58 GEOLOGY OF THE SON VALLEY, ETC. 



Chapter IV.— THE ROCKS OF BIJAWAR TYPE. 



PETROGRAPH1CAL NOTES. 

 (E. Vredenburg.) 

 Section I.— Introduction. 

 The notes which form the following chapter were not intended 

 for publication in the shape in which they appear here. They are 

 merely extracts from my progress report of 1896-97. During that 

 camping season, I crossed several times the outcrop of the Bijawars, 

 and I had occasion to see them also when tracing the boundaries of 

 some of the newer systems with which they come into contact. The 

 materials, both petrological and stratigraphical, are insufficient to 

 justify any critical examination, and the study which I made of them 

 was solely intended as a foundation for systematic work; but since 

 then I have had no further opportunity of visiting any more rocks of 

 that system. The following notes cannot therefore contain much 

 that is of general interest, but it is hoped that even in this unfinished 

 form they may be of use to future observers. 



In travelling across the country represented on map 476, from 

 south to north, it appeared to me that the structure is that of a 

 syncline, for the same rocks occur in the neighbourhood of the 

 northern and of the southern boundaries, while the central portion is 

 occupied by slates of a different type'. 



The rocks are generally much more schistose towards the 

 southern than towards the northern boundary. 



The bottom bed, sometimes visible along the southern boundary, 

 is a very schistose quartzite occasionally ren- 



Basal quartzite. . 



dered conglomeratic by pebbles or vein-quartz. 

 Resting upon it are slates, interbedded with limestones, chlorite- 

 schists, and lavas ; the lavas are absent from the portion of the 

 southern outcrop of this stage examined in map 476, but this may be 

 a local peculiarity due to the irregular distribution of these rocks. 

 These slates are overlaid by runs of jasper often ferruginous and 

 ( 58 ) 



