1008 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [ PaRT IV : 
manganese-oxide are seen to ramify out into the phyllitic rock, 
their direction tending to follow the lamination. In one place a section 
is exposed showing the altered clayey rocks traversed by a network 
of quartz veins. In this section there are also numerous nodules 
and veinlets of manganese oxide. These not only cut the clayey 
rock irregularly as regards the bedding or himination, but they also 
cut the quartz veins, showing that they have been formed after 
the quartz veins, and therefore after the phyllitic rocks that the 
quartz veins have pierced. This is supported by microscopic examina- 
tion, which shows that these nodules have been formed by replacement 
of the phyllitic rocks, remains of which they almost invariably contain. 
Other sections on this ghat road show small thicknesses of massive 
quartzites. These also have been in places impregnated with man- 
ganese oxide so as to be quite black, though still containing a large 
percentage of quartz ; whilst in other places nodules of manganese-ore 
have been formed in them, this ore being sometimes good hard 
metallic psiloraelane, though never present in sufficient quantity to 
be worth extraction. Any one examining these sections would, I 
think, agree with me, that in every case the manganese-ore is 
subsequent in time of deposition to the containing clayey rock. More- 
over he would agree that this clayey rock, which is often a variegated 
lithomerge, has been formed by the alteration of the phyllites seen 
fresh in some places. He would further agree that there was some 
connection between the alteration of the phyllit?s and the presence 
of manganese-ore. 
Let us no^v turn to Rilmandrug Main Bed. There, at the N. W. 
end of the main bench, is a good exposure, 
.socSins."'^'"^ '^^''^ ^''^ beside the tramway line to the ropeway at 
Prospect Point, of some of the rocks forming 
the ' country' on the foot-wall side of the deposit. The fresh form of 
the rock is a fairly hard greyish rock of rather dark grey colour with a 
greenish to brownish tinge. This rock dips into the hill-side conformably 
with the ore-deposit an 1 is finely laminated parallel to the dip, Tt would 
probably be best described as a laminated siliceous magnetite -slate, 
tending to be flaggy. Under the microscope it shows a finegrained 
mixture of magnetite and quartz, with limonite and a micaceous 
mineral. The rock is fairly heavy, and small chips of it are easily 
