182 NERBUDDA DISTRICT. 



containing the plants below. These latter are cut off on the south 

 by a fault, and, as far as they are seen, have a decided, though slight 

 dip to the south east, whereas the Mahadeva beds are here persist- 

 ently horizontal. Higher up the stream, the upper Damuda plant 

 beds have been traced, and the sandstones there overlying them, though 

 apparently part of the Mahadeva series, seem to have been affected by 

 the movements from which these have suffered, and which have bent 



„ , , their beds, and given them their undulating dip. 



Pseudo-conformity, ac- ° ° L 



counted for. £ ut t ] ie f act that the whole district has been vio- 



lently disturbed subsequently to the formation of the Mahadeva rocks (as 

 the faulted boundary of those rocks proves to have been the case) must 

 necessarily greatly obscure the unconformity between them and any of 

 the older rocks on which they rest : and it will readily be percieved 

 that when original unconformity was slight, lithological character similar, 

 and subsequent movements considerable, the difficulty of separating the 

 groups must be naturally very great. 



Indeed it is probable that close search might detect patches of upper 

 Damuda rocks intercalated between the lower Damudas and the Ma- 

 hadevas in places where they have hitherto escaped observation. Some 

 of the carbonaceous shales of this group may have been included among 

 those of the lower Damuda set, and some of its massive sandstones among 

 similar beds really part of the Mahadeva series. 



Nowhere in this district has the upper Damuda group been seen 

 to attain a thickness of more than 150 feet, where any approximation 

 to measurable limits can be assigned. But we have much to learn on 

 this subject still and many doubts remain to be cleared up. The lithological 

 characters of the group have already been shown to be very various; 

 and the plant remains are relied on as sufficient to identify the beds of 

 the Hurd glen with those of the Mahanuddi valley in spite of the differ- 

 ences, above pointed out, between the rocks of the two localities in other 

 respects. 



