SINGULAR ARRANGEMENT OF STRATA. (]^ 



windings of which, concealing it frooi your view till vou 

 reach it, render the picture more magical, and the surprise 

 the greatei'. 



It was in the cliffs forming the walls of this narrow basin. Strata distorted 

 that I had an opportunity of noticing sotne singular arrange- 

 ments of the strata composing it. Every thing exhibits 

 traces of the derangement I had observed in many other 

 parts of Jura, but here they appeared to rae larger and more 

 varied than any where else. I cannot give a better idea of 

 them than by the drawings I made on the spot, engravings 

 from which are annexed. See PL II, figs. 2 and 3. 



It is to be remembered, that ftg. 2 represents the face of c^yern, 

 the rock to the right of the cavern, the entrance of which 

 <oramences at a very little distance from the natural vault 

 A; so that the cavern has been opened through the strata 

 B, B, and those resting upon and parallel to them, which 

 dip toward the centre of the mountain at an angle of about 

 thirty degrees. This fact will give an idea of the effect and 

 of the time required for the water, or the acting power 

 whatever it was, thus to force its way through , immense 

 strata of a hard and compact rock. 



The strata A, C, &c. exhibit a semicircular arch; those Natural arches. 

 marked D, D, an elliptical arch. ^Both appear to rest on 

 the strata E, E, which are no doubt produced to the left un- 

 der an angle nearly similar to that of the strata B, B; and 

 probably receive the extremity A, C, of tiie smaller arches. 



All the little veins or laminae, that compose each stratum, Lamina of die 

 have regularly undergone the same curvature; so that the ^"■^^^'^'S"'^'^>' 

 arcades an^ all the curved parts of the strata of this moun- 

 tain exhibit the appearance of a book bent in different di- 

 rections. 



I could not get at the knowledge of the arrangement of Part beneath 

 the part below, FjF, which forms the floor of a sort of yard not visible, 

 belonging to the manufactory. Mr. Besson is making an 

 excavation under the natural arch D, D, for the purpose of 

 a storeroom or workshop. 



The existence of the portions or rudiments of strata. Depositions in 



G,G, G, H, H, H, '.via perhaps appear tiD<fular, but it is ^^^^ ^""'^^ "' 



1 , , , . T • T/. - • 1 , the aiches. 



i:iot the less real, and is very distinct. It i might be per- 



niitted to huzard an opinion respecting tlieiCj it vvou4d be, 



F 2 that 



