On the Vents of Hot Vapor in Tuseany. 213 
further to the N. and by W., we find that serpentinous rocks have 
there, as in the Tuscan Maremma, burst through alberese and 
macigno and in much greater volume. In truth, the copious ser- 
pentines and their accompaniments in and around the territory of 
‘Genoa, have converted the cretaceous strata into rocks having all 
part mechanically, the contiguous conglomerates and sandstones 
of miocene age, which on the sides of the pass leading from 
‘Genoa to Alexandria occupy very highly inclined positions. The 
phenomena in the Genovesato and Piedmont, like those in the 
Tuscan Maremma‘*, indicate that such beds of the middle tertiary 
age, whether marine or freshwater, have been dislocated along 
those lines of disturbance, which at an antecedent period had been 
marked by the protrusion of the serpentinous rocks in a molten 
state. In other words, it was by the post-eocene eruption that 
the great metamorphosis of the pre-existing strata was caused. 
A long period of comparative repose followed, one of the earliest 
Operations of which was the accumulation of mioeene conglome- 
Savona on the one hand, or in the Monferrato (Superga) on the 
¥. lorence, that trend from N. W. to S. E.—i. e. from the region 
of chief eruption—though divergent from the line of the Apuan 
Alps, and Tuscan Maremma, are exactly coincident with the 
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* See former Memoir and Section Quart. Journ. Geol, Soc., vol. ¥, p. 283 to 292, 
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