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GEOLOGICAL SOCIETY. 



November 7. — The Society having assembled this evening for the 

 session : — The reading of a paper " On the Geology of Nice," by 

 H. T. De la Beche, Esq. F.R.S. L.S. & G.S. was begun. 



Nov. 21. — The reading of Mr. De la Beche's paper "On the Geo- 

 logy of Nice" was concluded. 



The author after describing the situation of Nice, enters into a 

 detailed account of the diluvium and the strata in its neighbourhood. 

 I. — The diluvium (if indeed it can be so considered) is peculiar ; in 

 general it takes the form of breccia, either diffused irregularly or oc- 

 cupying clefts : appearing however in both situations to be intimately 

 connected. 



1. Most of the diffused fragments correspond mineralogically with 

 the rocks on which they rest ; some few are rounded, and seem to 

 have been transported from a distance. The cement varies in hard- 

 ness and colour with the substratum. Where the breccia reposes on 

 dolomite or light-coloured limestone, it is so hard as to be blasted by 

 gunpowder, is reddish and vesicular j the vesicles being lined with 

 calcareous crystals. — Where it rests upon gray secondary limestone, 

 or on any of the tertiary beds, it is soft, friable, and almost white. 

 Between Ville-franche and Hospice, the substratum is a sand full of 

 shells so like those of the Mediterranean as to have been called sub- 

 fossil: some of these shells retain traces of their native colour, the 

 rest are bleached. This sand-bed at Ville-franche is ten feet at least 

 above the sea : at Baussi Raussi, where it descends to that level, the 

 breccia exhibits pebbles of serpentine as well as limestone : — the 

 limestone pebbles perforated with lithodomi, and the cement con- 

 taining sub-fossil shells. None of these breccias contain bones. 



2. The other variety of the diluvium is lodged in fissures. A vein 

 on the south-east of the Castle Hill has its northern side perforated 

 by lithodomi, and yields two different kinds of pebbles in the blue 

 limestone of the lower part, and the magnesian above j this spot, 

 therefore, affords evidence of four distinct epochs. — 1. When the sea 

 higher than at present, introduced lithodomi into the fissure. — 

 2. \\Tien the lower part of the fissure was filled with pebbles trans- 

 ported from a distance. — 3. When its upper part was filled with the 

 broken bones of animals, shells terrestrial and marine, and with frag- 

 ments, principally but not solely, of contiguous rocks. — 4. When the 

 sea attained its present level. 



If any one doubt the diluvial origin of these breccias, because their 

 pebbles have been derived principally from contiguous rocks, inter- 

 mixed however with a few brought from a distance; let him recollect 

 the diluvium of Lyme and Sidmouth, where the flints unbroken and 

 unrounded seem rather to have been disengaged from the surround- 

 ing chalk, than transported from any greater distance by an abrading 

 torrent. 



The fossils under the breccia seem to have been quietly deposited 

 by a sea that stood several feet higher than the present Mediterra- 

 nean. To explain this difficulty, some authors imagine that the Me- 

 diterranean has sunk, by forcing its passage through the Straits of 



Gibraltar ; 



