Page:Great Neapolitan Earthquake of 1857.djvu/216

166 plains, however; some slope, gently but continuously in one direction.

Of the geology of the kingdom of Naples very little is accurately known. Within the parallels of 40° to 42°, the following are the leading facts so far as I have observed them, and learned from the sketch map of Italian geology of Colligno. Probably the lowest and most ancient visible stratified rock is the jurassic limestone, which constitutes the central mass of the axial, and all the higher lateral chains.

Lithologically, it is usually in heavy and well-marked beds, the line of strike being very commonly in the general direction of the chain, and the beds tilted to a high angle, so that a very large proportion of the whole mountainous surface of the country, consists of highly inclined beds, running about north and south. There are, however, large exceptions to this: in the mountain knot, of Muro and Bella, amongst other places, for example, the beds, nearly vertical, often cross the lines of valley at right angles. Again, in the great range of La Scorza, or Monte Albano,—south of the Salaris, and between the Val di Diano and the Plain of Pæstum—the beds support a large elevated and nearly level table land, with an east and west strike, and inclined at various angles dipping to the south, and are piled up fully 3,000 feet above the valley of the Rio Negro. They seem to dip inwards, towards the centre of the table on top, so as to rampart it all round: it is the largest surface of mountain table land in the kingdom.

Everywhere this lower limestone presents truces, of immense disturbance and dislocation, and of enormous denudation.

Its colour is most commonly yellowish ash gray, and