Chap. XL.] 
Vizaoapatam: taduru. 
1111 
in a directioti W. 6^ S. up a long slope of gneissosc granite, and then up 
a si )pe covered with loose blocks of manganese-silica te-rocks and some 
of calcareous gneiss, the manganese-silicate band is finally reached on the 
northern slope of a jungle-covered hill at a point some 150 or so feet 
above the lower ground cut out by the stream to the north. The map 
shown in Plate 55 is a very rough sketch-plan made during the course of 
the one day that was spent in the examination of this occurrence. It does 
not, therefore, pretend to show the geology in any but a very approxi- 
mate manner. 
The strikes and dips, for instance, are vShown in a generalized fashion 
and are, of course, really much mere complicated and varied. The posi- 
tion of the manganese-silicate band is shown only where it was seen. 
It crops out at a fairly uniform level along the hill side above-mention- 
ed and to the west it appears to die out. To the east it is not exposed 
in the stream, and no attempt was made to ascertain if it reappeared on 
the hills to the east of the valley. 
The probable relation of the manganes >silicate band to the associat- 
ed rocks is explained in the section shown in Fig. 2 along the line A B 
in Plate 55.^ 
The manganese-silicate band measured 8 paces across the outcrop at 
two different points ; assuming a dip of about 30° to the south, i.e., into 
the hill, the thickness of the band must be about 12 feet. It shows consi- 
derable variations in composition, but is com- 
The m.ngauese.py,.oxen- ^^^^^^ ^^^^j^^j^ ^ minCials. The chief of these 
is a rich brown, sherry-coloured to orange-red, 
manganese- [/yroiene , usually forming a granular aggregate of granules 
averaging ^ to inch iliameter ; and less abundant are pink rhodonite , 
usually assuming prismatic forms, in places up to an inch long, anda ricl< 
green manganese-pyroxene occurring usually in small granules, say ^j. inch 
in diameter, often enclosed in the rhodonite. The fourth mineral is a 
rich orange manganese-garnet , in some places forming a fair proportion 
of the rock ; in others it is quite absent. Although the three 
pyroxenes are so easily distinguished in hand-specimens by their different, 
colours, yet in really thin sections they are very difficult to difxri- 
1 This ie very similar to a section sketched for me by Mr. Middlemixs before luy 
visit. 
