13-J GEOLOGY OF THE SON VALLEY, ETC. 



A more extensive run of conglomerates, probably of later date^ 

 is found south of the lower Vindhyan outliers. 



Newer conglomerates. . 



Mr. Vredenburg has traced it continuously 

 from the neighbourhood of Madhopurwa to the Mohan river, which 

 it crosses immediately south of the boundary of the red shale series. 

 Thence it continues close to the southern boundary of the lower 

 Vindhyans to the Gopat. West of the Gopat the outcrop trends 

 away from the red shale boundary, and is very well seen in the 

 stream which flows down from Danri to the Gopat. Beyond this 

 the outcrop was not traced but was seen at intervals to about south 

 of Sendura, and is doubtless continuous or nearly so for the whole 

 of this distance. 



The conglomerates of this horizon are coarse and contain 

 numerous fragments of the red jasper of the Bijawar type. The 

 conglomerates pass upwards, in a northern direction, into soft slaty 

 or even shaly beds of grey and purple colour among which some 

 bands of sandstone and grit are found. Some of the beds are not 

 unlike those of the red shale series where these are most indurated J 

 but there is a marked unconformity between the two series. 



South of and running up approximately parallel to the conglomer- 

 ate outcrop just described is another conglomerate of very different 

 and peculiar type. It consists of a fine-grained argillaceous matrix, 

 now slaty or schistose, through which are scattered rounded pebbles 

 and boulders, some of great size. The rock is in fact an indurated 

 boulder clay, of a structure similar to the glacial boulder clays of 

 Europe and the Talchir boulder bed. Apart from this structure, 

 however, there are no other indications of glacial origin and the 

 simile employed must not be taken as intended to do more than 

 indicate the constitution of the bed. 



This boulder-bearing bed has been traced from the neighbour- 

 hood of Bannai to the Gopat. The rocks between it and the other 

 conglomerate are more schistose than those to the north of the 

 latter, and no fragments of red jasper have been found in the 

 boulder slate. Taking these facts into consideration it is at least 



( I3 2 ) 



