

RArT* 



AKAVALLI SYSTEM. 



quartz 01 ohe rock, a thin section of It shows a large percentage 

 of secondary contact-minerals developed in it. garnet being very 



Fig, ;;. 



r\ 



Delhi Quart y,i 

 Block 



/<■ 



Biotite Gneiss 



Fig. 4. 



noticeable in irregular interlocking areas, diopside and probably 

 zoisite. in similar areas and also in lather rounded grains, and 

 wollastonite in elongated fibrous laths nmch intergrown with 

 calcite. The central parts of the garnet areas are frequently 

 composed of some aggregate of doubly refracting minerals which 

 have not been determined. Some of this is of a rose-pink 

 colour and appears to be pleoohroio in pink and dirty vcllow 

 colours. It can be detected also in the hand-specimen. There 

 are some very small grains of sphene distributed through the rock. 

 No iron ores are present. 



