1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 213 



Other light than that of a huge superficial erratic derived from some 

 parent rock, which has either since been lost by subsidence and 

 buried beneath other deposits, or is hidden from sight under those 

 coverings of snow and ice, which necessarily impede observation over 

 so very large an area of the higher Alps. I fully admit that the small 

 bands of granitic rock above adverted to, are fairly intercalated 

 in the flysch, but the presence of geodes, the largest of which is not 

 above four feet long and a foot wide, can never satisfy me that a mon- 

 strous block, containing 400,000 cubic feet, was similarly formed; that 

 block not having the slightest appearance of having ever been a geode. 

 Again, no conglomerates known in any part of the flysch of the 

 Alps exhibit pebbles of more than a foot or two in diameter. But, 

 supposing this block to have been part of a conglomerate, and that 

 it was transported from a ridge of crystalline rock into the flysch 

 during the formation of that deposit, by what agency must we 

 suppose it to have been moved ? Certainly not either by solid or 

 floating ice ; for the period of the nummulites and flysch was any- 

 thing but one of glacier action, and was in fact one of considerable 

 warmth. 



Seeing then no satisfactory explanation of the deposit of a block of 

 this magnitude in finely laminated sandstone and schist (such as con- 

 stitutes the flysch of the sides of the valley of Habkheren) {g of 

 fig. 21), I necessarily reject the application of such reasoning to the 

 Bolghen. On re-examining that locality (see fig. 1 9, p. 209) 1 perceived 

 that the rocks which I had described as millstone grits, greensands 

 and schists, have each of them a persistent strike. Thus, quartz 

 grits, passing into highly indurated schists, the former assuming the 

 vitrified aspect of certain quartz rocks, trend from the slopes above 

 Ober Maiselstein to the summits of the Bolghen on the west. They 

 are, in fact, either vertical or dip 70° to 80° north and south. Now, 

 associated with these, and having indeed quartz rocks on both sides 

 of it, the chief boss of mica schist rock protrudes itself. From the 

 conical form of the chief mass, I suggested that it might have been 

 upheaved amidst these sediments, and have tilted them to the right 

 and left. On recently making a transverse section from the summit 

 on the N.N.W. to the gorge of the Schinbergerach on the S.S.E., I 

 perceived, however, that in parts, the black schists of the flysch passed 

 into a sort of Lydian stone, and that perfectly parallel to the higher 

 zone there were other less elevated peaky ridges of altered millstone 

 grit and sandstone, partially in a state of quartz-rock, with here and 

 there a sort of mica schist. These quartz rocks are sometimes in- 

 deed in an amorphous state, and often appear like so many dykes 

 of fused or semi-fused matter running through bands of highly altered 

 flysch limestone. With such appearances therefore on all sides, I 

 could not resist the impression, that the so-called gneiss and mica 

 schist, which I had supposed to be upheaved points of older crystal- 

 line rocks, are nothing more than certain courses of the "flysch" 

 which have undergone greater change than the others. Besides, the 

 phaenomenon occurs in a highly mineralized zone of the chain ; and 



