■564 BR. C. S. BIT RICHE PRELLER ON GLACIAL [Aug. 1 896, 



•described in previous papers, and on the right side a small cap of 

 the same conglomerate on an isolated hill called the Sulzberg. Thus 

 the Deckenschotter appears at three points across the valley, the 

 contact with Molasse being at the two extremes approximately at 

 contours 470 and 480, and in the valley at contour 362. 



Between the Teufelskeller deposit near Baden and that of the 

 Uetliberg near Zurich, several ledges of Deckenschotter occur on the 

 upper slope of the broad Molasse ridges locally called Heitersberg 

 and Hasenberg, the conglomerate being overlain by moraine of the 

 second glaciation to a depth varying from 50 to 100 metres, while 

 the opposite or Altberg ridge, between Sulzberg and Zurich, has 

 apparently been entirely denuded of all evidence of the first 

 glaciation, even the younger moraine overlying the Molasse being 

 of insignificant thickness as compared with that on the ridge of the 

 left side of the valley. 



Killwangen and Wurenlos. — Beturning now to the Limmat valley 

 and proceeding from Wettingen upward, we come, at a distance of 

 about 4 kilometres, to the remarkable moraine-wall of Killwangen, 

 which I described in an earlier paper as marking the limit of the 

 third glaciation. Near the village of Wurenlos, on the right side of 

 the valley, there is, in a large and conspicuously situated sandstone 

 quarry, a very striking and clean-cut exposure of moraine overlying 

 the Marine Molasse to a depth of 6 metres. The moraine, in which 

 are embedded large boulders of Miocene Nagelfluh and Sernifite, 

 shows that the glacier travelled over the Molasse without in the 

 slightest degree disturbing the latter, much less eroding it. This 

 moraine deposit, occurring, as it does, at least 1 kilometre in 

 advance of the terminal moraine of Killwangen, must, in my 

 opinion, be regarded as belonging to the second and not to the third 

 glaciation. 



Limmat Gravel-beds. — The Killwangen moraine-wall rests on 

 the so-called ' Limmat gravel,' which is the fluviatile product of the 

 second glaciation. Dr. Du Pasquier has been led to regard all 

 the valley-gravel and overlying moraine below Killwangen and as 

 far as Turgi as the product of the third glaciation : that is, as con- 

 stituting the glacis or ' Gletscherboden ' of the Linth glacier of 

 that Ice-period. It is, perhaps, somewhat hazardous thus to draw 

 a hard-and-fast line between the two Pleistocene gravels in the 

 Limmat valley. The glacier of the third Ice-period, after stopping 

 at, and receding from, Killwangen, remained probably for a long 

 time stationary at the lower end of the present Lake of Zurich, as is 

 evidenced by the belt of moraine-walls so characteristic of that 

 city. On Dr. Du Pasquier's theory, it would therefore follow that 

 all the gravel-beds between Zurich and Killwangen were deposited 

 during that second stoppage, and are consequently the product of 

 the youngest or third glaciation, whereas they undoubtedly belong 

 to the older Pleistocene series, since the Killwangen moraine-wall 

 distinctly overlies them. The material derived from the Zurich and 

 Killwangen moraine must therefore have been deposited on the 

 older gravel and moraine, and was by subsequent denudation in 



