Vol. 52.] DEPOSITS, ETC., IN STJBALP1NE SWITZERLAND. 565 



•great part or entirely removed, and carried beyond Turgi into the 

 Aare and Rhine valleys. On these grounds, the whole of the 

 younger gravels as well as the overlying thin coating of moraine in 

 the lower Limmat valley must, in my opinion, be regarded as, in 

 the main, the product of second glaciation, and as having probably 

 been deposited during the recession of the Linth glacier of that 

 period. The cliffs and other remuants in situ of old conglomerate 

 projecting from that gravel and moraine, and embedded in the 

 valley at Baden and "Wettingen, afford conclusive proof that, at the 

 time of the deposition of that old conglomerate, the floor of the 

 valley was already in existence. The great difference of level 

 between the Cavernous jSagelfluh or Deckenschotter deposits on the 

 ridges of the Molasse hills and those at the bottom of the valley 

 seem, at first sight, to point to subsequent erosion on an enormous 

 scale ; but, in my view, the high-level deposits were formed during 

 the maximum extension of the Upper Pliocene Subalpine ice-sheet, 

 which, filling the valley and spreading over the hills on both sides, 

 probably reached to the lower end of the Eaden basin, while the 

 low-level deposits were formed during the recession of the glacier 

 when the latter had already shrunk considerably, and was itself 

 embedded in the valley. 



Hongg. — About 11 kilometres from Killwangen, on the right side 

 of the valley, below the village of Hongg, and close to the road, a 

 conspicuous exposure or cliff of Cavernous Xagelfluh partially 

 excavated occurs at contour 420, about 30 metres above the present 

 river-level. The well-cemented, but coarse, indistinctly stratified 

 conglomerate, about 7 metres in depth, rests on sand, and is 

 overlain by about 2 metres of moraine and talus. The presence of 

 numerous scratched pebbles shows that it was deposited not far 

 from the glacier, but the overlying moraine, which has left it 

 entirely undisturbed, is a younger deposit, probably of the third 

 glaciation. The conglomerate must, in my view, be regarded as 

 Deckenschotter, and this is confirmed by a pit about 100 metres 

 lower down on the same road, where a much looser younger gravel, 

 interstratified with sand and overlain by moraine, is exposed. The 

 phenomenon already noticed at AVettingen and Baden, of younger 

 gravel being banked up against a remnant of older conglomerate, is, 

 therefore, observable also at Hongg, the younger gravel being, like 

 the extensive gravel-beds at the bottom of the valley, the product of 

 the second glaciation. 



Kussnacht. — Passing over the typical Deckenschotter deposit of 

 the Uetliberg, as well as the more recent deposits in the immediate 

 vicinity of Zurich already described in previous papers, the next 

 locality of interest is on the right shore of the lake, about 5 kilometres 

 above Zurich, in the Kussnacht ravine, deeply eroded in glacial 

 deposit and Molasse by the torrent or Tobel of the same name. In 

 the upper part of this ravine, about 4 kilometres from the lake, 

 several cliffs of Cavernous Nagelfluh crop out from the moraine by 

 which the Molasse is covered to a depth of 50 to 100 metres. At 

 one point on the left bank of the torrent, and at contour 520, one of 



