LOWER TRANSITION ROCKS. 159 



Another quartz-run occupying the position of a fault-rock occurs 



on the S. W. side of the Sandur area at a place 



Sanassyhalli fault- called Sanassyhalli, but here again it was not 

 rock. 



possible to see any contact phenomena between 



the Dharwar schists and the quartz rock. 



In the Mallapan Gudda (Chiknayakanhally) band of Dharwars, 

 Mudanur and Vara- two cases of quartz-runs in the position of 

 kanhalli fault-rocks. boundary fault-rocks were mapped: one at 



Mudanur (Moodanoor) two miles, and the other seven miles to the 

 south-east of Huvina Hadagalli (Hoovin Huddagully). Here, again, 

 no visible contact between the quartz and the country rock on either 

 side of the fault could be found. The second of these two runs 

 gives rise to a steep ridge standing up about 200 feet above the 

 plain. To the east of it, but at a considerable distance, granite rocks 

 crop up, while to the west a great show of trappoid occurs on the 

 broken ground stretching away towards Varakanhalli, only at some 

 distance from the quartz-run. 



(d) Trap dykes. 



The age of very many of the numerous dykes shown on the 

 map is still unsettled; and only those which are bond Jide eruptives 

 into the Dharwar system, can be with safety assigned to the post- 

 Dharwar period. 



Of a limited number only can it be asserted that they had 

 existed prior to the commencement of the deposition of the Dhar- 

 war rock system. The evidence in favour of their age is negative, 

 they are not seen to cut through schists, haematites and contem- 

 poraneous traps making up that system. 



Of much the largest number of dykes met with in the Bellary 

 district, the age cannot as yet be determined, for they are not in 

 contact with the Dharwar rocks ; but some of them may possibly 

 have penetrated the portion of those rocks now denuded away, which 

 lay between the present bands and outliers, and connected them. 

 Others, again, of greater age, may have been intruded into the 



( 159 ) 



