remains of elephants and 

 other quadrupeds, together with certain mai'ine strata (those of 

 CamuHu) formed near the mouth of that river, acquired their present 

 comparatively elevated position. The local eruptions of La Motta 

 and Paterno took place about the same time — i. e., during, or im- 

 mediately after the deposition of the older alluvium, when also the 

 leaf-bearing tuffs of Easano were fonned. In the course of the same 

 long period of elevation the cone of Trifoglietto, and probably the 

 lower part of the cone of Mongibello, were built up. Still later, the 

 cone last mentioned, becoming the sole centre of activity, over- 

 whelmed the eastern cone and finally underwent in itself various 

 transformations, including the truncation of its summit and the 

 formation of the Yal del Bove on its eastern flank. At length the 

 phase of lateral eruptions, which is still in full vigour, closed this 

 long succession of events — changes which may have required 

 thousands of centm^ies for their devellopment, although in the same 

 lapse of time the molluscous fauna of the Mediterranean has scarcely 

 undergone a twentieth part of one entii'e revolution." 



After a recapitulation of the principal arguments of the third part, 

 the author concludes his admirably lucid and logical paper with the 

 expressal of his conviction, that " upheaval has no where played such 

 a dominant part in the cone- and crater-making process as to warrant 

 the use of the term ' elevation-craters' instead of cones and craters of 

 eniption — a comdction in which we think most reflecting geologists 

 will concm', and which seems, through the medium of Sir Charles's 

 paper, to have attained influence in the head-quarters of the 

 supporters of the " elevation- theory" from the fact, that the 

 Geological Society of Berlin, at which city that h^'pothesis was first 

 propounded, has, by permission requested of its author, translated it 

 into German. 



No doubt the weight of such names as those of the late venerable 

 Baron Humboldt and M. EHe de Beaumont caused the " elevation 

 doctrine" to be received generally more from the credibility of such 

 authorities, than from the merits of the doctrine itself In the 



