42 KING : NELLORE PORTION OF THE CARNATIC. 



of false-bedded quartzites striking east-west. Quartzites are lying on the 

 top of the ridge in among the trap. At the eastern end of the ridge, 

 about due west of Thimmasamudrum tank, trap shows all round the 

 abrupt slope, the quartzites being distinctly situated on the top. Further 

 down the slope, however, there is a wide spread of greenstone, jointed in 

 lozenges, north-west to south-east, and north-east to south-west, enclos- 

 ing or embracing, as it were, bands of quartzite which appear burnt into 

 the igneous rock. 



Mr. Oldham writes of this region : — " The hill of Kanakandroyan 

 consists almost exclusively of trap, hard close-grained, rather amorphous, 

 having much the appearance of being bedded, striking north-west to 

 south-east and dipping generally at a very low angle to south-west, with 

 a tendency to break up pentagonally. Along the ridge, a little quartzite 

 is seen, nearly continuous, only the highest point being free from it. It 

 caps the ridge, apparently lying on the trap which in some large pieces 

 may be seen united to it, the trap below and the quartzite above, both 

 somewhat altered, the trap being close to the contact, more earthy, and 

 the quartzite more flinty." 



Proceeding northwards from this last ridge across the valley of the 

 Venkatagiri river, trap ridges are again met with on which are two 

 further long strips of Cuddapah quartzites. 



In all these cases the quartzites are intimately associated with the 

 basic igneous rocks and entirely separated from any gneiss. The resem- 

 blance to strata of the Cuddapah transitions is perfect, while they are 

 not like any quartzites of the crystallines. In the latter, it ia true, the 

 approach to ordinary compact and waxy beds of the newer series is very 

 close, but there are no such distinct conglomerates, and fair obliquely 

 laminated beds are rare. The difficulty was to account for the present 

 beds being in such unusual position, and the only conclusion we could 



Remnants of a fold in- '^ t0 at the W ° f ° Ur ^^ WaS tha * they 

 volved among and associ- are the remains of an outlying strip or portion of 

 ated with traps. r r 



a compound anticlinal which formerly extended in 



this direction from the area next to be noticed, that of Gelacapad and 



( 150 ) 



