Environs of Lons le Saunter. 155 



It attains at St, Maure, Cran9ot, and nearly to Mirbel, the 

 height of the oolitic and granular beds, whicli aflFord the best 

 building stone. 



Beds of compact limestone, with an undetermined and 

 conchoidal fracture occur near the latter village ; they pro- 

 duce the most esteemed lime in the country. 



The valley of Lons le Saunier, after having been enclosed 

 to the limit of the platform, suddenly opens to the right, near 

 the village of Perigny. 



This limit, distant 2 kilometres [about 1§ mile] on the east 

 of the town, passes by the villages of Pannessiere, Lavigny, 

 Voiteur, and Frontenay ; it afterwards turns a little to the 

 east towards Poligny and Arbois. 



The platform is prolonged, on the left of the valley, to 

 Montaigu, forming a rounded projection which separates the 

 two basins of Lons le Saunier and Macornais. 



Beyond the limit of the platform, the basin of Lons le 

 Saunier is bordered on the left by four longitudinal hills, 

 having a N. and S. direction, which are united together, 

 and to the projection of Montaigu by passes of little eleva- 

 tion ; it opens out to the right, and is bounded by very flat 

 hills. 



The oolitic rocks have, in this part, been almost entirely 

 carried away : some scattered patches only remain on the 

 gryphite formation, forming the knolls of Montmoret, Pi- 

 mont, I'Etoile, the hills of Chilles, le Pin, Montin, Plainoi- 

 seau, Arlay, &c. These are, it may be said, the witnesses 

 of the great convulsion that has torn away the platform which 

 covered all this country.* 



The gryphite limestone rocks have been laid open through- 

 out the greater part of this extent ; I shall observe, that in 

 all situations where the junction of the first marls of the last 

 formation with the gryphite rocks can be observed, they are 

 found disposed in beds parallel to the portions of beds on 



* These patches seem to be outliers resembling those of tlie same rocks ' 

 ih the vicinity of Bath, &c. (Trans.) 



