THE REUSS. 
207 
horizontal, and it is evidently a river valley due to 
erosion. 
The two sides (Fig. 140) are reflections one of 
the other, though, as the lake runs nearly north and 
south while the strike of the strata is south-west by 
north-east, the corresponding portions of the strata 
on the west side lie somewhat further south than 
those on the east. 
Between Kindlimord and Schwybbogen a moraine 
covers the bottom of the lake, and rises within 
50 metres of the surface.* 
The walls of the Bay of Uri are formed mainly 
of Cretaceous strata lying on Jurassic (Malm, Dogger, 
and Lias), and thrown into various folds and arches. 
As we approach Brunnen from the west, a mag- 
nificent arch of Neocomian, capped (Fig. 140) by 
Urgonian (on which the hotels of Axenstein and 
Axenfels stand), may be seen at the commencement 
of the Axenroad, and on looking back from Brunnen 
the counterpart can be traced under Seelisberg. The 
strata are folded back upon themselves, over the 
summit of the Frohnalp (Fig. 140), and down again 
in a deep trough at Sissikon where the Cretaceous 
and Eocene strata are perpendicular. This great 
fold shows itself near Bauen on the opposite side of 
* Heim, Beitr^ z, Geol. d. Schtv.^ L. xxv.. 
