432 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 4, 



the lime-works of the Silber-Hiitte, a few imperfect fossils were 

 long ago observed. At the latter, a limestone subordinate to greenish 

 and greyish schists is followed upwards by a much coarser grauwacke, 

 which becomes almost a conglomerate. Here the strike is nearly 

 N. and S. and the dip E. ; but, as the dips of these schists, grits, and 

 calcareous interpolations frequently change, we now only notice the 

 direction and inclination of the beds at the Silber-Hiitte, because 

 the strata there have a strike transverse to the usual direction of 

 the older rocks. 



Passing into the Selke-Thal, the continual undulation of the 

 strata is well seen in the gorge between Alexis Baden and Magde- 

 sprung. Unable to decide, in a rapid survey of this confused tract, 

 whether the rocks at Alexis Baden lie over or under those of Mag- 

 desprung, we met at that place with strata well exposed in quarries 

 on the left bank of the Selke, which have been much opened out 

 in the years which have elapsed since they were examined by Sedg- 

 wick and his coadjutor. There the succession is decidedly exposed, 

 and thanks to the labours of M. Bischof, Inspector of Mines, a rich 

 collection of fossils has been made, which, as we think, determines 

 one mass of these rocks (z. e. the calcareous member of them) to be 

 Silurian. (See fig. 5.) 



Fig. 5. — Section of the Upper Silurian Rocks at M'dgdesprung. 



Distance \\ mile. 



c. Schists and sandstone. a*. Altered schists. 



b. Limestone with Upper Silurian fossils. g. Greenstone and other eruptive 



a. Flagstones with Plants. rocks. 



The inferior strata visible, as exposed in the so-called " Treppen 

 Stufen" or great flagstone quarries opposite the hamlet of Magde- 

 sprung, have the normal strike of N.E.-S.W., and dip to the S.E. 

 at 65°. They are very fine-grained, have glossy surfaces, and are 

 of bluish-grey, purple, or greenish tints, so that they are distin- 

 guishable in mineral aspect from both the ordinary Devonian and 

 the Culm rocks of the chain. Either they have no cleavage, or the 

 divisional planes are coarse and coincide with the bedding. The 

 flagstones, the varied green and grey tints of which indicate the 

 successive strata, are cut across by devious and irregularly meander- 

 ing clefts called *' Stossen " by the workmen. These are fre- 

 quently accompanied by quartzose veins, and when they approach 

 to horizontality are made use of by the workmen as stages or tops 

 and bottoms for quarrying out the flagstones. The slabs are 

 often of very large dimensions, whilst their surface, exhibiting undu- 

 lation and ripple-marks, leave no doubt of the true nature of their 

 bedding. This is, indeed, still more unequivocally proved by their 

 exhibiting (though very rarely) traces of plants and apparently the 

 trails of animals. Some of the plants have the aspect of forked sea- 



