5 
the nature of the rock. The area is composed of alternate layers of hard flaggy chert or flint and blue 
limestone. I he latter, of course, weather much quicker than the siliceous rocks, which stand out iu ridges 
ana curves like heaps of tiles or fanciful shapes in pottery. This curious feature and the heaps of boulders 
with which the granite is weathered give the neighborhood of the Eveleen mine a somewhat bold scenery, 
in the absence of fossils, no decision can be given as to the age of these beds. They are extremely like 
limestones of Luiope often contain bands and nodules of chert. Under the microscope the limestone is seen 
to be.perfectly crystalline. This metainorpliisin may be due to the contact of the eruptive granite, or the 
:!r fl n ' at,0 ^i 0f W i lter ' i Tbo min . eral lode of tbc Eveleen has broken through these strata. Therefore 
the Along in of the salver-lead lodes is of later age than the carboniferous period. 
* f and * t0 ™-—Above the slates there is a complete absence of any fossiliferous rocks, and 
T 1 ’ C r tC ab . SOnce of hrae > cxce Pt m some places on the Katherine river and the Eveleen. The 
“Ki™ 1 ? f st F° n g that tbere never has been any subsidence into the sea or upheaval from it 
within what geologists call more recent times. 
viwlt!! mKH 0 ,! bnd "of| IC ' ei ,rt g 00 fl section is exposed is this. —A layer of loose white or red decomposed 
oft i],,' r .t- f > some o .01 lit. thick, lies on the upturned edges of the slates. Above this a layer, some 
notbonnte nt „ 7 wblch , has been surf »ce soil. Above this is from 14ft. to 120ft. of magnesite or 
Nnt nfton i'c . 111 a & nesia ’ 111010 or less impure, with silicates of alumina and iron, and mere traces of lime. 
T1ipr#» nr P r e 1 ' V \ e ’ °f * le stains brown, red, and purple, from iron oxide, permeate the whole. 
„nrnx-; ( W^ alS °T ands and Stra . ta > a foot and more in thickness, of yellowish-brown limonite or hydrated 
• ’• , n ' 11 ™‘ nl J cases it appears to be of the same mineral composition as the slates, and though 
SiSrr t t 1U ?T re; ; 1 ’- lherC is no doubt that tbe -v closely approximate in character, but the mag- 
S=ftt fied ’ IS I,e , vur C0Ilt0rted ’ Ithas no uniform dip, but its strata follow the inequalities 
nbieed there , le J test. 1 lie wholerock is essentially a decomposition product; it has not been 
tainino* olivino^ ° T*' °* 1 Nv ou |^ contain some marine remains. I believe it to be a decomposed ash con- 
referred to' 1 vrp«orff? fragmentary deposit carried into the air, when the extinct volcanoes of the south (to be 
not deter hr fmnwr - lrou gh the metalliferous slates. The extent and thickness of the deposit need 
ash sovernl feet * +v ? Xp ‘ lnatl0n * W^en in Java, during the eruption of Krakatoa, I have seen deposits of 
qw L l • thlckness ’ at more than a hundred miles distance from the volcano, 
eron out ahnx’r^tl lmp01 i an act connection with these rocks, and that is that the mineral lodes do not 
r i ale Head Port ry 11 , eS ‘V* 1010 1S thin : there is an interesting and instructive section visible at 
from the slates wl ai '\ m, ' V 110 . shows this, kive or six mineral veins of considerable hardness crop out 
awav considerable l?**/ 01 ? 111 vanous directions, at an angle of about 30°. The slates have been eaten 
covers them on tl » t 10 r , l ° n °/. t lc sea ' 80 that the lodes stand out like walls. But the magnesite formation 
were filled in T ° °i P ’ . ^ 11S we earn that the deposit is one which took place long after the lodes 
canic emanation* oln nl^u T’ because the magnesite formation is geologically a modern one. Similar vol- 
they are in this area ^ ^ ° miocene a S° 111 Southern Australia; and so I think it is highly probable that 
veloned in , seen n0 trace the cretaceous formation which is so extensively dc- 
fewfossiliferousnodnlPR^i/tlf ° ^ 0r . t ier ] 1 Queensland. But in that colony it is reduced by denudation to a 
are of same a«-e and h ° Summi !f t ie divide—and on the Hodkingson and Tate rivers. There the slates 
that area it is hit*] 1 - . ! .if same character as the slates here. If, then, the cretaceous sea once covered 
away. * S ) P^ 0 >'1 > e that it covered this too, though every trace of the formation has been swept 
resting on the o-r-mifo ln »ch as 80ft. of highly ferruginous sandstone, horizontally stratified, is found 
smal1 fl^toppe g d hills on the slate hills. Magnesite also 
covers a 
stones are of volcanic oridn?ako St W^f?«*f PeC ^ U ^ ab ,° ut Mount shoobrId S e - 1 belic '’e that these sand- 
nronose to treat tli.. 1 i & ' ■’ but. the evidence is too long and too technical to he entered into here. I 
q ^ 0nat an eavl - v P eriod m a complete paper on the desert sandstone. 
area of several hundred square mik^ n t' Katherh>e river > 011 thc telegraph line, there is a volcanic 
there arc of the an,.; , ’' miles. It would take some time to examine it closely and to find what remains 
ruseed andSonS^ ? fr T ? vbich So ,aacb ^va has been poured forth. The volcanic hills are 
peaks, hut all the volcaiiic'centreR' 1 i!‘ °r 400ft ’ nnd P erba P s more - This is insignificant for xolcanic 
to much weathering merc nioll ®,’ ^ U8tralia are of moderate elevation, and when they have been exposed 
rugged. The lavas n P « •. 1 m( * S ^°^ cn ^ es are the result. Here probably the mountains arc more 
incrusted with ptooi.* vesicu ai » an(1 in many of the specimens that I have seen every fragment of rock was 
lha& ahind gI ° SSy cl Tstals of olivine. J ° 
of magnesium ash tbr Y ^ iere uiust be some volcanic centres which had sent forth such quantities- 
theory. I do not think tl f 01111(1 011 khe ranges, and this olivine rock was a remarkable confirmation of the 
pQfphurv Rnnl • • V n 1 dU ? T valuable minerals will be found in connection with this volcanic area, 
of the magnesite t-iiVi i f^° . , e sources of the lliver Mary the metalliferous slates do not reappear south 
arid character! 10 Jf J? “ d ’ do . es tbe granite, but in its place a red porphyry rock of a very barren and 
This rock rises into smaThilk “f “ lx , tuie of <l uartz felspar, the crystals being plagioclase and small, 
lihn tlin pranitp Tf , s . 01 broken and angular diameter, never weathering into rounded masses 
2 "?“ r , 3 ° 0,t ' in W’.““ d !S~ “ b "“ t junction 
too, or .o in diomctOr incredibly F * 
j . .j v , utterly destitute of minerals. 
t y , ° n 9^°^crates .—These have already been described. They lie on thc banks of 
1 J T IT?* p °/ ph ^ but a few water-worn fragments of that rock were visible in the 
n £l° meK \ P ebb ^ es are white quartz, of which, strange to say, there are no veins in the 
P '^y 100 v * -^ bls san dstone forms tablelands on both sides of the river, and a mile or two in width for 
No. 122. 
some 
