CHAP. 3.] KADAPAH FORMATION.—CHEY-AIB BEDS. 197 
There are, of course, examples of extreme obscurity: as for in- 
stance, where there are clear cases of displacement of beds by fault- 
ing, or where intrusive trap shows; or, again, where there has evidently 
been some considerable local denudation of the upper surface of a flow 
prior to the deposition of the overlying shales. 
The number of these flows of trap varies, as some of them thin out 
.. in shorter or longer distances within the outcrop 
Two periods of volcanic 
RECTE. of the whole group; but there are four or five 
which are tolerably persistent all through. The strongest flows are 
low down in the series. In fact there seems to have been two periods 
of voleanic energy : the first and strongest early in the formation of the 
series ; the next, much less extensive and about two-thirds up in the series. 
Even at the very commencement of the formation of the Tada- 
purtee slates, voleanie forces were in action; and 
Early trap intrusive. : 1 ۱ 
the trap was then intrusive, for it has penetrated 
and overflowed, as already related, the beds of both the Poolavaindla 
(Naggery) quartzites and Vaimpully limestones below; and has even 
flowed beyond the edge of the KapaPaH rocks in their northern area, 
and touched on the CRYSTALLINES or GNEISS rocks. 
The thickest flows are, as far as can now be made out, from two to 
three hundred feet thick in their fullest outerops; but this is doubtless 
not their greatest thickness, and it is not now possible to ascertain 
accurately what that limit was, owing to the denudation which has since 
gone on, and the generally hidden state of the junction of the upper sur- 
face with the beds above. The lower surface and the rocks immediately 
subjacent are generally quite clearly exposed, the outcrops of the traps 
themselves forming well defined scarps along the western faces of the 
ridges, while the lower beds are seen on the slopes below. 
This gentle dip is not, however, preserved throughout; southwards, 
Tad یم‎ eher an the wide flat country (only diversified at 
strata. intervals by long low ridges) to the west of 
06 ۱۵ ۰ ( 
