122 GEOLOGY OF THE SON VALLEY, ETC. 



The porcellanite stage and the overlying beds south of the Son 

 present no specially noteworthy peculiarities between the Banas 

 and Long. S2 . 



To the east of the Banas the outlier of lower Vindhyans and 

 underlying red shale series can be traced for a 



Lower Viodhyan outlier. . 



distance of 20 miles, the outcrops of the two 

 combined being never so much as a mile in width. Throughout the 

 whole of this length the southern boundary is a natural one and the 

 northern a fault with upthrow to the north, and as an outcrop of 

 this form indicates, the beds are everywhere vertical or nearly so, 

 and very much sheared. 



The porcellanites of the lower Vindhyans are seen in the Banas 

 but die out against the boundary fault at between two and three 

 miles to the east. The bottom quartzite and shales associated with 

 it can be traced to a little beyond Mata, forming a tolerably continu- 

 ous ridge for the whole distance. 



The area occupied by the red shale series forms an open valley, 



bounded on one side by the ridge of lower 



Red shale series. , T . ,, . , . - , , , 



Vindhyan bottom quartzite and on the other by a 

 series of hills having a more or less E.N.E. strike, composed partly of 

 the transitions and partly of the bottom conglomerate of the red 

 shale series. This last appears to vary very much in thickness, 

 partly due to original variation of deposition, partly to subsequent 

 disturbance. The bedding is always at high angles and the pebbles 

 have been drawn out in the direction of dip, fractured and 

 indented by the pressure of adjacent pebbles. As a result of these 

 variations in thickness the conglomerate does not form a continuous 

 ridge but a discontinuous line of hills, the coatings between them 

 being covered up by recent deposits. 



About Sendhwa the beds above the bottom conglomerate consist 

 of a green schistose rock, full of grains of quartz, which would not 

 have been recognised as belonging to this series but for the 

 continuity of outcrop. 



At the eastern extremity of the outcrop of the red shale series 

 ( 122 ) 



