929 



Notes, principally Geological, on the Tract between Bellary and Bijapore. 

 By Capt. Newbold, F. R. S. %c. Madras Army. 



No. 1. 



The notes, of which the following paper is an abstract, were taken 

 during a survey ordered by Government of that line of Post Road, con- 

 necting Bombay and Madras, which lies between Bellary and the 

 ancient Mahomedan capital Bijapore. They commence from Bellary, 

 comprising a line of 164 miles extending in a north-westerly direction 

 through part of the Ceded Districts, the Nizam's dominions, and the 

 Southern Mahratta country, crossing at right angles the courses of the 

 Tumbuddra and Kistnah rivers as they hasten across the Peninsula 

 from west to east, to add their tribute to the Indian ocean. The route 

 chiefly lay over a vast undulating plain, constituting a considerable por- 

 tion of the great plateau that is elevated on the shoulders of the Eastern 

 and Western Ghats, and intersected by a few subordinate spurs, run- 

 ning nearly at right angles with the great lines of dislocation. 



From Bellary to Courtney, a distance of eleven miles, extends a plain 

 Ceded Districts from based on granite and gneiss, penetrated by numer- 

 Bellary to Yailbenchi. ous g ree nstone dykes. From Courtney to Yailben- 

 chi, four miles, the plain continues, as before, covered with a superstra- 

 tum of regur, or the black cotton soil of India, to a depth of from one to 

 eighteen feet, in many places resting immediately on the gneiss and gra- 

 nite ; in others on an intervening bed of a calcareous deposit, somewhat 

 resembling the travertin of Italy, though more nodular, and called by 

 the natives hanker. It is burnt by them for lime. Like rows of flints 

 in chalk, it is seen also in the lower layers of the regur, often with sharp 

 projecting spiculse of carb. of lime, which would have been broken off 

 had the nodules been drift pebbles. Here and there, on the surface, 

 and partly imbedded in the soil, greenstone occurs en boules, indicative 

 generally of a subjacent dyke. Angular fragments of both yellowish 

 and reddish quartz in many places literally strew the surface of the 

 ground, which close to Yailbenchi, changes to a red clayey soil ; and, on 

 examination, proved to be the result of the disintegration of a bed of 

 micaceous hornblende schist, with gneiss here rising to the surface. 

 Granite, greenstone, and a rock composed principally of a reddish foliat- 

 ed felspar, pierced by veins of the same mineral in a more compact form, 



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