1884.] on the Building of the Alps. 61 



the southiern flanks of the St. Gothard — a group also traceable in the 

 upper portion of the Binnenthal, though apparently far less perfectly 

 developed. I think also that in the gigantic anticlinal of the 

 Simplon we have evidence of sharp flexures on a great scale ; and 

 that these garnetiferous schists are only here and there preserved as 

 the lower ends of enfolded loops, so that the bulk of the massif, and so 

 far as I can tell the actual summit ridges of the Rossbodenhorner and 

 Monte Leone, are composed of the bedded gneisses and strong schists, 

 and perhaps of the more friable gneisses which have been already 

 described in the mountains further to the east. 



The mountains further west — the aspiring peaks which rise 

 around the two branches of the Visp, including among them some 

 of the highest summits of the Alps, such as Monte Rosa, the Mischa- 

 belhorner, the Matterhorn, and the Weisshorn — offer indeed magnifi- 

 cent sections, but are full of difficulty. The fundamental gneiss, 

 if I mistake not, is occasionally exposed — as, for example, in the 

 rocks of Auf der Platte, at the base of Monte Rosa; and in parts 

 of the Mischabelhorner blocks of coarse granitoid rock, often very 

 porphyritic, which I refer to the same series, are brought down by 

 the glaciers. There are also mica schists in plenty, such as the 

 summit rocks of Monte Rosa and the backbone — if the phrase be 

 permitted — of the Mischabel- and Saaser- horner, which I refer to 

 the second zone already described — that of the bedded gneisses and 

 strong mica schists. I have also seen specimens which closely resemble 

 the garnetiferous schists of the St. Gothard district, but we meet in 

 this district with a group of rocks which, if not altogether unknown 

 before, appears now to be developed to an exceptional extent, and to 

 become an important factor in the Alpine crystalline series. 



Those who are familiar with the environs of Saas and Zermatt 

 will remember how frequently schists or schistose rocks of a greenish 

 colour occur. Sometimes they are interbedded with strong mica schists, 

 or schisty quartzites ; sometimes they form homogeneous masses of 

 considerable extent. It is possible that some of the latter are in- 

 trusive masses of serpentine, to which subsequent pressure has given 

 a schistose aspect; certainly there are occasional masses of coarse 

 gabbro, which I think undoubtedly an intrusive igneous rock ; but 

 still, making all allowance for such cases, there is in this region a 

 considerable mass of greenish hornblendic, talcose, and serpentinous 

 rocks which appears to be non-igneous in origin. We find these all 

 around Zermatt. They form the ridges of the Gorner Grat and of the 

 Hornli. They break out through the snows of the Breithorn and 

 Little Mont Cervin, and constitute no inconsiderable portion of the 

 mighty obelisk of the Matterhorn. The whole of that peak, according 

 to the investigations of Sgr. Giordano — and with this my own recol- 

 lections correspond — consists of an apparently regularly bedded series 

 of serpentinous and micaceous schists, and of greenish gneisses, with 

 the exception of a gabbro, developed on the western side, which I have 

 no doubt is an intrusive rock. Can we trust these indications ? Are 



