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Show 78 Nl~WER PLIOCI~NE PE:RIOD· (Ch. VII. · · · f biacent beds of sand and observed m the enttre thickness o su J clay. · t the base of E tna, ·I S b y no The dip of the marme strata, a • !' th eastern side for example, they are some-m. eans . um1orm ; on e ' 1 . d t d tlle sea and at others towards the moun-tim. es mNe me tl owar sd uct at 'A derno, on the southern si. de, I tam. ear 1e aque . b d t t . 1 'n quarries not far distant from each o serve wo sec wns, 1 h b d f Clay and ye1low sand dipped, in one locality, ot1er, w ere e so 1 f .L' rty five degrees to the east-south-east, and in at an ang e o 10 - • • . • • the other at a much higher inclinatiOn m the opposite direction. These facts would be of small interest, if an attempt had not been made to represent these mixed marine and volcanic de-p osits which encircle part of the base of Etna, as the outer . t *, margin of a so-called ' elev.atwn era e~ · . . . Near Catania the marme formatwn, cousistmg chiefly of volcanic tuff thinly laminated, terminates in a steep inland cliff, or escarpment, which is from six hundred to eight hundred feet in height. A low flat, composed of recent lava an~ volcanic sand, intervenes between the sea and the base of this escarpment, which may be well seen at Fasano. (f, diagram No.ll.) Eastern side of Etna-Bay of Trezza.-Proceeding northwards from Catania, we have opportunities of examining the same sub-Etnean formations laid open more distinctly in the modern sea cliffs, especially in the Bay of Trezza and in the Cyclopian islands (Dei Faraglioni), which may be regarded as the extremity of a promontory severed from the main land. Numerous are the proofs of submarine eruptions of high antiquity in this spot, where the argillaceous and sandy beds have been invaded and intersected by lava, and where those peculiar tufaceous breccias occur which result from ejections of fragmentary matter, projected from a volcanic vent. I observed many angular and hardened fragments of laminated clay (creta), in different states of alteration, between La Trezza and Nizzitta, and in the hills above Aci Castello, a town on the main land contiguous to the Cyclopian isles, which could not be mistaken * See vol. i. chap. xxii. Ch. VII.] SICILY-CYCLOPIAN ISLES. 79 by on~ familiar with Somma and the minor cones of Ischia, for anything but masses thrown out by volcanic explosions. From the ~uffs and ~arls of this district I collected a great variety of marme shells >i', almost aU of which have been identified with species now inhabiting the Mediteranean, and, for the most part, now frequent on the coast immediately adjacent. Some few of these fossil sh~lls retain part of their colour, which is the same as in their living analogues. The largest of the Cyclopian islets, or rather rocks, is distant two huqdred yards from the land, and is only three hundred yards in ci~cumference, and about two hundred feet in height. The summit and northern sides are formed of a mass of strati£~ d marl (~reta), the laminre of which are occasionally subdivided by thm arenaceous layers. These strata rest on a mass of columnar lava (see wood-cut, No. 14)t, which appears to have forced itself into, and to have heaved up the stratified mass. No. 14. I '* See, in Appendix No. II., a list, by M. Deshayes, of sixty-five species which procured from the hills call~d Monte Cavalaccio, Rocca di Ferro and r{occ d' B~mpolel'e (or Borgia). ' a 1 t This cut is from an origin~l drawing by my friend Capt. W. H. Smyth, R. N, |
