CHAPTER 4.—' Tug BANAGANPILLY GROUP. 
Nearly all round the bases of the inner western hills, and fringing 
as it were the terraces of limestone described in the last chapter, is a 
thin series of quartzites cropping out from under the Jummulmudgoo 
limestones. These quartzites are mostly sandstones and grits with 
pebble beds and occasionally coarse conglomerates; and as these were 
gradually traced out in their boundary and 
Sands and grits of 
Banaganpilly. 
relations with the other rocks of the country, it 
was found that some of the beds are quarried at 
the present day for diamonds close to the town of Banaganpilly. There 
are, it is true, other diamond workings besides those of Banaganpilly, 
but nearly all of these are in recent gravels and debris of the original 
diamond-bearing rocks. The Banaganpilly mines, on the other hand, 
are in true rock workings; and this condition refers only to such rocks 
as were found to be on the same horizon with the Banaganpilly beds. 
Until very lately it seemed appropriate to designate this series as 
the diamond-bearing group, as there was no know- 
Might be called the 
dud) giat ledge of diamonds having been found in any 
other set of rocks of either the KARNÓLS or 
KADAPAHS. The old diamond-workings near Oostapully on the left 
bank of the Kistnah in the Kistnah district have, however, since been 
visited by Dr. Oldham, when from his observations it appears that they 
were executed in quartzites which certainly seem to be of the KADAPAH 
series. A local name, in accordance with the system of nomenclature 
adopted in this memoir, is therefore preferable, and at Dr. Oldham's 
suggestion that of Banaganpilly is adopted. 
Later still, Mr. Foote, in his examination of the same series of 
rocks in the neighbourhood of Juggiapett,* has likewise observed that 
* Frontier town on the borders of the Kistnah district and Hyderabad territory, left 
or north bank of Kistnah. 
) 0 ( 
