96 



MALLET, VINDHYAN SERIES. 



As the Vindhyans in this eastern region are not less than 3,000 feet 

 thick and are rippled throughout theii- entire thickness, it seems clear that 

 the ground must have been gradually sinking during their formation, as 

 otherwise either the water would have been at first far too deep for rip- 

 pling, or else the newly formed stMa would have risen to the surface, 

 and further subaqueous deposition been put a stop to. Supposing then 

 the estuary to have been of tolerably unifoi'm depth, and an equable 

 sinking throughout, after the deposition of the Kymores (which are 

 1,300 feet thick at Rotasgurh), while the depth of the water remained 

 the same at the upper end of the estuary, by the deposition balancing the 

 subsidence, there Would be at least 1,300 feet over the Kymores at their 

 most westerly limit, where they appear to die out. Under these circum- 

 stances, it is difficult to explain how the beds were rippled. It is highly 

 improbable that while the ground near the mouth of the estuary remained 

 stationary, the sinking increased from west to east, so as to balance 

 the decrease of sediment in the opposite direction. If, however; the 

 estuary be supposed to have had steep banks at the upper end, plunging 

 at once into deep water, while lower down they gradually became more 

 gently inclined as the estUary widened, then, if an equal depth of strata 

 were deposited in the centre of the channel throughout, as the ground 

 sank, the vipper beds on the sloping bottom would gradually overlap 

 those previously deposited, and the thickness near the shores would 

 always be small. Thus, where the beds are now exposed in the scarp, they 

 appear to thin out from east to west, and really do so along the coast line, 

 but in the centre of the basin the thickness may be constant. The water, 

 on this supposition, would be of nearly equal depth throughout, and the 

 beds would be rippled throughout, both vertically and horizontally.^ 



Being covered by no other beds, the original thickness of the upper 

 Bundairs cannot be determined. At Kuttungi there are 650 feet, and 



* These remarks, although introduced in connexion with the subject of rippling, 

 further favor the idea of the extension of the Kymores along the Nerbudda valley. Sec p. 54. 



( 06 ) 



