16G 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 SO 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. 



Position of Tertiary strata at Genoa. 



a, Ancient sea-beach. b, Blue marl with shells. 



Cj Inclined secondary strata of sandstone, shale, &c, 



beach, strewed with rounded blocks of Alpine rocks,, some of 

 which are drilled by the Modiola lithopliatja, 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 1S28, were examined by Signer Bonelli, of Turin, 

 and found to agree with Subapennine fossils. 



Albenga. At Albcnga these formations occupy a more ex- 

 tensive tract, forming the plains around that town and the low 

 bills 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 ihe assistance of Professor Viviani and Dr. Sasso 

 who called my attention to these phenomena when I visited Genoa in Jan. 1829. 



