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Show 92 NEWER PLIOCENE PERJOD. LCh. VII. cones, or, in other words, the channels which gave passage to the lava-currents and scorire that have issued from vents in the forest-zone. Some :fissures may have been :filled from above, but I did not see any which, by terminating downwards, gave proof of such an origin. Almost all the isolated masses in the Val del Bove, such as Capra, Musara, and others, are traversed by dikes, and may, perhaps, have partly owed their preservation to that circumstance, if at least the action. of occasional floods has been one of the destroying causes in the Val del Bove ; for there is nothing which affords so much protection to a mass of strata against the undermining action of running water, as a perpendicular dike of hard rock. In the accompanying drawing (No. 21) the flowing of the No. 21. f'iew of lite 1·ocks Finochio, Capra, and Musa1·a, Val del Bove. lavas of 1811 and 1819, between the rocks Finochio, Capra, and Musara, is represented. The height of the two last-mentioned isolated masses has been much diminished by the elevation of their base, caused by these currents. They may, perhaps, be the remnants of cones, which existed before the Val del Bove was formed, and may hereafter be once more buried by the lavas that are now accumulating in the valley. Ch. VII.] LAVAS AND BRECCIAS OF THE VAL DEL DOVE. 93 From no point of view are the dikes more conspicuous than from the summit of the highest cone of Etna; a view of some of them are given in the annexed drawing*. No.22. View from t!te summit of Etna into t!te Vut del Bove. Tlte small cone and C1'alet· immediately below were among those fiur"u" led (z u rm· g lt,t e e1·uptions ofl810 ancll8ll. L~vas and breccias.-In regard to the volcanic masses which .a re Intersected by dikes in the Val del B ove, th ey consi. st 111 great part, of graystone lavas, of an intermediate characte:· b~twecn basalt and trachyte, and partly of the trachytic vari~ ttes of laYa .. Beds. of scorire and sand, also, are very numeIOus, alternatmg With breccias formed of anO'ul bl k f j k o ar oc s o gneous roc . It is possible that some of the breccias may be referred to aqueous causes, as we have before seen that 'g reat f •t h This drawing j spart of a panoramic sketch which I made from the 't o c cone, Drcember 1st, 1828, when ever art f E sumnu except the V ul del Bove. y p o tna was free from clouds |