16G KHASI HILLS. 



repeated above the coal (as at Lakadong) tends rather to prove that they 

 all beloQg to the same formation. In either case, this coal, which has 

 here been so far mineralized as to produce a good blazing coal, of a fine ■ 

 jetty aspect and higldy bituminous character, is the representative of the 

 thin and small patches of lignite which occur abundantly in the tertiary' 

 strata of the North -West. 



And this analogy strengthens the conclusions drawn from an examina- 

 tion of these deposits in the Khasi hills, as to the uncertainty of any con- 

 tinuance of these seams. Both with reference to the coal at Lakadong and 

 at Cherra Poonjee, I have already pointed out the very irregular manner 

 in which the beds have been developed, and I am inclined to think 

 that this is only another instance in which the deposits of vegetable 

 matter, belonging to this geological epoch, are of local and limited exteat 

 resulting from local and limited causes. 



V/ith a few brief remarks on the disturbances to which these rocks 

 have been subjected, I shall conclude the foregoing outline. 



The approximation to a linear direction (East and West) in the 

 granitic areas has been noticed above. The only 



Granitic intrusion. i i • ,. ... 



really marked instance, however, of granitic in- 

 trusion, as distinct from granitic disturbance and elevation, does not 

 exhibit this direction (at Laidom) ; and from this and other circumstances, 

 it would appear that the line or axis of the greatest exhibition of gra- 

 nite has been a line of elevation, and not of intrusion or fracture ; in 

 other words, that the disturbances or dislocations on this line have been 

 long subsequent to the alteration of all the rocks affected. On the 

 other hand, the disturbances resulting from the exhibition of the other 

 class of igneous rocks (the trappean) have taken place along the lines, 

 or line of intrusion and of fracture. The coincidence in direction be- 

 tween these intrusions and the principal river-valleys in the Southern 

 part of the hUls, and the dependence of the physical features of the 

 district on this geological structure have been noticed above. 



