TERTIARY FORMATIONS OF SWITZERLAND. 



149 



this paper, and must for any further information refer to the work already 

 alluded to, published at Berne by M. Studer. 



Quitting the wide expanse of the great Helvetic Basin, I wish next 

 to direct attention to the circumstances connected with the tertiary 

 valleys of the Jura, and more particularly to the valley of la Chaux de 

 Fonds, which may serve indeed as a type of the rest. 



The villages of la Chaux de Fonds and le Locle, at the two extremities 

 of the same valley, are the richest, the most populous, and, in some respects, 

 the most remarkable of any in Switzerland. They are situated near 

 the frontier of France, one in the Northern and the other in the Southern 

 part of a valley which is about ten miles long and one broad, extending 

 in a North-Easterly direction, at an elevation of more than two thousand 

 feet above the level of the sea. There is no outlet to the valley for drainage 

 at either extremity, and its general appearance, as well as geological 

 structure, show clearly that it was formerly the bed of a mountain lake, 

 resembling in all probability those still existing in the Jura, such as the 

 Lac de Joux, the Lac de St. Point, and one or two others. As I first 

 visited la Chaux de Fonds from Neuchatel, and afterwards entering 

 the valley at its South- Western extremity, passed le Locle and again 

 reached the village on my journey Northwards, I will first describe 

 in a few words the section across the Jura, and then the peculiarities 

 which present themselves in tracing the beds in the direction of the 

 valley's length. 



SECTION II. 



Level of the Sea, 



ACROSS THE PRINCIPAL RANGES OF THE JURA. 



Ttte it Rang: 



City i 

 VaUengy. ^^^ of ft 



Scale i inch to a mile. 



City and hake 

 NeucMtel. 



Immediately on leaving the town of Neuchatel the road begins to 

 rise, although the passage across the first range of the Jura is rendered more 

 easy by its following the course of a transverse valley, which brings 

 a mountain torrent from the first and most Easterly valley to the lake 

 of Neuchatel. The naked walls of rock exhibited on each side of the 

 road show clear marks of the violent dislocation which must have accompa- 

 nied the upheaving of the mountain chain, and we can trace easily the 



