516 Notes, chiefly Geological, [No. 163. 



Their piled and separated appearance is entirely owing to that natural 

 process of spontaneous splitting, and concentric exfoliation when ex- 

 posed to the atmosphere, which I have attempted to describe elsewhere. 



These blocks, like phonolite and other rocks of basaltic origin, give 

 out a metallic sound when struck by a stone or hammer : and here, 

 from the peculiar and often delicately poised position of the blocks, the 

 effect is greatly enhanced. A few years ago an ingenious person in 

 London made a sort of harmonicon from slabs of basalt and other 

 rocks. The course of this dyke is South-westerly. 



Daroji. From Bellary to the great tank of Daroji, about fifteen miles, 

 the plain is flanked to the westward by the Copper mountain range, 

 which is gradually neared. Granite and gneiss are seen in low hills and 

 masses along its western base. A spur of this range ends at the S. E. 

 angle of the Daroji tank, throwing out a few outliers in the direction 

 of its line, viz. N. W. by N. This natural barrier line of elevation pro- 

 longed by an artificial embankment, or " bund," of stone and earth, 

 nearly three miles long, dams up the water flowing down the sides of 

 the ranges to the West, North-west, and South. It continues to the 

 village of Daroji, beyond which is another outlier of the Copper moun- 

 tain range. 



One of the rocks in the line of the tank bund presents a vertical sec- 

 tion of the strata, which do not materially differ from those forming the 

 crest of the Copper mountain already described, and have a similar ver- 

 tical arrrangement of laminse. Traces of the green carbonate of copper 

 also occur in it, and similar incrustations of the sulphate of alumina of an 

 earthy texture, are found at the bottom of a quarry in a small hill 

 crowned by a Hindu temple on the bund of the tank. Small seams in 

 the rock are filled with this mineral. Laterite, associated with a 

 blistery, and mammillary iron ore, occurs in a few small overlying 

 patches. 



A little to the North of this, beyond the village, lies a small hill of chlo- 

 ritic schist ; and on its flanks, a lofty and extensive outburst of granite 

 forming a chain of naked rugged peaks separated by deep trans- 

 verse gaps or valleys, stretching towards the South. It flanks the plain 

 West of the tank, and diverging towards the W., is lost in the still 

 loftier elevations of Sondur. 



