THE GEANITE. 55 



observation ; yet^ although my examination was pretty close^ I did not 

 notice a single ease of protrusion from the granite into the sedimentary 

 rocks, nor any dykes, great or small, in the neighbom-hood that might be 

 referred to such an origin. On the part of the Shillong series there is 

 little or no betrayal of special metamorphism along the contact — the strata 

 are not noticeably more mineralized here than at many places far removed 

 from the granite. Stratigraphically this indifference is even more 

 marked : the quartzites, the highest member of the series, are the rocks 

 most frequently found in contact, but they occur in every position- 

 striking against the boundary at any angle of obhquity, or dipping at 

 it or from it at any angle of inclination. All these conditions may be 

 observed along the west boundary of the Molim granite between 

 Lailangkot and the south-west base of Shillong hill. The only good case 

 of irregularity of outline with apparent mingling of the rocks on this line 

 is at the point of the ridge west-north-west from Lailangkot. The rib of 

 quartzite upon which the village is built projects obliquely into the 

 granite ; and this latter projects into the angle on the south side of the 

 ridge; but even here there is nothing Uke a dyke. The mutual re- 

 actions of the rocks are, however, very observable. 



The same remarks apply in a great measure to the granite of the 

 western area. It hes mostly in the deep gorges of the southern region 

 of the plateau, where everything is unfavorable to observation. There is 

 the same indifference of the strike of the strata to the position of the 

 granite; the same absence of general contact-metamorphism and of 

 special intrusive action. The line of contact can sometimes be traced 

 by the eye up the steep sides of the deep valleys ; it is always nearly 

 vertical, with a small underlie towards the quartzites. In the bed of 

 the Kalapani under Sm'arim on the north-west the contact is poorly 

 exposed : it is somewhat irregular, and there are decided effects of 

 special metamorphism. On the whole, there can, I think, be little doubt 

 that these great granite masses are truly intruded. 



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