1066 
MANGANESE DEPOSITS OF INDIA ; DESCRIPTIVE. [ PART IV 1 
A third xenolith of crystalline limestone in pyroxenic rock has 
already been mentioned (page 1064). In this place the limestone has 
evidently absorbed manganese from the pyroxenic rock, so that mangan- 
ese-garnets and -pyroxenes have been developed in it. It is possible 
that the blue apatite in the large xenoliths of crystalline limestone 
was absorbed from the manganiferous intrusives. 
At the western end of the quarry along its southern edge near the 
Q]^^^.^ water level were many huge blocks of brown 
chert in the lithomarges and decomposed 
quartz-felspar-rocks. During the chemical changes that have led to the 
formation of the manganese-ores large quantities of silica must have 
passed into solution. Such silica must to a large extent have been 
redeposited as these masses of chert. This chert contains ramifying 
chalcedony veins and small vein -like cavities, which are often found 
to contain water when newly fractured. 
Dr. Holland has described (see page 38) a specimen from Kodur of 
w magnetite containing 2 '16% Mn and 2 "52^ 
Mangan-magnetite. ° ° 
AI2O3. At Kodur I found this mineral only 
in the ores at A (page 1069) ; but what is probably also mangan- 
magnetite, containing perhaps a larger per cent, of Mn, is very 
common at Garbham and Avagudem. 
It is in the soft lithomargic and other rocks noticed above that the 
^, , manganese- ore bodies are embedded. At the 
The ore-bodies. . ° 
time of my visit the bottom of the pit was filled 
with a depth of about 8 feet of water, as shown on Plates 47 and 50. 
This water was due to unusually heavy rains in the previous monsoon 
(July to September) and was being slowly reduced by pumping. Two 
bands of ore were visible : one at the west end not more than 5 feet 
thick and dipping steeply to E. 20° N.; and another at the east end 
of similar thickness and dipping steeply to E. 10° N. The pit is thus 
cut at right angles to the strike of these ore-bands and the excavation 
between the west and east end of the pit would appear to have been 
made in practically barren lithomarge. But Mr. Tom Caplen, the 
manager of the Vizianagram Mining Co , Ld., tells me that ore 
occupies the whole bottom of the pit. 
Mr. W. H. Clark, who was formerly at Kodur, and is now manager 
of the Central Provinces Prospecting Syndicate^ tells me that large 
