286 KING: KADAPAH AND KARNÜL FORMATIONS. [PART IV. 
relation. For instance, there is a group of rocks ( Rewahs) occurring in 
the vixpHYAN formation which is diamond-bearing, and alone diamond 
bearing, as far as present knowledge goes, of all the groups of the 
formation; and there is a like group (the Banaganpilly) in the 
xARNÓL formation of Southern India; therefore on this ground alone, 
۰ ۰ ha 
it is reasonable to examine if the KARNULS are VINDHYANS. 
Again, on reading deseriptions and examining collections of the 
By examination of rock — VINDHYAN rocks, it is found that the KARNULS 
specimens: bear a strong general resemblance to them, though, 
indeed, in some respects the KADAPAHS do likewise, until all the 
groups are examined in detail and then the resemblance falls to the ground. 
The age, too, of the KARNÓL and KaADAPAH rocks must also be 
i taken into account in trying to correlate them with 
By relative age. : bur 
other rocks, their altered condition, and the fact 
of their being overlaid by fossiliferous rocks of the Aajmahals, necessi- 
tates our looking for ancient congeners among other series of like 
rocks, and here we are brought to look again at the vinpHyYANs and their 
associates. 
The vrNDHYANS and their associates have been reported on and 
Compared with vIw- largely worked out by Dr. Oldham and other 
DHYANS. members of the Geological Survey of India; and 
on comparing specimens of Madras rocks with others of theirs, and 
looking at the stratigraphy of these formations, the following resem- 
blanees are evident. 
First, with regard to the KARNÜLs as compared with the typical 
Upper VINDHYANS aS seen in the Rewah country: there is no particular 
resemblance lithologieally except that in both cases the rocks are quart- 
zites or sandstones, shales, and limestones. The sandstones and shales 
are strongest in the Rewah country; the limestones and shales are 
strongest in the Kurnool and Cuddapah area. There are conse- 
quently none of those grand scarps of sandstones so characteristic 
( 286 ) 
