388 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [April 9, 



well-known Gosauthal. This also ought formerly to have furnished 

 an ice-stream hardly less important than that which we suppose to 

 have descended the main valley. But the lower part of the Gosau- 

 thal is a narrow defile, a Y-like valley of river-erosion, ahout 6 miles 

 long, between the Ramsauer Gebirge to N. (highest summit 6066 

 feet) and the Plassen to S. (6403 feet). The valley then suddenly 

 expands into an oval fertile and level basin (about 2540 feet above 

 the sea), which has doubtless once been occupied by a lake some 

 4 miles long. Then it contracts again into a second glen, leading 

 up to the Vorder Gosausee (3051 feet). Above this, higher up 

 the glen, is the Hinter See (4078 feet), a much smaller lake, at the 

 very base of the Dachstein. The latter I was unable to visit. The 

 Vorder See is kept at its present level by a great debris talus, which 

 descends from the cliffs above its left bank. If, then, we suppose 

 that a glacier excavated this, passed down the glen below, and 

 scooped out, chiefly from the soft Gosau (Upper Cretaceous) beds, 

 the basin on which that straggling village now stands, how have the 

 marly (Cretaceous) beds escaped, which are visible at no great 

 height on the left bank of the intervening glen? Again, if the 

 glacier scooped out the Gosau basin, and then, attenuating itself, 

 passed out through the defile below, how was it that this was not 

 cut into a trough ? Or if we are to explain the y-shape by sub- 

 sequent denudation, why is the delta at Gosaumiihle so small? 

 Further, if a considerable glacier did descend this valley, and pass 

 over a shoulder of the Gosauhals (a spur of the Kalenberg), it 

 must have thrust the main ice-stream towards the right, and we 

 might expect to find some sign of the increased pressure on that side 

 by a corresponding curvature of the lake-basin. The following 

 extract from my note-book describes the real state of the case : — 

 " Opposite to Gosaumiihle the right bank of the lake is an almost 

 level w^ll of cliff, seamed in many places by small streams, some of 

 which have done no more than smooth out a slight channel." 



The above considerations appear to me insuperable difficulties to a 

 theory of glacier-erosion so far as regards the lake of Hallstadt. 



Two other small lakes which contribute to the Hallstadter See 

 may here be mentioned. These are the Alt-Aussee* and the 

 Grundlseet. Both these lie just within glens of a limestone range 

 of moderate elevation. Like the Vorder and Hinter Gosauseen, 

 they are just such as we should most readily concede to glacier- 

 erosionists ; but even here the great steepness of the mountains 

 around their heads seemed difficult to reconcile with the theory, and 

 they are certainly maintained at their present level by drift brought 

 down by lateral streams. 



The next district which I proceed to examine is the cluster of 

 lakes about the Schaffberg — the Bigi of the Salzkammergut. From 

 this commanding summit (5837 feet) the orography of the neigh- 



* About 2 miles long and f mile broad, 2247 feet above the sea, 180 feet 



t About 1000 yards long and loOO broad, 2164 feet above the sea, 21S feet 

 deep. 



