THE ENGADINE. 
247 
moved on both sides of the river, which flows over 
crystalline rock. 
At Zernetz the great crystalline boss of the Monte 
Baselgia forces the river to make a wide curve, after 
which it resumes its previous course. On the west 
side of the mountain the lateral streams join the Inn 
almost like the spokes of a wheel on some gigantic 
axle — the Ova Sparsa, Sursura, Susasca, Sagliano, 
Lavinuoz, and Tuoi. On the other hand, the original 
line of the valley, as indicated by the strata, passes 
in a straighter line to the south-east of the moun- 
tain. 
The mountain itself consists of Gneiss and Crys- 
talline — principally Hornblende — Schist. In the centre 
of the boss the strata-like divisions are perpendicular, 
with gaping fissures of great depth. 
The small plateau of Ardez is one of the most 
interesting parts of the Lower Engadine. The basis 
is Granite, which resembles that of the Julier, and in 
many places comes to the surface. It is often polished, 
doubtless by glacial action. 
Fig. 153, representing a section of the Inn Valley 
at Tarasp, shows that the strata are overthrown into 
compressed folds and the river runs in a synclinal 
trough.* 
* Theobald, Beitr. z.. Geol. K. d. Schw,, L. n. 
