Page:Great Neapolitan Earthquake of 1857.djvu/352

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CAMPOSTRINA—VIADUCT—GREAT FALL OF ROCK.

several lateral valley-gorges, and crossing the principal one by an imposing viaduct of considerable altitude, built of ashlar limestone, and carrying a narrow road, over a double range of semicircular arches, upon piers overloaded with material and buttressed out, transversely to the width of the road, to more than twice its breadth at their deepest bases. This viaduct must have received the shock very nearly transversely to its length, but emergent at a high angle. It has sustained no damage whatever, though a top-heavy mass, a sufficient proof of the value of good masonry in an earthquake country. Padre Mancini politely accompanied me on foot to the summit of the pass, about 21/2 Italian miles, to point out the site, of an enormous fall of limestone rock, which had been produced by the shock.

The general direction of the deep narrow gorge, in the bottom of which the foaming torrent of the Tanagro rolls for several miles along, is nearly N. and S. The limestone beds at either side, as well as the jagged serratures of the cliffs, in many places vertical or overhanging, correspond to each other, and prove it to have been torn by separation of the opposite mountain masses.

The strike of the beds is nearly N. and S., and they dip at various angles, but all very steep towards the S. and S. W. The bedding is not very clearly defined, and the rock is lithologically, softer and more of a cretaceous character, than that of Monte Alburno, and may probably belong to a different member of the limestone formation. No fossils anywhere met my eye, and other occupation precluded my looking for them.

The first great fall of rock I found had occurred about