276 M1DDLEM1SS: GEOLOGY OP HAZARA AND BLACK MOUNTAIN. 



(which was Wynne's latest view) there is the ever-present difficulty 

 of accounting for any sedimentary rock being of so uniform a mineral 

 facies as to yield under the influence of metamorphism, even in its 

 extreme form, a rock of such uniform characters throughout the range. 

 For those again who prefer to regard the rock as Archaean the diffi- 

 culties are less, no doubt, but even they must admit a pretty thorough 

 mixing of the material by some agency before it quietly found its 

 way in an intrusive capacity among the ancient sedimentary rocks. 



Of not less importance in discussing this question are the metamor- 

 phic effects of this granitic or gneissic material 



Its metamorphic ac- 

 tion on the intruded on the intruded rocks. I take it as proved over 



and over again that such effects are to be seen 

 in the Himalaya. Wherever sporadic appearances of this rock are 

 examined such as lie well to the south of the main crystalline axis, 

 whether the examples are taken from Hazara or from other places 

 geologically visited in the Himalaya, they are always found as some- 

 what isolated elliptical areas and surrounded by a concentric zone of 

 well-defined extra metamorphism. 



The greater, more continuous masses of the higher peaks of course 

 shew the same thing, but they are not so conclusive in their presenta- 

 tion of the true order of cause and effect as are these smaller detach- 

 ed areas of which the oft referred to Chor Mountain, Kalogarhi and 

 Dudatoli may be taken as brilliant examples. 



After what has been proved in the chapter devoted to the peno- 

 logical descriptions of the crystalline and metamorphic rocks, I think 

 it is hardly necessary to insist again here on the truly metamorphic 

 character of the schistose strata ; that they really do represent altered 

 sedimentary rocks. That being the case, the extra metamorphism of 

 a circular or elliptical zone surrounding the mass of the gneissose 

 granite can only be understood as a result following on the appearance 

 of the granite among them ; and therefore that rock, whether called 

 a gneissose-granite or a granitic-gneiss, has functionally acted here as 

 an igneous intrusive rock. 



( 276 ) 



