58 



Notes, chiefly Geological, of a Journey 



[Jan. 



one thousand feet above the plain, of peculiar conformation, 

 being of a conical shape with a vertical, ridgy projection, some feet 

 thick, down its eastern side from apex to base, dividing the hill into 

 two halves, a northern and southern portion. The strata forming 

 both sides have an opposite dip ; those to the north dip northward, 

 and those to the south, southward ; thus diverging from the projecting 

 ridge, as if from an anticlinal line (PI. 17 fig. 5). If this vertical ridge 

 had had a black, instead of a whitish grey, colour, as it appeared at a 

 mile distance, I should have taken it for abasaltic dyke, bursting through 

 the gneiss, and at the same time elevating the margin of the fractured 

 strata. I then recollected that, at the western foot of this mountain, 

 there was a dry deep nullah, in the bed of which were implanted large 

 masses of common granite, projecting many feet above it (No. 39). 

 From this I conclude that the lowest rock is common granite, which 

 elevated, and intruded into, the stratified rock. 



The appearance of the spiry, sharp-peaked mountains to the north, 

 seems to countenance the above mentioned surmise ; nor can we suppose 

 the enormous blocks in the bed of the nullah to be erratic boulders ; 

 because many had their extensive, convex surface a few inches only 

 above the bed of the torrent. The other rocks in this plain, are loose 

 pieces of lateritic iron ore, and below the soil a thick stratum of 

 kankar. Carbonate of soda incrusts the indurated sandy soil in some 

 places (No. 40). 



Waltair, Feb. 13.— From the last encampment to thi& place the 

 hilly appearance of the district continues ; the rock is gneiss, the strata 

 highly inclined, and, in some hills, nearly vertical, and traversed by 

 fissures, which, cutting the seams at an angle, the naked sides of the 

 hills are thereby marked with lozenge shapes. The plain before reach- 

 ing Vizagapatam, is covered with a white efflorescence, like hoarfrost, 

 produced by the small crystals of muriate of soda, deposited after the 

 evaporation of the sea water, with which this soil appears to be im- 

 pregnated. Numerous pits are dug in the soil, close to the hill of gneiss 

 in the road to Waltair, to obtain the shells many feet below, which are 

 burnt for lime; generally they are salt-water shells. If my memory does 

 not fail me, a portion of this plain has been lately drained, by which 

 the air, before proverbially unhealthy, has been rendered pure, and 

 many thousand acres of land have been reclaimed from the sea. 



The hills about Waltair are gneiss ; some of the strata are exclu- 

 sively formed of garnets, sometimes containing more mica than in other 

 localities, occasionally in nests (No. 41). The way from Vizagapatam 

 to Waltair lays through rocky knolls, hillocks and masses heaped one 

 over the other, and before reaching Waltair there is an undulating sandy 

 plain (perhaps not a quarter of a mile broad) of a red colour, the result 

 of the disintegration of the gneiss abounding with garnets. 



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