166 
OLDER PLIOCENE PERIOD. 
[Ch. XII. 
Genoa. — At Genoa the tertiary strata consist of blue marls 
like those of the northern Subapennines, and contain the 
same shells. On the immediate site of the town they rise 
to the height of only 20 feet above the sea, but they reach 
about 80 feet in some parts of the suburbs. At the base 
of a mountain not far from the suburbs there is an ancient 
Monte d'Origina. No, 28. 
Sea 
Position of Tertiary strata at Genoa. 
a, Ancient sea-beach. b, Blue marl with shells. 
C, Inclined secondary strata of sandstone, shale, &c, 
beach, strewed with rounded blocks of Alpine rocks, some of 
which are drilled by the Modiola lithophaga, Lamk., the 
whole cemented into a conglomerate*, which marks the ancient 
sea-beach at the height of 100 feet above the present sea. 
Savona. — At Savona, proceeding westwards, we find deposits 
of blue marl like those of Genoa, and occupying a corresponding 
geological position at the base of the mountains near the sea. 
The shells, collected from these marls by Mr. Murchison and 
myself, in 1828, were examined by Signor Bonelli, of Turin, 
and found to agree with Subapennine fossils. 
Albenga. — At Albenga these formations occupy a more ex- 
tensive tract, forming the plains around that town and the low 
hills of the neighbourhood, which reach in some spots an 
elevation of 300 feet. The encircling mountains recalled to 
my mind those which bound the plain and bay of Palermo, and 
* I have to acknowledge the assistance of Professor Viviani and Dr. Sasso 
who called my attention to these phenomena when I visited Genoa in Jan. 1829. 
