192 NERBUPDA DISTRICT. 



As far as the lower Damuda beds are concerned, the Morun River 



Mahadevas and lower section near Lokurtullye, and the Sita Riva section 

 Damuda. above Mopani, both of which have been described, 



Mahadevas and upper are satisfactory. And with reference to the upper 

 Damuda. Damuda series, the lithological characters and the 



fossils, seem sufficient to warrant the separation of the two groups, and 

 even if hereafter we find that the interval indicated by this separation is 

 not really so great as we now suppose, it must still remain a positive 

 separation nevertheless. 



If the upper Damuda and the Mahadeva rocks appear, when more fully 

 worked out, to belong to the same geological series, still the two must be 

 kept to some extent distinct, the former as the lower, and the latter as 

 the higher stage of the group. 



There is however one consideration which very frequently recurs, and 



_, „ „ , always strongly suggests real unconformity be- 



Contirmation of above J a J ^° J 



separation. tween the Mahadeva and upper Damuda beds in in- 



dividual sections ; and which, when considered in the aggregate of known 

 instances of its occurrence, may fairly be considered confirmatory, if 

 not conclusive as to the unconformity. It arises from the following 

 facts. 



The geological observer must be struck by the absence of intrusive 



trap among the Mahadeva sandstone of the Gondwarra range. These 



., e rr j i are often overlaid by basaltic flows, and dykes do 



Absence or Irap dykes J ' J 



among the Mahadevas. occasionally cut through their beds, but relatively 



to the subjacent formations, the absence of the intrusive igneous rock is 



certainly remarkable. 



The massive, straight bedded and undisturbed, rock escarpments of the 



Puchmurri range, are continually before the eyes 

 Dykes of the lower Da- 



mudas do not run up into of the explorer of the deep valley on the south of 

 the Mahadeva. 



those hills in which he finds a trap dyke under his 



feet at every turn. Many of these dykes he may trace up to the foot of 



