650 Notes, chiefly Geological, [No. 165. 



associated, apparently as a large vein, loses its mica, which is replaced 

 by minute silver scales of graphite. 



Nodules of lateritic iron ore occur, scattered with fragments of iron 

 shot quartz, a greenish actynolitic quartz and felspar ; fragments of 

 hornblende, schist, gneiss, granite, and basaltic greenstone, scattered 

 over the face of the country ; and occasionally patches of kunker. 



Bangalore. Gneiss is the prevalent rock about Bangalore, penetrated 

 by dykes of basaltic greenstone, and occasionally by granite, as is seen 

 near the pettah, and adjacent fields. The granite in these localities splits 

 into the usual cuboidal blocks, or exfoliates into globular masses. It 

 often contains hornblende in addition to mica. 



The gneiss strata though waving and contorted, as seen in the rock 

 in the middle of the tank near the Dragoon barracks, have a general 

 N. and S. direction, and often contain beds of whitish quartz preserv- 

 ing a similar direction. The strata are nearly vertical. 



Approaching Bangalore from the west, a bed of laterite is crossed, 

 forming a hill on which stands a small pagoda. This bed extends 

 northerly in the direction of Nundidroog, where laterite also occurs. 



In other situations, covering the gneiss and granite, a reddish loam 

 is usually found, varying from a few inches to twenty feet in depth, 

 containing beds of red clay used in making tiles, bricks, &c., the re- 

 sult evidently of the weathering of the granite, gneiss, and hornblende 

 rocks. 



Colar. A similar formation continues to Colar, a small fortified town, 

 notorious for its breed of vicious horses, and for being the birth-place of 

 the celebrated Hyder. It lies about thirty-eight miles to the E. N. E. 

 of Bangalore. The gneiss is occasionally interstratified with beds of 

 hornblende schist. 



The hill to the N. of the village, on which stands the ruined fort of 

 Aurungzebe's General, Cassim Khan, breaks the monotony of the sur- 

 rounding table-land. A spring and a small patch of cultivated land on 

 this eminence, probably tempted this Mahomedan noble to make it his 

 temporary residence. 



Baitmungalum. Granite, gneiss, and hornblende schist are the pre- 

 vailing rocks. Benza was inclined to believe that the blocks of granite 

 seen in the plain, a mile or two west of this place and north of Golcon- 

 dapatnam, are erratic boulders ; but, after careful examination, I am 



