■ 562 DR. C. S. DT7 RICHE PRELLER ON GLACIAL [Aug. 1 896, 



depth, mixed in its upper portion with boulders reaching the size of 

 a man's head, and passing into about 2 metres of moraine, on which 

 are stranded several enormous blocks of calcareous and polygene 

 Miocene Nagelfluh, measuring about 3x2x1 metres, namely from 

 10 to 15 tons in weight. In its lower portion, the conglomerate 

 shows irregular, somewhat oblique stratification, and numerous dis- 

 integrated pebbles, while many of the larger, often subangular 

 pebbles, as well as the boulders in the upper portion, exhibit ice- 

 scratches. This upward passage from glacio-fluviatile to purely 

 glacial deposit therefore marks a period of transition, in other words, 

 ;an oscillation of the glacier. 



Pig. 3. — Section at Eichthal, near Baden. 



Miocene Nagelfluh blocks 

 15 tons 



m. above 

 g sea-level 



> 



Not less instructive, although of a more complex character, is an 

 ^exposure on the opposite, that is, the Ennetbaden or right side of 

 the basin, on the Ehrendingen road which skirts the slope of the 

 Laegern. In this quarry, conspicuously situated at contour 412, or 

 about 60 metres above the Limmat, is exposed a cliff of obviously 

 very old, but, owing to disintegration, somewhat brittle conglo- 

 merate, about 15 metres in depth, banked up against the Jurassic 

 strata, and containing in its upper portion a number of natural 

 caves left by large well-rounded Miocene Nagelfluh boulders about 

 2 metres in diameter, which have gradually fallen down, and now 

 encumber the floor of the quarry. The Nagelfluh is irregularly 

 overlain and partially covered by morainic material mixed with 

 Jurassic detritus, while in front of it — that is, in a pit excavated 

 close to the road and at a lower level than the gravel floor — appears 

 a younger, much more sandy conglomerate composed of much 

 fresher pebbles. This later gravel, which was evidently banked 

 up against the Deckenschotter cliff, reappears lower down the road 

 and is excavated near the junction of roads at the upper end of the 

 iDasin. 



A fourth exposure examined in the Baden basin is that situated 

 at contour 467, under the shelter of a Jurassic knoll called Ghiggen- 

 buhl, below the village of Hertenstein, near the lower end and on 

 the right side of the basin. The two pits, facing each other, form 

 part of a larger deposit and are excavated to a depth of about 

 5 metres ; in both cases there are 3 metres of stratified, not 

 very compact, conglomerate resting on about 1 metre of sand and 



