130 NERBUDDA DISTRICT. 



the metamorphism of the schists : not as a cause, but as an index of the 

 causes to which that metamorphism is due, whatever those causes may 

 be conceived to be, — for it is certain that metamorphism on the great 

 scale ends with that series which can be proved to be anterior to the 

 granite, and among whose beds the granite has been intruded, while 

 that group next above the schists, (the Sub-Kymore) and which has 

 not been found to be affected by the granite, is not metamorphic. 



§ 3. Metamorphic Series. 



The metamorphic rocks of this district form a very widely spread and 

 very interesting group. Although their limits are laid down on our 

 map they have themselves been but cursorily examined, and the follow- 

 ing remarks must be considered more as preliminary and suggestive, 

 than as making any approach to exhausting the subject. 



The absolute superficial extent of these crystalloid rocks is much 



. ., greater than would at first appear from an in- 



Surface area consider- ° L l 



able * spection of our map : they underlie all the re- 



cenfi deposits of the valley, and frequently show here and there through 

 them, both near the foot of the hills, along the north and south side of 

 the valley, and also where the river and its tributaries have cut their 

 channels through the layer of clays, of sands, gravel, &c, and exposed 

 the rock below. Many such localities are marked on the map but many 

 more are too small to be indicated, which still in the aggregate represent 

 a very considerable area, and which from the scattered manner in which 

 they occur show the observer more of the general characters of the 

 rocks than he could probably learn from any equal area continuously 

 exposed. 



But besides occupying a great superfical area both in the Nerbudda 

 valley itself, and in that part of the country stretching north east from 

 Jubbulpur to the Ilewah country, these rocks again appear in that part 



