between Nice and the Col cU Tendi. 189 



colour, but giving rise to many springs^ ordinarily containing no fossils, 

 but presenting sometimes in its superior beds very ancient fossils; — it is 

 accompanied by rauchvvacke ; contains sometimes fetid limestone, and is 

 found frequently intermixed with gypsum ; its total thickness may be reckoned 

 at 1500 feet." 



M. Risso also informed me, that near the source of the Var this same elder 

 Alpine limestone contains gypsum, associated with sulphur and salt sprino-s. 



I did not examine the gypsum of Vinagrie and Requiez, on the east of 

 Nice, which Mr. De la Beche considers as connected with the Jura or 

 younger Alpine limestone ; and, at the gypsum quarry of Cimiez, a little north 

 of the town, I could find no decisive junction. But 1 think it remains to be 

 determined, by the analogies of other districts, whether the gypsum at these 

 three localities is protruded to the surface by the elevations and contortions that 

 occur in this neighbourhood, and occupies the usual place of gypsum below 

 the Jurassic and in connection with the elder Alpine limestone; or, whether 

 it ofiers the novel phenomenon of massive gypsum, coeval with the Jura or 

 younger Alpine limestone, a formation in which, thin beds of fibrous gypsum, 

 and selenites dispersed through beds of clay, are the only forms of sulphate 

 of lime which have, till lately, been noticed. The recent observations of IM. 

 Brongniart, M. Dufrenoy, and M. Elie de Beaumont, in the South-east and 

 South of France, favour the opinion of Mr. De la Beche, that the gypsum at 

 Nice belongs to the Jura limestone formation. It may, however, be stated, 

 that Mr. De la Beche's section *, is not inconsistent with the other hypothesis : 

 for the dip of the Castle Rock is towards and beneath the gypsum of Cimiez ; 

 and if this Castle Rock be referred to the dolomite of the new red sandstone 

 formation, it will occupy its usual place subjacent to the gypsum. It may be 

 observed still further, that should the Castle Rock belong to the Jura lime- 

 stone, its dip towards the gypsum of Cimiez may still be explained, by imagin- 

 ing a fault to cross the plain of Nice between Cimiez and the castle. 



The usual association of the members of the new red sandstone formation 

 may be seen also in the South-east of France, along nearly the whole line of 

 road from Toulon to Frejus and the base of the Estrelles. From beneath the 

 mountains of limestone that stretch north-east from Toulon, the new red 

 sandstone emerges, and presents nearly all the ordinary associations of red 

 marl and red sand, with gypsum, granular dolomite, rauchwacke, and red con- 

 glomerate, which are so familiar to us in Central Germany. Near the base 

 of the Estrelles, this conglomerate is loaded with pebbles of reddish porphyry, 

 derivative from these mountains, and much resembling the porphyritic pebbles 



* Plate 23. fis. 1. 



