182 On the Granite formation 



wide and three feet thick, may very frequently be seen em- 

 bedded among the lamination of the gneiss, conformably 

 with the strata. The composition of these blocks is hornblen- 

 dic, while the gneiss contains both hornblende and mica, 

 and no graduation or change is apparent between the two ; at 

 first sight therefore the blocks appear like eratic boulders, 

 embedded in the sedimentary rock ; but as on the Jowandy 

 hills, S. W. of Vellore, I have seen these blocks surround- 

 ed by concentric layers of gneiss, answering exactly to the 

 shape of the stone, and because in other parts a graduation 

 may be traced between the same gneiss and the larger mass- 

 es of granite, I am inclined to consider them parts of the 

 original structure of the rock, although I have not observed 

 any satisfactory proofs of their being so. 



Dr. Boase* appears to allude to similar embedded blocks 

 in Norway and Sweeden, in consequence of which, the gra-- 

 nites of these countries have been called "granitic gneiss," 

 while by some it is insisted that they are true granite. 



Dr. M'Clellandf appears to describe similar masses of 

 granite embedded in gneiss in Kemaon, at Chourapany, and 

 refers their denudation to the action of the air on the saline 

 constituents of the gneiss. 



I have not had an opportunity of proving that any portion 

 of the granite formation of this district does contain a 

 superabundance of saline matters ; but conceive it not im- 

 probable that the whole of the salts, which are plentiful 

 in the plain of the Barramahal, may be derived from the 

 granite ranges. 



Differs from Granite of Europe. 



It will be seen that the granite of India differs very mate- 

 rially in many essential points from the granite of Europe. 

 In the first place, it forms a vast and continuous bed at a 



* Primary Geology, page 33. f Geology of Kemaon, page 47. 



