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Geological Notes on the Khasi Hills. 



[No. 1, 



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dip of the gneiss is very marked, in a white coloured soft band that 

 crops out at the very base of the hill, and is continued E. S. E. past 

 the village of Laoburtun. 



From all I could see of this formation here, the Mokasa valley, 

 lies on a very sharp anticlinal bend of those gneisose rocks, the 

 granite appearing to curve over the Maotherichan ridge. 



Z The rock near the summit of Maotheric- 



han is very porphyritic, containing large 

 oblong crystals of felspar. In the valley it 

 disappears, and coloured gneiss, soft and 

 friable, comes in, to which is very probably 

 due the present configuration of the valley. 

 To the south near Mahaton, the porphyritic 

 granite is again seen, with a corresponding 

 rise in the hills. The above kind of granite 

 is very common about here, forming as a 

 rule the lines of the higher ground and ele- 

 vated masses ; it is of a very hard nature, 

 often pink, and is generally used by the 

 people for the monoliths set up beside the 

 ashes of their dead. 



On and about the summits of the low 

 hills, south of Maotherichan, that rise some 

 150 feet above the present level of the rice 

 cultivation, or what was originally the bed 

 of a lake, I was surprised to find, scattered 

 over the surface, a few well water-worn 

 pebbles, mostly of a hard quartzitic rock. 

 No beds exist anywhere near from which 

 such well-rounded pebbles could have been 

 washed, and I was quite unable to account 

 for their appearance. They were not nume- 

 rous, but sufficiently so to preclude the pos- 

 sibility of having been carried there by hu- 

 man agency, the nearest spot whence they 

 could have been brought was the bed of the 

 valley below. No well marked traces of any 



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