74 MALLET, VINDHYAN SERIES. 



beds forming Mils, even setting- aside the protection they would derive 

 from the greater ridge of Rewahs, it is diflEicult to understand how not 

 a single vestige of either limestone or sandstone should appear above 

 the alluvium along 30 miles of boundary. Thus there is much evi- 

 dence in favour of a fault and none against it, so that it is reasonable 

 to assume the boundary along here to be one. There is, however, no 

 trace of it in the Sone valley, and it probably dies out gradually, becom- 

 ing extinct near Bilheri or thereabouts. 



With regard to the south-eastern fault, that along the main boundary, 

 there is evidence of its existence between Sleemanabad and Mujouli. 

 The slate series and Rewahs are close to each other all along, but, as 

 we know that the lower Vindhyans exist in the valley to the north, their - 

 non-appearance between the two other formations indicates a faulted 

 boundary. To the south-west, north of Nursingpur, supposing the lower 

 Vindhyans to be extinct here, it is possible that the Rewahs might have 

 been deposited on sub-horizontal strata of the slate series which had 

 previously undergone denudation, and both subsequently been brought 

 to their present vertical position by the same movements. But though 

 at first sight this theory seems to simplify the case by dispensing with 

 one fault, it appears to render the production of the other still more 

 difficult, and the probability is strongly in favor of the boundary in 

 question being a faulted one. There is no trace of it, however, beyond 

 Omarpani. The infra-Vindhyan rocks are completely obscured to the 

 west by alluvium, and where they make their next appearance in the 

 Dhar Forest, the Vindhyans are found in superposition. 



The southern side of the Sohar (Bilheri) anticlinal is probably cut ofl 

 obliquely by the south-eastern fault near Kuttungi, as in the Hirun 

 river there, the slate series is foimd within a short distance of the northern 

 ridge. The latter can be traced at intervals a long way to the south-west. 

 The double fault may be well studied north of Nursingpur. Commenc- 



( 74 ) 



