CHAP. 4.] KADAPAH FORMATION.—NULLAMULLAY BEDS. 227 
of hills is followed out, it is gradually seen that the higher quartzites 
are by degrees overlapping different beds—ferruginous coarse sandstones, 
flags and shales, more particularly at the Cuddapah end of the range, 
and thus the unconformity becomes evident. 
The series consists of little else but massive beds of pale-colored 
quartzite sandstones, sometimes ferruginous, with a few bands of red 
and purple sandy shales, the latter of which are seen on the lower north- 
east slopes. There are thus displayed in the passage of the Penn-air 
river some 600 feet of strata. The cliffs are from 2 to 300 feet in height, 
showing the great beds dipping down towards, and finally underneath, 
the Jummulmudgoo country. 
The accompanying sketch (Pl. vii) of the Gundycotta gorge, taken 
from the fortress overhanging the cliffs, is illustrative of some of the 
features of these strata. 
In the low range of hills further north, these quartzites again rise 
up from under the limestones; and the outcrop of red and purple sandy 
shales which is seen at the foot of their steeper northern slopes are 
apparently representative of the shales in the Baukrapett valleys north 
of the Gundycotta fort. Beds of the same kind are seen further west 
at Pellnycota.* 
The low hills in the very middle of the Khoond-air valley—Poospa- 
dus geery and the smaller one of Goteloor—are of 
niers. 
quartzites, which would seem to be the same as 
those on either side of the valley. 
The Cumbum Slates. 
The Byrenconda quartzites of the Pollconda ridges, the Nullamul- 
| lays, and the Cumbum tank-ridge, &c., are overlaid 
Byrencondas over- 
laid by slates. by a great series of slates, which have no represent- 
atives in the western part of the field. They are continuous from the 
* South of Oopalpád plateau. 
