434 Journal of the Asiatic Society of Bengal. [N.S., XIV, 
or andesite, or whether it is more generally basic and nearer 
in chemical composition to basalt, or whether both types are 
equally abundant. In some instances, such as in the case of 
the Shevaroy hills, it has been ascertained that the prevailing 
form is the ‘‘ intermediate.” 
Judging from the chemical composition of its members, 
it is evident that the Charnockite Series consists of igneous 
rocks. Unfortunately, there is very little precise information 
available regarding the field-relations of these rocks. Their 
variation in chemical composition might be attributed to mag- 
matic differentiation, but their mineral composition, as far as 
the actual mineral species are concerned, is not that of any 
to a fe) 
agencies that have affected them all in a uniform manner. 
Holland has recorded instances of basic dykes traversing the 
tion, while establishing the intrusive character of such minor 
occurrences as fissure-dykes, Jeaves us in the dark concerning 
the real nature of the larger masscs. ; 
The amount of additional information directly concerning 
the geology of the Charnockites that has been gathered since 
the time of Holland’s original discoveries and investigations 
1s not very great: nevertheless, some useful purpose gid 
some of the more general problems connected with the Arch- 
ean geology of India ; 
e problem may be attacked from two points of view, 
the petrological and the stratigraphical. 
ROCKS APPARENTLY INTERMEDIATE IN THEIR CHARACTERS 
BETWEEN THE DHARWARS AND CHARNOCKITES. 
From the petrological point of view, a great deal of light an 
been thrown on this question by the researches of the memp® 
ment. ne 
must be mentioned W. F. Smeeth’s remarkable investigation® 
upon the development of secondary augite amongst the epidior - 
schists of the Kolar band of Dharwars (Bull. No. 3, 1909, hd 
Geol. Dept.). The mineral was first discovered in 1901 by Hi 
land who regarded it as probably referable to malacolite \ 
side), and who also recognised its secondary nature (Mem.,¥ 
Surv. India, Vol. XXXIII, p. 78). It is a monoclinic, Py 
oxene, occurring as a further development by recry stallicee a 
the secondary uralite of the epidioritic schists. It often * of 
