DECCAN TRAP SERIES. 51 



The late Mr. J. G. Medlicott, long ago, 1 discussed the view of 



Apparent alteration of Hi slop as to the probability of the intertrappean 



beds in Central India. bedg o£ the Central p rov inces having been invaded 



and altered by a subjacent sheet of trap; and in the area examined 

 by him he shows very good evidence against this view, principally that 

 *■' in every case within our experience, the sedimentary beds have been 

 deposited tranquilly on the previously indurated and moreover previously 

 demi dated surface of the trap rock : and in several cases a large portion 

 of the material constituting these sedimentary beds is derived from the 

 debris of the trap flows themselves" Unfortunately, the sections at 

 Pungadi or Kateru do not give such clear views of the condition of the 

 subjacent trap ; nor did I see a case of any inclusion of material derived 

 from it. On the other hand, though Medlicott is quite as decided in 

 his remarks as to the altered condition of the sedimentary beds between 

 the two traps being from above downwards, still he gives a section 

 illustrating the exceptional developments of the intertrappean rocks, that 

 is, developments in which the alteration is variable, or is distributed 

 through the beds in the opposite direction to that usually obtaining 

 or again, when there is no apparent alteration at all; which section, on 

 comparison with the details above given, will show what a strong resem- 

 blance there is between the conditions of the rocks in this exceptional 

 case and those more general ones in the Kateru and Pungadi outcrops. 



Concerning this section 2 , he says : — " It is exposed in one of the 

 glens of the Gorchutta valley, a few miles from the village of Singwarra. 



" In descending order — 



" 30 to 40 feet of sub-columnar trap, showing well a concentric structure. * * 

 3 feet to 6 inches of dove-coloured grey earthy limestone, containing many shells. 



This bed, which varies (as stated) considerably in thickness, does not seem to 



have been even slightly influenced by the superincumbent basalt. It rests 



on — 

 6 to 7 feet of a mass which is made up of irregular lenticular patches dying 



out and replacing each other, and which differ from each other as follows : — 

 a). — A grey limestone, somewhat like the bed above, but is more earthy 



1 1860, Mem. Geol. Surv. of India, Vol. II, p. 208. 



2 Mem. Geol. Surv. of India, Vol. II, pp. 203-204. 



( 245 ) 



