1918. ] The Charnockites and the Dharwars. 439 
Cambrian and later age, contain nothing that resembles 
these vast spreads of banded ferruginous and siliceous rock so 
frequent in many pre-Cambrian formations, and they seem to 
have originated from certain agencies that were active only at 
early periods of the earth’s history. The main point in connec- 
tion with the present enquiry is that they are truly interbedded 
and truly contemporaneous with the strata with which they 
are associated, and that no one who is familiar with the rock 
in its unmetamorphosed condition, as exhibited in the expo- 
sures of the Kadapah, Gwalior. or Bijawar series, could admit 
that the more or less metamorphosed but essentially similar 
rocks so frequent in the Dharwars, have had a different origin. 
stances are observed actually in the small fringe of the Char- 
nockite series represented on the published geological map of 
Mysore, and it has been necessary, in the index to that map, 
amongst the sub-divisions of the Dharwars, after the words 
~ Banded terruginous quartzites and iron-ores * to insert 
&@ parenthesis with “a few of Charnockite age’’, the Charnoc- 
Kite Series being regarded by the Mysore geologists as differing 
Mage, and as newer than the Dharwar Series. 
Roticeable in the Tainanda and Kolymullay hill-masses. ( aie 
ma Foote, ‘On the Geological Structure of Parts y 
of Salem, Trichinopoly, Tanjore, and South Arcot, 
ise) Presidency,’ Mem. Geol. Sur. India, Vol. IV, pt. 2, 
hi i ised as follows :— _ 
oS ae evidence may be summarise a okion 
‘nd Dharwars succeed and exclude one another in pny 
indicate that they may represent two phases 0 
Same system. a 
the secondly. The outlines of the Charnockite outerops Mt 
“k phy sical features which these rocks constitute correspe 
ose exhibited by the Dharwars. ? 
hirdly. The rede in some of the most important 
