Ch. XXXVIL] CRYSTALLINE ROCKS OF SWISS ALPS. 761 



this action has by no means been confined to the immediate vicinity 

 of granite. Granite, indeed, and other plutonic rocks, rarely make 

 their appearance at the surface, notwithstanding the deep ravines 

 which lay open to view the internal structure of these mountains. 

 That they exist below at no great depth we cannot doubt, and we have 

 already seen (p. 713) that at some points, as in the Yalorsine, near 

 Mont Blanc, granite and granitic veins are observable, piercing 

 through talcose gneiss, which passes insensibly upwards into sec- 

 ondary strata. 



It is certainly in the x\lps of Switzerland and Savoy, more than in 

 any other district in Europe, that the geologist is prepared to meet 

 with the signs of an intense development of plutonic action ; for here 

 we find the most stupendous monuments of mechanical violence, by 

 which strata thousands of feet thick have been bent, folded, and over- 

 turned. (See p. 58.) It is here that marine secondary formations of 

 a comparatively modern date, such as the Oolitic and Cretaceous, 

 have been upheaved to the height of 12,000, and some Eocene strata 

 to elevations of 10,000 feet above the level of the sea; and even de- 

 posits of the Miocene era have been raised 4000 or 5000 feet, so as to 

 rival in height the loftiest mountaius in Great Britain. 



If the reader will consult the works of many eminent geologists who 

 have explored the Alps, especially those of MM. de Beaumont, Studer, 

 Necker, Boue, and Murchison, he will learn that they all share, more 

 or less fully, in the opinions above expressed. It has, indeed, been 

 stated by MM. Studer and Hugi, that there are complete alternations 

 on a large scale of secondary strata, containing fossils, with gneiss and 

 other rocks of a perfectly metamorphic structure. I have visited 

 some of the most remarkable localities referred to by these authors ; 

 but, although agreeing with them that there are passages from the 

 fossiliferous to the metamorphic series far from the contact of granite 

 or other plutonic rocks, I was unable to convince myself that the dis- 

 tinct alternations of highly crystalline, with unaltered strata above 

 alluded to, might not admit of a different explanation. In one of the 

 sections described by M. Studer in the highest of the Bernese Alps, 

 namely in the Roththalj a valley bordering the line of perpetual snow 

 on the northern side of the Jungfrau, there occurs a mass of gneiss 

 1000 feet thick and 15,000 feet long, which I examined, not only 

 resting upon, but also again covered by strata containing oolitic 

 fossils. These anomalous appearances may partly be explained by 

 supposing great solid wedges of intrusive gneiss to have been forced 

 in laterally between strata to which I found them to be in many sec- 

 tions unconformable. The superposition, also, of the gneiss to the 

 oolite may, in some cases, be due to a reversal of the original position 

 of the beds in a region where the convulsions have been on so stu- 

 pendous a scale. 



On the Sattel also, at the base of the Gestellihorn, above Enzen, in 

 the vallev of Urbach, near Meyringen, some of the intercalations of 



