ENVIRONS OF NICE. 



441 



petrifactions, shewing that the deposition of shells had ceased 

 and commenced again. 



The occurrence of these marine remains proves, in the most 

 satisfactory manner, that the sea must have flowed greatly 

 above the level of these rocks, at a time when they were torn 

 asunder in all directions ; and, as if to prove that these opera- 

 tions had been carried on slowly, I found on the sides of 

 some of the fissures, since filled up with the Mediterranean 

 marble, the perforations of the pholas, with the shell of that 

 animal remaining in its place. 



But besides the hills composed of solid materials, there are 

 others of much importance, whether considered as to their ex- 

 tent, their altitude, or the geological inferences which may be 

 drawn from their structure and appearance, — I mean those 

 formed of gravel, principally occupying the west side of the 

 district. When travelling along the banks of the Rhone, 

 from Lyons to Avignon, I was much struck with the enor- 

 mous quantity of debris spread over a great proportion of 

 that line, and all or nearly all belonging to the alpine range 

 through which this mighty river flows. The debris on the 

 banks of the Var is of the same nature, composed of masses 

 of granite, mica-slate, quartz and jasper, pieces of compact 

 actynolite, and serpentine; but, so far as I perceived, there 

 were no fragments that could be referred to the trap rocks. 

 Saussure, § 1428. states, that he saw nothing among the 

 gravel of the Var but limestone and sandstone ; but he had 

 certainly not examined with his usual acuteness. The hills 

 formed of this gravel rise with a sharp acclivity from the 

 plain and the beach, forming a round-backed range, and of an 

 uniform elevation, but rising gradually from the height of 500 

 or 600 feet, till they rest high on the sides of Mount Cao. 

 Looking down upon this mass of alluvial matter from the sum- 



Vol. VIII. P. II. 3 K mit 



