840 
M VNGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [PaRT IV : 
locally. The.-e bands ar? not usually continuous for more than a few 
miles and often only for a fraction of a mile. As is usual in an 
Archajan complex the rocks are much folded and as a rule steeply dip- 
ping, sometimes to the north side of the strike and sometimes to the 
south side. 
There are two chief modes of occurrence of manganese-ores in this 
district. They occur principally as bands, often of considerable length, 
and usually thinning out in lenticular fashion, intercalated between the 
gneisses, schists, and quartziteS; of the crystalline complex, so as to con- 
form to the strike and dip of these rocks. This type of deposit is 
supposed, as already explained, to have been derived, at least in part, 
by the cherriical alteration of rocks composed of spessartite (manganese - 
garnet), rhodonite, and quartz, such rocks, in all stages of alteration to 
manganese-cre, being frequently found in association with the ores. 
Consequently, any bands of fresh or only partially altered manganese- 
silicate-rock are also shown in blue on the map and are also regarded as 
manganese deposits. The other mode of occurrence is as much smaller 
lenticles and bands of nodules of manganese-ore in crystalline limestone, 
usually in association with piedmontite. Tn one case, Junapani, the 
manganese-ore occurs in a bed-like band similar to those of the first type. 
A reference to the map (Plate 43) will show that the manganese- 
ore deposits are often arranged in lines conforming to the general strike 
of the rocks. 
The manganese zone in this district is 31 miles long from Kodegaon 
on the extreme west to Bhandarbori on the extreme east. The maxi- 
mum breadth of the zone as at present known is about 11 miles, meas- 
ured from Junawani on the north to Satak on the south ; but this will 
probably be considerably extended when the country to the north of 
Chorbaoli is carefully examined. On the west this zone is bounded 
by the large N. W.- — running bomidary fault, first noticed by Blan- 
ford^, that separates the metamorphics from the rocks of the Kamthi 
division of the Gondwina system ; it is connected — to the north 
of Kelod — to the manganese-bearing zone of the Chhindwara district. 
On the east the zone continues into the Bhandara district, while to the 
south it is bordered by alluvial plains. 
As regards the physical characteristics of the country, it is sufl&cient 
Physical charactoi s ^^7 ^^^^ Southern portion of the zone is 
of the country. occupied by an alluvial plain, at an average elevation 
of about 1,000 feet above sea-level, from which project low ridges and 
hills ; many of the manganese deposits reveal themselves only by the 
1 Mem. G. S. I.. IX, p. 310, (1872). 
