PHYSICAL GEOLOGY. 15 



The partially parallel arrangement of the land features in broad or 

 Correspondence of narrow strips of hill and plain is, as already 

 ESLn e t atU S S 3 incidentally noticed, dependent on a more or less 

 series - banded distribution of the later formations over the 



gneisses which give the most important and extensive outcrop, having 

 a width of some 40 miles between the low plateau ridge of Nellore, 

 &c., and the Veligondas. 



The oldest covering rocks or the Cuddapah series, consisting of detri- 

 tal quartzites and slaty beds, are very clearly displayed and denned in 

 the western mountain belt, though there are some important outliers in 

 the Kambak and Kalahasti ranges to the south-south-east and again 

 in the Udayagiri Droog and the Dargadevi Konda to the north of the 

 Penner. 



The next later formation is merely represented by the barest traces 

 of shales belonging to the Rajmahal group of the upper Gondwana 

 system, which are here exposed in well-sections at only a few spots under- 

 neath the lateritic band of Nellore. At the same time, it is quite 

 possible that these small patches are part of a hidden belt connecting 

 similar strata in the Madras and Kistna districts. 



Over these and covering them comes the broken strip of sandstones 

 and laterite forming the narrow plateau ridges running parallel with 

 the coast, on one of which the town of Nellore is situated. These sand- 

 stones are rangeable with the Cuddalore sandstones, distinguished by 

 Mr. H. F. Blanford as a group overlying the cretaceous rocks near 

 Cuddalore, or with my Rajahmundry sandstones 1 in the Godavari dis- 

 trict, which overlie rocks whose fossil ( ' relations appear to be rather 

 with the upper cretaceous rocks of South India/' 2 and are therefore 

 presumably of tertiary age. 



Of recent deposits, there is the belt of alluvium bordering the 

 eastern edge of the sandstone plateaus just noticed ; and of yet newer 

 age comes the thin strip of blown sands on the sea-shore. 



1 Rec. Geol. Surv. of India, Vol. X, p. 56. 



2 Manual of the Geology of India, p. 319. 



( m ) 



