298 PROF. G. DE LORENZO ON THE HISTORY OF [Aug. I904, 



That uplift, towards the end of the Miocene Period, raised our 

 mountains to a level probably higher than the present one, and 

 thus exposed them to long-continued denudation. In this way 

 there gradually disappeared from the summits of the great broken 

 calcareous massifs every trace of the softer Eocene and Miocene 

 sediments, which nevertheless remained sheltered in the wide and 

 deep synclines, and were mantled over by later deposits. 



After the great uplift, this region was subjected in Pliocene 

 times to another depression, and the sea flowed in again over the 

 mountains. Thus it is that we find the great Pleistocene terraces 

 carved out on Aspromonte up to an altitude of 4265 feet above the 

 present sea-level, and in the remainder of the Apennines up to 

 3280 feet and more. 



But when the Pliocene age came to an end, a fresh uplift 

 marked the beginning of the Pleistocene, an uplift which is still in 

 progress, and has been and is accompanied by seismic phenomena 

 and by the active vulcanicity of the Southern Apennines. To 

 such vicissitudes also the fundamental structure of the Pay of 

 Xaples has been subjected. 



Confining ourselves to that portion of the area which lies nearest 

 the volcanic formations, that is, to the Peninsula of Sorrento and 

 the Island of Capri, we find there (as before stated) dolomites and 

 limestones of Triassic and Cretaceous age. The Tertiary deposits 

 have been all but completely swept away by the long-continued 

 post-Eocene denudation, a mere patch of Eocene-Miocene Flysch 

 now surviving on the highlands between Amalfi and Castellamare 

 di Stabia ; while another, rather larger patch, lies amid the low- 

 lands of Sorrento and Massa, in the hollows formed by depression. 

 Not a remnant is now left among these hills of the Upper Pliocene 

 or the marine Pleistocene ; but the blocks thrown up from the old 

 crater of Vesuvius 1 and the artesian wells dug in Naples (at the 

 Royal Palace and on Piazza Vittoria) prove that such deposits, 

 containing shells nearly all of which are identical with species 

 now living in the Bay, occur at the very bottom of the basin, 

 beneath the deposits of volcanic material, at little more than 

 (350 feet below the present level of the sea. We may, then, conclude 

 that the volcanic eruptions of the Neapolitan area 

 began somewhere between the end of the Pliocene and 

 the beginning of the Pleistocene Period, upon the 

 bottom of a great synclinal basin, resembling those to 

 be seen elsewhere in the Apennines, but in part 

 drowned by the sea. 



The southern rim of this basin now projects above the waters, 

 in the shape of the Island of Capri and the Peninsula of Sorrento. 

 But, just as the various elevations and depressions of both island 

 and peninsula are primarily due to the transverse and longitudinal 

 fractures, which have broken up the calcareous massif into so 



1 H. J. Jobnston-Lavis ' The Ejected Blocks of Monte Somma ' Trans. 

 Edin. Geo!. Soc. vol. vi (1893) p. 314. 



