CHAP. 3.] KADAPAH FORMATION.—CHEY-AIR BEDS. 187 
pale purple clayey material appears to be in lapilli too. The rock 
weathers of a reddish brown color mottled with paler spots, and its 
deposition-surfaces are roughened with the granules. The specimen is 
from a thick band of these shales at the base of a low hill due north of 
Taudapurtee.* 
The finer-grained and more compact shales, with distinct spherules 
or ellipsoids of a like constitution with the mass of the rock, are more 
clearly concretionary in their structure than the 
Concretionary shales. Š 
speckled and granular flaky varieties. In some 
cases the concretions are more compact and of a darker color than the 
matrix in. which they lie. There is one case of a few bands of calcareous 
shales which are concretionary in a much larger and more irregular way ; 
the nodules being calcareous, compact, and sub-erystalline ; they crop out in 
the irregular hilly country below the south side of the Oopalpád plateau, 
and some eight miles east of Yadakee, whereabout the finest show of 
contemporaneous and intrusive traps, with associated shales, sandstones, 
speckled and granular shales, and chert-like bands of petrosilex, or 
compact felsites,is to be seen. The stream from Goodypaud to the north, 
after flowing for some time along the edge of the upper terrace of 
KARNUL rocks, falls over the edge and cuts deeply into the subjacent 
Tádapurtee slates, &c. There must be more than half a mile of shales, 
ashes, and felspathie bands exposed in the course of this stream, all of 
which are dipping regularly at 107-20" east or east-north-east, above 
and below which are flows of trap. Itis about the middle of this set 
* While referring to this locality, it is as well to give an instance of the peculiar 
changes which occasionally take place in the character and appearance of the trap rocks. 
A few miles north of this hill, near Cauvarysamoodra, there is a quarry opened close to 
massive greenstone. A portion of this trap, at the time of my visit, was weathered into 
a very fine grained mud-stone of dark green color, which broke up in sub-angular fragments, 
so soft and crumbly as to be carried away with difficulty. A fragment of this is now in 
the Geol. Surv. Museum, Calcutta, which is quite hard again, and not to be broken at 
the edges by the pressure of the fingers. In the field, if there had not been the massive 
rock close by, the weathered mass might have been called a volcanic mud.—W. K. 
Caer) 
