502 Notes, chiefly Geological, [No. 163. 



slate. From Nundaloor the range of hills flanking the western side 

 of the valley is crossed by a defile to the plains of Cuddapah. The 

 summits of many of these hills are capped with sandstone ; while lime- 

 stone and its associated shales are seen near their bases in the vallies, 

 as at Wontimetta and near Bankrapet. 



Cuddapah, Cuddapah is situated at the western entrance of the flat 

 valley of the Pennaur, from which river it lies about six miles south. 

 The height of the plain, in the midst of which Cuddapah is situated, is 

 about 500 feet from the level of the sea. The Pennaur flows at the 

 base of the northern range in an easterly direction towards Nellore, 

 below which it disembogues into the Bay of Bengal. The stream, 

 on the banks of which Cuddapah stands, takes its rise in the hills to 

 the south of the place, and pursues a northerly course to the Pennaur. 

 Other streams of minor note intersect the plain. The soil covering the 

 surface is generally black, mixed with sand and calcareous matter : to 

 the west of the cantonment, a thin stratum of sandy soil overlies a bed 

 of kunker, from one to four or five feet thick ; in some places compact 

 like travertine, and in others having a pisiform, tuberose, and tufaceous 

 structure. Some specimens when broken exhibit a crystalline radiated 

 structure; others a concentric form. Below this lies a bed of limestone, 

 generally purple and of a shaly structure, mingled with argillaceous matter. 

 The bed of kunker, however, does not always intervene : the latter rock, 

 where it is tufaceous, has often a concentric appearance resembling 

 stalactite ; and sometimes appears in pisiform concretions both detached 

 and adherent to the subjacent mass. It is still in process of formation 

 from water slowly percolating from below ; the stems of the grasses 

 around which it has formed, are often found undecayed. 



Eastern Range. Ghauts, North of Cuddapah. On ascending the range, 

 north of Cuddapah, where it overlooks the diamond mines of Chinnoor 

 and Ovalumpully, I found the base and sides to be covered with angular 

 fragments of a very hard ferruginous sandstone. Advancing a little way up 

 the ascent, a narrow bed of a greyish quartz, following the line of bearing, 

 is crossed. Here and there slightly convex plateaus of compact crys- 

 talline sandstone, passing into quartz rock, of various shades of red, are 

 observable amid the loose blocks and vegetation with which the surface is 

 almost concealed. Large amorphous masses of the greyish quartz rock 

 appear at irregular distances on the summit; some of them ten feet high. 



