GENERAL GEOLOGICAL DESCRIPTION OF THE FIELD. 5 



granite; (3) a younger intrusive granite which is certainly later 

 than the schists, as it is intrusive in them in their western border. 

 The proportion in which these three types are represented in the 

 area under description will be seen by reference to the map (PI. 21). 

 For petrographical details see the appendix to this report. 



The schist belt strikes north and south and extends to Srinivas- 

 pur, about 30 miles north of the Mysore Mine at Marikuppam ; 

 while to the south it has been traced for about 20 miles and passes 

 into the Madras Presidency. 1 In width it is variable, being of len- 

 ticular character. In the widest places it measures about 4 miles 

 across and in its narrowest about | of a mile. At Yerrakonda, a 

 prominent-hill about 3 miles south of Marikuppam station, the schists 

 split into two bands separated by the older granite ; and 10 miles 

 further south, a similar separation is found. Its synclinal character 

 is only indicated by a converging dip from opposite sides of the 

 belt ; the dip on the west side being to the east and on the east 

 and in the central zone, to the west. The bulk of the beds consists of 

 hornblende schist, but near the western margin runs a ridge of ferru- 

 ginous and jaspery quartzite much crumpled and brecciated in places. 

 The quartzite beds dip under the hornblende schist and are succeeded 

 by a band of mica schist which separates them from the granite-gneiss. 



This quartzite ridge can be followed along the western border 

 of the schist belt until it rises into the peak of Malapakonda, 9 miles 

 south of Marikuppam. On the eastern side the only place where the 

 quartzite may be seen is at Yerrakonda, 3 miles south of Mari- 

 kuppam, where the beds crop out with a westerly dip. These banded 

 hornstones and ferruginous quartzites are a common feature of the 

 lower beds of the Dharwar formation. 2 The iron is present partly 

 in the form of magnetite, partly as hematite. 3 



Along the eastern margin of the schist belt north of Yerrakonda 

 {e.g., at the village of Marsika, east of Marikuppam, and at Pedpalli, 



1 Report on the Kolar Gold-field and its Southern extension, by P. Bosworth- 

 Smith. Madras, 1889. 



2 Manual of the Geology of India, 3rd edition, p. 49. 



2 See appendix for an analysis made by Mr. T. H. Holland. 



