26 LA TOUCHE : GEOLOGY OF WESTERN KAJPUTAN'A. 



CHAPTER IV.-STRATIGRAPHICAL FEATURES. 



(Sedimentary rocks.) 



6. Vindhyan sandstones and limestones. 



The relations between the Vindhyan sandstones and the schists of 

 the Aravalli series is, as might be expected, one of complete uncon- 

 formability. A section of the junction occurs at Sojat, where 

 Mr. Hacket thus describes it. 1 " The Sojat hills are formed, at base, 

 of nearly vertical Arvali slates, capped by about 10 to 20 feet of a 

 conglomerate composed of small pebbles of quartz, very nearly hori- 

 zontal, or with a dip of 3 to north, passing up into a fine white and 

 reddish sandstone, of which there may be about 100 feet in thickness. 

 On the northern side of the hills are some beds of chert resting upon 

 the sandstone, and which in the large hills a mile to the north passes 

 up into a thick limestone. The sandstone resembles very closely 

 the Kaimur sandstone, and doubtless the whole, from the conglomerate 

 upwards, may be referred to the Upper Vindhyan series." 



Still further north, at Khatu, a similar section of the unconform- 

 able junction between the schists and sandstones is exposed, but 

 here there is another band of conglomerate with overlying sandstones 

 between the Kaimur sandstone and the limestone. This second 

 band of sandstone is referred by Mr. Hacket to the Bhander sub- 

 division, and is stated to be upwards of 200 feet thick. The middle 

 (Rewa) group of the Upper Vindhyans is absent. 



After the eruption of the Malani lavas a considerable period of 

 time may have elapsed before the sandstones of the Vindhyan system 

 were deposited upon them. The evidence of unconformability is not 

 so clear as in the case of the junction between the schists and sand- 

 stones, for as it happens the sandstones are never seen in contact with 

 the lavas in places where the latter have been disturbed, but wherever 

 the two formations occur together they are both nearly hori- 



1 Rec. Geol. Surv. Ind., Vol. XIV, Pt. 4, p. 300. 

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