20 



MEDLICOTT, SHILLONG PLATEAU. 



the beds of the upper bandj and undercutting those of the lower, as 

 in the figure : 



Fig. 2. Junction of Cherra and Langpar bands, Maosmai cliffs. 



Elsewhere this lower horizon of the Cherra sandstone is by no means 

 so well marked. In the angle of the cliffs under Cherra village on the 

 north (the only section I know of in which every bed of the series can be 

 got at) the distinctive composition of the Cherra band from that below it 

 is very decided, but there is only an approximate position assignable above 

 or below which the fine calcareous sandstone of the lower band or the 

 coarse sandstone and mottled sandy clays of the upper do not pass. 

 This vagueness may be due to the'aecident that the more characteristic 

 rocks of the two bands do not here happen to occur at the contact, as in 

 the other section ; but it also suggests a transitional and uninterrupted 

 formation for the whole series — the view I am inclined to adopt. The 

 lumpy, mottled, sandy clays or earthy sandstones, so well seen in this 

 locality, are characteristic of the lower part of the Cherra band on very 

 many sections ; but they are sometimes unrepresented. 



As far as it goes this top sub-group of the cretaceous series must of 

 course be recognized ; but its range is not extensive. It does not seem 

 to be represented in the section at Theria Ghat. In the parallel section 

 on the Bogapani at Chela, there is about 40 feet of fine hard pale sand- 

 stone in the position of the Cherra band, so far as that it immediately 

 underlies the bottom nummulitic limestone. 



The position of the Cherra band in the northern sections establishes 

 its connection with the cretaceous series. While all the peculiar rocks 

 of the southern scarp thin out and disappear northwards, the Cherra 



( 170 ) 



