Vol. 52.] DEPOSITS, ETC., llf SUBALPLNE SWITZERLAND. 



573 



deposited the Deckenschotter of the Menzingen plateau and Lorze 

 valley, already described in a previous paper, 1 must have flowed at a 

 much higher level, that is, probably 150 metres higher than the 

 Molasse-bed of the Preglacial Sihl near Geissboden, or that of the 

 present Sihl at Schindelleggi. 



In the foregoing description 

 of glacial deposits I claim to 

 have shown : (1) that deposits 

 and remnants in situ of Decken- 

 schotter occur not only on or 

 near the ridge of the hills, but 

 also at the bottom and on 

 the slopes flanking the Zurich 

 valley, notably at Baden, Wet- 

 tingen, Hongg, Kussnacht, Au, 

 and Altschloss, of which the 

 first four deposits appear re- 

 spectively at a gradually ascend- 

 ing level, while the last two 

 are now at a lower level than 

 they were at the time of their 

 deposition ; (2) that in the first 

 four cases referred to, younger 

 glacio-fluviatile gravel, in the 

 main the product of the second 

 glaciation, is banked up against 

 the old conglomerate, and that 

 in several cases, for example, 

 at Baden and Wettingen, the 

 old conglomerate resting on 

 Molasse, is buried under the 

 younger gravel, which, in its 

 turn, is overlain by moraine. 



These phenomena lead to the 

 conclusion that at the time 

 immediately preceding the de- 

 position of the Deckenschotter 

 — in other terms, at the advent 

 of the first glaciation, towards 



the end of the Pliocene period — the Ziirich valley was already 

 eroded, the depth of the lower part of the valley being approxi- 

 mately that which it has at the present day, while the floor of the 

 upper part of the valley was at a higher level than that of the 

 present lake, and, as I shall show in the sequel, was subsequently 

 lowered by a subsidence due to earth-movements. 



Quart. Journ. Geol. Soc. vol. li. (1895) pp. 369 et seqq. 



