Report on a quarterly inspection of the South Alligator Uranium field

BMR
Record C.
1961/8
COMMONWEALTH OF AUSTRALIA.
DEPARTMENT OF NATIONAL DEVELOPMENT.
BUREAU'OF MINERAL RESOURCES
GEOLOGY AND GEOPHYSICS,
RECORDS.
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~
,/c 8
)Yld"~
q11/Ltf'""Z- ~
4-· q
1961
3.
REPORT ON A QUARTERLY INSPECTION
... .
~
of the
SOUTH ALLIGATOR URANIUM FIELD
for
S;BPTEMBER 1 1961
by
C. E ,
I
''
P,r i char.~
The informaton contained in this report has been obtained by the
Department of National Development, as part of the policy of the
Commonwealth Government, to assist in the exploration and develop•
ment of mineral resources. It may not be published in any form or
used in a company prospectus without the permission in writing of the
Director, Bureau of Mineral Resources, Geology and Geophysics.
f; Mf<.
Re co-ra C ,
(qbI\~
'
REPORT ON A RUARTER LY INSPECTION
of the
SOUTH ALLI GATOR UR NI UM F IELD
for
by
c.
E. Prichard
Conten ts
Page
I NTRODUCTION
1
UNITED URANIUM Nc L.
Saddl e Ridge
Scinto No.5
El Sherana
Skull Prospect
Palette Area
Coronation Hill
1
1
1·
1
2
3
SOUTH ALLIGATOR URANIUM ti. L.
Roekhole Mine
~
ORE RESERVES
4
5
ORE RESERVES .. South Alligator Uranium Field
6
Airstrip Pros pect
,INTRODUCTION
An inspection of uranium company operations on the
South Alligator Uranium :B'ield was made from 11 th to 1 5th
September, 1961. The previous inspection was in June, 1961,
The road to the Field was receiving maintenance and
remains in good order.
UNITED URANIUM N.L,
Major underground exploration near Palette
cont.i nued throughout the quarter • The programme of
underground exploration has been completed at Coronation
Hill and temporarily suspended at El Sherana , Mos.t of the
ore produced during the quarter came from the Coronation
Hill open cut.
Saddle Ridgj
Cleaning up t he open eut was completed, Six
hundred tons of ore 9ontaining 44oo lbs. of u3o8were
obtained. No ore remains in sight.
Scinto No.J:
Twenty-three wagon drill holes· were drilled north
of the open eut without proving ore. Wagon drilling in
front of and at the southern end of t he open cut was mor~
suecessf'Ul and located 1100 tons of ore estimated to
contain 6ooo lbs. of u3 oa.
The 57 foot level Adit from t he open cut has been
extended lfO feet, the north-east crosscut extenq,ed 37 teet ,
and t he south-ea st crosscut extended 1lf. feet. Development
ore, including stripplng about 5 feet from the backs in the
sou'th-east crosscut, totalled 30 tons containing 14<:> lbs._.
of oxideo
Work has ceased temporari.l y but will be re.sumed when
miners. are available.
SkJilll prgspegt
A joint cont aining seeondary uranium minerals had
beenfound in Upper Proterozoic sandstone which outcrops as
a cliff at Skull Prospect.
Scree was removed from below this find to a dept h of
5o feet over a length of about 1 50 feet . Secondary urani urn
minerals are present in the original joint and in several
others. They also occur in the deeper scree and in weathered
Lower Proterozoic shale which ean now be seen abutting the·
Upper Proterozoic s andstone. No pitchblende wa s seen in
.... 2 these exposees ao:r was arJ.7 located ill 16 wag&n d.r ill hele:a
d;r.Uled at the base o.f t h e cliff.
t
!he comp3n1 intend!.a to remove tJt. little more se:ree
before ueoiding on the best method ef exploriJ18 f .o r a
posf!ihlt, pi tcablende lens.
Pale'tte uea
- thictergrounti expl6rat1oll was eoncatrated in t.bia
fa.'ea tllnushout the ql181"ter.
The south drive frcom No.2 Ad.i t is now 2)5 feet in
length and t h. e.·_.·. ~or"th d:rive ~ 42 f.eet.
sunk t o 4 t et depth at
21:0~
Winze·s . have been:
and to 73 .f eet at 65B and a
rise at TON ertend.s twelve :teet above t he backs. A weet
eroseeut at 325N was dri'Ven ll teet in Upper Proterozoic
sandstone ami a north ~os1Jc:ttt at 435J' extdda 22 .t eet
also in. san~stene., · Ore wu pr<n'e4 ollly in tb.e 65N _ winz•
and the 70N rise :from which 73 t0'ns containing 4500 lbs.
of oxide were recovered.
No.• 6 Adi t wu driven 66 :teet through Lower Pr()tero:ao1o
shale to No.2 Adit to improve ve:nt1latio~ in 'the North Dr ive.
No. 5 Ad-it .wW bee-n extendea to a total l ,e agth of
404 fe.et. !:be Eas.t Drive is 37 feet i n length along the
contact. hom 21 feet to 37 feet assays indicate o;ne fifth
of a pound of' oxide per ·tGn"" The West Drive has laeen
extended t o 60 feet alan~; the conta.e't. Only scattered
low r.adioaetivity was 1oeated.
N&,.2 West
llr1v~ ad
No. 2
East Drive were t hen co-mmenced from the Adit in .Lower
Prot r ozoic shale about 60 feet fron1 the eontaet with Upper
Pr ot-e rozoic s811dstone. I ·t was intended t o drive parallel
with and aeeut 60 feet from the eon:t&et and explore it h:r
lo-n g hole drill.ing every twenty- feet.. Ne.2 West Drive is
140 feet in length and Upper Prot erozoic sandstone appeared
in the face.. Long holes had been drilled from only two
chambers when i r.spected. fh.ese loca't·e d no ore and ind.ieated
the co.r:rtac-t continuing about 60 feet from the drive. Drilling
is eo:nt 1nu.1ng. No. 2 East Drive is 53 feet long in bleached.
shale throughout.
No. 7 A4it had bee.:n commenced t ,owaraa the end of the
period., The portal, in Lower Prot erozoic shale, is below
that of No. 3 Adit. Only about 70 feet bad be,e n driven
when inspeeted and the Upper Proter ozoic had not yet been
reached.
ExtEtns1 ve unde,.:ogro.und ,ex:plo:ration of th.e Upper
Proterozoic/Lower Proter ozoic contact between Palette No.1
Adit area
Cliff- face has been un:sueeessful so 'far as
only a fe• -tc~ e:t ore· have bee!l located. However, long
hole drilling has not been completed f'rom the exi&ting
openings .
- 3 ""
co.ronat1gn Hill
The Noo 2 Adit at RL900 has been driven to 511 feet.
The North Drive, eommP.ncing 460 feet from the portal of the
Adi ~' has been driven 250 feet. Rocks exposed i.n . the
world.ngs are altered and unusual types. Typical Upper
Proterozoic angular conglomerate with a sandstone matrix .
occurs at the end of the North Drive . A dark sheared and
altered roek1 possibly originally - volcanic; is common.
A little carbonaceous shale in irregular bands up to
several t'eet thick occurs within t he altered volcanic .
This exploration did not locate ore as had been expected
from the previous underground work which had explored from
RL1025 to RL975.
.
Open cut mini!}lg has continued at Coronation Hill.
The design of the cut was amended to allow its .deepening
by 10 feet to R11000. When inspected the RL10lto bench
was almost completed. To 19th August ,, 1·961 , 66lt2 tons of
ore containing 32,800 lbs . of oxide have been produced
from the open cut.
- lt ..
S.OUTH ALLIGATOR UR.AN'Iffi-1. N, L.
Explora tion and development ceased at t he end of
July a s sufficient ore had been developed t o complete the
existing contra ct. It is expected t hat this ore will be
mined and stockpiled before the Christmas elosedown.
Treatment of the ore will continue probably till March, 1962.
Rockhole
!Ant
In the
~To.
3 Adi t area stoping and development
pr?dueed 385 tons of' ore containi ng 11,500 lbs.
dhJ.efly from 1 5'00E to 1550E,
in this area.
U~OR
No developed ore relfia.Ins
From t he 1A Level between 1632E ~nd 1665E ~35 tons
of ore cont aining 19t500 lbs. u,oa .were obtained from
development and stopl.ng above tl1e levelo From 1'7801 to
1860E 270 tons o:f ore containing 5~. 700 lbs. u~oa were
obtained also :£'rom above the level. From a winze at 1980E
lt4o tons of ore containing 11,500 .lbs. U308 were raised
from belo:w the level.
From 623E in No. 2 Adit 20 tons of ore containing
1,300 lbs. U:;08 were raised from below Adit level.
Developed or partly developed ore near 1630Et· 1800E,
1980E, and 2000E. is s till to be mined.
Airstrip
Proanee~
A shaft at Airstrip Prospect was sunk to a total
depth o£ 75- feet·. From collar to 62 feet was in Upper
Proterozoie sandstone and from 62 feet to 75 feet in Lower
Proterozoie shale with the sandstone hanging \vall adjacent.
Slight radioaetivi ty was pre sent in t he shale but a drive
east from the bottom of t he shaft was in barren sandstone
for its tota.l length of six fee to
Work has stopped and e quipment has been removed.
-'ORE RESERVES
Un;t.t~g
Ur aniWA N.L.
Ore reserves have been r educed by 4,o6o tons
cont ai ni ng 39,4oO lbso of oxide trea ted during the quarter.
From Saddle Ridge 6oo . t ons not i ncluded in the
previous .estimate were mined. Palette area ore reserve has
not been al tared as t he 73 tons mined are development ore •
Wagon drilling at Scinto 5 has proved 1100 tons of ore·.
The ore reserve a t Scinto VI has been re-examined. Open
cutting at El Sherana . Saddle Ridge Scinto v, and
Coronation Hill ha s s~ovm consistently ·tha t ore mined
from the hi gher benches has been less t han ore estimated.
An -allowance has been made for this in the recalculated
figure for Scinto VI ., and for Cor onation Hill .•
Sout h
AJ.l~g a tor
Ur sm.ium
N.Jd.
A reappreci a tion of the ore re serves in the Rockhole
Mine wa s made. As most lenses of ore are only partly
developed and as grade is estimated from Phillips Pocket
Monitor r eadings of r adioactivity (controlled by recent
results fr,om mining similar ore occurrences) the results
are approximate only. Hm~eve r 1 care was t aken t hat they
are not unduly optimistic.
All t he ore remaining i n situ is in the 1A. level
where 900 tons containing 30,000 lbs. of oxide are estimated.
In addition 1500 tons cont aining 43,000 lbso of oxide are
s tockpiJ.ed.
During t he quarter 1250 tons containing 36 1 600 l'bs.
of oxide i!Tere treated.
It is pr obable t hat extraction of the partly
developed ore will r eveal extensions of t he l enses and
again i ncrea se ore reserves.
- 6 ORE f\EeERVE§
as at §eptember . 196]
UNITED URANIUM N.• lj.
Jwe ,J:£61
lbs,u3 o8
~
El Sherana
2100
Coronation Hill 19000
...
Saddle Ridge
Scinto v
Scinto VI
4ooo
Palette
300
Koolpin Creek
1800
stockpile
2800
10000
150000
30000
314100
-
...
-
23300
10000
10000
110800
Mines
s~~tem}2er al ~21
~
~·
tons
30
14o
2100
14ooo
4900
600
28000
44oo
-73 ...
-- -...
...
4500
~.u3o8
10000
100000
1100
-6000
300
1800
44-?0
14oOO
10000
10000
98000
27770
238000
4ooo
SOUTH ALLJ:G TOR UR§.NIUI:f N, L.
Jttn@al<£61 ·
Rockhole Mine
Stockpile
HLn~si
Septembe.r ., 1961
~
~. u3o8
ton§
lbs .
tons
lbs .u3o8
4300
81700
1550
lf9500
900
1 500
30000
43000
4300
81700
24oo
73000
TOTAL ORE RESERVES - September, 1961
South Alligator Uranium
Field
..
- 30 , 170 tons containing 311
,ooo
lbs.
u3o8 •