INTRUSIVE ROCKS IN CRAGS. 2$ 



advocate of this hypothesis must admit the existence of an ancient 

 recumbent fold, by which part of the abovementioned sedimentary 

 zone has been carried across the crystalline Kailas range into the 

 Chitichun area. Now the shortest distance between the crest of the 

 Kailas range (north of Tirthapuri) to Chitichun No. I is nearly 50 

 miles (80 km.). It would be difficult to explain, I believe, the mode 

 of formation of such enormous recumbent folds, in comparison to 

 which any fold, which has hitherto been actually observed, is ridi- 

 culously insignificant. I am well aware that several geologists, 

 like Schardt or Lugeon, suppose the region of the " Breche du 

 Chablais" in Savoy to have been formed by a recumbent fold of similar 

 dimensions, but I humbly confess my inability to understand the 

 mechanics of an overthrust of entire structural zones for a distance 

 of 50 miles. 



The second objection, which to me appears to be still more 

 cogent, is based on the intimate association of the Tibetan crags 

 with intrusive igneous rocks, which penetrate both the crags and 

 the geologically younger shales and sandstones in their proximity. 

 The localisation of the igneous rocks to the crags along their entire 

 line of strike seems to prove the coincidence of the eruptions with 

 the structural movements, by which the crags themselves have been 

 brought into their present position. This fact excludes any mode of 

 explanation, by which the crags are assumed to have been brought 

 into their present position from some distance, by recumbent folds 

 or overthrusts, but naturally involves the assumption, that they have 

 been brought to the surface from underneath, either as fragments 

 of a squeezed fold, or by faulting. 



The independence of the strike of the crags from the folds of the 

 Himalayan system in the Chitichun area is opposed to the exis- 

 tence of a squeezed fold. Thus the explanation, given by Gries- 

 bach in his preliminary notes (Records of the Geological Survey of 

 India, Vol. XXIV, p. 24) remains the most plausible. He explains 



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