102 POOTE : GEOLOGICAL STRUCTURE OF THE EASTERN COAST. 



the east of Hanumantapad are two or three vividly red hillocks piled 



up against the side of pale quartzite hills, and making a striking 



contrast of colours. 



As seen from the top of the quartzite ridge west of Kondareddipalle, 



the whole of the great fiat valley of Nandananam 

 Nandananam valley. ^ ^ ^^ ^^^ ^ -g-^ Ronda and ^ 



bend of the Vellakonda range, is seen to be covered by soil of the most 

 intense red colour — the reddest tract of country I can recall to mind. 

 The derivation of the red ingredient is a problem to be solved ; the 

 o-reat richness in iron of the local soil does not agree with the character 

 of the surrounding older rocks so far as they are seen. Both the mica 

 schists of the gneissic series and the quartzites and slate of the Kadapa 

 rocks are locally very poor in iron. This suggests that the ferruginous 

 material came from elsewhere, and I believe it will be found that there 

 was once a large development of lateritic beds in this old bay, remnants 

 of which remain in the lateritic gravels exposed here and there under 

 the sandy red soil of Nandananam at Ramapalle and Pondhovah, the 

 red sands themselves being detritus of parts of the formerly more 

 extensive beds. This redness of the soil is confined to the basin of the 

 Pal-eru, and is not seen on, or north of, the water-shed between it and 

 the Musi-eru. 



A solitary patch of similar bright red sand occurs piled against 

 the side of the Iskapilly hill, 30 miles to the 

 south. These red dunes are due to the action of 

 the local winds (generally strongest from the south-west), tearing up the 

 surface of the red soil during the dry weather. On a very small scale 

 they resemble the "terais" of Tinnevelly district, but are brighter in 

 colour, and contain a larger admixture of clayey particles. 



( 102 ) 



