Chap. IV. 1.] metamorphic uocks. 87 



gneissic system, and there seems a very strong probability that such con- 

 nection really exists in nature, thoug-h the extensive spreads of Regur 

 occurring between the two points render it impossible actually to prove 

 this. On the west side of the curve the succession of the strata is much 

 more obscure, and no clear connection with the Kalroyenmullay strata 

 appears to be indicated. 



As regards the succession or relation to each other of the different 



series of beds or bands of the metamorphic rocks. 

 Relation of beds. 



very little can be made out at present, except con- 

 clusions drawn from local observations. AVhen it is considered that South 

 India is mainly made up of these rocks, and that our own personal obser- 

 vations over a much greater extent of country than that included in 

 sheet 79 tend to show that the different members of the series extend 

 over immense areas, it will be seen that much more extended observa- 

 tions of these rocks will have to be made before any general conclusions 

 can be drawn. 



The foliation, or, in other words, the indication of strike of the rock 

 masses over the area now under consideration is, on the whole, from west 

 to east, Avith a tendency always to curve round more to the north of east 

 until a nearly north by east direction is attained at the northern edge of 

 our area. The relation of the beds may then be studied, to a certain 

 extent, by commencing at the southern limit and taking them according 

 to their succession northwards. 



In the valley of the Cauvery it appears that the rocks of this region 

 Beds of Cauvery ^^'^ composed of two series, which extend along the 



^^ ^^' valley as three bands in a nearly east-west direc- 



tion, the most southerly and narrowest being one of hornblendic rocks 

 and schists. Alongside of this is a broad belt of quartzose and quartzo- 

 felspathie gneiss, associated on its northern edge Avith an extensive 

 and nearly parallel development of granitic rocks. North of this comes 

 the third band, which is very similar in its constituent beds to the first, 

 namely, a hornblendic and schistose series, Avith intercalated beds of 



( 309 ) 



