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Show , CHANGES OF 'l'Im SURFACE l 36 · nor pen.e t . t far into the higher eminences of the Apenmnes, . h h1o a lee peninsula was evl.· . 1leys · for t e w and more ancient va '. f h me subterranean move-dently subjected to the actiOn o t e sa of strata changed their d I lder and newer groups ments, an t 1e o b t not to each other. 1e ve1, l·n relation to the sea, u . a;lcnnzne AND CLIMATE, CONTEMPORANEOlJS, 137 ferent assemblages of organized fossils. '!'he older tertiary groups generally rise to greater heights, and form interior zones nearest to the Alps. We may imagine some future convulsion once more to upraise this stupendous chaiu, togetheL· with the adjoining bed of the sea, so that the greatest mountains of Europe might rival the Andes in elevation, in which case the deltas of the Po, Adige, and Brenta now encroaching upon the Adriatic, might be uplifted so as to form another exterior belt, of considerable height, around the south-eastern flank of the Alps. Although we have not yet ascertained the number of different periods at which the Alps gained accessions to their height and width, yet we can affirm, that the last series of movements occurred when the seas were inhabited by many existing species of animals *-. There appears to be no sedimentary formations in the A1ps so ancient as the rocks of our carboniferous series; while, on the other hand, secondary strata as modern as the green sand of English geologists, and perhaps the chalk, enter into some of the higher and central ridges. Down to the period, therefore, when the rocks, from our lias to the chalk inclusive, were deposited, there was sea where now the principal chain of Europe extends, and that chain attained more than half its present elevation and breadth between the eras when our newer secondary and oldest tertiary rocks originated. 'l'he remainder of its growth, if we may so speak, is of much more recent date, some of the latest changes, as we have stated, having been coeval with the existence of many animals belonging to species now contemporary with man. The Pyrenees, also, have acquired the whole of their present altitude, which in Mont Perdu exceeds eleven thousand feet, since the origin of some of • Brocchi supposed the Subapennine beds to occur abundant!!/ on both sides of the plains of the Po ; bnt in this he was mistaken. The subalpine tertiary deposits are for the most part distinct. and older formations. Professors Bonelli and Guidotti informed me, that they have recognized the Subapennine shells in one or two districts only north of the Po. They form in these cases, as might have been anticipateu, the outermost belt, as at Azolo, at the foot of the Alps near the plains of Venice, and at Bassano, on the Brenta. In the section given by Mr. Murchison of the strata laid open by the Brenta, between Bassnno and the Alps above Cam. pese, it will be seen that the older chain must have partaken of the movement which raise1l the newest tertiary strata of the age of the Suba:pennines. Phil, Mag. and Annals, June, 1829. |