882 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [PaRT IV^ 
The dip of the ore-band in the south-east half is almost constantly 
Dips^. towards the north-east side, at angles lying usually 
between 45° and G0° (except in the Parsoda porti >n 
where it is 30^ to 45°). The band then becomes overturned, so that the 
dips are at 30° to G0° to the scuth-west side. This south-south- west dip 
continues as far as the highest parts of the hill, to the west of which the 
dip agam changes to the north- north- east at 55° to vertical, then to south- 
south west at 70°, and finally again to north- north -east, which is the dip 
seen in the quarry at the extreme west end of the Central Provinces Pros- 
pectmg Syndicate's concession, where the dip is very steep to alniust 
vertical. The varying dips given above for the part of the outcrop lying 
between the top of Mansar Hill and the west end of the deposit were 
those seen on the outcrop and in such openings as had been made up to 
January 1904. The opening up of most of this outcrop and removal of 
large portions of the upper part of the ore-band by December 1906 have 
shown that that there is a sharp fold, in one place violent enough to 
S. produce a small strike fault, in the ore- 
band some 50 feet below the highest 
point of the hill. As the outcrop to 
the west of this was considerably lower 
it actually cut into this fold, thus ac. 
counting for the variable dip. In 
several of the workuigs at the west end 
of the deposit the actual overturns can 
be seen in small sections of a few feet 
Fig. 59— Overturn in beds of j- i ■ 
manganes:-orc at Mansar. vertical, as m figure 59. 
The ore-band itself varies iii character. On Mansar Hill it is to a 
large extent composed of manganese-ore, often of the best quality. But 
on the descent down this hill to the south-east and right along the ore- 
band to its south-eastern end, the manganese-ores give v/ay in most 
places to various manganese-silicate-rocks. 
The commonest variety of these is spessartite-quartz-rock (gondite). 
Constitution of the occurring interbanded with what was thought m 
ore-band. the field to be a quartzite. Microscopic exami- 
nation, however, shows that the rock is a fine-grained granulitic gneiss 
contaming grains of a black ore, probably braunite, and a few of 
spessartite, together with an abundance of a pale yellovdsli pyroxene. 
In this reck thin bands of spessartite also occur. These rock-bands 
are often only an inch or two thick. The gneiss-bands weather 
out a little above the spessartite-bearing ores and often show crumplings 
on a small scale. Any ore-band can often be traced for some yards, but 
probably ultimately thins out in a lenticular fashion. There are also 
bands of dark grey quartzite containing abundant granules of a man- 
ganese-ore. 
