G30 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [TaRT IV : 
On a small plateau-area to the north of this phyllite hillock a further 
quantity of botryoidal and cavernous ore was exposed, resting on prac- 
tically horizontal quartzite.-;. 
As will be judged from the above, this occurrence is probably the best 
yet found ni the district ; but probably not more than a few hundred tons 
of ore of the above quality coidd be won by working the whole of the 
manganiferous area here ; whilst the railw ay at Chakardharpur is 
some 24 miles distant. Bi.stampur being 8 miles south of Chaibasa. 
9. Lagia (Lajia). 
According to Ball some of the iron-ore here is rich in manganese. 
This locality is about 7 miles west by a little south from Chaibasil. 
10. Leda Hill. 
Leda Hill is situated in Government Reserved Forest about 2| miles 
S. by a little W. of Goilkora station, Bengal-Nagpur Railway. It rises 
to 2,077 feet above sea-level and perhaps 1,000 feet above Goilkora. 
The top of the hill is nearly half a mile long and has a general N. W.- 
S. E. strike. Manganese-ores were first discovered here by Mr. R. 
Saubolle, prospecting on behalf of Messrs. Martin & Co., in 1907. 
This firm has since obtained the prospecting license for the occurrence, 
and has opened up a series of 28 pits and trenches, v/liich I v/as able to 
exanune in my visit to the hill in January 1908. The rocks of the hill 
as seen in the outcrops and exjiosed in these trenches consist of alter- 
nating quartzites and slates, traversed in places by vein-quartz. 
Their strike usually varies from N. N. W. to N. N. E. with dips varying 
from 45° to vertical to the west side ; but there are exceptions to the 
above figures. Almost everywhere these rocks have been partly replaced 
by oxides of iron and manganese at the surface with the production 
of the rock I have designated iateritoid. This consists of mixtures of 
iron-ore (limo iite and sometimes hematite) and manganese-ore (chiefly 
psilomelane) and usually shows residual patches of either quartzite 
or slate, or of lithomarge formed by the alteration of the slate. The 
pits and trenches show that manganese-ore that seems to be fairly 
good at the surface passes down in a few feet into partly replaced 
rock. Hence the ore is of superficial origin and, as far as can be judged 
from the pits and trenches, of very limited quantity at any one spot. 
Such ore as there is, moreover, frequently contains remains of the rocks 
from which it has been derived by replacement. I have not seen any 
analyses of the ores froni this hill, but I should say they v.ould tend to 
