164 FOOTE : GEOLOGY OF THE BELLARY DISTRICT. 



a very conspicuous object in the landscape when seen from the 

 east. 



South-eastward of the Kapgal hill, the dyke becomes obscure, as 

 it has been eroded down to the general level of the country rocks 

 both within the gneiss area and the Dharwar area, and is here and 

 there much covered up by superficial deposits. It can, however, be 

 easily followed down to the edge of the Haggari alluvium at Teggin 

 Budihal (Boodyall). 



To the N. W. by W. of Kapgal, the dyke can be followed for 

 a mile W. N. W. beyond the hill, and then it becomes obscured 

 by cotton-soil and is only seen again at two intervals, each at about 

 three miles distance south of Somasamudra and north of Yerra 

 Inglagi. 



In the Bellary section of the Penner-Haggari band is a very 

 interesting group of dykes of remarkable 



Blotchy Trap dykes . . 



south of Virapur Rail- character which consists of three large and 

 way Station. . , , ,. . 



conspicuous dykes, the eastern extremities of 

 which stretch away for more than a mile into the Anantapur district. 



The dykes lie four miles south of Virapur Railway Station on the 

 Southern Mahratta Railway and form two ridges about 100—150 feet 

 high above the bordering cotton-soil plain, with a course of about 5 

 N. of W. The special character of these dykes is their extraordinary 

 porphyritic structure, containing as they do millions of large rounded 

 enclosures of pink or pinkish white felspar, from J to over 2 inches in 

 diameter in a green matrix, which give the rock when seen from a 

 distance the strongest likeness to a coarse pebble bed. The visible 

 length of these dykes is about four miles. The enclosed felspar 

 masses are not at all amygdaloid in character. 



A single dyke of precisely similar character and colour runs along 

 Permadevanhalli the south side of the Bellary-Madras road for 



d y ke * about a mile, about half-way between Perma- 



devanhalli and Joladarashi. Its course is the same as that of the 

 three dykes just described, but it stands up so little over the cotton 

 soil surface as to be very inconspicuous, but has been blasted to some 



( '64 ) 



