1919.] The Sixth Indian Science Congress. exev 
galena and gold) ; Sikkim (copper, iron, lead, 
bis muth antimony, tellurium, cobalt) and Kolar 
s 
their present position to the intrusive action of 
granitic magmas, which are supposed to have pro- 
vided the metals as end- a aii on coolin ng. 
sis, Serve as an aria in istuiens the primary or nh 
character of such batholiths. 
Ore-deposits and minerals of economic value are compa- 
ratively scarce in the Eastern Ghats type of Archaeans, but 
mention may be made at this point :— 
(1) of the manganese-ores formed by alteration of the 
rocks of the kodurite series 
of aquartz-magnetite-ores and small segregati s of 
menite associated with the charnockite series 
(4) of the monazite of Travancore, associated with peg- 
matitic intrusions in the charnockite series, but per- 
haa also occurring in this series itself. 
EXPLANATION OF PLATE. 
Puate I1.—Geological sketch map of agiasioa showing 
mineral deposits. Scale 1 inch = 8 miles 
The pegmatites considered as an index to the age of some 
of the unfo marin rocks in the Indian Peninsula.— 
By E. VREDENBU 
Re _— are given for RE is that none of the Peninsular pegma- 
ites wer than the termination of th ———— period. In some 
instances sce doubt has been ex mang as to whether certain rocks 
are arwar or post-Dharwar aati : C) at of pegmati ite veins 
would fix their reference to the Dharw 
The peg paecig of ores of tungsten and tin in Burma.— 
B; wn Brown and A. M. Heron 
The and for tungsten caused by t misc aah war has resulted 
in the omen voc setae and prospecting of the wolfram deposits of 
Burma ; cassiterite, being intimately associated with wolfram, has 8 
