68 PROCEEDIN"GS OF THE GEOLOGICAL SOCIETY. 



In many places we find, as above, intercalated in the more granitoid 

 masses, bands of mica-schist or of a slabby fine-grained gneissic 

 rock, which might readily be taken for proofs of bedding, but which, 

 on examination, prove, at any rate in many cases, only instances of 

 pseudostromatism ; while, as we approach the southern part of the 

 chain, e. g. in the neighbourhood of the Eggischhorn and Sparren- 

 horn, and on their southern slopes, the rocks are generally more 

 distinctly foliated, and clearer indications of bedding are given by 

 definite changes in mineral structure. At the extreme western end 

 of the massifs on the way from Kix3pel to the Lotschen Pass, we 

 come upon sundry chloritic schists, which, I think, must indicate 

 some sort of stratification in the materials of which this central 

 massif is composed. These are referred by the Swiss geologists to 

 a newer series. If we examine the Maderanerthal, which occupies 

 a position in regard to the Mesozoic rocks similar to that of the 

 Gadmenthal, and at the head of which we have almost our last view 

 towards the east of the crystalline series, we find at first a rather 

 flintj^ schistose rock, which, however (like that already mentioned 

 near Amsteg), cannot be relied upon as a proof of bedding, as the 

 rock is endently greatly crushed, and the conspicuous structure is 

 due to sheen surfaces*. In the upper part of the glen we find 

 moderately fine-grained gneissic rocks, and almost at the foot of the 

 Hlifi glacier, very near to the base of the overlying Mesozoic rocks, 

 we have a most interesting series. Space forbids my entering into 

 details, so that I must ask to be allowed to quote the conclusions at 

 which I arrived after very careful work on the spot, corroborated by 

 subsequent mici'oscox^ic study : — 



(1) We have here two varieties of rock, both igneous in origin : 

 one not unlike the so-called Dimetian of Pembrokeshire, almost a 

 binary compound ; the other containing, in addition to quartz and 

 felspar, a fair amount of hornblende. The relations of these are not 

 now clear ; sometimes the former suggests intrusion into the latter ; 

 sometimes they seem to graduate rapidly one into the other. 



(2) Both contain fragments of a highly crystalline hornblende- 

 schist, often exhibiting a marked mineral banding like some of those 

 at the Lizard, Cornwall. The metamorphism of this rock was 

 evidently accomplished when the dislocation took place, as the 

 fragments lie about in the enclosing rocks in difi'erent direc- 

 tions. (A similar hornblende-schist occurs in situ at no great 

 distance.) 



(3) In close relation to the two igneous rocks is a considerable 

 amount of a gneissose rock. The evidence as to the relation of the 

 latter to the former is not absolutely conclusive ; but we have either 

 a case of igneous rocks intruded into metamorphic rocks of very 

 similar composition, or the foliation (which has generally a S.W.- 



* In the newly published map of the Swiss Geological Survey, I find that 

 the rocks of the Maderanerthal and of the Eeuss valley, up to near Grurtnellen, 

 are regarded as an infold of an upper series (Casanna Schists). This may be 

 quite right, but I did not see any evidence which placed the question beyond a 

 doubt. 



