52 KING : NELLORE PORTION OF THE CARNATIC. 



series with nearly or quite the same strike and in some parts almost coin- 

 cident in dip. And it is only by observing that in parts of the hill these 

 Cuddapah rocks overlie the metamorphic series at a very different angle, 

 that their general unconformability can be satisfactorily established. 



" A somewhat similar case is seen in Oodagherry (Udayagiri) hill 

 further north, where the low dip of the beds of quartzite which cap the 

 hill, sometimes almost exactly coincides with that of the rolling contorted 

 beds of talcose and micaceous schists and slates, which form the mass of 

 the hill, while this quartzite, although as I think generally, even in 

 small specimens, distinguishable, frequently so closely resembles quartz- 

 rock occurring in bands in the lower metamorphic rocks, that it renders 

 the distinction between the two at first sight difficult and doubtful. 



" Generally, however, as above noticed, the quartz-rock of the lower 

 series, or metamorphic rocks proper, contains minute grains or scales of 

 mica, which in some specimens are very clearly seen and appear to form 

 extremely thin layers in the rock (sometimes well seen on a slightly 

 weather-worn surface), but in other specimens are so minute as to be hardly 

 observable. 



" Here also, as in the other instance cited near Bomaram, though 

 apparent conformability exists locally, the general unconformability is 

 tolerably distinct. In both these cases, the capping quartzites form a fine 

 precipitous scarp, which in Oodagherry hill is of about 200 feet in height, 

 and almost vertical and wall-like. In Bomaram hill there is a much 

 greater thickness of these beds, probably 400 feet, appearing on the 

 southern face of the hill, and forming a remarkably fine precipitous bluff, 

 a most conspicuous object as the traveller approaches from the westward. 



" In smaller hills north-east of Chunchulur I found a thin capping 

 of quartzite lying over micaceous and hornblendic schists, the strike of 

 both locally exactly the same ; the upper beds dipping at lower angles 

 and in places the schists underneath vertical. 



" In a small ridge south of Govindapully, nearly due west of Musta- 

 fapuram, I note micaceous and quartzo-micaceous schists dipping at 

 70° to 75° to east-by-nortb, capped by quartzites which dip in the same 

 ( 160 ) 



