THE TICINO. 
233 
much metamorphosed as to be hardly recognisable, 
nipped as it were into some of the deeper folds. 
They are still, however, notwithstanding the pressure 
they have undergone, more destructible than the 
crystalline rocks, and often give rise to valleys, as 
for instance the trough which forms the Val Bedretto 
and crossing the Ticino the Val Piora; or the Rhein- 
waldthal at Spltigen.* 
One of the most important of these folds forms 
the valley of the Ticino from Locarno to Bellinzona, 
where it bifurcates, one branch formmg the Bregaglia, 
the other the Lower Val Tellina. 
At present, indeed, the Lower Val Tellina seems 
to be (Fig. 147) an anticlinal valley. But if we carry 
back our imagination to a time before denudation 
had proceeded so far, it is evident that the present 
valley once followed the line of the inclined synclinal 
* Studer, Geol. d. Schit)., vol. i. 
