158 M. ClIARBAUT ow i^e 



Mont-Orient, situated to the south of Lons le Sauaier, 

 behind the village of Courbouzon, presents very curious dis- 

 turbances of the beds. 



This mount intercepts the communication of two long 

 villages, being situated in the line between them, and 

 presents a very elevated escarpment oa the side of Cour- 

 bouzon, of two systems of beds upset to the E. and W. on 

 the bottom of the lower valley, and resting against its sides, 

 the beds of which are inclined towards the centre on the left, 

 and are horizontal on the right. 



To account for this singular disturbance, it is su£G.cient 

 to imagine that the waters that descended from St. Laurent 

 towards Courbouzon, having formed, in ihis broad part of 

 the valley, two galleries instead of one, separated by a 

 mass, either of gryphite beds, or marls more solid than 

 the rest, in each side of which the sinking took place 

 as in two different vallies, and that beyond, the two united 

 currents entirely carried away the beds, which were thus 

 left unsupported. 



These beds, leaning against each other, opposed such re- 

 sistance to the waters, that they were compelled to open a 

 passage to the west, near the village of Gevinge. 



The beds of the right side of this mount occur disturbed 

 under various angles ; they are first inclined at about 40°, 

 and afterwards at 75°. 



Lastly, these compact and oolitic beds are in a perfectly 

 vertical position ; but those on the left have sunk more than 

 the former. 



The country house of the late Peer of France, Vernier, is 

 situated on the summit of this mount, at the separation of 

 the two systems of disturbed beds. , 



At its foot is worked, in the gryphite limestone formatioi), 

 the gypsum quarry of Courbouzon. 



I ought to state, before I terminate this memoir, that the 

 two rock formations of the Jura chain have already been 

 noticed by several geologists ; but I should, at the same 

 time remark, that they considered that which contains 



