1842.] Tract between Bellary and Bijapore. 937 



ning down the slope of the plain, has a pseudo stratiform appearance, aris- 

 ing from nearly horizontal joints, which might be mistaken for the lines 

 of stratification. It continues as the surface rock as far as the village 

 S W li it of the °^ ^urdinny, near which it is overlaid by beds of 



great overlying Trap a friable trap, approaching wacke, with an ob- 

 f'ormation. 



scurely schistose structure, and penetrated by 



veins of an earthy carbonate of lime, calc spar, and quartz in crystals. 



It rises near the village into a small knoll, down whose declivity 



runs a rivulet, in the bed of which the first section of the great overlying 



trap formation of the Deccan met my eye. Depositions of hanker, both 



in beds on the surface, and veins penetrating the fissures in both rocks, 



occur in abundance ; it is found in a pulverulent and concrete state : the 



nodules are not so crystalline as those that are seen in the vicinity of 



the older trap dykes, which penetrate the granite and gneiss of the 



Carnatic, the Ceded Districts, and Mysore. 



About two miles to the north, on the rising ground on which stands 



the little fort of Beylhal, the road is literally 



S. Mahratta Country ' J 



from Gurdinny to Bag- paved with the boules of trap, which, exfoliating 



in concentric lamellae, leave circular and oval 

 nuclei, the latter in their turn, however hard and compact, evince a 

 tendency to a similar process of disintegration. This gives a singular 

 appearance to the surface of the road where the rock is uncovered by 

 dust ; presenting a surface paved, as it were, with mere pebbles of 

 compact basalt set in concentric rings of wacke. The nuclei remain 

 prominent from their superior hardness. Calc spar of various shades 

 of white, green, and pink, calcedony in perforated nodules, and in 

 geodes exhibiting concentric annular delineations, and lined with mi- 

 nute crystals of quartz, semi-opal and jasper occur in veins imbedded in 

 wacke. 



At Umblanur, a walled village in the jaghire of the Mahratta chief 

 Punt Pritti Niddhi, about three miles north from Beylhal, I found 

 the nuclei to consist of a hypersthenic felspar, imbedding crystals of 

 augite, fracture small grained uneven ; streak greyish white. Bits of a 

 dark flesh-coloured eurite, and a porphyritic rock composed of crystals 

 of dark dull green hornblende, imbedded in a paste of a faint bluish 

 green felspar, exceedingly tough under the hammer, occur in the plain. 

 I searched, but in vain, for these rocks in situ ; although judging from 



6 G 



