Chap. XXXVIII. ] 
SANDUR STATE. 
997 
still retaining the slaty cleavage or incipient schistosity of the phyUite, 
to variegated lithomarges still showing banding as far as colour goes, 
but often devoid of any remnants of the structures of the original 
phyllite or slate. The ' ferreous schists' and ' argil lites ' of Foote 
f regard as iron-impregnated and replaced phyllites. 
Foote's term ' hematite quartzite ' must be regarded as generic and 
not as accurately describing the mineral composition of nearly the whole 
of the rocks that he includes under it. It 
PpiTiigiuo'.is qiiartzitps. ... 
would be better replaced by ' ferrugmous 
quartzite lor the reason that these quartzites where I came in con- 
tact with them were at least as often magnetite-or limonite-quartzites. 
In fact I think it is probable that the original form of the rock in most 
cases was a magnetite-quartzite', in which magnetite occurred in scat- 
tered grains and bands in a quartzite, the siliceous matter being on the 
whole much more abundant than the magnetite. The ' quartzite ' part 
of the rock is often so fine-grained as to be better called ' jasper '. It 
is possible that there are some original hematitic beds amongst these 
rocks, and consequently some original hematite ; but the majority of 
the hematite occurrences I saw seemed, wherever the evidence was at 
all clear, to be of secondary origin and the result of the replacement of 
other rocks at \he surface by ferruginous solutions. The rock replaced 
was in some cases probably once a quartzite, perhaps ferruginous, but 
was also often the altered phyllites. If this view of the origin of the 
hematite-ores of the Sandur Hills be correct, they will be found to thin 
out in depth, in the same way as those of the Jabalpur district — supposed 
by Mallet to be of enormous extent — were shown to do by the prospecting 
operations conducted by Mr. E. P. Martin and Professor H. Louis 2^ 
and in the same way as the manganese-ore deposits yet opened up have 
been ^ound to do. If, however, any of the outcrops of hematite in this 
state do represent original deposits, — by which I mean the iron oxides laid 
down at the time of deposition of the Dharwars and since compressed, 
and probably rendered crystalline, during the earth-movements by 
which the rocks of the Sandur syncline were folded and metamorphosed,— 
; hen they may continue to great depths, in fact to as great depths 
1 By this I mean the original form as a quartzite ; for the Mysore gealogists have a • 
theory thut some of these ferruginous quartzites have been formed by the chemical 
alteration of a ro 'k rich iu the iron-amphibole, cummingtonite. 
2 Agricultural Ledger, No. 3 of 1904. 
2 C 2 
