1919.] The Sixth Indian Science Congress. excl 
Oldest. 
Pegmatites . Pegmatitic zone. 
{ Wolfram-quartz veins] ! 
Magnetite-apatite rocks > Pneumatolytic zone. 
Unknown uranium mineral]! 3) 
Chalcopyrite 
Argentiferous galena Hydrothermal zone. 
old 
Barren vein quartz 
There will, of course, prove to be local exceptions to this 
order. 
2. Sikkim. 
In Sikkim, numerous se ee lodes and 
argentiferous blende- -galena lodes have been discovered inter- 
bedded with the slates, phyllites and schists of the Dalin ing 
series, regarded as equivalent to the Dharwars of the Peninsula.’ 
rea occupied by the Daling rocks is not large, ~ is 
surrounded by gneisses, regarded as of younger a In 
addition, there is a granitic intrusion in the midst of the 
Dalings. Basic igneous intrusions are rare. Copper deposits 
have been found in many parts of the Daling area, both 
with reference to the Dalings, and, in vie w of the rarity 
of basic igneous rocks, we are on fairly safe Laer? in attribut- 
ing the minerals es the acid intrusives. Althou gh the condi- 
3. Kolar. 
The gold of Kolar occurs in veins of blue or grey quart 
enclosed in the hornblende-schists of the Lower Dharwars of 
the Mysore Geological Department, and in rnin relation- 
ship to these hornblende-schists is a gneiss 
Champion gneiss by the same Department. in "addition to 
1 Exact position of minerals in brackets uncertain. 
2 Rec., G.S.I., XLT, p. 74 (1912). 
