PETROGRAPHICAL NOTES. 59 



frequently interbedded with slates of various colours, limestones and 

 thick beds of lava. 



This lower stage was termed by Mr. Medlicott the " Agori 

 division/ 1 but he regarded it as an upper horizon, Its repetition 

 along the northern and southern boundaries with essentially the 

 same characters make it more probable, however, that the slates 

 situated between these two runs belong to a higher stage, the struc- 

 ture being mainly that of a syncline ; these slates are usually inter- 

 bedded with a large proportion of fine-grained imp ure sandstones 

 and never contain any jasper or lava. 



In the most western part of the district which I visited, the 

 Bijawar outcrop becomes much narrower, and it may be fairly assumed 

 that only the lower part of the system is represented there. The fact 

 that the entire width of the western outcrop consists of rocks typical 

 of the " Agori stage/' lends some support to the above conclusion. 

 But it must be admitted also that a similar distribution might result 

 from the " Agori stage w resting unconformably upon a still older 

 system, a view which was suggested, in fact, by Mr. Medlicott, and 

 has been adopted in the Manual of the Geology of India. 



It would require a detailed survey of a large portion of the 

 outcrop in order to obtain any degree of certainty as to its conform- 

 ation : the structure above suggested is therefore only conjectural. 

 A number of specimens, however, were collected, and these form the 

 subject of the following notes. 



Section II.— Sedimentary rocks. 



a. — Sandstones and quartzites. 



The quartzite forming the bottom rock along the southern 



boundary, south of Chingo, specimen -gV^, is a remarkable example of 



a veritable quartz-schist in which the schistosity is almost entirely due 



to the quartz itself, for the rock contains very 

 Quartz-schist. ,. , , ... J 



little else than this mineral. In the hand- 

 specimen it is pure-white in colour, and it is very fissile along the 



( 59 ) 



