CHAP. 4.] KADAPAH FORMATION.—NULLAMULLAY BEDS. 295 
or disappear. Traces of lead are still, however, apparent, and the 
ore was worked largely in the Cumbum slates north of the Nundy 
Cunnama pass. 
Tt 1s 1n these silicious limestones of the Nundiallumpett part of the 
SANE IL C: Nullamullays that the old lead-mining operations 
HOSOI: of the Moguls were carried on; and in which there 
are still good traces of that mineral. Report says likewise that lead 
has been found in the western slope of the Lunkamullas, and down in 
the bed of the Penn-air south of Goomconda; but no traces of such 
were observed by the Survey. 
In certain regions these slates are extensively impregnated with 
e oE quarts, dint white quartz: and this is most conspicuously 
pregnations, displayed along the middle third of their area, 
that is, between the Penn-air river and Giddaloor, about twelve miles 
south-south-west of Cumbum. Within these limits the quartz-runs come 
to the surface along the middle of the depression between the Nulla- 
mullays and the Yellaeonda range, and to some extent along the 
taleose and chloritie slate outerop at the western base of the latter 
mountains between Budvail and Porenaumla. There is an enormous 
quantity of this mineral distributed among the slates in the middle 
band; so much so that the country is marked for several miles 
from north to south with white ridges and reefs and scattered debris of 
the same. 
Again, in the northern part of the Cumbum country the slates are 
occasionally largely charged with quartz, more particularly around 
Mootakoola (20 miles north-north-east of Doopad) and in the Gung- 
waram hill to the west and south-west of that village. For the most 
part, the quartz is interlaminated with the slates, occurring only partly 
in the interspaces of cleavage: and it is most thickly deposited in or 
near the curves of undulation. 
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