14 HAYDEN AND HATCH : GOLD-FIELDS OF WAINAD. 



throughout : similar conditions probably prevail in almost all the 

 more striking hill ranges in south and south-east Waindd, with the 

 exception of the granite masses at Sultan's Battery and Kalpetanear 

 Meppadi. The whole range of Velliramalai in south Waindd and 

 most of the hills to the north of Vayitri are composed of charnockite. 

 The intrusion of these great masses, when the rocks were probably 

 at great depths below the surface, would amply account for the 

 degree of alteration of the constituents of the gneiss. 



(3) Dharwars. 



To the north of Devala and south-west from Needle-rock peak 

 „ . the crest of the Marpanmudi ridge is formed of 



Ferruginous quartz r o 



schlst> a band of rock, composed of granular quartz* 



iron ores and garnet, standing up in hard vertical wall-like masses 

 and forming a striking contrast to the majority of the rocks, 

 which are usually decomposed to a depth of a hundred feet or more 

 from the surface. This rock was described by Dr. King ' as " a very 

 hard . . . highly quartzose and ferruginous gneiss, containing 

 laminae of grey haematite " : 3 it has not been found elsewhere in 

 south-east Wainad, and occurring as it does in the form of a small 

 band in the archaean gneiss would naturally have been included with 

 them as a more siliceous and ferruginous variety of that series. 



Under the microscope, however, it is at once seen to be entirely 

 different to the gneisses ; the granular character of the quartz, the 

 absence of felspar and other minerals characteristic of the gneiss, and 

 the presence of much haematite and magnetite are all features which 

 serve to distinguish it from the surrounding rocks. It has in fact 

 the usual characters of the quartz-iron-ore schists of the Dharwars 

 and is now referred to that system. 



1 Rec. Geol. Surv. Ind„ Vol. VIII, Pt. 2, p. 28. 



2 Loc. cit., p. 37. 



( M ) 



