246 
MANGANESE DEPOSITS OF INDIA : GEOLOGY. [ PaRT II : 
gneisses, or gneissose granite, that crop out a little distance away on 
either side of the manganiferous outcrops, the intervening ground being 
covered by alluvial soil. At most of the localities visited, namely, the 
Kodur mines, Perapi, and Kotakarra II, calcareous gneisses were found 
cropping out on the low ground close to the manganese-ore band, 
whilst at the remainder, the following were the nearest exposed 
rocks : — 
GarbMm. — Quartz-rock close to the deposit, garnet-bearing quartzites 
some 1,500 feet to the south, and gneissose granite some 1,500 feet to 
the north, of the west end of the manganiferous band. 
Kotakarra I. — Coarse quartzite or vein quartz some distance away. 
Avagudem. — Immediately to the north is a low ridge of white 
quartz and white gametiferous quartzite passing to the east into a high 
ridge of khondahte. 
Rdmahhadrapuram. — In the excavations the manganiferous rocks 
are in contact with laminated quartzites, sometimes gametiferous ; 
whilst in another place, on the open ground between the Sonpuram 
and MamidipilLi workings, there is an outcrop of banded pyroxenic 
quartzite. 
The only cases in which the mining operations have clearly revealed 
the rocks immediately adjacent to the koduiite rocks^ are (1) atDevada 
(page 1074), where the calcareous gneisses are seen in the excavations to 
form the western wall of the kodurite band ; (2) at Perapi, where 
felspathic khondahte is seen to overUe the ore-band and associated fels- 
pathic rocks (page 1078 and fig. 83 ) ; and (3) at Ramabha drapuram, 
where quartzites are seen (above). 
The quartzites (often gametiferous) noted above as occurring in proxi- 
mity to the manganese-ore bands may be regarded as forming a part of 
the khondahte series. Hence we see from the evidence given above that 
the bands of the kodurite series seem to be more closely associated with 
the khondahte series and the calcareous gneisses than with the gneissose 
granites. Regarding for the moment the khondalites and calcareous 
gneisses as forming a succession of metamorphosed sediments, it is seen 
that the evidence, scanty as it is, does not bear out the theory suggested 
by the Taduru and Chintelavalsa rocks that the manganese-sihcate-rocks 
1 As will be explained later, the large masses of decomposed felspathic rocks 
that often form the immediate ' country ' of the mangauese-ore bodies and are well 
exposed in several of the quarries are considered to form a part of the kodurite series. 
