\ , , " e: - -_-:,,; .! . r / '" '(: , " " r \ \ \ \ , • 7- 1"--- . COMMONWEALTH OF AUSTRALIA. DEPARTMENT OF NATIONAL DEVELOPMENT. BUREAU OF MINERAL RESOURCES GEOLOGY AND GEOPHYSICS. RECORDS: 1964/86 PART II MISCELLANEOUS MINOR CHEMICAL, PETROGRAPHIC AND mNERAGRAPHIC INVESTIGATICNS CARRIED our IN GEOLOGICAL LABORA'llORY. JUNE TO DECEMBEJR, 1963. Compiled by F. ICousal The information contained in this report has been obtained by the Department of National Development, as part 'of the policy of the Common- wealth Government, to assist in the exploration and' development 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 It may not be published in any form or used in a company prospectus without the permission in writing of the Director, Bureau of Mineral Resources, Geology and Geophysics. , .:j
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COMMONWEALTH OF AUSTRALIA.
DEPARTMENT OF NATIONAL DEVELOPMENT.
BUREAU OF MINERAL RESOURCES GEOLOGY AND GEOPHYSICS.
RECORDS:
1964/86
PART II
MISCELLANEOUS MINOR CHEMICAL, PETROGRAPHIC AND mNERAGRAPHIC INVESTIGATICNS CARRIED our IN f~HE GEOLOGICAL LABORA'llORY.
JUNE TO DECEMBEJR, 1963.
Compiled by
F. ICousal
The information 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' development 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 It may not be published in any form or used in a company prospectus without the permission in writing of the Director, Bureau of Mineral Resources, Geology and Geophysics.
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1 •
2.
MISCELLANEOUS MINOR CHEMICAL, PETROGRAPHIC AND MINERAGRAPHIC INVESTIGATIONS CiffiRIED OUT IN THE GEOLOGICAL LABORATORY.
JUNE TO DECEMBillR, 1963.
Compiled by F. Kousal.
PART II. ffi:JCORDS 1964/86.
CONTENTS.
Sp0ctrographic analysis of samples from Wabag, T.P.N.G. by D.J.Howard.
Spoctrographic analysis of soil samples from Rum Jungle, N.T. by E.J. Howard.
3. Spectrochemical analysis of geochemical samples from Rum Jungle,N.T. by E.J.Howard.
-4.
6.
Spectrograthic analysis Popondetta, Papua.
Estimation of phosphate Basin, N.T.
Spectrographic analysis
of stream sediment. samples from Safia -by II:.J.Howa.rd.
on core samples from Rum Jungle and Amadeus by S. Baker.
of geochemical samples from Dobbyn, Queensland. by E.J.Howard.
1. Analysis of water samples from the Australian Capital Territory. by S. Baker.
8. Identification of core from Ooramina No.1 :Bore. by E.J • Howard and S.Goadby.
9. Somcrsby Sandstone. by W.Oldershaw.
10. Analysis of phosphato samples from Rum Jungle. N.T. by S. Baker.
11-
12.
White Bundanoon Sandstone. by W.Oldershaw. Water analysis, A.C.T. samplos. by S. Baker.
13. The petrography and goochemistry of thro~ specimens from the Gordon Downs area, Western l~ustralia. by W.R.Morgan, E.J • Howard and S. Baker.
14. Spectrographic analysis of samples from Rum Jungle, Northern Territory. by E.J.Howard.
15. Spectrochemical ~J:'ysis of geochemical sample s from Ingharil, Q,ueensland. by E.J.Howard.
16. Spectrographic analysis of stream sediments from Mount Garnet,Q,ueensland. by E •. T • Howard ,
11. Spectrographic analysis of geochemical samples from Rum Jungle, N.T. by E.J.Howard.
18. Spectrographic analysis of samplo.s from Rum Jungle, N.T. by E.J. Howard,
19. Spectrographic analysis of diamond drill core samples from Tennant Creek. Northern Territory. by E.J.Howard.
20. Spectrogra.phic analysis of geochemical samples from Rum Jungle, lit.T. by E.J.Howard.
21. Spectrographic analysis of geoch00ical samples fron Run Jungle, N.T. by E.J.Howard.
22. The petrography of sheared gr0ywacke from tho Pine Croek area, N.T. by W.R. Morgan.
23. Spoctrochemical anclysis of saL1plos froe Run Jungle, N.T. by E.J.Howard.
24. Mineragraphic description of minoralization in Run Jungle coro, Drill Hole D.G. 24. by I.R.Pontifex.
The inforoation contained in this report has been obtained by the Department of National Developtl0nt, as part of the policy of tho COt'Llonwealth Govornment, to assist in the exploration and development of oineral resources. It may not be published in any fOrL1 or usod in a conpany prospectus without the peroission in writing of tho Director, Bureau of Mineral Resources, Geology and Geophysics.
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SPECTROGRAPHIC ANALYSIS OF S.AMPLES FROM WAEAG TNG • . by
E.J. Howard
Semiquanti"tntive estimations were made of the nickel, cobalt, copper, vanadium, moltbdenum, tin, load and beryllium content of stream sediment samples from vlabag W'G. The samples were submitted by F. Dekker.
The following results are expressed in parts per million.
Sample No. Ni Co Cu V Mo Pb
F1 20 20 20 70 a a
F2 15 15 10 50 a 5 F5 20 20 20 150 a 5 F10 15 20 15 100 a a
F13 10 15 10 50 a a
F16 5- 20 30 150 a 5 F17 20 20 30 150 a 5 F18 10 15 15 30 a 5 F20 15 20 20 150 a a
F24 20 15 15 100 a a
F25 20 15 15 to ~ a ''':'''''
F27 20 15 20 70 a 5 F30 20 15 20 70 a a
F31 20 20 20 70 a a
~'35( 1) 15 15 15 50 a a
F35(2) 20 20 20 100 n. 5 F39 20 15 20 50 a 5 F42 20 ,20 15 70 a 5 F53 10 15 'L5 70 a 5 F56 5- 15 10 100 a a
F57 5- 15 10 100 a a
F59 5- 15 15 70 a a
F60 5- 15 10 70 a a
:&'63 15 15 15 50 a 10
F509 60 30 30 70 a 5-F537 80 30 30 150 a 5 F544 60 20 50 150 a 5 F512 60 30 30 200 a a
F548 30 30 20 200 a a
F549 30 20 20 70 a 5 F589 60 20 20 100 a a
F511 30 20 10 200 a a
F7 40 20 20 150 a 5 F550 30 20 20 100 a 5 F515 80 30 30 100 a 5 F506 60 20 20 100 a a
Serial No. Ni Co Cu V Mo Pb
F539 40 20 30 150 a 5 J?504 40 30 20 200 a -8
F529 30 20 20 100 a a
F544 40 30 20 150 a 10
F517 40 40 30 200 a a
F584 20 30 20 300 a a
F585 10 15 20 70 a 5 F586 15 20 20 70 a a
F587 15 20 30 150 a 8
F588 30 20 20 50 a 5 F502 15 30 30 300 a a
F503 60 40 30 100 a a
F513 60 30 20 100 8 a
F52 - Insufficient sample for analysis.
Tin and beryllium were not detected in any sample. ~
105'-110'F 1.4 170'-175'F 1.1 110'-115'C 1.7 175'-180' C 2.2
110'-115'F 1.0 175'-180'F 2.8
Drill Hole API {Amadeus Basin) percent P205 percent P,0:2
83'7"-83'8" 3.0 9287t"-93'1" 1.0 83'8"-84' 8.8 93'1"-93'5" 5.2 84'1"-84'4" 3.0 93'5"-94' 1.0 84'11"-87' less than 1.0 94'-94'2" 9.2 -
r 87'-87'6" less than 1.0 94'2"-94'4" 2.7 87'6"-87'11" less than 1.0 94'4"-95'4" less than 1.0 87'11"-88'5" 2.0 94'4"-96'1" 1.3 88'5"-89'7" 1.0 96'1"-97'3" less than 1.0 89'7"-90'7" less than 1.0 97'3"-97'4" 4.7 90' 7"-90' 10" 9.5 97'4"-98'11" 1 .1 90 i 10"-92'3" 1.0 98'11"-99' 1.4 92'3"-92 i 7" 1.0
99'-99'10" 1.2
99'10"-100' 1~-" 11.0 l 100' 12 "-100' 5'2-" 1.3
100'5~"-100'6t" 6.2 100' 6-~"-101' 22 " less than 1.0 101' 2i"-101' si" 11.3 101'5'2"-102'311 less than 1.0 102'3"-103' " " 1.0 103'-103'5" " " 1.0
Serial No. 1122
,"
Spectrographic Analysis of Geochemical Samples from Dobbyn, Qld.
by
E.J. Howard.
153/Q/1
Semiquantitative estimations were made of the trace metal content of 26 geochemical samples from Dobbyn, Qld.' The samples were submitted by D.O. Zimmerman.
million:
Sample No.
DDS 1
2
3 4
5 6
7 8
9 10
1 1
12
13 14
15 16 17 18
19 20
21
22
23
24 25 26
The following results are expressed in parts per
Ni -5-5-5-5-5-5-5-5-5-5-5-5-5-5-
15
5-5-5-5-5-5-5-5-5-5-5-
Co 10
5 10
5 5 5
10
5
Cu
25
5 5-7
7 15 20
10
y. 20
50
30 20
30
30 30
50 5 10 50 7 15 50 5 7 50
5 7 50 5 10 100
15 5 80 10 10 50
10 5- 50
5 5- 50 7 5- 100
10 7 30 12 10 50
5- 20 30
5 5 20 7 10 30
7 5 30
5 7
15
5-30 50
Zn, Mo, Sn, Pb, Be and P were not detected in any sample.
Plate Nos 660, 661 Lab Serial No. 1375.
16'
:
Report No.
Analysis of Water Samples from the AiC.T.
by
S. Baker Following are results for the Analysis of Bore Water Samples, submitted by G.M. Burton:
City No. 4 City No.6 Hall No.12 Conductivity (micromhos/cm) 980 600 ) 1020 pH 7.7 7.3 7.0 Cl (p. p.m) 125(3.52) 100(2.82) 90(2.54) HC0
Figures in brackets refer to m.s./litre. Serial No. 1391
Report No.
Estimation of Phosphate on Samples of Black Shaie from Queensland. by
S. Baker
Following are results for the analysis for phosphate on Black Shale samples from Baralaba, Q'ld, submitted by F. Olgers.
Field No. Percent P205 BA 898 less than 1.0 BA 858/3 less than 1 .0 BA 750 less than 1 .0 B.A: 914 less than 1.0 BA 889 less than 1.0 BA 888 27.0
Serial No. 1384, 1385.
'i
File No. 62/1132
IDENTIFICATION OF CORE
FROM OORAMINNA NO. 1 BORE
by
E. J. Howard & S. Goadby
A sample of core, described as evaporite, was submitted
by J. N. Casey for chemical checking and identification.
Details of the sample locality are Ooraminna No. 1 Bore
25 ml.S.E. of Alice Springs, Northern Territory (1:250,000
International Series F53/14), depth 6085 ft.
Chemical tests and X-ray diffraction showed the sample
consisted mainly of halite with minor calcite, gypsum and.
clay. Trace elements were limited to those normally found
in evaporites.
---------------
Report No.
SPECTROGRAPHIC ANALYSIS OF CUTTINGS FROM WATER BORE, KERRIDY WATERHOLE, NORTHERN TERRITORY.
by E. J. Howard
Three samples from water bore No. F 52/12-44 were submitted by T. Quinlan for spectrographic analysis.
The following results were obtained:
Depth Ni Co Cu V Pb 100-110 feet 10 15 15 10 100 130-140 feet 15 15 15 10 100 180-185 feet 15 15 20 10 200
The above results are expressed in parts per million.
Zinc (100 p.p.m.), gold (10 p.p.m.), silver (2 p.p.m.) were not detected in any sample. Manganese was present in all three samples
Spectrographic Plate No. 530
Lab. Serial No. 1121
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Report No.
SOMERSBY SANDSTONE " -
by
IV. Older shaw
187ACT/1 29/7/63
A sample of white Somersby Sandstone was submitted for petrographic examination to determine its suitability for use as a facing stone on the new Bureau of Mineral Resources building.
The sample is a homogeneous even-grained pale grey sandstone containing scattered glistening flakes of white mica and black specks of biotite and graphite. No bedding, colour banding, stains or other blemishes were seen on the sample.
Under the microscope the sandstone is seen to consist of closely packed sub-roundod grains of Quartz, 0.3 nun. to 0.6 mm. across,/ cemented togethor by ... thin discontinuous pellicles of secondary Quartz and set in a sparse matrix of stained illite and chlorite comprising 27 percent of the rock.
'C' There are a few small grains of epidote, zircon and hematite, contorted stained flakos of mica and irregularly shaped masses of graphite.
There has beon extensive solution and deposition of quartz along tho boundaries of many contiguous Quartz grains; these grains have sutured or intergrown contacts and are thus "welded" together. Many of the grains are also enveloped by thin pellicles of secondary quartz which are continuous with the thin pellicles round other quartz grains. 'l'hus many of the quartz grains have been w'elded together and many have been oemented together by the solution and deposition of seconds.ry Quartz.
Tho clay matrix between the quartz grains consists of micromosaics, felted masses and intergrown flakes of illite, chlorite and a little kaolin. The chlorite is olive green and the illite is limonite stained.
This sandstone has been used on the Fisher Library in Sydney. It appears to be a competent facing stone and is unaffected by the atmosphere; though it may darken slightly on oxposuro unless sealod with a silicono seal. There is a faint colour banding in S011e samplos and care must be taken to select sui table slabs of similar appearance for prominent positions.
COMPARIOON OF COlvlPOSITION .AND SOME PHYSICAL PROPERTIES
A sample of white Bundanoon Sandstone was submitted by ·A.G. and A.M.Morris of Tumut, for examin~tion to determine its suitability for use as a facing stone on the second stage of tho Royal Mint.
The sample is a homogeneous~ even-grained~ wh1.te~ clayey sandstone containing a few scattered flakes of white mica and blaok biotite; no iron stains, bi:mding or other blemishes wero $eon. The sample had matured for about a month and was quite hard, in that it was difficult to remove grains fron the surface by rubbing~ or to break off th:) edges. However, before a thin section could be prepared from the srunpl(~ it had to be impregnated Irlth Canada Bnls&~. The rock is not affected by acid. Its hardness, density and porosity are similar to other woll known clayey sandstono building stonos (see table).
Under tho nicroscope the rock is seen to consist of quite closely packed irrogularly shaped grains and angu18.r fro,gr.1cmts of quartz, ranging fron 0.2 to"0.4 nnn. across~ partly cementod togother by socondary quartz and sot in a clay matrix which comprises 33 percent of the rock.
No felspar grains were found. Thore are a few small grains of zircon 9 epidote, henatito and fl~es of Duscovito and biotite.
The marginal parts of many quartz grains in contact with other quartz grains havo boen dissolved and re-crystallized; thus some quartz grains have sutured cont.;wts and have boen IIweldod ti togothor. Each quartz grain is surround.od by a thin pellicle of secondary quartz, and SOIDe of these pelliclos join tho pelliclos around other grains, thus comenting thOD togethor.
Tho cleW matrivc. betwoen the quartz grains consists of about 70 percen t kaolinite and 30 percent illito. The kaolinite occurs as masses of mir1Uto colourless hoxagonal accordeon-like plates, whereas thG illi to forms wisps and intorgrown mosaics. These are small irregularly shaped patchos of lilJ.onito dust scattorod through tho matrix~ SOLlO of whicl: is faintly limonite stained.
Stono from the quarry, from which th8 sClL1plo w"s taken, has boon used for numerous buildings in tho area~ e.g. - the Courthouse and the Jail at Goulb01.U'n~ andtho Mount Carmol Convent in Yass. Tho stone seGms to have been satisfactory; it hardens up on exposure and seoms quite durable and unaffected by tho atmosphero. Tho colour appears to be constant 9 but it would be advisablo to inspect the buildings listed above to see if there has beon any significant colour c.hangcs with weathering. It Vlould also be advisable to inspoct tho quarry to soe if there is an ~doquato supply of :.h..c: good 9 knovm stone. '"" - ,"::". ::~'~." ... .',:: ..... : ".:.: - "'::.:,.:._ 4 .: ;.:'.,'.J-'
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COMPARISON OF Cm1POSITION AND SOME PHYSICAL PROPERTIES
Sandstone
Eundanocm White Bundanoon Brown Somersby
Gosford
Grains Cloy " Cement
Quartz
60
60
58
54
Others Matrix
2
1
2
3
33
36
37
37
Silica Carbonato
5
3
3 2 5
Specific Gravity
2.5
2.6
Porosity
12 + 2 -
13 + 2
13 + 2 -14 + 2 -
"
Report: WATER ANALYSIS
by
S. Baker
-------------"~ --
ACT H5/1
Following are results for the analysis of samples of Water from the A.C.T. submitted by G.M. Burton.
Conductivity p;B (micro mhos/cm)
Field NO. 11 Unnamed Creek 71 7 .. 4
,
13 Gibraltor Creek 55 7.3 14 Paddy's River 55 7.7 22 Tidbinbilla Creek 70 7.6 23 Woolshed Creek
(Naas ,Road) 180 7.4 25 Tracking Station 38 6. 1 L1 Orroral River 71 7.3 31 11 11 70 7.5
Sample L1 11. p. p. m. m. e./l p. p.m. m. e./l
Cl- 7 0.2 6 0.2 S02-
4 ,(2 <::2 HC0 3
- 45 0.7 45 0.7 0.9 0.9
Ca2+ 12 0.6 12 0.6 IvIg2+ < o. 5 -< o. 5 Na+ 7 0.3 7 0~3
Fe < 0.1 4( 0.1
N0 3 not detected npt detected
0.9 0.9
'i
Report No.1 .....
The Petrogt.'aphy and Geochemistry of three specimens from the. Gordon Downs Aroa~ Western 'Australia.
by
W.R.Morgan~ E.J.Howard~and S.Bakor.
Introduction~ Tho speci~~ns were submitted by D.B.Dow for laboratory examination. Their field numbers~ museum registered nurnbors~ and localities arc listed:-
The petrography is by W.R.Morgan; a spectrographic examination was carried out by E.J.Howard. S.Baker assayed D.R.1 for copper~ lead, and zinc.
R.15104 : Gossam In hand specimen the rock isfin8-grainod~ fGrruginous~ and in places, stained with green malachite. Numerous irregular cavities that are present range up to a millimetre or so in size; some are filled with qunrtz.
In thin section (10057)~ the spec~en is composed mostly of hydre~od iron oxide, together with some red cuprite in mammillary intergrowth. As noted in the hand specimen, numerous cavities are present. Some are partly filled with granular quart z gTains about 0.5 mD. diameter, and others with green malachite. Fairly small amounts of finG fibro-prismatic crystals of probablo bydrozinf)ite are commonly radially arranged and intergrown with ~rdrated iron oxide. HYdrozincite is enclosed by both quartz and malachite; malachite is enclosed in Quartz. Vory small accounts of a colourless chloriteliko minoral ar8 present •
The assay results are~- Cu; 19.1%, Ph; 0.34%, Zn; 1.6%.
R.15105z Augite and olivine-bearing hypersthene pyroxenite. On a fresh surface the hand specimen is a dark greenish-gray~ coarse-grained rock. Weathered surf'ac0s are stained by iron oxide and small amounts of green malachite.
In thin section (10058)~ about 85 to 90% of the rock is eeen to be composed of roughly prismatic cryst5.ls of very pale pink, faintly pleo -chroic hypersthene that contains exsolution lamellae of clinopyroxene. The remainder of the rock consists of olivine, augito, some interstitial plagioclase, and an interstitial brown flaky mineral -possibly bowlingite. A single grain of olive-green hornblende ~~s noted, and accessory black iron oxide~ none altored to henatite, is present. In general texture, tho specimen is inoquigranular and bypidiomorphic; the grain-sizos range from 0.2 mw.to 4 Clln.
Spectrographic analySis, in p.p.m' 9 of this sample is~Ni, 500, Co, 70, Zn, 200; cu, 5000; v, 10; Pb, minus 10.
R.15106~ Tremolite - epidote granofels~ The hand specimen is a fine~grained epidotic-green rock. Some randomly distributed black crystals larger than the matrix grains aro about a millimetre in aver3ge size, an~ are most noticeab10 on out surface of the specimen. The weathered surfaces are stained
with bydrated iron (':tide.
The thin section (R.10059) was stained with sodium cobaltinitri to in order to identify potash feldspar. The rock ··has an average groundIi1nsS grain-Size of 0.06 mrn.? tho porphyroblasts range up to 0.7 lJ.[;}. diameter. Tho texture is granoblastic. The groundmass consists mostly of granular~ pale yellow epidote, together with smallor amounts of poikiloblastic (or cavityfilling) calcite and randomly oriented fibro-prismatic crystals of very pa.le green actinoli to. Some interstitial green chlorite is present. Veins a...'1.d irregular cavities in the rock are filled with quartz and probable microcline, the veins are about 0.1 rum. thick. Tho large black crystals noted in the hand specimen are opaQue, and were examinod by W.M.B.Roberts in polished section; he describes them as altered magnetite. He also noted small amounts of pyrite forming grains about 0.3 rnn. di~ater. '
Spectrographic analysis of this specil;len shown in p.p.m., the follovling - Ni, 20; Co? 30; Zn9 n.d.; cu, 100; v, 150; Pb, 10. ',.
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Report No. 84NT/4li,
SPECTROGRAPHIC ANALYSI.S OF SAlVIPLES FRC»'I RUM JUNGLE, N .1..
by
E.J. Howard
Semiquantitative estlluatians were made of the nickel, cobalt, copper, vanadium, tin, molybdenum, berylliwll a":~d lead content of samples from Rtim Jungle, N.T.
The samples were submitted by A.L. Mather as part of the geochemical survey of the area.
The following are the results expressed in ppm.
Area 22
Hole Nos. Depth (ft) Ni Co Cu V Ma Sn Pb Be
4200 BaH ~O 15 1000 300 5 a 5000+ a
4201 BaH 60 60 1500 200 10 a 5000+- a
4202 BaH 500 300 1500 150 a a 5000+ a
4203 BaH 500 500 700 150 a a 500 a
4204 (404N/114E) 10-12 60 40 150 100 7 a 50 a
4205 BaH 700 300 3000 150 5 a 5000+ a
"4206 (53/101f) BaH 100 12 150 200 a a 5000+ a
4206 (7S/1OVl) BaH 100 40 700 300 30 a 5000+ a
4207 BoH 40 5 20 100 5 a 500 a
4207 (3rd BaH 30 5 10 drilling)
70 a a 300 a
4208 BoH 60 40 500 200 a a 5000 a
4209 BaH 40 10 50 150 5 a 1500 a
4209 2j-15 30 5 30 100 " a a 700 a
4212 . 21i-10 150 150 500 150 5 50 1 COO a
4212 BaH 200 150 1500 150 5 10 1000 a
4213 2~27t 300 150 1500 70 5 150 1500 "" a
4213 BoH 700 500 5000+ 70 5 20 2000 7 4214 2~-12* 150 150 100 70 a 50 300 1.5 4214 BoH 150 200 150 50 50 50 300 a
4215 1. 1 7r122 60 40 70 5- 5 200 100 30
421 5_ 12~ 1lit 80 " 80 20 5- a 150 50 30
4215 20-27i 60 40 10 5- , a 200 20 20
4215 27~"-35 80 60 15 5- a 150 30 70
4215 45-58 150 80 50 5 a 300 30 15 4215 BoH 100 150 70 10 a 70 30 30 4215 7t-5l~ 60 80 50 5- a 200 50 15
578 5- 5- 5- 5- 7 8. 70 2/5134 579 5- 5- 5- 5- a a 70
580 5- 5- 5 5- 2 a 50 6/5012 580A 5- 5- 5- 5- a 10 50 2/5136 581 5- 10 5 10 a a 10 7/5040 581A 5- 10 5 10 El a 20 2/5136 582 5- 5 5 10 10 a 20 7/5040 582A 5- 10 5 10 a a 70
583A 5- 10 5- 10 a a 10 L'r/5008 584 5- 10 5 10 a 8. 50
585 5- 10 5 5- a a 50 6/5014 5862. 5- 10 15 10 D- a 50
586b 5- 10 10 10 a a 50 586c 5- 5 5 5 a a 10 58711 5- 10 10 10 a a 30 587b -5- 15 10 10 a a 50
2/5136 583 5- 10 10 5 10 a 20
Beryllium and phosphorus were also sought but were not detected in any s8mple.
"f.1" - not detected 115- 11
- less than 5 p.p.m.
Lab serial No. 1004 Spectrograph plate Nos. 490-496.
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0'
" File No. 198Q/5
SPECTROGRAPHIC ANALYSIS OF STREAM SEDD,:!ENTS FROM MT. GABN:&'"'T 2 QUEENS1A.L~
by
E.J. Howard
Semiquantitative estimations were made of the trace metal content of stream sediment samples from Gurrumba and Return Creek areas, Mt. Garnet, Queensland. The samples were submitted by K. Yates.
The following are the results expressed in parts per million.
Sample No. Ni Co Cu V Mo Sn Pb
MG5/25/1 5- 5 5 5- 5 a 50
MG5/27/2 5- 10 10 5- 5 10 20
3 5- 5 10, 5 5 15 20
4 5- 5 5 5- 5 a 30
5 5- 5 5 5- 5 10 20
6 5- 10 5 5- 5 a 20
7 5- 5 5 5- 5 10 20
8 5- 10 5 5- 5 10 30
9 5- 10 10 30 5 15 30
10 5- 10 10 20 a 30 20
MG4/119/11 5- 10 10 20 5 a 20
12 5- 5 5 20 5 a 20
13 5- 10 20 10 5 200 30
14 5- 10 5 30 a a 20
MG5/27/15 5- 10 10 50 5 50 30
16 5- 10 15 20 5 200 30
MG5/25/17 5- 5 5 5"- 5 a 30
18 5 10 10 20 5 300 20
19 5- 5 5 5- 5 10 20
20 5 10 15 30 5 200 20
21 5 5 5 5- 5 10 20
22 5 10 5 5 a 70 pao MG2/11/23 5- , 5- 15 5- a 50 200
24 5- 5 20 5- a 100 300
MG2/9/25 5- 5 15 5- a 70 300
26 "5- 5 10 5 a 20 70
27 5- 5 5 5 a ,20 20
"28 5- 10 5 5 5 20 50
29 5- 5- 20 5- 5 70 200
30 5- 5 10 -5 a 70 200
31 5- 5- 10 5- 5 70 200
32 5- 5- 10 5- a 200 200
33 5- 5- 15 5- a 500 300
'.
cf' ~ ~ \tl
I: 0'
, File No. 198Q/5
SPECTROGRAPHIC ANALYSIS OF STREAM SEDIMENTS FROM MT. GABNb"T 2 Q.UmmLfu""ID
by
E.J. Howard
Semiquantitative estimations were made of the trace metal content of stream sediment samples from Gurrumba and Return Creek areas, Mt. Garnet, Queensland. The samples were submitted by K. Yates.
The following are the results expressed in parts per million.
2 50 700 a 5 50 1000 a a 10 5000 a a 10 2000 a a 10 2000 a
a a 5000+ a
a a 5000+ a
a a 5000+ a
a a 5000+ a
Hole Nos.
4225
4226
4226
4227
4227 4228
4228
4228
4229
4229 4200
4201
4201
4202
4202 4203 .
4203 4204
4205
4206 4206
4207 4208
BROVlN'S
4055
4055
4055 4055 4088
MT, FITCH
5215
5236
5237 5238
5239 5240
5241
5242 5243
Depth ~(feet )
BoH 5-20
BoH 2~-15
BoH 5-20 BoH BoR BoH
7~-15
2-4
2-4
4-64 0-2
4-27 2-4
4-42 - 6-34
2~'-1071J
0-2i
2t-45 21\-15
2-~-55
8-10
20-30 10-20
30-40
14-24·
6-10 6-12
6-10
4-12
6-14
6-17 2-10
6-10
8-12
Ni
150
150 100 200
200
80
- 5 -
Co
150
150 100
)
150 100
60
60 60
80 100
100150
80 150
40 20
40 15 60 40
100 100
300 200
Cu V Mo
700 150 a .
500 200 a 150 150 a 150 150 a 150 100 a
50 5- a 20 5- 2 50 5- 2
300 5- a 300 . 10 2
300 300 10
300 300 5
500 200 7
200 150 10
700 70 a
80 60 200 200 5 200 200 500 150 a
60 40 300 300 20
300 200 1500 150 5
60 15 200 300 10 100 15 300 300 a
40 5- 50 150 5 100 15 300 200 a
300 500 2000 200 5
500 1000 5000+ 200 7
300 500 5000 300 10 500 1000 5000+ 200 10
40 60 5000+ 200 70
10 10 30 60 100 1000
300 40 70
700 300 1500 300 200 2000
100 20 200
300 200 1000
700 200 2000
500 700 2000
5- 5 50 5 20 a
30 15 50 a 20 a
10 5 70 a
20 5
Sn Pb
a 5000
a 2000
a 700
a 500 a 700
300 30
Be
a
a a
a
a
50 500 30 70 300 100 20
100 100 15
200 500 15
a 5000+ a a 5000+ a
a 5000+ a a 1500 a a 1000 a
a 5000 a
a 1500 a a 5000+ a
a 5000+ a
a 5000 a
a 5000+ a
a 500 a.
a 5000+ a
a
a
a a
a
a a
a a
8.
a
a a a
100 a 100 a 100 a
100 a 300 a
20
10 10
10 200
30
30 10
10
a
a a
a
a
a
a
a a
Phosphorus was not detected in any sample. Spec. Plate Nos. 470-477
SPECTROGRAPHIC AN.L'.LYSIS OF DD\.MOND DRILL CORE Sll1iIPI.ES FROM TENN1~T CREEK, N.T.
by
E.J. Howard.
Thirty-seven samples from two drill holes were submitted by P.G. DUWl for spectrographic analysis. The holes are designC1ted Porphyry Drill Hole and No. 5 Cat's Whiskers Tennant.Creek} N.T.
The following results are expressed in parts per million.
Porphyry Drill Holo
Depth (ft.) Ni Co Cu V Mo Pb
183 5- 10 15 20 5 10
190 5- 10 150 10 2 10
200 5- 10 15 15 2 10
210 30 20 50 20 a 5 220 5- 10 10 10 '2 10
230 5- 20 100 5~ 5 a
240 5- 40 10 5- 5 a
250 5- 15 5 5 5 a
260 5- 20 10 10 5 20
210 5- 10 20 5 a 10
280 5- 10 5 5 5 a
290 5- 10 50 5 15 a
300 5- 10 10 5 5 a
No. 5 Cat's lfuiskers
196 5- 5- 5- 10 a a
206 5- 5- 5- 30 a a
216 5- 5- ~ 20 a a
226 5- 5- 5'~ 10 a a
236 5- 5- 5- 20 a a
246 5- 5- 5- 20 a a
256 5- 5- 5- 20 a. a
266 5- 5- 10 20 a a
216 5- 5- 10 10 a a
286 5 10 5 30 a a
296 5- 5 5 20 a a
No Depth given 5 5 20 20 a a
316 5 20 50 5- 2 a
326 10 20 200 20 a a
336 '10 .15 10 20 a a
346 5 10 10 20 a a
356 20 20 500 10 2 a
366 10 20 200 10 2 a
2.
Depth (ft. ) Ni Co Cu V Mo Pb
376 10 20 70 10 a a
386 5 15 200 30 a a
396 10 150 500 5<;- 2 a
425 5- 80 200 5- a
435 5- 60 50 5- 5 a
448 5, 30 200 10 a a
"5-" less than 5 ppm.
"a" not detected (Pb - 10 ppm, Mo 2 ppm)
Lab. serial No. 1032
Tho results from Catrs Whiskers No.5 are of special interast as the hole intersected a quartz-magnetite lode containing about 2% copper at depths between 396 1 and 425 1 •
It will be noted that the cobalt-nickel ratio is greater than illlity near the lode wherens in genoral it is of the order 0.8. This may be 'worth further consideration.
l~omalous copper values extend through the black metamorphosed beds but only a few feet into the overlying mudstone - boundary between 316'~26. Black crystals are visible in the mudstone near the rock boundary and these may be responsible for tho slightly anomalous copper values.
It may be of interest to exrunine the black metamorphosed bods some distance from the lode to compare copper values in the rock unaffected by the lode.
Spectrographic Analysis of Geochemical Samples from Rum Jungle -Northern Territory.
"'.Jy
E.J. Howard.
Semi quanti tati ve estimations were made of the trace metal content of samples from Rum Jungle N.T. The sDmples were submitted by P. Pritchard as part of a geochemical survey of the area.
The following are,the results expressed in parts per milliop..
Brown? s West
Hole No. Depth Ni Co Cu V Mo Sn Pb
4370 8-18 15 10 10 10 : 3 a 20 4376 15-23 5- 5- 10 150 15 a 50 4377 20-33 5- 5- 20 70 10 a 100 4378 7i-18 5- 5- 20 70 20 a 20 4379 7!-18 15 30 15 30 a a 10 4380 10 10 5 30 70 20 a 20 4380 10-18 ,5- 5- 10 70 1U a 5 4381 7~ ... 18 15 5- ' 15 50 2 a 10 4382 7-i-18 10 5- 10 50 2 a 20 4383 7i--18 30 5 30 70 10 a 20 4384 12j-23 20 5- 20 100 20 a 30 4385 30-53 30 60 15 5 5 a 50 4386 7i-11 10 10 20 10 2 a 200 4387 5-30 10 5- 30 70 2 a 100 4388 7i--28 5 10 30 30 2 a 300 4389 7ft-30 5 15 30 30 2 a 300 4390 15-28 5 5 20 30 3 q 100 4391 7i-18 5 5 30 30 2 a 150 4-392 40-61 150 200 100 20 5 a 70 4392 25-40 150 60 100 30 7 a 50 4392 10-25 150 100 70 20 10 a 50' 4393 10-28 80 40 50 30 5 a 150 4394 10-35 20 10 20 10 7 a 50 4395 5-45 200 100 200 5- 2 a a
4396 10-23 30 15 30 30 10 a 70 '4397 5-17i 10 10 20 30 2 a I 70
4398 7i-35 80 100 30 30' 10 a 70 4399 2i--25 5- 5- 10 70 7 a 20 4400 5-20 5- 5- 5 30 5 a 10
'\ '.
2.
Hole No. Depth Ni Co 1'"" ..... V Mo Sn Pb \.r~1..
4"401 5-20 5- 5- 5 100 10 a 10 4402 5···,15 5- 5- 15 100 15 a 20 4403 5-45 100 100 200 20 a a 5 4404 5 ... 15 5- 5- " 10 50 10 a 20 4405 5-25 10 5 15 30 2 a 20 4406 5-25 ~o 20 15 10 a a a
4406 15 t 30 80 30 70 a a a
4407 5-15 10 5 30 200 15 a 70 4408 2·~-15 10 5- 30 200 20 a ",:'1
~~. '-4409 2i-25 300 60 200 100 a a a
4410 7i-19 5- 5- 20 200 20 a 50 4411 5-23 60 30 20 50 a a 30 4411 100 60 30 20 a a a 4412 100-48 60 30 50 50 5 a 20 4412 40-48 100 60 30 30 5 a " 10 4413 10-18 5- 5- 20 200 15 a 50 4414 12i-38 80 20 70 50 a a a
4415 15-28 5- 5- 50 150 20 a 20
Mt. Burton - Mt. Fitch 4100 " 8-44 30 20 70 50 5 a 20 4101 12-16 30 i5 20 .50 5 a 20 4102 12-32 30 10 100 300 20 a 30 4103 19-28 60 30 70 150 10 a 30 4104 12-18 60 30 100 100 7 a 20 4105 12-51 100 20 100 200 10 a 20 4106 2-8 60 100 30 70, 7 a 20 4106 16' 60 5 70 200 10 a 70 4107 14-44 100 20 30 30 2 a 5 4108 14-32 80 20 30 30 2 a a
4109 4' 5- 30 15 5- 5 a a
4125(37N/ 125E ) 10-26 5 30 20 50 5 a 20
4124 8-30 10 40 20 30 2 a 50 4123 16-46 10 30 20 10 2 a 50 4122 8-14 10 10 30 20 2 a 50
3.
Brown's West Hole No. Depth Ni Co C'" "'- V Mo Sn Pb
4300 10 10 15 5 2 a 5 4301 15 10 15 5 5 a 10 4302 10 10 10 5- 2 a 10 4303 15 15 15 5 3 a 50 4304 15 15 15 10 5 a 5
Brownt s Intermediate Copper Prospect 40'10 TIoH 40 15 20 '[00 20 a 20 4015 BoH 30 15 70 100 30 a 20 4019 BoH 24' 40 10 300 150 2 a 100 4020 BoH 60 1 150 150 5000+ 200 30 a 70 4022 BoH 30 80 5000+ 200. 20 a 70 4025 BoH 200 100 5000+ 200 30 a 70 4030 BoH 100 80 5000+ 200 30 a 50
'.'
4038 BoH 150 80 2000 200 30 a 70 ..
4041 BoH 300 500 5000 300 15 a 50 ,'\
4045 BoH 16'500 700 5000+ 100 20 a 30 4046 BoH 300 500 5000 70 10 a 70 4050 BaH '500 300 3000 150 15 a 70 4055 BoH 42 300 1000 5000+ 150 10 a 70 4065 BoH 14t 150 1500 5000+ 150 5 a 50 4060 BoH 300 2000 5000+ 100 5 a 50 4083 6.8 f 150 40 2000 150 2 a 10
'. "
\
Beryllium and phosphorus were not detected in'any sample.
Plate Nos. 496-499.
REPORT NO. 167/NTS/1
THE PETROGRAPHY OF SHEARED GREYWACKE FROM THE PINE CREEK AREA, NORTHERN TERRITORY
by
W. R. Morgan
The specimen was submitted by D •• A. White for petro .... graphical examination, and was collected from an area 6 miles north-north-west of Pine Creek (Plane Table Sheet K, point 115).
The hand specimen is a hard, dark grey, inequigranular and medium-grained sandstone that has a faint sheer fabric.
In thin section (11087) the rock is seen to consist of grains of quartz, sodic plagioclase 7 chert, intermediate volcanic material, microcline-perthite, and granitic material, enclosed in a fine-grained quartz-sericite matrix. The grains range in diameter from 0.05 mm. to 0.53 mm., and are mostly angular. Some .show the effects of straining, but not obviously so.
The matrix has an average grain-size of about 0.02 mm., and shows a fairly promi~nt shear-texture, due mainly to lineated and strung-out fine sericite flakes. Together with the sericite, the matrix consists of granular quartz and feldspar. In one or two places, some sign of possible contact metamorphism can be seen in that some of the matrix quartz has assumed a granoblastic texture, and a few of the matrix plagioclase grains form pellucid crys~als with only a small amount of multiple twinning. It .must be emphasized that these features are not present throughout the matrix; they are not present in the grains enclosed by the matrix.
• ."..
J , .~ \ ' , ,',
Report No. File No. 84NT/1
SPECTROCHEMICAL ANALYSIS OF SAlVIPLES FROM RUJlII JUNGLE,
nORTHERN TERRITORY. by E.J.Howard
Semiquantitative estimations were made of the trace metal content of geochemical prospecting samples from Rum Jungle, Northern Territory. The samples were submitted by P. Pritchard.
The following are the results expressed in parts per million.
Browns Intermediate Copper Prospect.
, : Hole No. DeEth (feet) Ni Co Cu V' Mo Sn Pb Remarks
4083 . 14-16 300 60 2000 300 5 a 20 4083 ,~t6-18 300 60 3000 150 3 a 20,
----------- No Result 300 200 2000 5 a a 10 Be(15)
----------- No Result -----~----- No Result
Hole No.
5245
5246
5247 5248
5249
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261 5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5273
5274
5275 5276
5277 5278
5279 5280
5281 5282
5283
5284
5285
5286
5287
fepth feet)
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH BoH
BoH
BoH
BoH BoH( 1)
BoH(2)
BoH
BoH
BoH
BoH
BoH
BoH
"BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
- 5. ~
Ni Co Cu V Mo Sn Pb Remarks
300 300 300 30
200 300 1000 10
80 40 30 300
300 200 30 100
150 60 50 150
40 30 50 200
200 100 300 150
----------- No Result
----------- No Result
----------- No Result
----------- No Result
100 80 300 20
200 150 500 30
300 40 200 100
100 40 500 100
----------- No Result 80 40 500 100
150 60 100 150
300 80 500 100
2 a 10
7 a 10
15 a 20
a 10 10
10 10 20
10 20 50 -2 a 30
5 a 50 5 a 100
a a 70 a a 30
2 a 100
2 a 10
5 a 70. 700 300 700
700 700 700
300 500 1000
100 30
150 15 200 a
a 10
a 30
a 5 a 200
a 70
a 50
a 50
60 30 200
10 10 100
15 15 200
100 60 300
50 5 10 2
5 2
5- 5 ----------- No Result 20 30 70 5
30 40 70 5
300 150 3000 5
a 10 a
a 10 a
7 a 5 Be ( 10)
300 300 5000+ 10 2 30 50 P
150 80 2000
15 15 100
15 15 100
10 10 70
100 150 700
150 100 1500
150 500 1000
200 150 500
150 500 1500
5 2 a a B8(15)
20 a
30 a
50 a
100 5
100 15
50 20
30 15
100 30
a 20
a 50 a 100
a 50
a 50
a 70
a 50
a 50
----------- No Result -------------200 200 1500
300 200 2000
100 5 150 a
a 10
a 30
.,
'.
Hole No.
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303 5304
5305
5306
5307
5308
5309
5310
'5311
5313
fiPth eet)
BoH
BoH
BoH
BoH
BoH
BoH
,BoH
BaH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
5314 ' BoH (442N/113+50)
5314 BoH (442/112+50)
5315
5316
5317
5318
5319 5320
5321
5322
5323
5324 , 5325
5326
5327
5328
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
BoH
,.. 6 -
Ni Co Cu v Mo Sn, Pb Remarks
150 70 3000 30 a a a
60 20 2000 150 a a a
60 100 700
80 150 300
5- 10
50 15
70 20
70 70
50 10
a 30 Be(15)
a 20
300 1500 500
200 700 500
',50 200 200
80 60 70
60 60 200
300 500 200
a 30
a, 50 a 20
200 5 a 70
100 2 a 20
10 20 60 100 200
300 500 700
300 200 500
200 200 1000
100 150 200
100 10 a
20 10 a
10 10 a 20 Be(15)
5- 5 a
5- 7 a 150 5 a
5 Be(20')
20 Be(10)
20
60 80 200 150 5 a 10
30 60 5 70 2' a 5 50 30 80 200 5 5 a
30 80 500 30 40 200
150 500 1000
100 300 500
100 100 500
100 80 500
100' 100 70
30 a 30 a 20 a
30 a 50 5 30 10
50 10
----------- No Result
30 60 15 150 20
80 40 500 5 2
80 80 500 20 5 100 300 200
80 200 500
80 SO 500
5- a 10 20
100 100
----------- No Result 60 60 1000 5-
100 80 200 10
20 20 50 5------------ No Result ----~------ No Result
a
50
5
a 500 a a
a' 5 a 5 a 5 a 5 a 50
a 20
a 10
a 20
a 5 a 20
a 100
a a
a
a
5 a
100 150 1000 10 20 a 20
10 30 200 10 2 a a
----------- No Result
Be(5)
'.
Hole .No.
5329
5330
5331 5332
5333 5334
5335 5336
5337 5338
5339 5340
5341
5342
5343
5344 5345 5346
5347 534·8
5349
5350 5351 5352
5353 535 f t-
5355 5456
5357
5358
5359 5360
5361 5362
5363 5364
5365 5366
5367 5368
5369 5370
5371
fep~~ fee )
BoH BoH BoH BoH BoH BoH BoH BoH BoH
. BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH BoH
, BoH
BoH BoH BoH BoH· BoH BoH 'BoH BoH BoH BoH BoH BaH BoH BoH
Ni
30 100
30
- 7 -
Co· Cu
30 100 80 1000
80 100
30 40 200
100 100 30
150 300 200 80 80 200
10 10 200
30 80 500
20 60 100
80 100 700 100 -80 200
200 80 200
30 40 300 80 60 500
40 60 50 40 80 300 20 20 50
80 80 700
20 40 70 80 80 200
80 80 200 60
30 60 20
80
15 20
40 200
30 300
40 500 20 150 80 200 20 30'
30 50 100 80 700
30 30 500 100 60 700
30 60 50
30 30 300
10 15 50 40 80 70 20 20 100
15 30 50 40 40 70 80 20 100
80 40 200
60 20 200
150 100 500
v Mo
5 3 20 20
50 7 10 20
5 a 5 a
5 a 5- a
10 a
5 2
10 a
10 a
10 2
5 7 10 5 5 a
10 a 5 2
10 2
5 2
10 2
5- 20 20 20
10 5 5 a
10 . 5
10 10
5 a 5- 2
5- a 5 a 5- a
5 a 10 2
5 a
5 a
5- a 5 a
10 a
50 5 70 2
150 15 150 2
Sn Pb Remarlm
a a
a 20
a 30 a 10
a a
a 10 a a
a 10
a 20
a a
a 5 a 5 a 5 a 10
a 5 a a
a 5 a 10
a 10
a 10
a 150 a -10 a 20
a 10
a 5 a 30
a 70
a 50
a 15 a 30 a 10
a 50
a 70 8 1000
a 70 a 1000
a 200
a 200
a 700 a 200 a 1000
8 5000 10 200
-... 8 -
, ,.
Hole No; fiPth Ni .co Cu V Mo' Sn Pb Hemarks eet") 0.0....- --
5372 BoH 30 15 150 30 2 a 70 5373 BoH 60 15 100 50 2 a 70
5374- BoH 10 5- 50 150 10 a 100
5375 BoH 60 40 200 70 7 a 500 5376 BoH 100 80 100 20 a a 200
5377 BoH 30 30 100 30 5 a 200
5378 BeH 60 30 70 30 3 a 100
5379 BoH 20 20 50 20 2 a fO 5380 BoH 60 60 70 30 2 a 100 5381 BoH 20 20 70 20 a a 50 5382 BoH 20 20 20 20 a a 20 5383 BoH 20 20 30 10 2 a 70 5384- BoH 60 60 100 20 5 a 70 5385 BoH 10 20 15 5- a a 5 5386 BoH 10 15 10 20 a a 20 5387 :SoH 40 60 150 50 a a 500
"a" - not detected
" 5" less than 5 p.p.m.
" P" - Phosphorus present "Be(10)" - 10 p.p.rn. beryllium "No Result" Poor arcing properties using general procedure
Plate Nos. 500-517.
Report No. 84NT/1
Mineragraphic description of mineralisation in Rum Jungle core, drill hole D.G. 24.
by
I.R. Pontifex.
Introduction
The investigation of 6 selected specimens from this hole was made in conjunction with the detailed logging of the core by D.O. Zimmerman and the proposed chemical analysis of selected sections by A.D. Haldane. The specimens 'were taken from cuttings representing 5 ft. intervals in the hole.
Summary
The entire core is extensively leached and silicified. Only minor occurrences of mineralisation are intersected by the hole and the distribution of this is sporadic. With the
exception of a specimen examined from 205' to 210' which consists entirely of psilomelane, the ore minerals consist mainly of chalcocite with relatively accessory amounts of bornite, malachite pyrite, hydrated iron oxide, native Cu and ?native Au.
In two sections from 250' to 251' chalcopyrite is altered to secondary copper minerals. This chalcopyrite has been extensively leached and as a result, along grain boundaries and fractures it has been altered to bornite and chalcocite and these respectively represent successive stages of iron removal from the original chalcopyrite. The removed iron has concentrated as hydrated iron oxide in the centre of the alteration veins and this forms the beginning of gossan boxworks. Pyrite shows no evidence of incipient boxwork development.
In a silicified rock from 350' to 355' chalcocite stringers follow grain boundaries which often have a rhombohedral shape. These boundaries were inherent to tho component grains pre-silicification.
Native Cu and ?Au in 2 samples from 350' to 355' occur as fine grains which are loc·a.lised in leached vOids within massive siliceous gangue.
C onclusi ons
Chalcopyrite is the only primary ore mineral observed in the core. The alteration of chalcopyrite to secondary copper minerals, in situ, is the result of the widespread leaching. The common occurrence of secondary copper minerals which are not spatially related to any primary minerals, (and in fact are present at greater depth than the intersected chalcopyrite) may represent the complete alteration of pre-existing primary minerals in situ. The mode of occurrence of these secondary minerals however indicates that they were introduced by supergene agencies. The relationship of chalcocite to inherent grain boundaries suggests that it was introduced before or contrmporaneously with the silicification of the enclosing country rock. The localisation of native Cu in leaChed voids suggests that it was introduced and deposited post-silicification or possibly contemporaneously with it. The native elements are not evident in the hand specimen and were only detected because the sections were examined for a microscopic study of minor copper mineralisation.
.. 2 •
It is suggested that the two specimens indicated are assayed for gold and copper content in the subsequent chemical analyses.
Depth - 205' to 210' Ore minerals - PSilomelane.
Macro - The specimen consists entirely of an aggregnte of radiating stalactitic columm of a soot black, soft mineral.
Micro - Micro chemical test indicated the presence of Mn.
The entire section has a fine felted ice flower-like texture and consists of a grey-white mineral of strong anisotropism. The mineral is psilomelane.
Although occurring alone, associated core cuttings consist of leached, silicified calcareous material. Psilomelane is recorded to occur as a replacement product in calcareous or dolomitic rocks, formed by meteoric waters.
Depth - 250'11" to 25117" (2 specimens were eXamined)
Macro Buff coarsely crystalline dolomite contains chalcopyrite which is ramified by a network of chalcocite.
Micro - Massive chalcopyrite is ramified by a net-work of alteration veins of chalcocite and other secondapy minerals. The chalcopyrite occurs as remnant isolat-ed irregular shaped grains up to 5 mms. across, essentially filling -chG cells produced by the secondary minerals. The grains are leached and as a result they are often extremely porous and in polished section they have a marked low relief in relation to the surrounding secondary minerals which replace them. The chalcopyrite is replaced around grain boundaries and along fractures within the grains.
The width of the replacement veins and coronas varies up to a maxiIIl'Um of 3 mms,. and this expresses the variation in the degree of alteration. The wider veins comruonly consist of 3 secondary products. Hydratediron oxide forms a central core as the innermost constitu-ent of the vein.
ChalCOCite is the most abundant and widespread of the secondary minerals and this borders the hydrated iron oxid~ on the Side nearest the chalcopyrite, or in the case of some veins replacing along fractures, on both sides. Often Chalcocite is the only secondary mineral in anyone vein.
Bornite is in places assoc~ated with chalCOCite and it forms irregular poorly defined zones between chalcocite and chalcopyrite. Bornite often merges with feather like prOjections into adjacent chalcocite and chalcopyrite, without any distinctive boundary.
! 3.
Accessory amounts of small pyrite grains are dispersed through the chalcopyr1te and may occur independently in the gangue. The distribution of pyrite is apparently at random, however some grains are, strung. 9Ji\~::h str¥.m.e~'.3.1!;'if~~W1ally parallel to chalcoc1 te ve1ns I "·Th1S Q1rErd-t":lon may be a crystallographic direction within the chalcopyrite. Marcasite often partially replaces pyrite grains.
Depth-350' to 355' Ore minerals - Chalcocite, malaohite, native Cu.
Macro -
Micro -
Reddish dense siliceous rock with sporadic distribution of skeletal masses of chalcocj,te and associated malachite which measure up to several roms. acruss.
Several discrete irregular p3tches and veins of chalcocite occur at random through the section. It makes up about 5% of the section. Some chalcocite veinlets cut dense siliceous grains, the larger masses however, are localised in irregular apparent leach voids in the siliceous mass.
Approximately 3% of the section consists of fine grains of native Cu which are dispersed at random with an even distribution throughout. The maximum size of these grains is about 0.075 mms. across and they are invariably localised within irregular leached voids in the siliceous aggregate.
Depth - 350' to 355'
Ore minerals - Chalcocite, native Cu, ?native Au.
Macro
Micro -
Buff grey silicified fjne grained rock. A fracture face in the rock is lined with fine quartz crystalS.
The entire rock is ramified by veinlets and stringers of chalcocite. These veins almost invariably follow grain boundaries inherent to the component grains which existed before the rock was Silicified. Often the grains have a rhombo-hedral outline suggesting that the pre-existing rock was a carbonate. In anyone field of view the Chalcocite constitutes less than 3% of the minerals present.
Minor accessory amounts of highly reflective grains of the order of 0.001 mm. in size are dispersed sporadically through the section and there are localised in intergranular voids. The id·entification of these grains was not conclusive, they do however, appear to be grains of native Cu as found in another section in this depth range. Some are possibly grains of native Au.
It is suggested that this section is analysed for gold in the subsequent chemical analyses,