46 KING : NELLORE PORTION OE THE -.CARNATIC. 



schists and granitoid rocks which are also dipping eastward on their sea- 

 ward edge. To all appearance, this ridge might be one of a set 



Appearance of uncon- of quartzites in the schistose gneisses were it 

 formity with the gneiss. n0 ^. fo^ j think there is some sign of general un- 

 conformity of the beds on the schists to the westward, and that the 

 schists on the eastern side do not follow the regular and marked curve 

 of the rido-e beds. It will also be seen directly how, in the prolongation 

 of these beds beyond the Penner, good evidence of unconformity was 

 noted by Charles Oldham. 



There must be a curved line of fault running along the eastern edge 



Faulted eastern boun- o £ this rid g e ; though all direct evidence of such 

 dar y- is concealed beneath superficial deposits. The 



crushed-up curve in the middle of the ridge length, the altered condition 

 of the beds themselves, the enormous quantity of quartz collected in 

 lamination and cleavage fissures all over and in the neighbourhood of the 

 ridge, are all points in favour of this view. 



About the middle length of the ridge, where there is a sharp bend in 



the strike of the beds, the quartzites are compact 

 Crushing and alteration. ,,. , ,.-■ j 1jL JU , ■ o i-, 



nint-like and much traversed by strings or white 



quartz silvered with mica and talc. The lower beds forming the back 

 of the ridge are coarser ; and with them are some thin outcrops of trap. 

 Further north towards the great tank, flint-like or jaspideous green 

 quartzites are frequent, and the intrusive traps are tremendously deve- 

 loped in a main sheet cropping up down the valley between the now 

 widened and double ridge and in two other smaller ones. These extra- 

 vasated traps continue northwards to the Penner, but not always between 



the same beds, for, though I could never find them 

 Trap flows, intrusive. . 



breaking through, they disappear and re-appear 



above or below well-marked outcrops, the large one of the valley appear- 

 ing to have passed up over the highest quartzites as it is seen under the 

 village of Kaluvaya, which is outside or to the eastward of the quartzite 

 outcrops. At the same time, there are many similar outcrops run- 

 ning with the schists on the eastern side of the ridge. Some of the 

 ( 15A ) 



