CiiAi'. xxxvr.i 
XA(;]'rH : sa i ak. 
903 
being abruptly cut ott" at the surface by overlying talus or soil, bends 
over on to the underlying rocks and rests unconforinably on their 
upturned edges, so that the banils, all taken together, tend to form 
a horizontal layer stretching along the whole length of the cutting 
near the surface, thus accounting for the great width of out- 
crop. It follows from what has been written abo\e that, if the section 
seen in this cutting is representative of the whole ridge, no great qmntity 
of ore is to be obtained from the rock in situ. It has been niention((l 
above that the ore-bands are best at the surface, the ore deterioratijig 
in depth both in (quantity and ([uality. The quality of the ore being 
extracted fioni the talus-ore deposits is much better than that of the 
ore in situ ; one must suppose from thb- that the portions of the ore 
band, that were removed in the formation of the talus-ore deposits 
were of better quality than that now left in the ore-mound and that 
consequently the ore-bands must have improved towards the surface 
still more than they do now. 
The manganese-ore seen in situ along the ridge is the hard crystalline 
mixture of biaunite and psilomelane, but it is difficult to find a piece 
free from at least a little impurity (usually white felspar or quartz). 
A pit on the north side of the east end of the ridge showed (5 feet 
^ J . -t ■ pebbles of manganese-ore separated from under- 
le a uh-uic pi . lying biotite, musccvite, and felspathic schists, by 
a 1-foot layer of gravel of mica and quartz ; whilst other pits along the 
base of the ridge on the north side showed up to G-i feet of detrital ore 
resting on decomposed schists and pegmatite. In places these deposits 
are as nmch as 10 feet thick. The detrital ore, as mentioned above, 
is of better quality than that found in situ ; and, during 1906, owing to 
the high price of manganese, was extensively woi'ked. 
Tram-lines have been put down in the cutting above mentioned 
and bifurcate on the north side of the deposit so as to run through these 
talus-ore pits. The ore extracted is carted to .Salwa station. 
A sample was taken, partly from the ore seen in situ in the pits on 
Nature iiiid quality the ridge, and partly from the detrital ore. 
of the ore. fj^g ^^j-g ^^r^g evidently a mixture of bramiite and 
psilomelane, several pieces containing whitish qiiartzose, jaspery, or 
felspathic, patches. The analysis made at the Imperial Institute is 
as follows : — 
■SV( /;/ pi e Xd . 24. 
Mangajiese peroxide . . ....... 40 'Ol 
JMangane^^c protoxide . . . . . . . . 30")S 
F erric oxide . . ......... (i ■2(> 
Silica (combined ) . ......... ;'>T)2 
8ilica(free) 0-17 
Phosphoric osidc . . . . . . . • . . 0'ir> 
Moisture at 100°C. . . . ' OIG 
