16 foote: geological structure of the eastern coast. 



shrines in that region. It is one of the most picturesque spots in the 

 northern half of the Nellore district, some of the great masses of 

 mica schist having fallen over and lying about in. wild confusion inter- 

 spersed with trees and buildings. The great numbers of crystals which 

 crowd the rock give it a very rough surface. 



The staurolite crystals are generally of large size, 2 to 3 inches long 

 by lj to If in width, but both larger and smaller sizes are met with. 

 The large crystals are almost invariably of coarse texture and much 

 covered with a film of mica which conceals the true colour. Some of 

 the smaller crystals have a fair amount of lustre, and are of dull blackish- 

 red or reddish-brown colour. Twin crystals forming true crosses and 

 diagonal (St. Andrew's) crosses are common, especially at the Mala- 

 konda, but not often of good shape. Along the west side of the 

 Malakonda ridge and also at Kotapalle, two and a 

 half miles north-west-by-north of Chundi, the sur- 

 face is thickly strewn with the prisms weathered out. In various damp 

 spots the weathered crystals get covered with a shining ferruginous coat- 

 ing and pass gradually into a species of lateritic concretion, as do also 

 some richly ferruginous garnets in other parts of the gneiss country. 

 The kyanite was seen only in the Malakonda beds, in which the crystal- 

 line masses are nearly as numerous as the staurolite prisms. 



The staurolite crystals were met with in two other localities, one in 



the ridge forming the extreme south point of the 

 Of Lingasamudram. . 



Chundi hills westward of Lingasamudram village, 



the other, a low hill, about two miles south-west 

 Near Picherla Konda. 



of Picherlakonda Trigonometrical station. In 



the former case, the crystals are rather' small and not numerous; 

 in the latter they are large and very numerous, and the general appear- 

 ance of the rock agrees with that occurring at Kottapalle near Chundi, 

 except in the absence of kyanite. 



Several of the quartzitic beds in the Chundi hills are locally rich 



,. . , . in tourmaline crystals. In a thin bed on the 



lourmalme m quartzite. 



crest of the ridge west of Chundi, the rather 

 ( 16 ) 



