88. KING: KADAPAH AND KARNÜL FORMATIONS. [PART If. 
the old workings are not confined to any particular. set of quartzites 
either of the older or newer formations of the rocks under discussion.* - 
This set of quartzites is always regularly overlaid and sometimes 
overlapped by limestones of the Jwmmulmudgoo 
Relations with other 
zonis group, and it always rests unconformably on any 
underlying rocks, so that there is an absolute 
certainty about the different beds of quartzites belonging to the one 
group so long as it is continuous. Unfortunately there is no particularly 
distinctive feature in the sandstones of this group which is constant for 
any time except this one of relation with the rocks associated with it. 
In constitution the beds vary continually, and they are very like the 
sandstones and grits. of other series of quartzites in the KADAPAH 
rocks, so that in cases where the continuity of the group is broken, it. 
is very difficult to say if the detached beds are really on the same 
horizon. 
We might even expect the occurrence of diamonds to be a 
sufficiently distinctive character; but such is not the case, for there are 
extensive tracts of outcrop in which no diamonds are found, the gangue 
apparently being only locally dispersed through the group. 
The thickness of the Banaganpilly group is often very small, only 
Thickness variable, but about 4 or 5 feet; and the general thickness is sel- 
small. dom more than 20 feet; while there are instances, 
in the hills north-west of Banaganpilly about Gooraman Conda, and below 
the Oondootla plateau, of the deposit being from seventy to a hundred 
feet thick. The group has, however, been very much denuded among the 
undulations outside and west of the main ranges of hills, so that a fair 
* I myself, again, have seen some of the old workings in the Kistnah and Hyderabad 
countries, and am constrained to believe that they were really excavated in what are- 
KADAPAH Rocks; though there is still the doubt as to whether true rock-workings in these 
beds were ever successful. Some of the workings which I have seen were actually in the 
limestones, or rather in hollows of the same where quartzite, gravel, &c., had collected.—W. K. 
( 88 ) 
