150 KING: KADAPAH AND KARNUL FORMATIONS. [PART 1. 
old shores; all evidencing river feeders from the westward, and powerful 
denudation over a rugged coast almost close to the water's edge. 
Subsequent to this was a period of local formation of clays and 
shales, rapidly succeeded by calcareous deposition with possibly an inter- 
mittent flow of thermal waters as indieated by numerous bands of 
silicious matter consisting mainly of peculiar minute concentrically 
layered globules which give the rock sometimes quite an oolitoid 
character. 
These deposits were then: brought under the influence of denu- 
dation which, by the way, must have been more of a marine than sub- 
ESI character, for, except to the south-west of Cuddapah town, 
there are no traces of any valley erosion along the outcrop, the floor now 
seen having apparently been planed down very uniformly. 
Upon this denuded floor were deposited successive groups of sand- 
stones and shales, with intervals of limestone formation; during which 
time there was a period, or perhaps two periods, of volcanic action, 
the rocks of which were confined to certain parts of the basin. 
The area of deposition at this time too was more extensive north- 
ward and southward than that of the first period; while it seems 
probable from the strongly detrital character of the quartzites and even 
of the limestones to the southward, together with the evident thinning 
out of both to the north, that the deposits of this group must have had 
one great source of supply somewhere to the south. The quartzites of 
Naggery, Narnaveram, and Tripetty hills are of enormous thickness 
and very coarse; while even the limestones, in the valley north of 
Tripetty, are many of them most angular breccias. 
Denuding forces were again brought to bear on the second group of 
deposits so formed ; and then there was another filing in of a much 
larger sea with other sandstones and shales, and only local depositions of 
limestones. 
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