566 DR. C. S. DTJ RICHE PRELLER ON GLACIAL [Aug. lSg6 r 



these cliffs is accessible, the section here exposed being shown in 

 the diagram, fig. 5. The extremely compact, but in some parts 



Fig. 5. — Section in the Kussnacht Ravine. 



disintegrated and brittle conglomerate, about 20 metres in depth? 

 dips up the valley at an angle of no less than 40 degrees, and 

 against it are banked, at its upper end, several alternations, each 

 about 1 metre in depth, of younger stratified sand and gravel 

 dipping in the opposite direction. In a small pit, a few hundred 

 metres farther up the ravine and at about the same level, there 

 appears, in superposed layers of 2 metres each, fresh sand and gravel 

 overlain by moraine with large boulders, this deposit being evidently 

 part of the same deposit as the younger sand and gravel in the other 

 exposure. The moraine which overlies the gravel in both these 

 exposures exhibits the irregular, mound- and knoll-shaped contours 

 so characteristic of the moraine of the third glaciation. The 

 contact of the Cavernous JNagelfluh with the Molasse, near the edge 

 of the torrent, is buried under gravel detritus, although the Molasse 

 appears immediately below and above the deposit ; but at a short 

 distance higher up the ravine, the torrent, whose bed is throughout 

 encumbered with erratic blocks of occasionally enormous size, 1 

 flows no longer on Molasse but on glacial clay, an additional proof 

 of the great age of the upper part of this valley. The Molasse 

 strata in the lower part show a gentle but very distinct dip up the 

 ravine ; it would, however, be hazardous to infer that the steep 

 reverse dip of the Cavernous Nagelfluh is the result of the same 

 displacement by earth-movements. At all events, the various 

 phenomena described warrant the conclusion that that conglomerate 

 can only be Deckenschotter, while the gravel banked up against it 

 is the product of the second glaciation. 



1 The largest of these erratic blocks in the Kussnacht ravine i3, according to 

 my measurements, 3x3x3 metres, equal to 60 tons in weight, and bears the 

 name of ' Alexanderstein,' in memory of the late Dr. Alexander Wettstein, 

 who described the Kussnacht ravine in his ' Geologie von Zurich, etc.,' 1885, 

 and a few years later lo*t his life on the Jungfrau. 



