CRETACEOUS . SERIES. 29 



From what has already been said it will have been expected that 

 the sub-divisions of the cretaceous strata on the plateau will not 

 answer for those seen in the low ground to the south of the axis of 

 flexure. In the three sections abeady noticed in the latter position^ 

 in the Theria river, the Bogapani, and the Jadukatd (comprising a 

 distance of more than thirty miles) the identity of the great bottom 

 sandstone has been noticed. In the first locality there is about a 

 quarter of a mile between this sandstone and the bottom nummulitic 

 limestone; it is only for about forty yards in the middle of this 

 space that rock is exposed — dark and pale blue shales^, locally nodular 

 and calcareous, ferruginous and concretionary, with some layers of 

 flaky earthy limestone and of fine hard earthy sandstone. They 

 probably represent portions of the Langpar and Mahadeo bands; 

 and exhibit the completion of the tendency towards the substitution of 

 earthy for arenaceous deposits. In the Bogapani there is about the 

 same thickness between the sandstone and the limestone; and here 

 it might be possible to make out a complete list of the intervening rocks. 

 With the exception of the forty feet of fine sandstone immediately under 

 the nimamulitic limestone, and which may belong to the Cherra or to 

 the Langpar band, all the beds seem to be of shales and limestones like 

 those at Theria. On the Jadukata all the beds above the sandstone 

 have been denuded away for some distance from the river ; sugo-estiag 

 the presence of soft rocks. Thus in the southern sections one would 

 only recognise, in a cursory survey such as mine has been, two divisions 

 — a massive sandstone at the base, succeeded by shales with subordinate 

 limestone. 



To the west of the Jadukata (or Umblai) I have not seen the 

 cretaceous rocks within a distance of more than thirty miles, as they 

 appear on the Sumesari, ten miles from the plains of Mymensino-. 

 Although so far from the alluvial flats the elevation is but little higher 

 than in the river at Theria, yet all the features are much changed. 

 Y { 179 ) 



