GO KING : NELLORE PORTION OF THE CARNATIC. 



The Paremkonda-Kaluvaya ridges are also intruded 011 by sheets 



Intrusive traps of Pa- of diorite which £or a g 0od P art ° f theil ' leil ^ th 

 remkonda. appear to be contemporaneous. However, on fol- 



lowing them out they are seen to vary much in thickness, swelling out 

 every now and then, while they die out and are succeeded in the strike 

 too suddenly by other similar outcrops above and below the adjacent 

 quartzites to be contemporaneous flows. They commence thinly in the 

 sharp curve north-west of Paremkonda, and then rapidly increase in 

 thickness towards and under Kaluvaya. It is of course difficult to re- 

 cognise in generally altered strata any effects produced by such intrusions, 

 but the quartzites in their vicinity are certainly jaspery or flinty, an 

 uncommon condition of these beds, and they and the traps themselves 

 are epidotiferous. 



To the south of Gelacapad, there is again an unmistakable region 

 Irregular outbursts of o£ fl° ws and ill-defined outbursts of basic rocks, 

 tra P- which, though probably part and parcel of one 



great igneous development, is certainly disconnected from that of Parem- 

 konda, either by an area of milder action, or, as I prefer to think, by an 

 actual break along the Rapur line of faulting. I have represented this 

 southern area as continuous by the Potagunta ridges 1 on to Kandra in 

 the map, and there is every reason to consider that it is so in fact, but a 

 good part of it is covered up by the superficial deposits of the Venkata- 

 giri river. 



At first sight, the Kandra or Kana-Kondroyan hills seem to be 



wholly of trap, like the remains of a great pro- 

 The Kandra outburst. J . . . 



truded mass of volcanic rock ; but on examination 



they are found to be really of massive hornblendie and chlorito-horn- 



blendic rock, extensively traversed by dykes and irregular masses of trap, 



running mainly in north-west to south-east, east-west, and east-by-north 



to west-by-south directions, the whole occupying a wide belt thinning out 



1 Tbe Potagunta ridges were examined by diaries Oldham, and he seems to have con- 

 sidered that they, on the whole, consisted more of massive and schistose hornblendie strata, 

 with fewer trap dykes and dioritic masses. 

 ( 163 ) 



