294. THE BEAUTIES OF NATURE CHAP. 
Chamouni, the Valais, the Urseren Thal, 
and that of the Vorder Rhine really form — 
part of one great fold is further shown by 
the presence of a belt of Jurassic strata 
nipped in, as it were, between the crystalline 
rocks. 
This seems to throw light on the remark- 
able turns taken by the Rhone at Martigny 
and the Vorder Rhine at Chur, where they 
respectively quit the great longitudinal fold, 
and fall into secondary transverse valleys. 
The Rhone for the upper part of its course, as 
far as Martigny, runs in the great longitudi- 
nal fold of the Valais; at Martigny it falls 
into and adopts the transverse valley, which 
properly belongs to the Dranse; for the 
Dranse is probably an older river and ran in 
the present course even before the great fold 
of the Valais. This would seem to indicate 
that the Oberland range is not so old as the 
Pennine, and that its elevation was so 
gradual that the Dranse was able to wear 
away a passage as the ridge gradually rose. 
After leaving the Lake of Geneva the Rhone 
follows a course curving gradually to the 
