the jura. 
23 
While most river valleys, being due mainly to 
erosion, slope to one end, the valleys of the Jura are so 
entirely the result of geological causes that they are 
sometimes horizontal, or even lowest in the middle. 
■w. 
Ei. 
. Rieia 
Huningen Ilcin-Basel 
Rhein Si.Jakol) 
Schwoizerhall 
SalzlUB ft. 
sS'i 
level 
K... 
xqs 
3935 ft. below sea level 
79. — Section across the Rhine Valley. 
iind ill several cases closed at both ends. The result 
is that they are' often dry valleys, or contain streams 
running from the two ends towards the centre. 
Thus between Biel and Delemont we have the 
Val de St. Imier, in which the Suze, running to the 
"W. 
Basel 
Veltsteinbrucke „ 
Eomli 
Greuzacher- 
Junkkolz 
¥yleii 
Fut. 80. — Section across the Rhine Valley at Basic. 
E., meets the stream which comes down the Combe 
de Pery, and the two together find an exit thiough 
the Cluse de Pery to Biel. A little north is the Val 
de Tavannes, where again two streams, one from the 
N.E., and the other, the Birse, from the S.W. meet 
