ARCH/EAN AND PLUTONIC ROCKS. 49 



fs a banded grey micaceo-hornblendic granite gneiss traversed by- 

 several pegmatite veins. One of these, running nearly N. 25 E., had 

 been the cause of the fall of a very large mass of the granite gneiss 

 which had broken away from the rest of the rock along the line of 

 the vein. I had often seen such fractures on a small scale, but 

 never on so large a one ; the fallen mass must have weighed 

 many tons. 



3. The Hirahal Sub-division, — About 2 J west-north-west of the 

 Hoss gudda boss we come across the southernmost rocks belonging 

 to the third or Hirahal sub-division of the metamorphic area, the 

 position of which was defined above (p. 30). This sub-division is 

 by far the smallest to be considered. Its northern part belongs to 

 the Hospet taluq and its south-eastern includes the extreme south- 

 ern end of the Bellary taluq in which lies the large village of Hirahal 

 (Hirrahall) that gives its name to the sub-division. To the south- 

 west it abuts against the Mysore boundary. 



A great deal of rock is to be seen, but it presents very few fea- 

 tures of any interest or importance. 



The low ridge south of the Travellers' bungalow at Hirahal 

 consists of gneiss -partly schistose, partly quartzose, and granular 

 in character ; but the latter variety does not much resemble the 

 granular quartz beds of Madura district. The gneiss is here over- 

 laid by a thin bed of hornblendic schist, and this, apparently, by grey 

 granite gneiss of the ordinary local type. To the east, this set of 

 beds seems to be overlaid by a banded micaceous granite gneiss 

 weathering of a reddish or brownish grey, the same as seen on the 

 Jazerhalli hill immediately to the south. 



To the north-east of Hirahal several beds of true banded mica- 

 Gneiss north-east of ceous gneiss alternating with hornblendic schists 

 underlie the Dharwar system with apparent con- 

 formity, but it is uncertain whether some of them should not be reckon- 

 ed to the younger system. I could not satisfy myself completely as 

 to this, but incline to think that the lowest hornblendic schist should 

 be regarded as the basement of the Dharwars. 



D ( 49 ) 



