BARE ۰ 
CHAPTER l.-—'TuE KARNÜL FORMATION.—KHOOND-AIR GROUP. 
This series occupies only a small portion of the field of altered 
Dn rocks, and is not of any great thickness. Tt 
lies mainly in the central basim, or Khoond-air 
valley, being confined on the east side by the bases of the Nullamullay 
mountains. At the southern extremity it is spread over the 
Cuddapah basin to the edges of the encircling hills, and thence extends 
northwards up to and slightly beyond the Kistnah river. On the west 
side it reaches from the Cuddapah basin up to the Gundycottah range 
of hills, and eventually overlaps them, in their northern extension, 
almost as far as the outer western hills, finally overlapping even these at 
Kurnool, beyond which town it extends for some miles to the north-west 
and north. 
The KARNÜLS occupy about one-third of the area of the altered 
rocks, giving a good superficial and vertical 
Extent and thickness. 
display, their greatest thickness being at least 
twelve hundred feet. 
THE KHOOND-AIR GROUP. 
The uppermost group of the formation is a series of altered shales 
and limestones, the shales being highest; though from the prevalence 
of the limestones and the essentially calcareous character of the shales, 
it might be called generally a limestone series. 
The Nundial shales. 
The Nundial shales, so called from the most important village 
in the Khoond-air valley, are essentially shaly 
Nundial shales. À 1 
argillaceous limestones ; though they are often more 
shales than limestones, sometimes more limestones than shales, and 
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