86 MALLET, VINDHYAN SERIES. 



a thin band of impure red and greyish limestone which is not observable 

 elsewhere. Above this we find the ordinary greenish-grey, aluminous, 

 slightly micaceous silty shales which form the great mass of the 

 Sirboos. They are so brittle that it is impossible to obtain a hand 

 specimen; in places they become red, and thin layers of earthy 

 sandstone are not uncommon. The above characters are very con- 

 stant and may be observed through several hundred feet, till near the 

 top they gradually lose their aluminous character and become more and 

 more arenaceous till they pass into the upper sandstone. The thickness 



of these strata in the Singrampur valley is about as follows :— - 



Feet. 

 Gunoorgurli shales ... ... ... ... ... 250 



Bundair limestone ... ... ... ... ... 200 



Lower Bundair sandstone ... ... ... ... 200 



Sirboo shales .... ... .„ ... ... 800 



Lower Bundair s ... ... ... ... 1,450 



Upper Bundairs ... ... ... ... 650 



Bundairs ... ... ... ... ...2,100 



From Kuttungi to some miles beyond the meeting of the Hiran 

 and Nerbudda rivers, the lower Bundairs are sunk out of sight by the 

 northern fault, save in one or two places where the highest beds imme- 



Fig. 9. Section of Bundair scarp and adjacent hills near mouth of Hiran river. 

 «, Slate series : b, Sirboo shales : c, Upper Bundairs. 



diately below the upper sandstone are visible, and where they are, in 



consequence of that fault, thrown up into a nearly vertical position 



(Fig. 9). 



To the north of Nursingpur, where the Bundair escarpment turns 

 northwards to meet the trap, the Sirboo shales are found again, several 

 ( 86 ) 



