204 KING: KADAPAH AND KARNUL FORMATIONS. [PART 11 
it overlies the Naggery quartzites, and the only grounds for assuming 
that it is a representative of the beds on the Penn-air are, first, that both 
lie on quartzites which are only themselves possibly the same in different 
parts of the field ;* second, that there is some petrological resemblance 
between the two; third, that they are overlaid unconformably in each 
region by a set of quartzites; and Jastly, that if the whole series of 
KADAPAHS be traced downwards from their uppermost beds, as they are 
now being described upwards, it is found that the succession of strata in 
the various parts of the country lead to the same conclusion, viz., that 
the Tadapurtees are the same as the Poolumpetts. 
Both in the Chey-air basin and in the Tadapurtee valley this sub- 
CUO EN OES group is a series of slates with limestone interca- 
ME and lime- lated. To the south of the Chey-air, or in the 
valley of Poolumpett, after which town the series 
has been named, it is a thick group of grey and brown clay-slates, largely 
seamed with beds of generally compact silicious limestone, which are 
arrangeable in two bands. These seams are thicker and more frequent 
towards the Chey-air, decreasing in thickness southwards, until, in the 
isolated patch at the extreme end of the field, there are now no traces 
of limestones at all. Denudation may, of course, have had to do 
very largely with this absence of limestone bands to the south, but 
it is very evident that there was also originally a thinning out of 
these deposits to the southward. 
In the Balbapully, or southernmost patch of the Poolumpett beds, 
the rocks are principally brown, grey or purple clay-slates, much cleaved 
and jointed, and lying in a tolerably regular basin, on the bottom 
quartzites. From this they roll sharply up to the east, and then 
down again over the southern spurs of the Yellaconda range, the rocks 
of this part of the range being mainly Naggery quartzites, while the 
* I think itis almost quite clear that the Poolavaindla quartzites and the Na ggerys 
are the same.—W. K. 
( 904 ) 
